Hubbry Logo
HymenopteraHymenopteraMain
Open search
Hymenoptera
Community hub
Hymenoptera
logo
8 pages, 0 posts
0 subscribers
Be the first to start a discussion here.
Be the first to start a discussion here.
Hymenoptera
Hymenoptera
Hymenoptera
View on Wikipedia
from Wikipedia

Hymenoptera
Temporal range: Triassic–present 235–0 Ma[1]
Hymenopterans from different families; Clockwise from top-left: Red imported fire ant (Formicidae), Vespula vulgaris (Vespidae), Tenthredopsis sordida (Tenthredinidae), and Western honey bee (Apidae)
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Clade: Holometabola
Superorder: Hymenopterida
Order: Hymenoptera
Linnaeus, 1758
Suborders

Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described,[2][3] in addition to over 2,000 extinct ones.[4] Many of the species are parasitic. Females typically have a special ovipositor for inserting eggs into hosts or places that are otherwise inaccessible. This ovipositor is often modified into a stinger. The young develop through holometabolism (complete metamorphosis)—that is, they have a wormlike larval stage and an inactive pupal stage before they reach adulthood.

Etymology

[edit]

The name Hymenoptera comes from Ancient Greek ὑμήν (humḗn), meaning "membrane", and πτερόν (pterón), meaning "wing".[5]

Evolution

[edit]

Molecular analysis finds that Hymenoptera is the earliest branching group of Holometabola.[6]

Hymenoptera originated in the Triassic, with the oldest fossils belonging to the family Xyelidae. Social hymenopterans appeared during the Cretaceous.[7] The evolution of this group has been intensively studied by Alex Rasnitsyn, Michael S. Engel, and others.[8]

Holometabola
Hymenopterida

Hymenoptera (sawflies, wasps)

Aparaglossata
Neuropteroidea
Coleopterida

Coleoptera (beetles)

Strepsiptera (twisted-wing parasites)

Neuropterida

Raphidioptera (snakeflies)

Megaloptera (alderflies and allies)

Neuroptera (Lacewings and allies)

Panorpida
Amphiesmenoptera

Lepidoptera (butterflies, moths)

Trichoptera (caddisflies)

Antliophora

Diptera

Mecoptera (scorpionflies)

Siphonaptera (fleas)

Phylogenetic relationships within the Hymenoptera, based on both morphology and molecular data, have been intensively studied since 2000.[9] In 2023, a molecular study[9] based on the analysis of ultra-conserved elements confirmed many previous findings and produced a relatively robust phylogeny of the whole Order. Basal superfamilies are shown in the cladogram below.

Hymenoptera
Hymenoptera

Tenthredinoidea

Xyeloidea (Triassic–present)

Pamphilioidea

Unicalcarida

Siricoidea (horntails or wood wasps)

Xiphydrioidea (wood wasps)

Cephoidea (stem sawflies)

parasitism

Orussoidea (parasitic wood wasps)

"wasp waist"

Apocrita (ants, bees, wasps)

200mya
250mya
Symphyta (red bar) are paraphyletic as Apocrita are excluded.

Anatomy

[edit]
Bombus muscorum drinking nectar with its long proboscis

Hymenopterans range in size from very small to large insects, and usually have two pairs of wings. Their mouthparts are adapted for chewing, with well-developed mandibles (ectognathous mouthparts). Many species have further developed the mouthparts into a lengthy proboscis, with which they can drink liquids, such as nectar. They have large compound eyes, and typically three simple eyes, ocelli.

The forward margin of the hind wing bears a number of hooked bristles, or "hamuli", which lock onto the fore wing, keeping them held together (hamuli wing coupling). The smaller species may have only two or three hamuli on each side, but the largest wasps may have a considerable number, keeping the wings gripped together especially tightly. Hymenopteran wings have relatively few veins compared with many other insects, especially in the smaller species.

In the more ancestral hymenopterans, the ovipositor is blade-like, and has evolved for slicing plant tissues. In the majority, however, it is modified for piercing, and, in some cases, is several times the length of the body. In some species, the ovipositor has become modified as a stinger, and the eggs are laid from the base of the structure, rather than from the tip, which is used only to inject venom. The sting is typically used to immobilize prey, but in some wasps and bees may be used in defense.[7]

Hymenopteran larvae typically have a distinct head region, three thoracic segments, and usually nine or 10 abdominal segments. In the suborder Symphyta, the eruciform larvae resemble caterpillars in appearance, and like them, typically feed on leaves. They have large chewing mandibles, three pairs of thoracic limbs, and, in most cases, six or eight abdominal prolegs. Unlike caterpillars, however, the prolegs have no grasping spines, and the antennae are reduced to mere stubs. Symphytan larvae that are wood borers or stem borers have no abdominal legs and the thoracic legs are smaller than those of non-borers.

With rare exceptions, larvae of the suborder Apocrita have no legs and are maggotlike in form, and are adapted to life in a protected environment. This may be the body of a host organism, or a cell in a nest, where the adults will care for the larva. In parasitic forms, the head is often greatly reduced and partially withdrawn into the prothorax (anterior part of the thorax). Sense organs appear to be poorly developed, with no ocelli, very small or absent antennae, and toothlike, sicklelike, or spinelike mandibles. They are also unable to defecate until they reach adulthood due to having an incomplete digestive tract (a blind sac), presumably to avoid contaminating their environment.[7] The larvae of stinging forms (Aculeata) generally have 10 pairs of spiracles, or breathing pores, whereas parasitic forms usually have nine pairs present.[10]

Reproduction

[edit]

Sex determination

[edit]
Main article: Haplodiploid sex-determination system

Among most or all hymenopterans, sex is determined by the number of chromosomes an individual possesses.[11] Fertilized eggs get two sets of chromosomes (one from each parent's respective gametes) and develop into diploid females, while unfertilized eggs only contain one set (from the mother) and develop into haploid males. The act of fertilization is under the voluntary control of the egg-laying female, giving her control of the sex of her offspring.[7] This phenomenon is called haplodiploidy.

However, the actual genetic mechanisms of haplodiploid sex determination may be more complex than simple chromosome number. In many Hymenoptera, sex is determined by a single gene locus with many alleles.[11] In these species, haploids are male and diploids heterozygous at the sex locus are female, but occasionally a diploid will be homozygous at the sex locus and develop as a male, instead. This is especially likely to occur in an individual whose parents were siblings or other close relatives. Diploid males are known to be produced by inbreeding in many ant, bee, and wasp species. Diploid biparental males are usually sterile but a few species that have fertile diploid males are known.[12]

One consequence of haplodiploidy is that females on average have more genes in common with their sisters than they do with their daughters. Because of this, cooperation among kindred females may be unusually advantageous and has been hypothesized to contribute to the multiple origins of eusociality within this order.[7][13] In many colonies of bees, ants, and wasps, worker females will remove eggs laid by other workers due to increased relatedness to direct siblings, a phenomenon known as worker policing.[14]

Another consequence is that hymenopterans may be more resistant to the deleterious effects of inbreeding. As males are haploid, any recessive genes will automatically be expressed, exposing them to natural selection. Thus, the genetic load of deleterious genes is purged relatively quickly.[15]

Thelytoky

[edit]
Main article: Thelytoky

Some hymenopterans take advantage of parthenogenesis, the creation of embryos without fertilization. Thelytoky is a particular form of parthenogenesis in which female embryos are created (without fertilisation). The form of thelytoky in hymenopterans is a kind of automixis in which two haploid products (proto-eggs) from the same meiosis fuse to form a diploid zygote. This process tends to maintain heterozygosity in the passage of the genome from mother to daughter. It is found in several ant species including the desert ant Cataglyphis cursor,[16] the clonal raider ant Cerapachys biroi,[17] the predaceous ant Platythyrea punctata,[18] and the electric ant (little fire ant) Wasmannia auropunctata.[19] It also occurs in the Cape honey bee Apis mellifera capensis.[20]

Oocytes that undergo automixis with central fusion often have a reduced rate of crossover recombination, which helps to maintain heterozygosity and avoid inbreeding depression. Species that display central fusion with reduced recombination include the ants Platythyrea punctata[18] and Wasmannia auropunctata[19] and the Cape honey bee Apis mellifera capensis.[20] In A. m. capensis, the recombination rate during meiosis is reduced more than tenfold.[20] In W. auropunctata the reduction is 45 fold.[19]

Single queen colonies of the narrow headed ant Formica exsecta illustrate the possible deleterious effects of increased homozygosity. Colonies of this species which have more homozygous queens will age more rapidly, resulting in reduced colony survival.[21]

Diet

[edit]

Different species of Hymenoptera show a wide range of feeding habits. The most primitive forms are typically phytophagous, feeding on flowers, pollen, foliage, or stems. Stinging wasps are predators, and will provision their larvae with immobilized prey, while bees feed on nectar and pollen.

Main article: Parasitoid wasp

A huge number of species are parasitoids as larvae. The adults inject the eggs into a host, which they begin to consume after hatching. For example, the eggs of the endangered Papilio homerus are parasitized at a rate of 77%, mainly by Hymenoptera species.[22] Some species are even hyperparasitoid, with the host itself being another parasitoid insect. Habits intermediate between those of the herbivorous and parasitoid forms are shown in some hymenopterans, which inhabit the galls or nests of other insects, stealing their food, and eventually killing and eating the occupant.[7]

Classification

[edit]
Symphyta, without a waist: the sawfly Arge pagana
Apocrita, with narrow waist: the wasp Vespula germanica

The Hymenoptera are divided into two groups; the Symphyta which have no waist, and the Apocrita which have a narrow waist.[4]

Symphyta

[edit]

The suborder Symphyta includes the sawflies, horntails, and parasitic wood wasps. The group may be paraphyletic, as it has been suggested that the family Orussidae may be the group from which the Apocrita arose. They have an unconstricted junction between the thorax and abdomen. The larvae are herbivorous, free-living, and eruciform, usually with three pairs of true legs, prolegs (on every segment, unlike Lepidoptera) and ocelli. The prolegs do not have crochet hooks at the ends unlike the larvae of the Lepidoptera.[4] The legs and prolegs tend to be reduced or absent in larvae that mine or bore plant tissue, as well as in larvae of Pamphiliidae.[23]

Apocrita

[edit]

The wasps, bees, and ants together make up the suborder (and clade) Apocrita, characterized by a constriction between the first and second abdominal segments called a wasp-waist (petiole), also involving the fusion of the first abdominal segment to the thorax. Also, the larvae of all Apocrita lack legs, prolegs, or ocelli. The hindgut of the larvae also remains closed during development, with feces being stored inside the body, with the exception of some bee larvae where the larval anus has reappeared through developmental reversion.[clarification needed] In general, the anus only opens at the completion of larval growth.[4]

Threats

[edit]

Hymenoptera as a group are highly susceptible to habitat loss, which can lead to substantial decreases in species richness and have major ecological implications due to their pivotal role as plant pollinators.[24]

See also

[edit]

References

[edit]
[edit]
Revisions and contributorsEdit on WikipediaRead on Wikipedia

Hymenoptera

View on Grokipedia
from Grokipedia
Hymenoptera is an order of within the class Insecta, encompassing a diverse array of including , bees, wasps, and sawflies, notable for their membranous wings and, in the more derived groups, a constricted that distinguishes the from the . These typically possess two pairs of wings that can hook together in flight, chewing mouthparts adapted for various feeding strategies, and undergo complete with legless, worm-like larvae. The order is divided into two main suborders: the Symphyta, which includes the primitive sawflies and wood wasps lacking a waist constriction, and the Apocrita, comprising the advanced wasps, bees, and ants characterized by their parasitic or stinging lifestyles. Within Apocrita, many species are parasitoids, while the clade Aculeata includes stinging forms such as bees, ants, and wasps, reflecting evolutionary adaptations for host exploitation and defense. With approximately 154,000 described species—representing about 15% of all described insect species—Hymenoptera exhibits remarkable diversity, particularly in tropical regions, though estimates suggest the true number could exceed 2 million species. Hymenopterans play pivotal ecological roles as pollinators, predators, and parasitoids, contributing to , , and nutrient cycling in nearly all terrestrial habitats. Many species, especially in the , form complex eusocial colonies with division of labor, including castes for workers, queens, and soldiers, which enhances their impact on ecosystems and human agriculture through services like honey production and biological pest management.

Etymology and Overview

Etymology

The name Hymenoptera derives from the words hymḗn (ὑμήν), meaning "membrane", and pterón (πτερόν), meaning "wing", a reference to the thin, membranous wings typical of in this order. The order was formally established by the Swedish naturalist in the 10th edition of his published in 1758. Within Hymenoptera, the suborders also carry etymological significance tied to morphological features. Symphyta, encompassing sawflies and related forms, originates from Greek syn- ("together") and phytós ("grown" or "united"), describing the broad, fused junction between the and lacking a narrow waist. In contrast, , which includes wasps, bees, and ants, comes from Greek apó- ("away from" or "separate") and kritós ("separated" or "divided"), alluding to the distinct constriction or "" that articulates the from the .

General Characteristics

Hymenoptera is one of the largest and most diverse orders of insects, encompassing approximately 154,000 described species, with estimates suggesting a total exceeding one million species worldwide. This order includes familiar groups such as ants, bees, wasps, and sawflies, which play crucial ecological roles as pollinators, predators, parasitoids, and herbivores. Members exhibit complete metamorphosis, transitioning through egg, larval, pupal, and adult stages, and are distinguished from other insect orders by several key morphological traits. The defining diagnostic features of Hymenoptera include two pairs of membranous wings, with the hindwings typically smaller and connected to the larger forewings by a row of hooks called hamuli, enabling coordinated flight. Antennae are often elbowed or geniculate, particularly in the suborder Apocrita, facilitating sensory detection, while mouthparts are primarily adapted for chewing, though modified in some groups like bees for nectar ingestion. The body often features a constricted "wasp waist" between the thorax and abdomen, and the order is broadly divided into the suborders Symphyta (sawflies and horntails) and Apocrita (ants, bees, and wasps). Hymenopterans vary greatly in size, ranging from as small as 0.15 mm in (family Mymaridae), among the tiniest known flying , to up to 5 cm in some wasps. They are predominantly terrestrial, inhabiting diverse ecosystems from forests and grasslands to urban areas across all continents except , though some larvae develop in aquatic environments as parasitoids of water-dwelling hosts. This global distribution underscores their adaptability and ecological significance.

Evolutionary History

Origins and Fossil Record

The order Hymenoptera belongs to the clade , also known as Endopterygota, which encompasses undergoing complete . Within this group, Hymenoptera occupies a basal phylogenetic position, serving as the sister taxon to the remaining endopterygote orders, including Coleoptera, Diptera, and . This placement is supported by phylogenomic analyses of mitochondrial and nuclear genomes, highlighting shared ancestral traits such as internal embryonic development. Molecular clock estimates, calibrated with fossil constraints, indicate that Hymenoptera diverged from other holometabolous insect lineages around 300 million years ago during the late Carboniferous to early Permian period. Subsequent diversification within the order began in the late Permian or , approximately 249 million years ago (95% highest posterior density: 229–272 Ma), coinciding with post-extinction recovery following the Permian-Triassic mass extinction event. These estimates derive from Bayesian relaxed-clock models applied to large genomic datasets, incorporating multiple fossil calibrations to account for rate heterogeneity across lineages.30059-3) The earliest definitive fossils of Hymenoptera date to the period, around 235–248 million years ago, primarily consisting of primitive sawflies from the Archexyelinae within the family Xyelidae. These specimens, such as those from the Madygen Formation in , represent the Symphyta suborder and exhibit basal morphological features like membranous wings. Possible Permian precursors, potentially ancestral to Hymenoptera and related orders like Raphidioptera, have been identified in deposits from that era, suggesting an even earlier emergence near the Carboniferous-Permian boundary. A significant fossil site for early Cretaceous Hymenoptera (~115 million years ago) is the Crato Formation in northeastern Brazil, a lagerstätte preserving diverse insects in fine-grained limestones. This locality has yielded well-preserved specimens of early wasps, including crabronids (basal Apoidea relatives of bees) and horntail wasps (Siricidae), as well as potential early bees exhibiting apoid-like traits. These fossils provide critical insights into the radiation of parasitoid and aculeate lineages during the mid-Mesozoic.

Key Evolutionary Developments

The order Hymenoptera exhibits several pivotal evolutionary innovations that facilitated its diversification into over 150,000 described species, spanning phytophagous, parasitoid, predatory, and social lifestyles. A fundamental transition occurred from the primarily ectophytophagous Symphyta, represented by sawflies that feed on plant tissues, to the , which predominantly adopted parasitoidism as a feeding strategy. This shift, estimated to have begun around 281 million years ago during the early Permian, marked a major , with parasitoidism becoming the dominant life history by the approximately 210 million years ago. The evolution of parasitoidism allowed Hymenopterans to exploit new ecological niches by laying eggs inside or on host , leading to a dramatic increase in compared to their plant-feeding ancestors. Within the , the infraorder represents another critical innovation: the modification of the into a functional sting apparatus, enabling active predation and defense. This adaptation, which repurposed the egg-laying structure for injection to subdue prey or deter predators, originated in the stem group of during the , around 142 million years ago. The sting's evolution coincided with the transition from parasitoidism to predation, allowing aculeates like , , and wasps to hunt larger or more mobile prey, thereby expanding their ecological roles and contributing to further lineage diversification. The Cretaceous period, approximately 145 to 66 million years ago, witnessed the rise of eusociality in multiple aculeate lineages, including ants, bees, and wasps, which evolved cooperative brood care, division of labor, and overlapping generations. This social complexity emerged concurrently with the radiation of angiosperms, providing abundant floral resources that supported colony growth and foraging behaviors in early social forms. Fossil evidence indicates that eusocial ants, for instance, originated in the Early Cretaceous around 100 million years ago, with their diversification accelerating as they colonized diverse terrestrial habitats alongside flowering plants.00041-5) Underpinning these social advancements is the haplodiploid sex determination system, a genetic innovation unique to Hymenoptera that produces haploid males from unfertilized eggs and diploid females from fertilized ones. This mechanism enhances average relatedness among female siblings to 0.75, compared to 0.5 with full siblings, promoting altruistic behaviors like worker sterility that are essential for eusocial colony stability. Haplodiploidy is widely regarded as a predisposing factor for the multiple independent origins of eusociality in the order, facilitating kin selection and the evolution of advanced social structures without requiring other genetic prerequisites.

Taxonomy and Classification

Suborders

The order Hymenoptera is traditionally divided into two suborders: Symphyta and , based on morphological differences in body structure and larval form. These suborders encompass a diverse array of , with distinguishing traits related to the connection between the and , as well as larval morphology and feeding habits. The suborder Symphyta, comprising sawflies and their relatives such as horntails and wood wasps, is characterized by the absence of a constricted "waist" between the and , resulting in a broad junction. Larvae of Symphyta are typically caterpillar-like, possessing thoracic legs and abdominal prolegs, and are predominantly herbivorous, feeding on tissues. This suborder includes approximately 14 families and around 9,000 described species, representing a smaller portion of hymenopteran diversity. In contrast, the suborder Apocrita, which includes wasps, bees, and ants, features a narrow "waist" formed by the petiole, creating a distinct constriction between the thorax and abdomen. Larvae are grub-like, legless, and often sedentary, developing within host tissues or provisioned nests. Apocrita is further divided into two informal groups: Parasitica, consisting of parasitoid wasps that lay eggs on or in other insects, and Aculeata, which includes stinging species such as bees, ants, and vespid wasps. This suborder accounts for the majority of hymenopteran species, with approximately 145,000 described. Phylogenetically, Symphyta is considered paraphyletic, as it does not form a single evolutionary and likely represents a basal grade within Hymenoptera, while is monophyletic, sharing derived traits such as the constricted waist. This arrangement reflects the evolutionary transition from plant-feeding ancestors in Symphyta to more specialized parasitic and social lifestyles in .

Major Families and Diversity

The order Hymenoptera encompasses over 154,000 described species, organized into suborders such as Symphyta and that provide the taxonomic framework for understanding its diversity. Among the most prominent families are those in the , particularly within the clade and the parasitoid-rich Parasitica. These families illustrate the order's ecological breadth, from pollinators and predators to parasitoids, with species richness varying widely across groups. The family Formicidae, comprising , includes approximately 16,000 described species and represents a cornerstone of hymenopteran diversity due to its ecological dominance in terrestrial ecosystems. Similarly, , which includes many such as honeybees and bumblebees, accounts for approximately 6,000 described species, playing a in worldwide. Vespidae, encompassing social and solitary wasps like yellowjackets and paper wasps, features about 5,000 described species, noted for their predatory behaviors and nest-building habits. In contrast, the Parasitica subgroup boasts the family , with over 25,000 described species of ichneumon wasps, which are primarily parasitoids targeting other . Hymenopteran diversity is highest in tropical regions, where environmental complexity supports elevated ; for instance, alone constitute up to 20% of total biomass in these areas, underscoring their pivotal role in dynamics. Estimates suggest that more than 200,000 species remain undescribed within Parasitica, highlighting the vast untapped in lineages and the challenges in taxonomic inventory. Biogeographically, basal hymenopteran groups, such as certain symphytan families like Pergidae, exhibit strong affinities to the , reflecting historical patterns linked to Gondwanan distributions. This southern concentration contrasts with the more cosmopolitan spread of derived aculeate families, emphasizing regional hotspots for conservation priorities.

Morphology and Anatomy

External Features

The body of adult Hymenoptera is divided into three primary tagmata: the head, , and , following the typical insect body plan. In the suborder Symphyta (sawflies and horntails), the junction between the and is broad, allowing for a more continuous appearance. In contrast, members of the suborder (ants, bees, and wasps) exhibit a constricted "wasp waist," where the first abdominal segment fuses with the to form the propodeum, and the second segment forms a narrow petiole that connects to the remaining (metasoma or gaster). This petiole varies in form, appearing as a node, scale, or slender stalk, and enhances flexibility in movement. The head capsule houses prominent sensory structures, including large compound eyes composed of numerous ommatidia for detecting motion and color, and three dorsal ocelli that primarily sense light intensity. Antennae arise from the frons. In , they are typically geniculate (elbowed), consisting of a scape, pedicel, and multi-segmented with females generally having 12 or more antennomeres and males 13, enabling functions such as chemoreception and mechanosensation; in Symphyta, antennae are often filiform or serrate with fewer segments. Mouthparts are primarily mandibulate, adapted for chewing, with strong, toothed mandibles used for manipulation, defense, or nest-building; the maxillae and labium form a flexible proboscis-like structure in some groups for liquid feeding, though remaining unspecialized in many basal forms. Wings, when present, consist of two pairs of membranous fore- and hindwings arising from the thoracic segments, with the forewings typically larger than the hindwings. Venation patterns vary phylogenetically: Symphyta display relatively complete wing venation with multiple closed cells for structural support, while in , venation is often reduced, as seen in bees where fewer veins form simplified cells like the submarginal and discoidal cells. The wings couple during flight via rows of hook-like setae called hamuli along the anterior margin of the hindwing, which interlock with a folded ridge on the posterior margin of the forewing, ensuring coordinated flapping and aerodynamic efficiency. Female Hymenoptera possess an ovipositor, a specialized egg-laying appendage at the abdominal apex, formed by modified valvulae; in Symphyta, it is saw-like for cutting plant tissues, whereas in Apocrita, it is often modified into a stinging apparatus or reduced/absent in some parasitoids and social species. Abdominal cerci, sensory appendages at the posterior end, are greatly reduced or vestigial in most Hymenoptera, differing from more prominent cerci in other insect orders. The abdomen itself is segmented, with terga and sterna forming flexible sclerites that accommodate visceral expansion during feeding or egg production.

Internal Systems

Hymenoptera possess an open typical of , in which —a colorless fluid analogous to —bathes the organs directly rather than being confined to vessels. The primary pumping structure is a dorsal vessel extending along the length of the body, functioning as a heart with segmental chambers that contract to propel anteriorly through the toward the head. composition includes , ions such as sodium, , and , organic molecules like sugars and for transport, and hemocytes that aid in immune responses and clotting. In honey bees (Apis mellifera), a representative hymenopteran, the system facilitates the distribution of hormones, nutrients, and waste products, with flow rates influenced by temperature and activity levels. The in Hymenoptera relies on a tracheal network that delivers oxygen directly to tissues, bypassing the for . Spiracles—valved external openings—line the and , with most featuring ten pairs: three thoracic and seven abdominal, though the prothoracic pair may be reduced or absent in some groups like . Air enters through these spiracles into tracheae, which branch into finer tracheoles that permeate organs and muscles, allowing diffusion of oxygen based on concentration gradients. In adult honey bees, the propodeal spiracles (between and ) open during abdominal contractions to facilitate ventilation, particularly under stress or high metabolic demand, while remaining closed in normal conditions to minimize water loss. This system supports the high oxygen needs of flight and social behaviors in many hymenopterans. The of Hymenoptera consists of a centralized in the head and a ventral nerve cord running posteriorly through the and , with segmental ganglia fusing in more derived for efficient control. The , or supraesophageal ganglion, integrates sensory inputs and coordinates complex behaviors, featuring prominent —paired neuropils crucial for olfactory learning, memory, and multimodal sensory integration. These structures receive inputs from the antennal lobes and exhibit voluminous calyces in hymenopterans, reflecting adaptations for advanced in social like and bees. The subesophageal ganglion handles feeding and mouthpart movements, while the ventral cord's ganglia innervate limbs and abdominal organs, enabling rapid reflexes. In honey bees, undergo experience-dependent plasticity, enhancing associative learning. Digestion in Hymenoptera occurs along a tubular alimentary canal divided into , , and , optimized for processing , , or prey depending on the species' diet. The , derived from , includes the , , , and —a for temporary storage, particularly prominent in nectar-feeding bees. The , the primary site of enzymatic digestion and absorption, is lined with a that protects epithelial cells and facilitates passage; it secretes and maintains a neutral to alkaline . The , also ectodermal, reabsorbs water and ions from waste, forming . is handled by Malpighian tubules—blind-ended structures arising at the midgut-hindgut junction—that filter to remove nitrogenous wastes like , which are then processed in the for conservation of water in terrestrial environments. In and bees, this system efficiently handles diverse diets, with adaptations like enlarged crops in social species for trophallaxis. The reproductive systems of Hymenoptera are sexually dimorphic, with females typically equipped for egg production and storage, while males focus on generation. Female ovaries consist of paired structures containing multiple ovarioles—tubular units where occurs sequentially from germarium to vitellarium—varying in number from dozens in solitary wasps to thousands in queen honey bees for high . Eggs mature and pass into lateral s, converging at a common oviduct, with a serving as a sac-like reservoir for long-term storage post-mating, ensuring fertilization of eggs over extended periods. In social hymenopterans, the 's glandular nourishes stored , maintaining viability for months or years. Male testes are paired, each comprising multiple testicular follicles that produce spermatocytes, maturing into transferred via and ducts during copulation; accessory glands contribute fluids to the . These systems support haplodiploid sex determination, though genetic details are addressed elsewhere.

Reproduction and Life Cycle

Sex Determination and Genetics

The in Hymenoptera is characterized by , where males develop from unfertilized haploid eggs and are thus hemizygous (effectively XO), while females develop from fertilized diploid eggs and are homozygous at sex-determining loci (XX). This arrhenotokous mechanism is the predominant mode across the order, distinguishing Hymenoptera from most other that employ diploid-diploid sex determination. A key genetic implication of is the asymmetric relatedness among siblings: full sisters share three-quarters of their genes by due to identical paternal contributions, compared to only one-half relatedness to their brothers or own . This elevated sister-sister relatedness has been proposed as a foundational factor favoring the in Hymenoptera, as it can make cooperative investment in sisters kin-selectively advantageous over personal . However, the precise role of in driving remains debated, with empirical evidence showing it facilitates but does not solely explain eusocial transitions. Superimposed on is complementary sex determination (CSD), the primary genetic mechanism regulating sex in most Hymenoptera species. Under single-locus CSD (sl-CSD), sex is determined by heterozygosity at a sex-specific locus (csd); fertilized eggs heterozygous at this locus develop into females, while homozygosity results in diploid males, which are often inviable or sterile due to disrupted development. Multiple-locus CSD variants exist in some lineages, requiring homozygosity at multiple loci to produce diploid males, thereby reducing costs. Diploid males arise primarily from inbred matings and impose a fitness load on populations, as they consume resources without contributing reproductively. Karyotypes in Hymenoptera exhibit remarkable variation, reflecting evolutionary divergence across suborders and families. Diploid chromosome numbers (2n) for females range from as low as 2n=2 in certain (e.g., Myrmecia pilosula) to over 2n=120 in some ponerine , with haploid males (n) accordingly half that value. This diversity, spanning from 2n=8 in pteromalid wasps to 2n=92 in , arises from frequent chromosomal rearrangements such as fusions, fissions, and inversions, which have facilitated adaptive radiations without major impacts on fertility. Such variability underscores the genomic plasticity underlying the order's ecological success.

Parthenogenesis and Thelytoky

Parthenogenesis in Hymenoptera typically manifests as , the standard reproductive mode where unfertilized eggs develop into haploid males, while fertilized eggs produce diploid females. This system is integral to the order's haplodiploid genetic framework, but certain species exhibit , a form of in which unfertilized eggs develop into diploid females. enables of female offspring, contrasting with by restoring diploidy without fertilization. The cytogenetic mechanisms underlying thelytoky in Hymenoptera include automixis and . In automixis, occurs but diploidy is restored through fusion of meiotic products, such as central fusion between the two central nuclei after the second meiotic division, which preserves heterozygosity at the . This mechanism is exemplified in the (Apis mellifera capensis), where queens and workers produce female offspring via automictic thelytoky, leading to clonal lineages with reduced genetic diversity over generations. , by contrast, involves the production of diploid eggs without , resulting in fully homozygous offspring; it occurs in wasps like Trichogramma species and Diglyphus wani, where thelytoky is genetically determined without bacterial influence. In some cases, endosymbiotic such as induce thelytoky by manipulating host reproduction, as observed in certain wasps, though this is less common in eusocial taxa. Thelytoky provides evolutionary advantages in social Hymenoptera, particularly for colony founding and worker reproduction in the absence of males. In eusocial species, it allows workers to lay unfertilized eggs that develop into females, facilitating independent colony establishment or supplementing queen production during times of stress. For instance, in the clonal raider (Ooceraea biroi), thelytoky supports an all-female society through automixis, enhancing reproductive autonomy and invasion potential. Similarly, in the little fire (Wasmannia auropunctata), thelytokous queens produce daughters asexually, while males arise from , promoting rapid population spread. Across eusocial bees, wasps, and , at least 51 species demonstrate or are claimed to exhibit , underscoring its role in adaptive flexibility within haplodiploid systems.

Developmental Stages

Hymenoptera undergo holometabolous (complete) , progressing through four distinct life stages: , , , and (). This developmental pattern allows for dramatic morphological changes between stages, with the and occupying different ecological niches. The stage is brief, typically lasting a few days to weeks depending on and environmental conditions; eggs are usually microscopic, elongated, and deposited by females in locations suited to larval survival, such as foliage or host tissues. The larval stage is the primary growth phase, consisting of 3 to 7 s marked by molts, during which the legless, worm-like grubs feed intensively to accumulate resources for later stages. e lack functional wings or compound eyes and are often soft-bodied and white, adapted for protected or concealed feeding. Following the final , the larva enters the pupal stage, a period of histolysis and reorganization where adult structures form within the protective ; pupation can occur openly or enclosed in cocoons, lasting from days to months. The adult emerges after , fully formed and sexually mature, ready to reproduce and forage. Developmental patterns differ between the suborders Symphyta and . In Symphyta (sawflies and relatives), larvae are eruciform (caterpillar-like) with thoracic legs and prolegs, actively feeding on plants externally; pupation is external, often in or leaf litter without a cocoon, reflecting their phytophagous lifestyle. In contrast, (ants, bees, and wasps) feature apodous (legless) larvae that are either endoparasitic, developing inside host insects, or nest-provisioned with food by adults; pupation typically occurs within silken cocoons in nests or , and many incorporate —a dormant phase—to overwinter or survive adverse conditions. These adaptations align with the predatory or provisioning behaviors prevalent in . In social Hymenoptera, such as ants, bees, and some wasps, developmental polymorphism produces distinct castes from genetically similar larvae: long-lived queens for reproduction, sterile workers for colony maintenance, and short-lived drones (males) for mating. Caste differentiation arises primarily through differential larval nutrition, with well-fed individuals developing into queens, though genetic factors also influence outcomes in some species. This polyphenism enhances colony efficiency by specializing individuals for specific roles.

Feeding and Behavior

Diet and Foraging Strategies

Hymenoptera larvae exhibit diverse feeding habits depending on the suborder and family. In Symphyta, such as sawflies, larvae are primarily herbivorous, consuming leaves, needles, or other plant tissues in a manner similar to caterpillars. In contrast, larvae of , particularly parasitoids, are mostly carnivorous, feeding on host tissues after being laid as eggs inside or on prey. Aculeate larvae, including those of bees, wasps, and , are provisioned in nests with paralyzed prey, pollen-nectar mixtures, or fungi, remaining stationary while consuming these stored resources. Adult Hymenoptera diets vary widely across groups. Bees primarily feed on and pollen, with some species incorporating oils or resins from flowers. Wasps, including vespids and sphecids, often capture and consume prey such as or spiders, though many also sip or honeydew. Ants display omnivorous tendencies, harvesting seeds, fungi, , and prey, with specialized castes sometimes focusing on particular items like fungal cultivation in leafcutter ants. Adults generally favor liquid diets, imbibed via an elongated adapted from mouthparts for efficient extraction. Foraging strategies in Hymenoptera range from solitary to collective approaches, tailored to resource distribution and colony needs. Solitary foragers, common in many wasps and non-social bees, hunt independently or visit flowers on fixed routes known as trap-lines, revisiting predictable nectar sources to maximize efficiency. In social species like ants, collective foraging predominates, with individuals using pheromone-based scent trails to guide nestmates to food patches, enabling rapid recruitment to ephemeral resources such as insect prey or seeds. Some hornets and bees also employ trap-lining in group contexts, maintaining stable paths amid clustered resources. Hymenoptera occupy multiple trophic levels, reflecting their dietary versatility. Sawflies function as at the primary consumer level, while predatory wasps and act as secondary consumers by capturing herbivores or smaller carnivores. Parasitoids, a dominant group in , target hosts across trophic tiers, often regulating herbivore populations as tertiary consumers. Many bees and qualify as omnivores, blending and animal matter, which elevates their trophic positions beyond strict herbivores or predators.

Social Organization

Hymenoptera exhibit a wide range of social structures, from solitary living to highly complex colonies, with being particularly prevalent in , , and some wasps. is characterized by three defining traits: a reproductive division of labor where certain individuals (queens) specialize in reproduction while others (workers) forgo it; cooperative care of the brood by colony members; and overlapping generations where adults from different cohorts coexist and contribute to colony maintenance. In (Formicidae), such as leafcutter (Atta spp.), queens lay thousands of eggs while sterile female workers perform foraging, nest building, and defense, with cooperative brood care ensuring high survival rates for larvae. Similarly, in honey (Apis mellifera), the queen monopolizes egg-laying, workers nurse the young and maintain the hive, and overlapping generations allow multi-year colony persistence. In social wasps like yellowjackets ( spp.), foundress queens initiate nests, but workers soon take over non-reproductive tasks, fostering brood through shared feeding and protection. Social organization in Hymenoptera spans a spectrum from solitary to advanced eusocial forms. Solitary species, comprising the majority of Hymenoptera (over 90%), live independently, with females provisioning nests alone without assistance from others. Primitively eusocial groups, such as many paper wasps (Polistes spp.) and sweat bees (Halictidae), show flexible role division without distinct morphological castes; dominant individuals lay eggs, but subordinates can reproduce if the queen dies, and brood care is shared among sisters. Advanced eusociality, seen in most ants, honeybees, and stingless bees (Meliponini), features irreversible sterility in workers and pronounced physical differences, like the smaller size and reduced ovaries of workers compared to queens; for example, in fire ants (Solenopsis invicta), workers are morphologically specialized for tasks and cannot reproduce. This progression reflects evolutionary adaptations enhancing colony efficiency and survival. Communication is essential for coordinating these social behaviors in eusocial Hymenoptera. Pheromones serve as primary signals: alarm pheromones, such as in honeybees and 4-methyl-3-heptanone in ants like Pogonomyrmex spp., are released during threats to recruit defenders and induce aggressive responses across the colony.30049-6) Trail pheromones, deposited by ants (e.g., (Z)-9-hexadecenal in Argentine ants, Linepithema humile), guide nestmates to food sources by forming chemical paths that degrade over time to prevent overuse.30049-6) In honeybees, the communicates resource locations; a scout bee performs figure-eight runs on the comb, with the waggle phase duration indicating distance and angle relative to the sun's position, as elucidated by . Stridulation, involving rubbing body parts to produce vibrations, occurs in some (e.g., Myrmica spp.) and wasps for alarm or recruitment, transmitting signals through substrate to alert nearby individuals without chemical release. The evolution and maintenance of altruistic behaviors in these societies are underpinned by kin selection theory, where workers aid relatives to propagate shared genes. Hamilton's rule provides the conceptual framework: altruism evolves if the benefit to the recipient (B), weighted by genetic relatedness (r), exceeds the cost to the actor (C), or rB > C; in haplodiploid Hymenoptera, sisters share 75% relatedness, favoring worker sterility to rear siblings over personal reproduction. This high relatedness, combined with ecological pressures, explains the prevalence of in the order.

Ecology and Human Interactions

Distribution and Habitat

The order Hymenoptera exhibits a near-cosmopolitan distribution, occurring on all continents except Antarctica and being largely absent from extreme polar regions such as the high Arctic tundra. Species are also missing from certain remote oceanic islands due to isolation barriers that limit dispersal, though many have been introduced anthropogenically to such locations. This broad presence reflects the order's adaptability to diverse terrestrial environments, with approximately 154,000 described species spanning temperate, tropical, and subtropical zones worldwide. Hymenopterans inhabit a wide array of ecosystems, including forests, grasslands, deserts, and even urban areas, where they exploit varied microhabitats for survival. Nesting strategies contribute to this versatility: many species, particularly ground-nesting bees and wasps, into , favoring well-drained sands or loams; others, like certain and woodwasps, excavate galleries in dead wood or pithy stems; and some, such as paper wasps, construct aerial nests from plant fibers or mud attached to or structures. These habits allow occupancy from arid scrublands to humid rainforests, with often dominating and layers across biomes. The altitudinal range of Hymenoptera extends from to over 5,000 meters, with alpine bumblebees (Bombus spp.) recorded foraging and nesting at elevations up to 5,600 meters in the , where low oxygen and cold temperatures challenge physiological limits. Most species remain sedentary within local populations, tied to stable nesting sites and resource patches, though some bees exhibit seasonal mass migrations, particularly in spring, covering distances of several kilometers in response to constraints.

Threats and Conservation

Hymenoptera populations, particularly pollinating species like bees and wasps, face multiple anthropogenic threats that exacerbate their vulnerability. Habitat loss due to urbanization, agriculture intensification, and land conversion is a primary driver, fragmenting ecosystems and reducing floral resources essential for foraging and nesting. Pesticides, especially neonicotinoids, pose significant risks by impairing navigation, reproduction, and immune function in exposed individuals, leading to sublethal effects that accumulate across populations. Climate change further compounds these issues through altered phenology, such as mismatched blooming times with insect life cycles, and increased frequency of extreme weather events that disrupt habitats. Invasive species, including non-native pathogens and competitors like the varroa mite, introduce novel pressures that native Hymenoptera lack defenses against. Global assessments indicate substantial declines in Hymenoptera diversity and abundance, with approximately 40% of invertebrate pollinator species, including many bees, classified as threatened with extinction as of 2016. Updated evaluations through 2025 reveal persistent trends, with 34.7% of assessed native North American bee species facing elevated extinction risk, driven by the interplay of these threats. A notable case is colony collapse disorder (CCD) in honeybees (Apis mellifera), first widely reported in the mid-2000s, where adult workers abruptly disappear, leaving hives with brood and stores untended; multifactorial causes include varroa mite infestations transmitting viruses, pesticide exposure, and nutritional deficits from habitat scarcity. Similarly, bumblebee (Bombus spp.) populations have declined sharply, with over 25% of North American species at risk, attributed to habitat fragmentation, pesticide use, and pathogen spillover from managed bees, resulting in localized extirpations and reduced genetic diversity. Conservation efforts for Hymenoptera emphasize mitigation of these threats through targeted strategies. Protected areas, such as national parks and reserves, safeguard critical habitats by limiting development and maintaining corridors that support mobility. Community-driven initiatives like gardens promote native plantings to enhance local foraging resources and nesting sites, fostering resilience in urban and agricultural landscapes. Regulatory measures, including the European Union's bans on pesticides since 2018 (with ongoing enforcement and expansions), demonstrate policy interventions that reduce chemical exposures and have correlated with stabilized populations in restricted regions. Integrated approaches, such as the Pollinators Initiative revised in 2023, combine monitoring, restoration, and international cooperation to address transboundary threats like .

Economic and Ecological Importance

Hymenoptera play a pivotal role in global agriculture through pollination services, primarily provided by bees, which support the production of numerous crops. Approximately 75% of leading global food crops, including fruits like apples and nuts such as almonds, depend to some extent on animal pollination for yield and quality. The economic value of insect pollination worldwide is estimated at over US$800 billion annually (as of 2025). In the United States alone, honey bees contribute to pollinating crops worth $15 billion each year, underscoring their indispensable contribution to food security and economic stability. Beyond pollination, many Hymenoptera species, particularly wasps, serve as key agents in , reducing the need for chemical pesticides and enhancing sustainable farming. For instance, species in the genus Trichogramma are widely deployed against lepidopteran pests like the , with applications in over 50 countries leading to significant yield improvements in crops such as . The broader economic benefits of natural biological control by arthropods, including parasitoids, highlight their role in minimizing agricultural losses. These wasps parasitize host eggs or larvae, effectively regulating pest populations and supporting systems that lower production costs. Ecologically, Hymenoptera contribute to stability through diverse functions, such as soil aeration and cycling by , which act as engineers. Ant colonies excavate tunnels that improve porosity, water infiltration, and aeration, while also facilitating by breaking down and dead , thereby enhancing availability for . Additionally, many hymenopterans function as predators, controlling populations and maintaining ; for example, prey on small , preventing outbreaks that could disrupt communities. These roles collectively support healthy terrestrial , including forests and grasslands, where alone influence properties and dynamics on a global scale. Despite their benefits, Hymenoptera can impose negative economic and ecological costs in certain contexts. Invasive ants like the red imported fire ant (Solenopsis invicta) cause substantial damage through aggressive foraging and stinging, resulting in over $5 billion in annual U.S. losses from agricultural impacts, medical treatments, and property damage. Some sawflies, such as the wheat stem sawfly (Cephus cinctus), inflict crop losses by girdling stems, leading to lodging and reduced yields; in regions like the U.S. Great Plains, this pest alone accounts for $25–70 million in annual wheat damages. Fire ant stings, in particular, pose public health risks, contributing to medical expenses and productivity losses due to painful, potentially allergic reactions.

References

  1. https://www.si.edu/spotlight/buginfo/hymenoptera
  2. https://australian.museum/learn/animals/insects/sawflies-wasps-bees-ants-hymenoptera/
  3. https://genent.cals.ncsu.edu/insect-identification/order-hymenoptera/
  4. https://www.royensoc.co.uk/understanding-insects/classification-of-insects/hymenoptera/
  5. https://www.chrysis.net/resources/taxonomy-of-hymenoptera/
  6. https://jhr.pensoft.net/article/60054/
  7. https://www.royensoc.co.uk/understanding-insects/facts-and-figures/
  8. https://bmcecol.biomedcentral.com/articles/10.1186/s12898-018-0176-x
  9. https://genent.cals.ncsu.edu/insect-identification/hymenoptera/
  10. https://www.etymonline.com/word/Hymenoptera
  11. https://bugguide.net/node/view/59
  12. http://eagri.org/eagri50/ENTO231/lec26.pdf
  13. https://bugswithmike.com/glossary/apocrita
  14. https://dr.lib.iastate.edu/bitstreams/cd8d48fa-3b81-4e3e-b484-e2b9ceaca9cf/download
  15. https://faculty.ucr.edu/~legneref/entomol/hymenoptera.htm
  16. https://u.osu.edu/oramulu.1/2020/07/28/hymenoptera/
  17. https://biology.byu.edu/00000174-7e97-dc52-a77f-ffb7ca260000/11-hymenoptera-lab-sheet-2008-doc
  18. https://pmc.ncbi.nlm.nih.gov/articles/PMC1626634/
  19. https://www.mapress.com/zootaxa/2007f/zt01668p548.pdf
  20. https://www.researchgate.net/publication/249447053_Phylogeny_of_the_holometabolous_insect_orders_Molecular_evidence
  21. https://www.sciencedirect.com/science/article/pii/S1055790324001362
  22. https://pmc.ncbi.nlm.nih.gov/articles/PMC11336256/
  23. https://zookeys.pensoft.net/article/3608/
  24. https://www.sciencedirect.com/science/article/abs/pii/S0195667122001124
  25. https://www.mapress.com/pe/article/view/palaeoentomology.3.4.10
  26. https://www.cell.com/current-biology/fulltext/S0960-9822(17)30059-3
  27. https://www.nature.com/articles/s41467-023-36868-4
  28. https://arthropod-systematics.arphahub.com/article/31991/
  29. https://elifesciences.org/articles/08918
  30. https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2023.1118748/full
  31. https://faculty.ucr.edu/~legneref/entomol/familyhy.htm
  32. https://bugguide.net/node/view/112
  33. https://resjournals.onlinelibrary.wiley.com/doi/10.1111/afe.12510
  34. https://pmc.ncbi.nlm.nih.gov/articles/PMC2873417/
  35. https://resjournals.onlinelibrary.wiley.com/doi/10.1111/syen.12645
  36. https://adowling.hosted.uark.edu/PDF/Sharkey2011.pdf
  37. https://www.sciencedirect.com/science/article/pii/S2214574523000238
  38. https://www.pnas.org/doi/10.1073/pnas.2201550119
  39. https://www.museumoftheearth.org/bees/diversity
  40. https://www.waspweb.org/Vespoidea/Vespidae/index.htm
  41. http://www.ichsofna.org/
  42. https://bmcecolevol.biomedcentral.com/articles/10.1186/1471-2148-10-109
  43. https://soil.evs.buffalo.edu/index.php/Hymenoptera
  44. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/apocrita
  45. https://theraulaz.ch/en/macrophotography/hymenoptera/
  46. https://pesticidecert.cfans.umn.edu/sites/pesticidecert.cfans.umn.edu/files/2022-03/3.Insect_Morphology.pdf
  47. https://www.royensoc.co.uk/wp-content/uploads/2021/12/Vol06_Part01_ed2.pdf
  48. https://theraulaz.ch/en/macrophotography/hymenoptera/symphyta/
  49. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/hymenoptera
  50. https://www.danforthlab.entomology.cornell.edu/wp-content/uploads/5danforth_1989_jzoollond.pdf
  51. https://www.researchgate.net/publication/238318166_Hamuli_in_the_Hymenoptera_Insecta_and_their_phylogenetic_implications
  52. https://uq.pressbooks.pub/insect-science/chapter/orders-of-insects-hymenoptera/
  53. https://entnemdept.ufl.edu/media/entnemdeptifasufledu/honeybee/pdfs/abj-field-guide-to-beekeeping/21%2C-September-2015%2C-Internal-Anatomy%2C-low-res.pdf
  54. https://agriculture.institute/beekeeping-introduction/circulatory-system-honey-bees/
  55. https://www.sciencedirect.com/science/article/pii/0022191085900514
  56. https://americanbeejournal.com/respiration-and-circulation-in-honey-bees/
  57. https://journals.biologists.com/jeb/article/31/4/589/12842/The-Respiratory-Currents-in-the-Tracheal-System-of
  58. https://pmc.ncbi.nlm.nih.gov/articles/PMC5980188/
  59. https://www.honeybeesuite.com/respiration-and-circulation-in-honey-bees/
  60. https://pmc.ncbi.nlm.nih.gov/articles/PMC4876875/
  61. https://pmc.ncbi.nlm.nih.gov/articles/PMC4024300/
  62. https://repository.si.edu/bitstreams/a025f660-9f96-45e0-bfef-0e5e65376a86/download
  63. https://genent.cals.ncsu.edu/bug-bytes/digestive-system/
  64. https://uq.pressbooks.pub/insect-science/chapter/the-contented-insect-feeding-nutrition/
  65. https://www.researchgate.net/publication/255483313_A_comparative_study_of_the_spermatheca_in_bees_Hymenoptera_Apoidea
  66. https://www.nature.com/articles/s41598-022-23104-0
  67. https://genent.cals.ncsu.edu/bug-bytes/reproductive-system/
  68. https://pubmed.ncbi.nlm.nih.gov/17803453/
  69. https://www.nature.com/articles/hdy1993157
  70. https://www.nature.com/articles/ncomms15920
  71. https://www.journals.uchicago.edu/doi/10.1086/677283
  72. https://www.pnas.org/doi/10.1073/pnas.0701285104
  73. https://www.pnas.org/doi/10.1073/pnas.0502271102
  74. https://pubmed.ncbi.nlm.nih.gov/15354193/
  75. https://www.nature.com/articles/s41598-019-55135-5
  76. https://pmc.ncbi.nlm.nih.gov/articles/PMC11933897/
  77. http://journals.fcla.edu/flaent/article/viewFile/80389/77630
  78. https://pmc.ncbi.nlm.nih.gov/articles/PMC10632776/
  79. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/thelytoky
  80. https://www.nature.com/articles/6800565
  81. https://karger.com/sxd/article/8/1-3/50/296590/Thelytoky-and-Sex-Determination-in-the-Hymenoptera
  82. https://www.nature.com/articles/hdy2014127
  83. https://pmc.ncbi.nlm.nih.gov/articles/PMC9899834/
  84. https://www.mdpi.com/2075-4450/13/1/9
  85. https://www.amentsoc.org/insects/fact-files/orders/hymenoptera.html
  86. https://earthlife.net/hymenoptera-ants-bees-wasps-ichnuemonids/
  87. https://pmc.ncbi.nlm.nih.gov/articles/PMC2398704/
  88. https://www.annualreviews.org/content/journals/10.1146/annurev-genet-111523-102510
  89. https://biokids.umich.edu/critters/Hymenoptera/
  90. https://extension.oregonstate.edu/catalog/em-9426-vegetarians-predators-parasitoids-lesser-known-wasps-oregon
  91. https://faculty.ucr.edu/~legneref/pollination/pollinat2.htm
  92. https://www.journals.uchicago.edu/doi/full/10.1086/704281
  93. https://pmc.ncbi.nlm.nih.gov/articles/PMC10577024/
  94. http://keyserver.lucidcentral.org/key-server/data/05060b08-0f0e-4d04-8c01-070203010505/media/Html/Hymenoptera.htm
  95. https://pmc.ncbi.nlm.nih.gov/articles/PMC5496863/
  96. https://app.sib.illinois.edu/suarez/local/suarez/uploads/2020/01/AntEcology_Chapter12.pdf
  97. https://pmc.ncbi.nlm.nih.gov/articles/PMC12009247/
  98. https://academic.oup.com/jinsectscience/article/6/1/25/869167
  99. https://www.researchgate.net/profile/Roger-Beaver/publication/249140424_On_the_Trophic_Relations_of_Insects_A_Food-Web_Approach/links/54bf69900cf2acf661cdfe7d/On-the-Trophic-Relations-of-Insects-A-Food-Web-Approach.pdf
  100. https://www.nature.com/scitable/knowledge/library/an-introduction-to-eusociality-15788128/
  101. https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2021.727124/full
  102. https://www.nature.com/articles/s41576-018-0044-8
  103. https://pmc.ncbi.nlm.nih.gov/articles/PMC3279739/
  104. https://pmc.ncbi.nlm.nih.gov/articles/PMC7027560/
  105. https://www.nature.com/articles/s41598-021-84925-z
  106. https://pmc.ncbi.nlm.nih.gov/articles/PMC3982664/
  107. https://www.nature.com/articles/nature09833
  108. https://pmc.ncbi.nlm.nih.gov/articles/PMC6355736/
  109. https://esc-sec.ca/wp/wp-content/uploads/2017/03/AAFC_hymenoptera_of_the_world.pdf
  110. https://www.ars.usda.gov/ARSUserFiles/20800500/encyclopediaofentomologycanebees.pdf
  111. https://pmc.ncbi.nlm.nih.gov/articles/PMC11552452/
  112. https://www.sciencedirect.com/science/article/abs/pii/S1146609X97800513
  113. https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2664.13768
  114. https://www.xerces.org/endangered-species/wild-bees
  115. https://www.pollinator.org/threats
  116. https://www.museumoftheearth.org/bees/threats
  117. https://pubs.usgs.gov/publication/cir1556/full
  118. https://files.ipbes.net/ipbes-web-prod-public-files/spm_deliverable_3a_pollination_20170222.pdf
  119. https://www.natureserve.org/news-releases/over-one-fifth-native-north-american-pollinators-elevated-risk-extinction
  120. https://www.pnas.org/doi/full/10.1073/pnas.2418742122
  121. https://www.epa.gov/pollinator-protection/colony-collapse-disorder
  122. https://www.xerces.org/bumble-bees/conservation-efforts
  123. https://environment.ec.europa.eu/topics/nature-and-biodiversity/pollinators_en
  124. https://www.bc-europe.eu/webpage.php?name=eu-pollinator-initiative
  125. https://www.nature.com/articles/s41598-025-19426-4
  126. https://www.usda.gov/about-usda/general-information/initiatives-and-highlighted-programs/peoples-garden/importance-pollinators/honey-bees
  127. https://pmc.ncbi.nlm.nih.gov/articles/PMC11277535/
  128. https://myrmecologicalnews.org/cms/index.php?filename=volume11/mn11_191-199_printable.pdf&format=raw&option=com_download&view=download
  129. https://besjournals.onlinelibrary.wiley.com/doi/10.1111/j.1365-2656.2010.01796.x
  130. https://www.indianfarmer.net/uploads/IndFarmVol10Issue08_06.pdf
  131. https://pmc.ncbi.nlm.nih.gov/articles/PMC10146602/
  132. https://extension.sdstate.edu/sites/default/files/2020-03/S-0005-22-Wheat.pdf
  133. https://ant-pests.extension.org/other-impacts-of-fire-ants/
Add your contribution
Related Hubs
User Avatar
No comments yet.