Reticulitermes is a termite genus in the family Heterotermitidae. They are found in most temperate regions on Earth including much of Asia and Western Europe, and all of North America.

Reticulitermes species have three general castes: reproductive, worker, and soldier.

In two Reticulitermes species, R. virginicus and R. speratus, mother-son breeding systems have been found. This means their colony members are more related to their mothers than their fathers since 50% of their genotype comes from their mother and 50% from their father who also shares 50% of his genotype with their shared mother. This has shown to bias female alate production over males, likely because colony members favor caring for those who they are most related to (see Kin Selection).

Reticulitermes species have bifurcated development and so they have a true worker caste, although workers retain a high level of plasticity and can become ergatoid reproductives due to the hemimetabolic nature of most termites. Those who do not can either become soldiers or stay workers. Workers typically focus on brood care and general nest management.

The soldier caste of most Reticulitermes defend the nest by either using their mandibles to attack invaders or by using their large heads to plug the entrances to their nests. They are most well known for their defensive abilities, though they are known to do many other tasks, such as aiding colony reproduction by accompanying alates and stimulating the production of supplementary reproductives. Like other termite soldiers, they are unable to feed themselves due to their large mandibles.

Many species of Reticulitermes have sex biases in their soldier castes with significantly more female soldiers than males. Some species, like R. virginicus, have next to no male soldiers at all. This is believed to be caused by the sexual dimorphism in termites in which females have a larger size potential than males and the fact that soldiers need to be able to plug entrances with their large heads. However, in R. flavipes, where there is no sexual dimorphism in the reproductive caste, there is also no sex bias in soldier production.

Reticulitermes flavipes (former santonensis) is found in western France, Reticulitermes grassei in southwestern France, northwestern and southern Spain and Portugal, Reticulitermes banyulensis in the Roussillon region of France and Reticulitermes lucifugus in the Provence region. The subspecies, Reticulitermes lucifugus corsicus is found in Corsica and Sardinia. Reticulitermes urbis, a newly described species is found in urban zones in the southeast of France (Marseille in the west to Italy in the east).

Reticulitermes clypeatus is found in Middle East.
Reticulitermes lucifugus is found in Turkey.
Reticulitermes chinensis, Reticulitermes guangzhouensis, Reticulitermes leptomandibularis and Reticulitermes khaoyaiensis are found in China.
Reticulitermes kanmonensis Korea, China and Japan.
Reticulitermes amamianus, Reticulitermes speratus, Reticulitermes miyatakei, Reticulitermes okinawanus and Reticulitermes yaeyamanus are found in Japan.
Reticulitermes arenincola is found in India.
Reticulitermes speratus is also found in all place in South Korea as well as Japan and North Korea