Figure 2.

Developmental pathways of (A) wood-dwelling termites such as Z. nevadensis and (B) foraging higher termites such as M. natalensis. Wood-dwelling termites have totipotent immature stages that can explore all caste options, whereas higher termites have a bifurcating caste development pathway splitting into a nymphal line leading to winged dispersing alates and an apterous line leading to workers and soldiers. In M. natalensis this bifurcation is already established in the egg stage. (i) progressive development via nymphal instar(s) into winged sexuals (alates) that disperse and found a new nest elsewhere; (ii) stationary molt remaining in the same instar; (iii) regressive development into an “earlier” instar (gray semi-circle); (iv) development into a soldier, and (v) development into a neotenic replacement reproductive that reproduces within the natal nest. Part (a) is adapted from Korb et al. (2012b). (Photo credits: Judith Korb).