Prolonged maternal care inElasmucha dorsalis (Heteroptera: Acanthosomatidae)

Female parents ofElasmucha dorsalis attend their offspring and show specific sequential defensive behavior when disturbed. Intense responses of brooding females such as wing fanning were usually triggered by exposure to crushed nymphs. Maternal care continued for a long time, sometimes into the fourth or last nymphal instar. Female removal experiments showed that maternal defense is highly effective under field conditions. High egg mortality observed in the field was probably due to the predation by an ant,Myrmica ruginodis, which occurred at high densities on the host plant,Aruncus dioicus. Most of the egg masses were found on the leaves subtending axillary inflorescence of the female plants, and nymphs usually aggregated and fed on fruits in the inflorescence. Because the food of nymphs is temporally limited, the female can produce only a single brood. Thus, temporality of food resources as well as a heavy predation pressure may have led to prolonged maternal care.