Egg-dumping lace bugs preferentially oviposit with kin

Egg dumping, or abandoning eggs and young to the care of other conspecifics , results in an extreme form of alloparental care. It is unclear, however, if egg dumpers discriminate among kin and nonkin egg recipients. In the lac e bug Gargaphia solani (Heteroptera: Tingidae), some females with eggs (gua rds) also accept and defend eggs of conspecifics. Other females (egg dumper s) abandon their offspring after oviposition, leaving a single guard as the caregiver. We asked if egg dumpers preferentially dump their eggs among un guarded eggs of kin or nonkin. When given a choice between dumping among eg gs of full Siblings and eggs of nonsiblings, most eggs (67%) were dumped wi th full siblings' eggs. Furthermore, egg dumpers were just as likely to ovi posit among eggs of kin with whom they had interacted on a shared host plan t during juvenile development as they were to oviposit with, kin reared on different host plants. Thus, egg dumpers discriminate kin by using cues ass ociated With eggs, and such cues are not likely to be acquired through inte raction on a common host plant environment. (C) 2000 The Association for th e Study of Animal Behaviour.