Paternity and egg cannibalism in the ringlegged earwig Euborellia annulipes (Dermaptera: Anisolabididae)

Abstract

Cannibalism is a common occurrence in nature, and many cannibals prey on relatively small and defenseless life stages, such as eggs or young juveniles. Such behavior provides many benefits to the cannibal, but cannibalistic individuals also face risks, including the cost of decreasing their inclusive fitness by eating close relatives such as siblings or offspring. This risk can be mitigated if cannibals can recognize and avoid preying on kin. Here, we tested whether male ringlegged earwigs Euborellia annulipes avoid cannibalizing eggs that they had sired. In this species, females care for their own eggs, but males provide no care and frequently prey upon eggs. We found that when presented with an unguarded clutch of eggs, male earwigs nearly always cannibalized some eggs, but that the proportion of eggs eaten was smaller if the male had sired the clutch. This suggests that males can distinguish between their own offspring and unrelated offspring and that they avoid harming their kin.

Egg Cannibalism Varies With Sex, Reproductive Status, and Egg and Nymph Ages in Arma custos (Hemiptera: Asopinae)

“…This selective cannibalism would not only extend the lifespan of the adult insects but also ensure the survival of most offspring, which is more helpful in preventing populations from dwindling (Polis, 1981;Smith and Reay, 1991;Manica, 2002). Our results were similar to those for Euborellia annulipes Lucas (Dermaptera: Anisolabididae) (Jacobs and Stigall, 2019). This process is not only beneficial for the health of offspring, but also beneficial for females (Okada et al, 2015).…”

“…Similar results have also been obtained for Anisolabis maritima Bon. (Miller and Zink, 2012) and Euborellia annulipes Lucas (Jacobs and Stigall, 2019). Our results also demonstrate that neither A. custos nymphs nor female adults consumed all of the available eggs, and the emergence ratio was > 70%.…”

Parental Sex and Not Kinship Determines Egg Cannibalism in Arma custos Fallou (Hemiptera: Pentatomidae: Asopinae)

“…Cannibalism, the consumption of conspecifics, is a behavioral trait observed in several animal species (Fox, 1975;Elgar and Crespi, 1992). Egg cannibalism, an important mechanism for selfregulating population size (Fox, 1975;Polis, 1981), is widespread in insects (Dobler and Kölliker, 2010;Parsons et al, 2013;Schultner et al, 2013;Bayoumy and Michaud, 2015;Jacobs and Stigall, 2019), including Hippodamia convergens (Guerin-Meneville) (Bayoumy and Michaud, 2015) and Tribolium confusum (du Val) (Parsons et al, 2013) of the order Coleoptera and Forficula auricularia L. (Dermaptera) (Dobler and Kölliker, 2010), Formica aquilonia Yarr. (Hymenoptera) (Schultner et al, 2013), Rhinocoris tristis Stal (Thomas and Manica, 2003), and Callicorixa producta Reut.…”