Injured mother bugs compensate for reduced provisioning ability by increasing trophic egg production

In the burrower bug Adomerus triguttulus, females exhibit parental care, including provisioning of trophic eggs and nutlets of Lamium spp. Trophic eggs are deposited on egg clutches during egg care and are consumed by nymphs soon after hatching. After hatching, females progressively deliver nutlets into nests harbouring the nymphs. Females sometimes sustain injuries before oviposition, possibly due to predator attacks. Such non-lethal injuries may result in reduced nutlet provisioning ability or reduced residual reproductive value and may thus induce adaptive changes in trophic egg production. To test the hypothesis of increased trophic egg production as compensation for decreased nutlet-provisioning ability or as terminal investment triggered by injury, females were divided into three experimental groups: hind-leg removal, forewing removal and control (no injury) groups. Females in the hind-leg removal group produced more trophic eggs than those in both the forewing removal and control groups, which did not differ from each other. The nutlet-carrying speed of females in the hind-leg removal group was lower than those of females in the forewing removal and control groups. These results suggest that females that have lost a leg compensate for their decreased provisioning ability by increasing trophic egg production.