The role of relatedness and diet in kin recognition was investigated in the aphidophagous ladybirds Propylea dissecta and Coccinella transversalis. Third instar larvae of both species exhibited kin recognition, as they were reluctant to consume related first instar larvae. They spent significantly more time prior to cannibalism when interacting with genetically related victims; this indicates the presence of a kin recognition system. Kin recognition, however, was not evident in fourth instar larvae as they ate both related and unrelated victims. This result reveals that the need of fourth instar larvae to attain a critical weight for pupation might subdue kin recognition. The diet of cannibals did not affect cannibalism, number of encounters or time that elapsed prior to cannibalism. This indicates that kin recognition is not dependent on exogenous cues derived from the diets of the cannibal and victim.
The reproductive behaviour of a ladybeetle, Coccinella septempunctata was studied in detail. Males became sexually mature within 8.8 ± 0.3 days at 27°C, while females took 11.2 ± 0.4 days. Males exhibited courtship display in five steps: approach, watch, examine, mount and copulatory attempt. A prominent rejection display was shown by certain females who had not matured sexually, had recently mated or were about to oviposit. Males appeared to recognize females through chemical and some visual cues, such as size and body shape, with the chemical cues possibly playing a more significant role. Multiple matings took place within the same day. There was a gradual decrease with time in reproductive parametres, such as the duration of copulation, the number of copulatory bouts and the latent period from first to subsequent matings on the same day. The interval between mating bouts slightly increased from first to subsequent matings. The sexual status of males and females affected the duration of copulation, which was greatest in the case of unmated males and virgin females. Multiple matings increased the oviposition period, fecundity and percent hatching of eggs.