Kin recognition by cannibals is modulated by hunger level in a generalist predatory mite Amblyseius herbicolus (Chant) (Acari: Phytoseiidae)

Cannibalism is a commonly found behaviour in the animal kingdom. The biggest concern of cannibalism is that it reduces the inclusive fitness of the cannibals by eliminating close relatives. Kin recognition is a strategy used by many cannibals to benefit from cannibalism without the cost of reducing their inclusive fitness by eating close relatives. Most members of the family Phytoseiidae are cannibalistic. Previous studies suggest that specialist phytoseiids practice kin recognition, while generalists use species recognition or discrimination due to the diet specification and frequent intraspecific interactions. We examined whether kin recognition is used by a type‐III generalist phytoseiid, Amblyseius herbicolus (Chant) (Acari: Phytoseiidae). The cannibalistic adults with different hunger levels (0‐, 24‐ and 48‐hr starvation) were given a choice of kin and a non‐kin larva. Kin recognition of A. herbicolus was affected by the hunger level. Adults not starved before the test significantly preferred cannibalizing non‐kin larva. Conversely, adults starved for 24 and 48 hr showed no statistically significant preference between kin and non‐kin larvae. Furthermore, the latency reflected hunger level, where not starved adults had the most prolonged latency, while adults starved for 24 and 48 hr had intermediate and shortest latency. This study suggests A. herbicolus use innate recognition mechanisms to avoid kin cannibalism since the adults and larvae had no prior association before the experiment. The effect of familiarization on kin recognition in A. herbicolus should be further investigated.