Biocontrol Agent Profile

Wasps of the genus Aphelinus are specialized aphid parasitoids of the family Aphelinidae.  They are very different in biology from the Braconid aphid parasitoids (Aphidiinae).  Aphids mummified by Aphelinus tend to be black and rather flattened, rather than tan and swollen.  They tend to attack only the small aphid instars and cannot parasitize nearly as many aphids as aphidiine species, because they carry far fewer eggs.  However, they are much longer lived and can resorb eggs to extend their lives when aphids are not available.  They also cause some additional aphid mortality by host feeding behavior, in which the female stabs the aphid with her ovipositor and then drinks haemolymph from the wound.  They are also immune to the secondary aphid symbiont Hamiltonella defensa that can protect aphids from parasitism by aphidiine parasitoids by preventing their eggs from hatching.