[3] It seems to use a symbiotic bacteria, Wolbachia pipientis, to weaken the tick's immune system.
The wasp larvae then exist as koinobiont parasitoids in the tick for 28 to 70 days before emerging.
Ticks from the genera Ornithodoros, Amblyomma, Dermacentor, Haemaphysalis, Hyalomma, Ixodes and Rhipicephalus are recorded as having been infected by I. hookeri.
In Europe, Ixodes ricinus appears to be the preferred species and the marsh tick Dermacentor reticulatus is not used as a host.
[5] Different populations of I. hookeri around the world show different host preferences, complicating attempts to use this species as a biological control for ticks.