Intraguild predation reduces the performance of Neoseiulus barkeri.

Intraguild predation distinctly altered the population parameters and predation capacity of two biological control agents used against Tetranychus urticaeThe negative impact fell on Neoseiulus barkeri. Already Scolothrips takahashii It maintained its performance and increased its population potential under the same conditions.

Life table analysis, using an age-stage approach and considering both sexes, indicated a decrease in pre-adult survival for both species under intraguild predation. Neoseiulus barkeriDevelopment occurred in a shorter time. Fecundity decreased. The net reproductive rate (R0) fell from 30,76 to 10,51 offspring per individual. The intrinsic rate of increase (r) fell from 0,2555 to 0,1872 per day. The finite rate of increase (λ) went from 1,2911 to 1,2059 per day.

Em Scolothrips takahashiiDevelopment and fecundity remained stable. There was no significant difference in R0, r, λ, and mean generation time (T) between the groups with and without intraguild predation.

The net predation rate (C0) of Neoseiulus barkeri The number of arrests per individual decreased from 381,00 to 172,97. Scolothrips takahashiiThe index fell from 416,58 to 25,31. Computer simulations projected smaller populations and less predation potential for Neoseiulus barkeri under intraguild predation. For Scolothrips takahashiiHowever, projections indicated population growth and increased purchasing power.

The results point to specific adaptive responses among predators and contribute to the planning of multi-agent programs in biological control.

More information at doi.org/10.1002/ps.70678