Functional response of Trichogramma pretiosum Riley Hymenoptera Trichogrammatidae to Tuta absoluta Meyrick Lepidoptera Gelechiidae eggs effect of host age Resposta funcional de Trichogramma pretiosum Riley Hymenoptera Trichogrammatidae parasitando ovos de Tuta absoluta Meyrick Lepidoptera Gelechiidae efeito da idade do hospedeiro
Faria, C.A.; Torres, J.B.; Farias, A.M.
Anais da Sociedade Entomologica do Brasil. Marco; 291: 85-93
The functional response of Trichogramma pretiosum Riley parasitizing Tuta absoluta (Meyrick) eggs on industrial var. IPA-5 tomato leaves was studied for individual females at 12-36, 36-60 and > 60 h old eggs during one day exposition time. The handling time (Th = 0.77 h) and attack rate (a' = 0.80 h-1) were obtained from the linearization of parasitism by means of Woolf's equation. Based on these results, the functional response fitted the Type II: Na = Nt(1 - exp (-0,80 / (1 + 0,0258Nt))), but only when eggs were 12-36 h old. The estimated maximum number of parasitized eggs was 31.1, while the maximum observed number was 30; at the egg density of 60. The Th was 3.22% of the total exposure time. The increase in parasitism was up to 55 eggs/leaflet density, showing a Type I functional response for lower egg densities (y = 4.53 + 0.288 (+-0.054)x), while in higher densities the parasitism was stable and similar to that achieved at the 56-80 and 81-100 eggs/leaflet densities (mean +- SD = 20.1 +- 4.01 eggs). Increase in host density was not followed by increase in parasitism for eggs 36-60 h old and older than 60 h.