Inheritance of host finding ability on structurally complex surfaces

Abstract

The connectivity of a surface (structural complexity) can have a significant effect on the host finding behavior and efficiency of parasitoids that must search the surface for hosts. We investigated whether the generalist egg parasitoid, Trichogramma nubilale Ertle and Davis (Hymenoptera: Trichogrammatidae), found hosts more efficiently on simple or complex surfaces, and evaluated the potential genetic basis of this variation using a full-sib/ half-sib mating design. Of the egg masses parasitized 63.8% were on the simple surface while only 36.2% were on the complex surface. There was significant repeatable variation among females (repeatability =0.59, n=19 females), with some better at finding hosts on simple surfaces and others better on complex surfaces. These results reinforce previous findings that structural complexity can affect host finding by parasitoids. The additive genetic variance in this character was not significant (sires =23, dams =46, progeny =92), but the maternal plus dominance variance ( V(m)+1/2 V(d)) was significant (P<0.036), and accounted for 48.8% of the total phenotypic variance. The maternal or dominance effects could have complex evolutionary consequences, causing the evolution of other foraging traits to be retarded, to overshoot their optima, or to have complex selective regimes. Thus, the evolution of foraging behavior may depend strongly on the mechanistic details of foraging behavior, including the effects of structural complexity on host finding.

Effects of Intra- and Interpatch Host Density on Egg Parasitism by Three Species ofTrichogramma

“…In these trials, two species of Trichogramma performed best at a smaller scale, while the third performed best at the largest spatial scale observed. Alternatively, multiple investigators have shown that habitat complexity affects Trichogramma foraging success in the laboratory (Andow and Prokrym 1990; Lukianchuk and Smith 1997; Gingras and Boivin 2002; Gingras et al 2002, 2003; Andow and Olson 2003). Thus, it is possible that physical/structural homogeneity of the arenas used in this trial may have predisposed all three species to parasitize more hosts than when they were in a more heterogeneous habitat.…”

Host-Foraging Success of Three Species of Trichogramma (Hymenoptera: Trichogrammatidae) in a Simulated Retail Environment

“…In these trials, two species of Trichogramma performed best at a smaller scale, while the third performed best at the largest spatial scale observed. Alternatively, multiple investigators have shown that habitat complexity affects Trichogramma foraging success in the laboratory (Andow and Prokrym 1990;Lukianchuk and Smith 1997;Gingras et al , 2003Andow and Olson 2003). Thus, it is possible that physical/structural homogeneity of the arenas used in this trial may have predisposed all three species to parasitize more hosts than when they were in a more heterogeneous habitat.…”

Parasitismo de ovos de Heliothis virescens por Trichogramma spp. pode ser afetado por cultivares de algodão

“…A ocorrência natural de parasitismo de ovos de lepidópteros-praga do algodoeiro por Trichogramma demonstra a possibilidade de utilização destes parasitóides no manejo de pragas daquela cultura (HOHMANN;SANTOS, 1989;FERNANDES et al, 1999). O ponto-chave é a compreensão das relações entre o inimigo natural e o meio em que o hospedeiro se encontra (QUAYLE et al, 2003;ANDOW;OLSON, 2003;GRIESHOP et al, 2007).…”