Host preference of the egg parasitoids Telenomus remus and Trichogramma pretiosum in laboratory

Abstract

Host preference of the egg parasitoids Telenomus remus and Trichogramma pretiosum in laboratory. This research aimed to evaluate the host preference of the egg parasitoids Telenomus remus and Trichogramma pretiosum. Trials were carried out in laboratory, under controlled environmental conditions (25 ± 2ºC temperature; 70 ± 10% RH; and 14 h photophase). The parasitoid searching behavior was evaluated based on the distribution (%) of eggs parasitized by each parasitoid, on egg masses of each host species. Results showed the host preference of T. remus by Spodoptera cosmioides eggs. T. pretiosum, reared in A. gemmatalis eggs, choose to parasitize always eggs of the host where the parasitoid had been reared. The egg preference was not observed when T. pretiosum was reared in S. frugiperda eggs. These results show that, in general, host preference of T. remus is less influenced by the host where it is developed than T. pretiosum. Host preference is an important parameter for biological control programs because more than one pest species may occur in the field, different from those where they were reared in the laboratory.<br>Preferência hospedeira dos parasitoides de ovos Telenomus remus e Trichogramma pretiosum em laboratório. Este trabalho objetivou avaliar a preferência hospedeira dos parasitóides de ovos Telenomus remus e Trichogramma pretiosum. Os experimentos foram conduzidos em laboratório, sob condições controladas (temperatura de 25 ± 2ºC; umidade relativa de 70 ± 10%; e fotofase de 14 horas). O comportamento de busca dos parasitóides foi avaliado através da distribuição (%) de ovos parasitados por espécie de parasitóide, em massas de ovos de cada hospedeiro na combinação estudada. Os resultados mostraram que T. remus preferiu parasitar ovos de S. cosmioides. T. pretiosum, criados em ovos de A. gemmatalis, preferiu parasitar sempre os ovos dos hospedeiros nos quais foram multiplicados. Essa preferência não foi observada quando T. pretiosum foi multiplicado em ovos de S. frugiperda. Esses resultados mostram que, em geral, a preferência hospedeira de T. remus é menos influenciada em relação a T. pretiosum pelo hospedeiro em que o parasitóide se desenvolveu. A preferência hospedeira é um importante parâmetro a ser considerado em programas de controle biológico porque em condições de campo mais de uma espécie praga pode estar presente, diferente daquela em que foi criado em laboratório

Biological parameters and parasitism capacity of Telenomus remus Nixon (Hymenoptera: Platygastridae) reared on natural and factitious hosts for successive generations

“…These conclusions differ from Goulart et al (2011) who had previously reported non-preference of T. remus for S. frugiperda eggs after the parasitoid be reared on those eggs for several generations. Accordingly to these authors it would demonstrate that the host acceptance or preference behavior of the T. remus females could not be attributed to the pre-imaginal conditioning described by Cobert (1985) and Kaiser et al (1989).…”

“…Accordingly to these authors it would demonstrate that the host acceptance or preference behavior of the T. remus females could not be attributed to the pre-imaginal conditioning described by Cobert (1985) and Kaiser et al (1989). However, it is important to point out that Goulart et al (2011) compared T. remus preference among Spodoptera spp. eggs.…”

Telenomus remus (Hymenoptera: Platygastridae) Parasitism on Eggs of Anticarsia gemmatalis (Lepidoptera: Eribidae) Compared With Its Natural Host Spodoptera frugiperda (Lepidoptera: Noctuidae)

“…The number of A. gemmatalis eggs parasitized by T. remus when the parental female was reared on the same species was lower than the number of parasitized eggs of its natural host S. frugiperda at all temperatures. These results support the assumption of co-evolution of those species (Goulart et al 2011). Even when parasitoids were reared on the alternative host (A. gemmatalis) for one generation, parasitism was still higher on eggs of its natural host (S. frugiperda) on which the parasitoid was reared in the laboratory for years.…”

New method for rearing Spodoptera frugiperda in laboratory shows that larval cannibalism is not obligatory

“…Despite that, Brazilian researchers have reported exclusively the individually-cultured larvae when rearing FAW, always justifying it with the occurrence of larval cannibalism (e.g. Goulart et al 2011;Vilarinho et al 2011;Bueno et al 2010Bueno et al , 2008.…”