Biologia e exigências térmicas de Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae) em ovos de Diaphania hyalinata L. (Lepidoptera: Pyralidae)

Abstract

-The development and parasitism of Diaphania hyalinata L. eggs by Trichogramma atopovirilia Oatman & Platner and its thermal requirements were studied at the temperatures of 18, 21, 24, 27, 30 and 33°C. Thirty eggs of D. hyalinata were exposed to three females of T. atopovirilia for 5h at 25°C and incubated at the different temperatures. The developmental time from egg exposure to adult, parasitism viability, number of adults per parasitized host egg and progeny sex ratio were monitored. The developmental time from egg to adult emergence of the parasitoid exhibited inverse relationship to the temperature, lasting 24.12 days at 18°C and 7.36 days at 33°C. Parasitism viability at 24, 27 and 30°C was higher than 90%. The ratio of T. atapovirilia adult produced per egg and its sex ratio were not affected when using D. hialynata as host. The lowest threshold temperature (Tb) and estimated degree-days over Tb required by T. atopovirilia to develop on eggs of D. hyalinata was 11.99°C and 130.42 o C, respectively. Considering the temperature regimes of two areas where cucurbitaces are cultivated in Bahia State (Rio Real and Inhambupe County) it was estimated that T. atopovirilia can achieve more than 32 generation per year. The results suggest that T. atopovirilia has potential to control D. hyalinata eggs with better chance of success under temperature regimes ranging from 24 to 27°C that meets the suitable field conditions for cropping cucurbitaces.

Performance of four Trichogramma species (Hymenoptera: Trichogrammatidae) as biocontrol agents of Heliothis virescens (Lepidoptera: Noctuidae) under various temperature regimes

“…For all species, results of the different rearing/testing temperature regimes were always close to those obtained at the same testing temperature (i.e., similar results for temperature regimes 25/30 and 30/30, and 25/20 and 20/20°C). Despite the fact that higher temperature during parasitoid development (rearing) usually decreases developmental time (Molina et al 2005;Melo et al 2007), parasitism rate itself thus apparently depends largely on ambient temperature at the time parasitoid females attack hosts. In our study, parasitism rates were lower at 30°C regardless of the rearing temperature (Fig.…”

Seletividade de inseticidas, recomendados para cucurbitáceas para Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae) em condições de laboratório

“…Dentre as estratégias biológicas, o controle de pragas agrícolas, com o uso de parasitoides do gênero Trichogramma, tem-se destacado, por sua alta eficiência e relativa adequação com outros métodos de controle (Melo et al, 2007). Para o sucesso de um programa de manejo fitossanitário, a integração de produtos químicos com o controle biológico é necessária .…”

Seleção de hospedeiro alternativo para três espécies de tricogramatídeos neotropicais

“…Essas espécies incluem T. atopovirilia Oatman & Platner, 1983, para o controle de Gymnandrosoma aurantianum Lima, 1927 em citros (Molina et al, 2005). O parasitóide T. atopovirilia também apresenta potencial para o controle da broca-das-cucurbitáceas, Diaphania hyalinata L. (Melo et al, 2007), Anticarsia gemmatalis Hübner, 1818 (Cañete & Foerster, 2003) e Spodoptera frugiperda (J.E. Smith) (Beserra & Parra, 2004 (Nava et al, 2007).…”