Influência do fotoperíodo na reprodução e longevidade de Orius insidiosus (Say) (Heteroptera: Anthocoridae)

Abstract

Effect of Photoperiod on Reproduction and Longevity of Orius insidiosus (Say) (Heteroptera: Anthocoridae) ABSTRACT-Orius insidiosus (Say) is an important predator of thrips and photoperiod can affect the reproduction of this insect. The objective of this work was to verify the occurrence of reproductive diapause in O. insidiosus in laboratory conditions. The experiments were carried out in environmental chambers, at photoperiods of 9L:15D, 10L:14D, 11L:13D, 12L:12D, 13L:11D and 14L:10D, temperature of 25±1ºC and RH of 70±10%. Fecundity and sex ratio were not affected by the different photoperiods; an average number of 162.0, 189.8, 175.8, 195.2, 132.2 and 125.1 eggs/female, respectively, were found on these photoperiods. However, the photoperiods affected longevity of the predator. Longevity varied from 77.1 days, at photoperiod 10L:14D, to 40.1 days at photoperiod 9L:15D. O. insidiosus did not enter reproductive diapause in the conditions carried out in this experiment. This information is important to understand the factors that are involved on performance and use of O. insidiosus on biological control of thrips on protected cultivation.

Influence of photoperiod on Orius thyestes Herring (Hemiptera: Anthocoridae) reproduction and longevity

“…Significant difference (P < 0.05) was found for egg number/female between 9h and 12h of light only. Argolo et al (2002) Mean female and male longevity of O. thyestes was similar among the 12L:12D, 11L:13D and 10L:14D photoperiods, but was significantly shorter (P < 0.05) at 09L:15D (Table 1). In general, males live from 36% to 49% less than females (Table 1).…”

“…Argolo et al (2002) observed a longer pre-oviposition period of O. insidiosus submitted to 11h of photofase and found a direct relation between the number of hours of light and the oviposition period of the predator.…”

“…Comparing O. thyestes to O. insidiosus (Argolo et al 2002), longevity of O. insidiosus is greater than in O. thyestes in both sexes (Table 1) on all tested photoperiods, longevity varying from 53 to 41 days in adults of O. insidiosus.…”

“…In Brazil, Argolo et al (2002) did not detect diapause in Orius insidiosus (Say) when submitted to constant photophases from 9h to 14h. did not observe sensibility of this predator to alternate photoperiods between pre-imaginal and adult phases.…”

Toxicidade de produtos fitossanitários para adultos de Orius insidiosus (Say) (Hemiptera: Anthocoridae)

“…Na cultura do crisântemo ocorrem vários insetos-praga que podem causar injúrias diretas e/ ou indiretas, exigindo, na maioria das vezes, a intervenção do produtor para promover a redução de suas populações a fim de se evitar prejuízos. O uso de inimigos naturais do gênero Orius (Wolff) tem despontado como tática viável para o manejo de pragas nessa cultura, pois são insetos pequenos, com alta capacidade de busca e estão presentes em locais da planta comuns aos de muitas pragas, aumentando as chances de encontro (BUENO, 2000;ARGOLO et al, 2002;MENDES et al, 2002;SILVEIRA et al, 2003).…”