Efeito da temperatura nos estágios imaturos de Anastrepha fraterculus e Anastrepha obliqua (Diptera: Tephritidae).

Abstract

Anastrepha fraterculus (Wiedemann) and Anastrepha obliqua (Macquart) are two of the main pests of global fruit farming, causing economic damage to exporters. In a scenario of climate change, possible changes in the development of these insects can influence their distribution and, consequently, their potential for damage to fruit farming. This work evaluated the effect of different temperatures (15º, 20º, 25º, 30º and 35ºC) on the development time and survival of the immature stages of A. fraterculus and A. obliqua. The development time was inversely proportional to the temperature, with the longest development time of the stages evaluated at 15ºC and the shortest time varying between 25º and 30ºC, for both species. While at 35ºC there was no development of the evaluated stages for A. fraterculus and A. obliqua. The survival rate differed between the evaluated temperatures and the studied species. Anastrepha fraterculus had the highest survival rate of the egg stage at 30ºC (69%), while A. obliqua had the highest rate between 20º and 30ºC (70% and 72%). Survival rates of the larval stage were higher at 25ºC, for both species. However, A. fraterculus was reduced to 15ºC (264 pupae), while A. obliqua was reduced to 30ºC (142 pupae). Survival of the pupal stage was higher at 20ºC and 25ºC for both species. However, A. fraterculus suffered reduced survival when exposed to 30ºC (33 adults), while A. obliqua reduced to 15ºC (49 adults). The development time to adult for both species is shorter in (25 days) at temperatures of 25º and 30ºC. The results suggest a possible reduction in populations of A. fraterculus and A. obliqua in regions that already have high and/or near high temperatures. However, in cold regions where they also occur, an increase in these flies may occur and thus, an increase in the damage they can cause to the cultivated fruit.