Tuta absoluta (Lepidoptera: Gelechiidae): Thermal requirements and effect of temperature on development, survival, reproduction and longevity

Abstract

Tuta absoluta (Meyrick, 1917) is the main pest of tomato crops in South America. Recently, it was also reported in several countries in Europe and the Middle East. Because of its invasive potential and the lack of information on the biology of T. absoluta, the present study aimed to estimate its thermal requirements and evaluate the effect of temperature on its development, survival, reproduction and longevity. The experiments were carried out at constant temperatures of 10, 15, 20, 25 and 30°C. T. absoluta completed its development at all these temperatures. The thermal requirements were estimated by linear regression; the insects required 416.7 degree-days to complete the cycle from egg to adult, and the lower temperature threshold was estimated to be 8.0°C. The upper temperature threshold estimated for the egg-adult cycle was 37.3°C. The pre-oviposition period was longer at 10°C, but the oviposition period was similar at all the temperatures tested. Fecundity was highest at 20 and 25°C, with averages of 134.8 and 149.1 eggs per female, respectively. The highest percentages of fertile eggs were recorded at 15, 20 and 25°C. At 10 and 30°C, only one egg clutch was laid by T. absoluta. No differences were recorded in the longevity of females and males of T. absoluta. The tomato leaf miner can develop over a wide range of temperatures; however, its reproduction and survival were negatively affected at the extreme constant temperatures tested. The temperature variation recorded in natural environments is suitable for this pest to infest tomato crops.

Keywords

• lepidoptera
• gelechiidae
• tuta absoluta
• tomato leafminer
• degree-day
• thermal requirements
• fertility