Thermal requirements and estimates of the annual number of generations of Lobiopa insularis on strawberry crop

Exigências térmicas e estimativas do número de gerações anuais de Lobiopa insularis em morangueiro

ABSTRACT

Lobiopa insularis is one of the main pests of strawberry crop, causing direct damage to fruit, making them unfeasible for consumption and commercialization. This study aimed to estimate, under laboratory conditions, base temperature and thermal requirements of the eggs, larvae, pupae and the biological cycle (from egg to adult) of L. insularis. Insects were reared on artificial diet based on strawberry fruits, at temperatures of 16, 19, 22, 25, 28 and 31°C, using air-conditioned chambers (70±10% R.H.; 12 h photophase). The number of annual generations of L. insularis was estimated for eight municipalities belonging to the main strawberry growing regions in Brazil, considering base temperature and thermal constant. Development time of L. insularis was proportional to the temperature increase. The best development rate was obtained when insects were reared at 22 and 25ºC. Based on thermal requirements of L. insularis, the number of annual generations was estimated between 5 and 7 per year, according to the studied region.

Keywords:
Fragaria x ananassa, strawberry sap beetle; biological cycle, base temperature