Population fluctuation of thrips associated with common bean (Phaseolus vulgaris L.) and their control by entomopathogenic fungi

Abstract

The thrips complex (Thysanoptera: Thripidae) is one of the most damaging insect pest groups affecting Phaseolus vulgaris in Cuba. With the objective of determining the population fluctuation of the thrips complex associated with P. vulgaris and its control by entomopathogenic fungi, a study was carried out at the San José farm, belonging to the municipality of Santa Clara, Cuba, during the months of October to April in the 2018-2019 and 2019-2020 planting seasons. During the first campaign, the presence of Thrips palmi was recorded in the phenological stage BBCH 21, which realized its population peak at the beginning of flowering with 46.61 % of the insects quantified. Although with lower incidence, the occurrence of Thrips tabaci was also recorded with two individuals during the entire crop cycle. In the second season, T. palmi made its population peak with the appearance of the first flower buds and the species Megalurothrips usitatus appeared in the BBCH 28 phase, which gradually reached its maximum population level at the beginning of flowering with 37.1 % of the insects quantified. The effectiveness of Beauveria bassiana Bb-18 on M. usitatus and T. palmi was demonstrated with 73 and 100 % mortality, respectively, while Metarhizium anisopliae Ma-30 caused 69 and 90 % mortality. Knowledge of the population fluctuation of thrips and the effectiveness of B. bassiana and M. anisopliae for their control are elements of interest for the establishment of an integrated management of thrips in Cuba.

Keywords

• beauveria bassiana
• biological control
• phenological stages
• fabaceae
• peak