Assessment of a potential bioproduct for controlling Cerotoma arcuata tingomariana (coleoptera: Chrysomelidae)

Abstract

Aims: The leaf-feeding pest Cerotoma arcuata tingomariana (Bechyné) (Coleoptera: Chrysomelidae) produces huge economic losses in different crops. This study aimed to produce conidia by semisolid-state fermentation and to establish the insecticidal activity of two formulation prototypes based on a native Beauveria bassiana isolate for controlling this pest. Methods and results: A novel fabric-based semisolid-state fermentation strategy for quick and large-scale conidia production was performed and characterized. Conidia were formulated as an emulsifiable concentrate (EC) and a water-dispersible granulate (WG). Afterwards, the mortality of C. a. tingomariana adults was assessed. A conidia concentration of 2.9 × 109 conidia cm−2 was obtained after 9 days-course fermentation and a yield of 33.4 g kg−1 dry-substrate. Conclusions: The polyester fabric-based fermentation is an efficient technique for producing and collecting B. bassiana spores. Regarding LC90, the potency analysis showed that the EC was 21-fold more potent than the non-formulated conidia, and ~ 2.6-fold more potent than the WG. Significance and impact of study: A high throughput fermentation based on polyester fabric as support for B. bassiana conidia production and subsequent formulation as an EC comprises a promising strategy for obtaining a bioproduct to control adults of C. a. tingomariana and other Chrysomelidae pests.