Oviposition Activity of an Invasive Fruit Fly Species at Different Densities in Laboratory

ABSTRACT The carambola fruit fly (CFF) ( Bactrocera carambolae Drew & Hancock) is one of the most harmful pests of fruit production. It is an exotic species in Brazil, restricted to the northern region (Amapá, Pará, and Roraima States), and a threat to the national fruit production and exportation. The oviposition activity of this pest is not well known, imposing barriers to understanding its host attack in the field. We aimed to evaluate the daily pattern of oviposition in B. carambolae and compare the number of eggs at different female densities (one couple, five couples, and 15 couples) from 07:30 a.m. to 5:30 p.m. We also compared their oviposition depth on different substrates (guava and an artificial substrate). Data were analyzed using a generalized linear mixed model (GLMM) on the software RStudio. Our results showed that B. carambolae exhibits a distinct pattern of oviposition activity at different densities during the day, with no preferential oviposition period at higher density. However, increasing density did not affect the number of eggs laid per female during the day. We did not find a significant difference when comparing the oviposition depth of CFF on a guava piece and an artificial device. Our results improve knowledge about the oviposition activity of B. carambolae and suggest that its species adopt oviposition strategies to ensure their offspring.