Effect of temperature on reproduction, development, and phenotypic plasticity ofDrosophila suzukiiin Brazil

Abstract

Temperature is a determining factor for the development and establishment potential of insect pests. The present study describes the impact of temperature (13, 18, 23, 25, 28, 30, and 33 °C) on the life cycle parameters and phenotypic plasticity of South American populations of Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) in the laboratory. Secondary objectives were to determine the lower thermal threshold and thermal constant to estimate the number of annual generations of the insect in small‐fruit‐producing regions in Brazil. The highest egg‐to‐adult survival was recorded at 23 and 25 °C. At 30 and 33 °C, no emergence of D. suzukii was observed. The egg‐to‐adult development time was shortest at 25 and 28 °C (ca. 10 days). The net reproductive rate (R0), and the intrinsic rate of population increase (rm) were highest at 23 and 25 °C. In contrast, temperatures of 13 and 28 °C generated largest and smallest body sizes, respectively, and caused reductions of 99 and 93% in R0. The estimated lower thermal threshold was 7.8 °C for egg‐to‐adult survival. The estimated thermal constant was 185.8 degree days, and the estimated annual number of generations of D. suzukii ranged from 17.1 in cold regions to 27.2 in warm regions. The results of the present study are important for understanding D. suzukii occurrence in the field, contributing to more informed and precise pest management.

Effects of temperature and relative humidity on mating and survival of sterileDrosophila suzukii

“…The thermal biology of D. suzukii was extensively studied in the past few years. Laboratory studies showed that optimum temperature for population increase is between 23 and 25ºC (Kinjo et al., 2014; Ryan et al., 2016; Sánchez‐Ramos et al., 2019; Schlesener et al., 2020; Tochen et al., 2014). In fact, it was shown that exposing insects to 25ºC during mating resulted in higher oviposition and fertility, when compared to higher temperatures (Kinjo et al., 2014).…”

“…In fact, it was shown that exposing insects to 25ºC during mating resulted in higher oviposition and fertility, when compared to higher temperatures (Kinjo et al., 2014). On the other hand, temperatures below 10ºC or above 30ºC may impair several biological parameters (Enriquez & Colinet, 2017; Ryan et al., 2016; Sánchez‐Ramos et al., 2019; Schlesener et al., 2020; Tochen et al., 2014). In food‐provided flies, we found that temperatures of 10ºC and 35ºC impaired mating, since in these temperatures less than 10% for both fertile and sterile females contained sperm in their spermathecae.…”

“…Environmental factors can also decrease SIT effectiveness, by affecting the ability of sterile insects to mate and survive after being released (Chidawanyika & Terblanche, 2011; Tejeda et al., 2017). Previous studies showed that development, population growth and survival of D. suzukii are strongly affected by variations in environmental conditions, mainly temperature and relative humidity (Eben et al., 2018; Enriquez & Colinet, 2017; Hamby et al., 2016; Kinjo et al., 2014; Ryan et al., 2016; Schlesener et al., 2020; Tochen et al., 2014; Tochen, Woltz, et al., 2016). Reproductive success of D. suzukii was abolished at temperatures lower than 10 and higher than 30ºC, while the critical thermal maximum for D. suzukii survival at 32ºC (Enriquez & Colinet, 2017; Kinjo et al., 2014; Ryan et al., 2016; Tochen et al., 2014).…”

“…Females from this species have a robust, double‐serrated ovipositor that allows them to oviposit in ripening healthy soft‐skinned fruits, where larvae develop, rendering fruits unmarketable and causing great economic losses (Walsh et al., 2011). At optimum environmental conditions, D. suzukii can develop up to 27 generations per year (Schlesener et al., 2020), and its wide host range and high reproduction potential make this species harmful and difficult to control (Van Timmeren & Isaacs, 2013).…”

“…Environmental factors can also decrease SIT effectiveness, by affecting the ability of sterile insects to mate and survive after being released (Chidawanyika & Terblanche, 2011;Tejeda et al, 2017). Previous studies showed that development, population growth and survival of D. suzukii are strongly affected by variations in environmental conditions, mainly temperature and relative humidity (Eben et al, 2018;Enriquez & Colinet, 2017;Hamby et al, 2016;Kinjo et al, 2014;Ryan et al, 2016;Schlesener et al, 2020;Tochen et al, 2014;Tochen, Woltz, et al, 2016).…”