Applying Satyrization to Insect Pest Control: The Case of the Spotted Wing Drosophila, Drosophila suzukii Matsumura

SIMPLE SUMMARY: Satyrization, a form of sexual interaction between males of one species with females of another species, has attracted renewed interest in pest management strategies. By inducing fitness costs in one or both interacting species, satyrization may indeed dramatically affect population dynamics, being a valuable tool to be used alone, or in conjunction with other area-wide control approaches. Here, we aimed to investigate the potential use of satyrization to control the invasive pest Drosophila suzukii by using D. melanogaster males. By realizing courtship tests, spermathecae analysis, and multiple-choice experiments, we showed that D. melanogaster males were able to successfully court, mate and reduce the offspring of D. suzukii females. These results, overall, showed that the use of D. melanogaster males can be an effective tool to control D. suzukii and lay promising foundations for testing the application of this approach in field conditions. ABSTRACT: Drosophila suzukii represents one of the major agricultural pests worldwide. The identification of safety and long-lasting tools to suppress its populations is therefore crucial to mitigate the environmental and economic damages due to its occurrence. Here, we explore the possibility of using satyrization as a tool to control the abundance of D. suzukii. By using males of D. melanogaster, we realized courtship tests, spermathecae analysis, and multiple-choice experiments to assess the occurrence and extent of pre- and post-zygotic isolation between the two species, as well as the occurrence of fitness costs in D. suzukii females due to satyrization. Our results showed that: (i) D. melanogaster males successfully courted D. suzukii females; (ii) D. melanogaster males significantly affected the total courtship time of D. suzukii males, which reduced from 22.6% to 6.4%; (iii) D. melanogaster males were able to inseminate D. suzukii and reduce their offspring, inducing a high fitness cost. Reproductive interference occurs at different steps between D. melanogaster and D. suzukii, both alone and in combination with other area-wide control approaches.