|RAMADAN, MOHSEN - Hawaii Department Of Agriculture|
|GUERRIERI, EMILIO - National Research Council - Italy|
|MESSING, RUSSELL - University Of Hawaii|
|JOHNSON, MARSHALL - University Of California|
|DAANE, KENT - University Of California|
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/20/2021
Publication Date: 7/24/2021
Publication URL: https://handle.nal.usda.gov/10113/7458847
Citation: Wang, X., Ramadan, M., Guerrieri, E., Messing, R.H., Johnson, M.W., Daane, K.M., Hoelmer, K.A. 2021. Early-acting competitive superiority in opiine parasitoids of fruit flies (Diptera: Tephritidae): implications for biological control of invasive tephritid pests. Biological Control. https://doi.org/10.1016/j.biocontrol.2021.104725.
Interpretive Summary: Fruit flies include some of the most destructive pests of fruit and vegetable crops worldwide. Biological control by using parasitic wasps has been an effective management strategy for control of invasive fruit flies. Understanding potential competitive interactions among different natural enemies is important when designing biological control programs that employ multiple natural enemy species such as parasitic wasps. Research on competition between species of parasitic wasps revealed the competitive superiority of species attacking young host stages over those attacking older host stages. This has important implications for selecting the most effective wasp species for biological control programs.
Technical Abstract: Understanding and predicting potential competitive outcomes is critical in the design of biological control programs when considering multiple agent introductions. Tephritid fruit flies (Diptera: Tephritidae) include some of the most destructive pests of fruit and vegetable crops worldwide. Parasitoid guilds of fruit-infesting tephritids are dominated by opiines (Hymenoptera: Braconidae: Opiinae) that have been the main agents used for biocontrol of pest tephritids. All opiine parasitoids are solitary koinobiont endoparasitoids that attack host eggs or larvae and emerge as adults from host puparia. Thus, a host initially attacked by an egg-larval parasitoid can be subsequently attacked by a larval parasitoid, providing an ideal system to test the Early-acting Competitive Superiority Hypothesis (i.e., the first species occupying a host or exploiting early host stages has an advantage over competitive species). The literature on interspecific competition among opiine fruit fly parasitoids reveals strong evidence supporting the early acting competitive superiority hypothesis by egg-larval over larval parasitoids, through physiological suppression mechanisms. Competitive outcomes among larval parasitoids, however, depend on early action as well as the morphological characteristics used in direct physical competition of their first instars (e.g., size of mandibles). We discuss the range of ecological mechanisms facilitating coexistence of interacting species and highlight the ecological consequences of interspecific competition as evidenced by historical competitive displacements of introduced opiine parasitoids for biological control of tephritids. Finally, we provide a framework for exploring the role of interspecific competition, among other factors, in selecting opiine parasitoids for biological control of invasive tephritids.