Ectoparasitism of the Flightless Drosophila melanogaster and D. hydei by the Mite Blattisocius mali (Acari: Blattisociidae)
1
Section of Applied Entomology, Department of Plant Protection, Institute of Horticulture Sciences, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
2
Department of Biometry, Institute of Agriculture, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland
*
Author to whom correspondence should be addressed.
Insects 2023, 14(2), 146; https://doi.org/10.3390/insects14020146
Submission received: 24 December 2022
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Revised: 19 January 2023
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Accepted: 28 January 2023
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Published: 31 January 2023
(This article belongs to the Section Insect Behavior and Pathology)
Simple Summary
There are a number of reports on the dispersal of predatory mites on insects, although much less is known about their mutual interactions and possible relationships. While some mite species use insects only as means of transport, others also feed on them, significantly lowering the carriers’ fitness. Blattisocius mali is a promising predatory mite for pest control, and a thorough understanding of its dispersal pathways in crops could be crucial for successful plant protection. So far, it has been reported as transported by several species of drosophilids. Our research indicates an ectoparasitic relationship between this species and drosophilid fruit flies. We used the flightless D. melanogaster and D. hydei commercially raised as live pet food. Female mites not only attached to flies but also fed on them, and their presence resulted in an increase in fly mortality. Although both fly species used similar defense tactics, mites had more difficulties getting onto D. hydei. Whether the wild D. hydei and D. melanogaster can also transport B. mali will be shown by further laboratory and field studies.
Abstract
Predatory mites dispersing by means of insects are often ectoparasites and may use various tactics to get onto the host, counteract its defenses, and diminish its survival. Blattisocius mali is a promising biological control agent which has been reported as transported by several drosophilid species. Our goal was to determine the type of relationship between this mite and fruit flies. We used flightless females of Drosophila melanogaster and D. hydei, which were commercially raised as live pet food. The predatory females mostly attacked the tarsi of the flies and then preferentially moved to the cervix or close to coxa III, where they eventually drilled their chelicerae and started feeding. Although both fly species used similar defensive tactics, more B. mali females did not attack D. hydei or did so with a delay, and a higher percentage of mites fell off the D. hydei tarsi during the first hour of observation. After 24 h, we noted the increased mortality of flies exposed to the presence of mites. Our study indicates the ectoparasitic relationship of B. mali with drosophilids. However, further research is needed to confirm the transport of this mite on wild D. hydei and D. melanogaster, both in the laboratory and under natural conditions.
Keywords:
Blattisocius; Drosophila; predatory mite; phoresy; ectoparasite
