RESUMEN

Research in recent years has shown that some species of predatory mites, considered to be typically associated with soil and litter, can also be found on plants. Such species include Blattisocius mali, which is an effective predator of acarid mites, nematodes and the eggs of moths and which can disperse by means of drosophilid fruit flies. Apart from soil and litter or storage, it has also been recorded on the bark of apple trees and the leaves of strawberries, thus suggesting its possible predation of/feeding on herbivorous mites and insects. Our goal was to examine whether B. mali could consume different development stages of two polyphagous herbivores, the two-spotted spider mite, Tetranychus urticae, and the western flower thrips, Frankliniella occidentalis, as well as the drosophilid fruit fly Drosophila hydei. In 24 h cage tests, single, starved B. mali females consumed all types of prey offered, i.e., the eggs, males and females of spider mites; the first-instar larvae and prepupae of thrips; and the eggs and first-instar larvae of fruit flies. The potential for B. mali to prey upon these insects and mites was confirmed. However, to estimate whether it can also effectively reduce their population, additional tests on the predator's survival, fecundity and prey preference are needed.

RESUMEN

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.

RESUMEN

A new species of Blattisocius Keegan 1944 is described from specimens collected from a grain store in Giza, Egypt. Blattisocius flagellatus n. sp. has 33 pairs of long and flagellate setae on the dorsal shield, the ventrianal shield possesses three pairs of pre-anal setae, and the fixed digit of the chelicera is shorter than movable digit. A key is provided for the eight species of Blattisocius known from Egypt.

Asunto(s)

Ácaros , Animales , Grano Comestible , Egipto

RESUMEN

Worldwide, the potato tuber moth (PTM), Phthorimaea operculella (Zeller), is one of the most severe pests affecting potato (Solanum tuberosum L.), whether in open-air crops or during tuber storage. This work examines the potential control of this pest by two species of predatory mites, Macrocheles robustulus (Berlese) and Blattisocius tarsalis (Berlese), on pest eggs under laboratory conditions. In the two first assays, the acceptance rate of the pest eggs was assessed for each predatory mite. Then, in a third assay, the functional response of B. tarsalis was studied. The results showed that Macrocheles robustulus did not prey on the pest eggs (number of eggs surviving = 4.33 ± 0.38), whereas B. tarsalis did (number of eggs surviving = 0.5 ± 0.5). Likewise, B. tarsalis showed a type II functional response when it killed the eggs. The results showed the potential use of Blattisocius tarsalis as a biological control agent of P. operculella in potato under storage conditions.