Potrditev prisotnosti plenilske hržice Feltiella acarisuga (Vallot, 1827) in plenilskega kratkokrilca Oligota oviformis Casey, 1893 na navadni pršici (Tetranychus urticae Koch, 1836) v Sloveniji

The two spotted spider mite, <em>Tetranychus urticae </em><a title="Carl Ludwig Koch" href="https://en.wikipedia.org/wiki/Carl_Ludwig_Koch">C. L. Koch</a>, 1836 is one of the most important pests of greenhouse crops worldwide. Due to its polyphagic range of hosts and rapid development it forms great populations and as such represents a suitable host/prey for lots of natural enemies usable in biological control. Most commonly used predators of Tetranychid mites are predatory mites (<em>Phytoseiulus persimilis </em>Athias-Henriot, 1957, <em>Amblyseius swirskii </em>Athias-Henriot, 1962<em> </em>,…), but among most voracious predators is the larva of a predatory gall midge, <em>Feltiella acarisuga</em> (<a title="Jean Nicolas Vallot" href="https://en.wikipedia.org/wiki/Jean_Nicolas_Vallot">Vallot</a>, 1827) that was found also in greenhouses of the Biotechnical Faculty in Ljubljana on eggplant leaves in 2017. Besides the predatory gall midge also another predator, staphylinid <em>Oligota oviformis </em>Casey, 1893<em> </em>beetles and larvae were found in great numbers. After positive identification of <em>F. acarisuga </em>found naturally in Slovenia, it can be added to the list of indigenous species of natural enemies and thus can be used in biological control programs in greenhouse crop protection against spider mites.

Effects of photoperiod on induction of diapause in Feltiella acarisuga (Diptera: Cecidomyiidae)

Larvae of the predatory gall midge Feltiella acarisuga (Vallot) diapaused as prepupae in tightly woven, brown, silk cells on leaf surfaces. Photoperiod alone, at day lengths from 16 to 8 h did not induce diapause at either 20 or 25 °C. A low incidence of diapause was induced by a combined photoperiod and thermoperiod of an 8-h day at 25 °C and a 16-h night at 15 °C. The incidence of diapause was higher under these conditions if the larvae were fed diapausing spider mites, Tetranychus urticae (Koch) (Acari: Tetranychidae). Because F. acarisuga only diapauses at daylengths equivalent to mid-winter, when its prey, T. urticae, is also in diapause, it can be used as a biological control agent for T. urticae in British Columbia greenhouses throughout most of the growing season.

APHANOGMUS FULMEKI ASHMEAD (HYMENOPTERA: CERAPHRONIDAE), A PARASITOID OF APHIDOLETES APHIDIMYZA RONDANI (DIPTERA: CECIDOMYIIDAE)

The predatory gall midge, Aphidoletes aphidimyza (Rondani 1847), is a biological control agent used worldwide to control aphids. Mass-production methods are well established in Canada, the Netherlands, England, Germany, Finland, and the former U.S.S.R. (cf. van Leiburg and Ramakers 1984). In early March 1991, after 6 years of massproduction of A. aphidimyza on a rapidly increasing scale, two minute adult hymenopterous parasitoids were observed eclosing from a sample of pupae at a commercial insectary in British Columbia. It is likely that the founding parasitoid individual(s) entered the greenhouse before winter, as parasitoids appeared too early in the year to have entered from outdoors at that time.

Predatory Gall Midge (unofficial common name), Feltiella acarisuga (Vallot) (Insecta: Diptera: Cecidomyiidae)

The predatory gall midge, Feltiella acarisuga (Vallot), is one of the most effective and widespread natural enemies of spider mites (Tetranychidae) (Gagne 1995). It is a particularly important natural enemy of the twospotted spider mite, Tetranychus urticae Koch, in a number of cropping systems (Opit et al. 1997). F. acarisuga could be particularly useful for integrated pest management of spider mites that attack greenhouse crops (Gillespie et al. 1998). This document is EENY-269, one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: June 2002. EENY269/IN549: Predatory Gall Midge (Unofficial Common Name), Feltiella acarisuga (Vallot) (Insecta: Diptera: Cecidomyiidae) (ufl.edu)