Health for humans, animals & plants

First record of the egg parasitoid Trissolcus basalis (WOLLASTON, 1858) in Austria (Hymenoptera: Scelionidae).

The non-native green rice bug(Nezara viridula Linnaeus, 1758) has caused quite a stir in Austria in recent years due to its sometimes mass occurrence on numerous agricultural and horticultural crops. Especially in private gardens and glasshouses in urban regions (Vienna and Graz), damage has been recorded due to their sucking activity on young shoots, fruits and seeds. Besides legumes (soybean, common bean), solanaceous plants (tomatoes, peppers) and berry bushes (raspberries, blackberries) are popular food plants of the adult and larval bugs.

The control of the tree bug, presumably originating from Africa, is a great challenge for many professional and hobby gardeners, since due to the great resistance of the bugs no sufficient effect can be achieved with the small number of plant protection products available on the market. Due to the fact that some ichneumon flies are able to parasitize the egg clutches of the green rice bug, we started a bug egg clutch monitoring in 2021 to investigate the occurrence of native natural counterparts in Austria. This resulted in the first evidence of an important egg parasitoid, which preferentially occupies the eggs of the green rice bug, but also parasitizes those of the marbled tree bug (Halyomorpha halys Stål, 1855), which originates from Asia. This is the wasp Trissolcus basalis (Wollaston, 1858) (Hymenoptera: Scelionidae), which is only 1-2 mm in size. It has a presumably worldwide distribution and could be detected in eight Viennese municipal districts in the course of the monitoring. To date, such beneficial insects against exotic bugs are not available in Austria, but their first detections could facilitate registration procedures and thus allow their use as an alternative or additional control measure.

Author:s: Anna Moyses, Sarah Mottinger, Stephan Manhalter, Richard Gottsberger

Publication in the Journal for Cultivated Plants

Last updated: 14.09.2022

automatically translated

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