The green rice bug belongs to the family of tree bugs and is approximately 14–16 mm long, 8 mm wide and usually green in colour, although there are also specimens with a white head and the front edge of the nuchal shield, and very rarely orange-coloured specimens. In autumn, reddish-brown specimens, or those with a white head and the front edge of the nuchal shield, are frequently seen. The young bugs (nymphs) vary greatly in colour and change their appearance with each stage of development. Newly hatched bugs are bright orange and subsequently turn reddish-brown. As they develop further, they take on a black colouration with white or yellow spots and red areas. Towards the end of their development into adult bugs, the green colour usually predominates again, although the lateral margins and the centre of the abdomen show red areas.

As temperatures rise in spring, adult bugs leave their overwintering sites (such as leaf litter and buildings) to begin feeding. In April/May, the bugs mate and the females lay their egg clusters, which are initially cream-coloured and later turn orange, containing up to one hundred and thirty individual eggs. The nymphs that hatch from these eggs go through five stages of highly variable colouration, usually remaining on plants in groups. In Austria, depending on the temperature trend in early summer, their development is complete after about two months and the first adult bugs of the first generation appear, which begin laying eggs again in June/July. This gives rise to the second generation of rice bugs, which usually make a very conspicuous appearance in late summer. A sharp increase in the bug population can be observed in years with hot, dry summer conditions. In Austria, the green rice bug can produce up to three complete generations, depending on the weather.

The green rice bug can cause sucking damage to all above-ground parts of the plant. As a plant-sucking insect, it is able to pierce plant tissue on fruits, seeds, leaves and shoots with its proboscis in order to feed on the sap. Although phytopathogenic viruses are not transmitted to the plants in this way, the sucking activity leads to the formation of spots, corking, deformities and signs of dieback. Fruit becomes unsightly, may fall prematurely and is no longer marketable. 

In addition, the secretion of an unpleasant-smelling substance causes a deterioration in flavour, and the puncture marks can serve as entry points for pathogens.

An infestation by the green rice bug therefore affects the yield both qualitatively and quantitatively.

In Europe, the green rice bug was initially only found in the Mediterranean region. Due to global warming, however, it is increasingly spreading northwards. Until 2015, only individual animals were found in Austria. In the meantime, the green rice bug is considered established, as numerous larvae and adult bugs have since been detected in home gardens and glasshouses, especially in urban regions (Vienna and Graz).

In 2021, we were able to determine in a monitoring programme that the bug causes damage to gardens and agriculture, especially in late summer in Vienna and Graz, but also in Lower Austria and Burgenland. The green rice bug has also already caused damage to vegetables in protected cultivation. In greenhouse crops, the bug becomes active as early as January or February, as it can survive the winter in a dormant stage in structural parts of heated glasshouses. Due to the fact that the green rice bug has developed into a significant pest in recent years, a warning service has been carried out together with the Chamber of Agriculture since 2023 and 2024 to inform farmers about the current occurrence of the bug. Thanks to the numerous reports we have received in the course of rice bug monitoring, we have been able to create a distribution map for Austria.

In 2024, only infestation reports from agriculture were made. These are shown as petrol-coloured dots on the map of Austria.

• Check your plants regularly to identify any infested plants as early as possible and remove any eggs, larvae or adults by hand. A jam jar works best for this; place the jar in the freezer for a few hours afterwards to gently kill the bugs.
• To prevent bugs from flying into the greenhouse, fine-mesh (1–1.5 mm) insect screens can be fitted to the vents.
• Check greenhouses for bugs before planting susceptible crops.
• Direct control using approved insecticides against sucking insects is possible, but difficult, as they are usually not sufficiently effective against adult bugs.
• Encourage natural enemies, such as parasitic wasps, lacewing larvae, predatory bugs, spiders, birds, etc.
• Egg parasitoids (the parasitic wasp Trissolcus basalis) and endoparasites (the caterpillar fly Trichopoda pictipennis) are described as natural enemies. In Austria, according to the Plant Protection Products Register, the parasitoid wasp Trissolcus basalis is authorised for professional use in field, vegetable, fruit and ornamental plant cultivation, as well as for various crops in domestic and allotment gardens, both outdoors and under glass, and is commercially available.