Coastal Fly - Rice Lover

2024 Author: Gavin MacAdam | [email protected]. Last modified: 2023-12-16 13:38

The coastal fly on the territory of Russia lives mainly in the steppe zone. This pest is a big rice lover, developing in three generations per season. In this case, the greatest harm is caused by the larvae of the first generation. They usually harm from the moment tiny shoots appear and up to the stage of their full tillering. At the same time, damaged crops often float to the water surface. Coastal flies are most harmful in late crops and in fields with sufficiently high soil and water salinity. If you do not take measures to get rid of them in time, the harvest is unlikely to please

Meet the pest

The coastal fly is an insect up to 4 mm long, painted greenish with a pronounced metallic sheen. The wings of these pests are transparent and long, and the legs are characterized by a slight reddish tint.

The larvae of coastal flies, which grow up to 7 mm in length, can be either yellowish or whitish. On the tips of their bodies there are a pair of long processes with spiracles, and on the abdomens of pests there are nine pairs of false legs. Dark brown puparia, the shape of which follows the shape of the larvae, endowed with small tail processes.

Adults overwinter under the remains of plants, as well as under soil lumps located on unplowed fields, on road shoulders and on canals. Towards the end of April or early May, flies start flying. And the egg-laying process begins approximately on the second or third day after the flooding of the rice fields. Eggs are laid by females on moist soil, as well as on the roots of weeds or rice ladders. The total fertility of females averages eighty to ninety eggs.

The embryonic development of coastal flies usually takes six to seven days. Around the end of May, the mass hatching of larvae begins, gnawing with appetite young rice stalks with leaves and roots. The harmful larvae develop for about three weeks, after which they pupate on weeds, as well as on rice leaves, roots and stalks. In the pupal stage, coastal flies stay for seven to ten days. When the flies fly out, the remains of the former pupae can be seen on the plants. Second generation flies fly out in July and August. By the way, the larvae of the second generation do not cause the death of growing crops, nevertheless, they still significantly weaken them, which in turn provokes a significant decrease in yield. And the surviving plants are characterized by a decrease in the weight of straw and bushiness, as well as a significant increase in the number of puny and empty grains.

It is noteworthy that the mass breeding of coastal flies almost always occurs after snowy winters.

How to fight

The most important preventive measures against coastal flies are strict adherence to the rules of rice crop rotation and prompt elimination of weeds. Rice should be sown with sufficient wrapping of the prepared seeds, and in the period from the emergence of seedlings to the moment of complete tillering, it is extremely important to observe the irrigation regime. An equally important measure is a two-fold discharge of water, followed by drying the fields for four to five days (in this case, it is necessary to observe the interval from eight to twelve days).

Treating rice seeds with disinfectants with an insecticidal effect also helps to achieve good results.

In case of emergency, growing rice may be sprayed with insecticides. The Metaphos solution will be an excellent assistant in the difficult task of getting rid of coastal flies.

Coastal flies and natural enemies are abundant. Pests in the preimaginal stage are readily eaten by some fish, dragonfly larvae, predatory bugs and swimming beetles. And adults are destroyed by horse beetles, whirligig beetles, water striders, dragonflies, spiders and birds.