What are the control methods for rice midge?
It is a fairly common pest whose larvae damage the roots of rice, affecting the normal growth and development of rice and even causing floating seedlings and dead seedlings. So what are the methods to control it? When does it appear?
What are the control methods for rice midge?
1. Agricultural control
When rice midge damage is found, drain the field and sun-dry it for 2-3 days (until the field surface is about to crack), which can suppress the occurrence and damage of rice midge.
2. Chemical control
(1) At a rate of 100-200 grams of copper sulfate per mu, calculate the amount for each ridge, put it into cloth bags, and place them at the water inlet so it flows into the rice field with the irrigation water; this both controls the pest and prevents algae. Alternatively, after draining the water, place a cloth bag containing 90% crystal trichlorfon at the water inlet; when the water is released to a depth of about 1 cun, block the water inlet, and after 12 hours you will find the rice midge crawling out of the water, poisoned, curled up and dead.
(2) After draining the water, apply pesticide to the soil layer in the root zone. Use 70-100 grams of 15% chlorpyrifos (Lorsban) granules per mu, or 133-200 grams of 3% carbofuran granules, mixed with soil or fertilizer and broadcast. You can also choose 48% chlorpyrifos at 50-80 milliliters per mu diluted with water for spraying, 41% abamectin·chlorpyrifos at 75-100 grams per mu diluted with water for spraying, or 90% crystal trichlorfon at 600 times dilution for spraying, spraying 1-2 times depending on the pest situation.
(3) Use 1 kilogram of 5% phorate granules per mu, mixed with 15 kilograms of soil (sand) and broadcast, which can also control other pests with very good results.
When does rice midge appear?
Rice midge generally has four generations per year and overwinters as adults. Overwintering adults appear in late April of the following year, begin laying eggs in early May, and the first-generation larvae occur in mid-May. The first-generation adults begin in late May and choose plots with heavy, sticky soil such as black soil, meadow soil, saline-alkali soil, and old rice fields to lay eggs; the eggs hatch into larvae after 4-5 days, and the larvae swim and burrow down to the rice roots to feed on the young roots. When the larvae grow to 2 millimeters they turn red, and thereafter they live on the rice roots in the active mud and continue to cause damage. The larvae pupate after 12-14 days. Among the four generations of rice midge, the first and second generations damage rice more severely, while the third and fourth generations, although they also live in the rice field, basically show no damaging symptoms.
Rice midge is generally distributed in Heilongjiang, Ningxia, Hunan; Longnan (Kang County) and other places, and the vast number of rice growers should pay attention to its control.