On October 9, at the invitation of the town government, the technical staff of the plant protection station came to the town's Shuidong Village to investigate and mediate the problem of late rice not being fruitful raised by villager Lu Huilin and several other farmers. The damaged villagers suspected that it was caused by the influx of water into the fields after a night of herbicide spraying in the adjacent large households. After field inspection, the possible influence of herbicides was ruled out, and it was found that all the unsteady fields were adjacent to those that had been harvested overnight, and the farther away they were, the lighter the damage, the severity was decreasing, the damaged rice ears were straight and did not hook their heads, the fruiting rate was low, or they were not grouted, there were many arsenic grains, the fruiting rate was generally 40-60%, and the serious ones were only about 15%, and the yield reduction was serious. After on-site consultation by the technicians, the preliminary judgment was caused by the enrichment of rice bugs after one night of harvesting.
In recent years, with the advancement of land circulation, rice flower arrangement has intensified in the morning and evening, and the impact on rice diseases and insect pests has also increased. The occurrence of rice bugs is one of the obvious changes, and there is a trend of aggravation year by year. According to years of field investigation, the rice field is dominated by rice green bugs, black bugs and large rice edge bugs, especially the rice green bug population density is the largest. Generally, after one night of harvest, it is harmful to the neighboring two nights, resulting in the phenomenon of non-fruiting, which seriously affects rice yield and even fails to harvest.
<h1>Morphological characteristics, pest methods, living habits and control methods of rice black bugs</h1>
Rice black bugs
Rice black bugs are distributed in southern Hebei, Shandong and northern Jiangsu, and in the provinces and regions south of the Yangtze River. The main harm to rice is also wheat, millet, corn, sugar cane, beans, potatoes, citrus and so on.
Pest characteristics: adult and nymphs suck the sap of rice stems, leaves and ears, produce macula at the affected place, and severe tillering and development inhibition, resulting in the death of the whole plant. In recent years, with the changes in the ecological environment of farmland and the change of crop layout, the pest of this insect has increased year by year.
Morphological characteristics: Adults are 8.5–10 mm long and 4.5–5 mm wide, oblong-oval, black-brown to black, the mid-lobe and lateral lobes of the head are equal in length, the compound eye is prominent, and the beak is long and inter-segmental forefoot. The anterior corner of the dorsal plate of the forebreast is stabbed flattened to the side. The small shield is tongue-shaped, slightly concave or flattened at the end, almost as long as the end of the abdomen, and the lateral margins are slightly curved inward in the middle. The eggs are nearly short barrel-shaped, reddish-brown, 0,9×0.8 (mm) in size, with pseudo-ovoid rounded protrusions, surrounded by 40-50 small tooth-like respiratory sperm foramen; the egg shell mesh pattern has small notches and is covered with white powder. Indyna nymphs have a brown head and thorax, a yellowish-brown or purple-red abdomen, a red node, and a reddish brown spot on the abdomen and dorsal area, with a body length of 1.3 mm. The 3rd instar nymph is dark brown to grayish brown, with small reddish-brown dots scattered on the abdomen, and the forewing buds are slightly exposed, and the body length is 3.3 mm. The 5th instar nymph has a light black head and thorax, a slight green belly, and obvious hindwing buds, with a body length of 7.5-8.5 mm.
Hazard characteristics of rice bugs
Life habits: Jiangsu, Zhejiang annual 1 generation, Jiangxi 2 generations, Guangdong 2-3 generations. Adults and a few elderly nymphs overwinter under stones, 5-10 cm in soil crevices, or at weed rhizospheres, between rice stumps, and in bark crevices. Early the following summer, the stings appeared and clustered on the rice. Adults and nymphs like to lurk near the water surface at the base of the rice bush in the clear day, and in the evening or on cloudy days, they go to the leaves or ears to suck, and lay the eggs on the leaf sheath 6-9 cm from the water surface of the rice plant, and the egg blocks are mostly 14 grains, arranged in 2 rows. 75 eggs are laid per female. Early sown fields with vigorous growth and thick green leaves occur heavily in hilly and mountainous ridge fields. Natural enemies mainly include rice bug black egg bee, white zombie fungus, hunting melt, spider, frog and so on.
Control methods: (1) The use of adult insects to lay eggs on the near-water surface rice stem and eggs in water soaked in the spore for 24 hours can not hatch the characteristics, in the spawning period first proper drainage, reduce the spawning position, and then irrigate to 10-13cm, soak the spores for 24 hours, every 3-4 days and then drainage once, continuous 4-5 times can kill a large number of egg blocks. (2) Spray 2.5% preserved emulsion 1500 times liquid or 20% cypermethrin emulsion 2000 times liquid 190% crystalline diphthalmid 800 times liquid in the young nymph stage, and prevent it again after 15 days. If you use 10% imidarin wettable powder 2000 times liquid, although the effect is slower, the effective period is as long as 25-30 days, and the production can be promoted and applied.
<h1>Morphological characteristics, pest methods, living habits and control methods of rice large green bugs</h1>
Rice green bugs
Rice green bugs are also known as horned shoulder bugs, horned shoulder bugs, long-snout bugs, and ridge bugs. Distributed in Jiangsu, Zhejiang, Hubei, Jiangxi, Hunan, Fujian, Taiwan, Guangdong, Guangxi, Guizhou, Sichuan and other provinces. It mainly harms rice, millet, sorghum, corn, sugarcane, tea, citrus, apples, pears, sand fruits and so on
Pest characteristics: adult and nymphs suck the sap of rice plants, and the seedlings are damaged, like fire-like scorched wilting; tillering stages are affected, resulting in dead seedlings; and at the panicle extraction stage, causing millet or white ears.
Rice green bug egg mass
Morphological characteristics: Adult body length of about 22 mm, green, long shield shape. Antennae filamentous 5 segments. The anterior edge of the dorsal plate of the forebreast is protruding in an angle on both sides, and the edges of the "shoulders" are black, and they have many large black notches on them. The small shield is long and large tongue-shaped. The eggs are pale green and spherical. Nymphs are 5 years old, 1-3 years old are pale yellow to reddish yellow, with dark spots. 4 years of age have green thorax, yellow abdomen, and prominent wing buds. 5 years green all.
Life habits: 1 generation per year in the south, with adults overwintering in dense branches and leaves of fruit trees and various crevices such as buildings. In April of the following year, the stinging activity began, spawning in May to October, laying the most eggs in July, mostly on the leaf surface, often 14 grains clustered into blocks, neatly arranged. In August, the nymphs are in full bloom, and the 1-year-old group does not feed, the 2-year-old begins to eat, the 2-3-year-old often has a 3-5 head cluster, and the 4th and 5th year olds disperse the active feeding. Most of the feathers turn into adults in November, and the overwintering begins in early December. Predators include orange-spined bugs, flat-bellied wasps, yellow ants, praying mantises and spiders.
Control methods: (1) Kill adults and nymphs in the morning and evening. (2) Removal of egg masses and hatching nymphs. (3) Pharmaceutical control Before the overwintering adults lay eggs after stinging, the hatching to the 3rd instar stage is the key period for control. When the amount of insects is large, 10% imidacloprid wettable powder can be sprayed 20 grams of wettable powder or 5% acetamidine wettable powder 20-25 grams, or 40% chlorpyrifos 75 ml. (4) Protect and utilize natural enemies.
To sum up: First of all, rice bugs are rare migratory rice pests, in order to improve the control effect, it is required to achieve unified prevention and control. Secondly, the drug control was carried out during the rice ear extraction stage, and the spraying effect was better in the morning and evening when the dew was not dry. In addition, immediately after the one-night harvest, the next two-night field block is focused on prevention and control, especially along the side of the one-night field, focusing on the prevention and control of rice bugs, leafhoppers and rice planthoppers.