The occurrence and Control of White Star Flower Beetle

White star flower beetle belongs to Coleoptera, flower beetle family, alias white striped copper flower beetle, white star flower potential, white star beetle, copper gram beetle. It is distributed in Northeast China, North China and Huanghuaihai.

After the white starflower beetle damaged crops, the commodity of light ones was greatly reduced, and the serious ones lost their commodity completely, which brought serious economic losses to growers.

The host plants are corn, sunflower, tomato, watermelon, peach, grape, plum, strawberry, hops, large Compositae weed, willow and elm.

The damage characteristics of white starflower beetle are mainly adults, among which fresh corn is the most serious damage, followed by sunflower, willow and elm. In the middle and late May, the earliest adults began to feed on willow and elm sap, which had a great impact on the growth of young trees and newly transplanted trees. In the middle and late June, the large Compositae weed Calycea began to bloom, and a part of white starflower beetle transferred to the flower bud of Calycea to suck sap. After July, the damage was further aggravated. White star beetle began to harm fresh corn, sunflower, flat peach, plum, grape, watermelon, tomato and hops. Because fresh corn was mainly sweet and glutinous varieties, it suffered most seriously, especially early-sown corn. White starflower beetle directly feeds on corn kernel juice at the top of ear during corn filling and milk ripening period, which affects the growth and development of ear. For sunflower, it damages the flower disk, causing the flower disk to rot and causing yield reduction. Because my division sunflower area is very small, although the harm is serious. however, there have been no economic losses so far. However, some early-maturing aromatic grapes and white starflower beetles bite the fruit into holes, and then feed on the juice, which flows to the surrounding unbitten fruits, greatly reducing the commodity of grapes, and the economic losses of growers are also large.

Morphological characteristics Adult body length 17~24 mm, width 9~12 mm, oval with bronze or bronze luster, body surface scattered with numerous irregular white velvet spots. The front edge of lip base is folded upward, concave, with frames on both sides and downward inclination on the outside; the antennae are dark brown; the compound eyes are prominent; the pronotum has irregular white velvet spots, and the rear edge is concave; there is a triangle between the rear angle of pronotum and the front angle of elytra, i.e., the middle and rear side plate; the elytra is broad, nearly rectangular, and covered with coarse incised points, and the white velvet spots are mostly transverse waves; the hip plate is short and wide, with 3 white velvet spots on each side arranged in a triangle; the abdomen 1~5 webs have white velvet spots on both sides; Feet are thicker, knees have white velvet spots; after the foot base, the outer end angle is sharp; the outer edge of the forefoot tibia is 3 teeth, and the top of each foot tarsus has 2 curved claws. Adults often lay eggs in the soil at the junction of dung and soil, larvae (grubs) mostly feed on putrefaction and travel on their backs.

Life habits occur once a year, larvae overwinter in compost, humus piles and soil containing much humus. Adults began to appear in early May, June to July for the peak period, serious damage, the number of gradually reduced in late September. After July began to lay eggs, adults will lay eggs in compost, humus heap, rich in humus soil, larvae to humus for food, generally do not cause harm. In May of the following year, overwintering larvae pupate in soil chambers where they live.

Adults are active during the day, flying ability is strong, but in the morning and evening or cloudy days when the temperature is low, more inactive, and there is pseudo-death, easy to catch.

White starflower beetle has no phototaxis. According to the author's statistics on the forecasting lamps for many years, it was found that a large number of white starflower beetles occurred only 20~30 meters away from the forecasting lamps, but the forecasting lamps did not lure a single adult white starflower beetle. Therefore, the frequency vibration type insecticidal lamp has no trapping effect on the white star flower beetle.

Adults have strong chemotaxis. It has a taste for sugar and wine vinegar.

Control methods 1. Do a good job of farm manure management. Because adults have strong tropism to undecomposed farm manure and humus, they often lay eggs in it, so farm manure should be concentrated and decomposed by high temperature fermentation to reduce the places for adults to lay eggs and reproduce. 2. Before the middle of May, the dung pile shall be overturned or applied, the larvae and pupae of white starflower beetle shall be picked up, and 50% phoxim emulsifiable concentrate 1000 times or 40% dimethoate emulsifiable concentrate 1000 times and 80% trichlorfon soluble agent 1000 times shall be sprayed when necessary for centralized elimination. 3. According to the characteristics of adults having social hazards, artificial capture can be adopted in the morning and evening or cloudy days when the temperature is low, and concentrated killing can be carried out. 4. At the initial stage of white starflower beetle, hang a small bottle on the trees around sunflower, corn, orchard, etc., use a wine bottle or washed waste pesticide bottle, hang the bottle height of 1~1.5 meters, put a little pulp or wine vinegar in the bottle, and then put 2~3 white starflower beetle, which can effectively lure other adults into the bottle. 5. Cut watermelon or melon into two halves, leave part of the flesh, which sprinkle a little wine vinegar and dichlorvos and other pesticides, but also effective trapping adults. 6. The artificially captured and trapped adults are smashed, soaked in water for 2~3 days, filtered out, diluted with water, sprayed on the fruit, which can play a role in rejecting adults and avoiding damage to the fruit. 7. Phoxim EC and omethoate EC can be mixed and sprayed twice to control white starflower beetle on willow and elm. It has contact, systemic and stomach toxicity, and the control effect is obvious.