Occurrence and Control measures of Maize aphids

Corn aphids are widely distributed in maize producing areas, which can harm corn, wheat, sorghum, rice and many kinds of Gramineae weeds. At the seedling stage, adult aphids and nymphs cluster in the heart leaves, and after heading, the ears are harmful, absorb sap, hinder growth, and spread a variety of Gramineae cereal viruses. Belongs to Homoptera, Aphididae. Commonly known as wheat, greasy worms, ant insects. Distributed all over the country.

[damage characteristics] adult and nymph aphids suck plant tissue sap, causing leaves to turn yellow or red, affecting growth and development, and in serious cases, the plant dies. Corn aphids often cluster in the heart leaves and secrete honeydew when damaging the leaves, resulting in black mildew. Different from sorghum aphid. On compact corn, it is mainly harmful to male flowers and upper 1Mel 5 leaves, and the lower leaves are lightly damaged, sucking the sap of corn, causing leaves to turn yellow and dead, often causing mildew and blackening of leaves, affecting photosynthesis, reducing grain weight, and spreading virus diseases, resulting in reduced yield. Host corn, sorghum, wheat, bristlegrass and so on.

[description] the female aphid of winged fetus is 1.5 to 2.5 mm long, black in head and chest, gray-green in abdomen, and dark lateral spots in front of abdominal canal. Antennae 6 segments, antennae, beak, feet, ventral internodes, ventral canal and tail black. Wingless parthenogenetic aphids are long ovate, live insects are dark green, covered with thin white powder, black appendages and reddish brown compound eyes. The head and chest are shiny black, and the abdomen is yellowish red to dark green. The antennae are 6 segments shorter than the body. Other characteristics are similar to those of wingless type. The egg is oval.

[occurrence regularity] there are more than 10 to 20 generations a year from north to south, generally overwintering as wingless female aphids in the heart leaves of wheat seedlings and Gramineae weeds. At the end of April and the beginning of May, it migrated to spring corn and sorghum. Before heading, corn has been clustered in the heart leaf to reproduce and spread to the male ear and female ear after heading. Flowering stage is the most favorable period for maize aphid reproduction, so the appropriate period for control should be before maize heading. It is suitable for temperature and high humidity, that is, the ten-day average temperature is about 23 ℃ and the relative humidity is more than 85%. When corn is in the flowering stage, it is most suitable for the multiplication and damage of corn aphid, and the storm has a great control effect on corn aphid. In the fields with heavy occurrence of weeds, the occurrence of corn aphid was also more serious.

[prevention and control methods]

1. Clear the weeds in the field in time and eliminate the breeding base of corn aphid.

2. In the corn heart and leaf stage, the rate of aphids reaches 50%, and when the number of 100 aphids reaches more than 2000, 50% aldicarb 3000 times, or 40% omethoate 1500 times, or 50% dichlorvos 1000 times, or 2.5% enemy kill 3000 times solution can be sprayed evenly, or the above solution can be used to infuse the heart, or 40% omethoate 50 times can be used to coat the stem.