Green onion field fly

Delia antigua (Meigen) belongs to Diptera, Anthomyidae. Commonly known as onion flies, onion maggots, garlic maggots. It is a worldwide pest and is distributed throughout China. Omnivorous pests that harm almost all crops. In addition to spinach, onion, garlic and cruciferous vegetables in vegetable areas, it can also harm melons, beans, corn, potatoes, cotton and hemp crops. Larvae bore into onions, garlic bulbs, etc., causing rot, leaf yellowing, wilting and even death into pieces. After leek is harmed, it often causes lack of seedlings and broken ridges, even the whole field is destroyed.

I. Morphological recognition

1. The dorsal hairs on the forewing base of adults are very short, less than 1/2 the length of the dorsal middle hairs behind the intershield groove. The narrowest part of the frontal band between the two compound eyes of male flies is narrower than that of the middle eye; the center of the lower part of the hind foot tibia is about 1/3 - 1/2 of the length of the whole tibia, and there are rows of sparse and approximately equal short hairs. Female flies have two bristles on the outside and upper part of the middle foot. 2. Larvae grow to 7 mm, milky white and yellowish. In addition to one pair of distinct spiracles at the tail end, 7 pairs of fleshy projections can be seen from the back, all of which are not bifurcated. The seventh pair is very small, the first pair is higher than the second pair, and the sixth pair is significantly larger than the fifth pair.

II. Rules of occurrence

Life history and habits: North China occurs 3 - 4 generations a year, and overwinters in the soil or dung. The adults bloom in early May, and the eggs are laid in piles in the onion leaves, bulbs and topsoil 1 cm deep around the plant. The egg stage is 3 - 5 days, and after hatching, the larvae quickly drill into the bulbs to do harm. Larval stage 17 - 18 days. Mature larvae around the victim plant? Nailin thanks track plan? Four days.