How to identify Helicoverpa armigera and Helicoverpa armigera of Noctuidae? How to prevent and cure it?

Helicoverpa armigera and Helicoverpa armigera are two very similar insects, which are difficult to distinguish in production. They both belong to the family Lepidoptera, also known as Helicoverpa armigera and Spodoptera litura, widely distributed. So how to identify Helicoverpa armigera and Helicoverpa armigera? How to prevent and cure it? In daily life, cotton bollworm harms cherry tomatoes, okra, lettuce, kale, Brussels sprouts, melons, lentils, Dutch beans, sweet peas, sweet corn, vegetable soybeans, apples, pears, oranges, peaches, plums, grapes, figs, strawberries, cotton and other crops. Tobacco green insects harm tobacco, pepper, tomato, pumpkin, cotton, corn, sorghum, hemp, soybeans, peas, lentils and so on.

How to identify

Helicoverpa armigera, Lepidoptera and Noctuidae are widely distributed in China and around the world, and occur in cotton and vegetable growing areas in China. The cotton areas in the Yellow River Basin and the Yangtze River Basin suffered more seriously. In recent years, cotton areas in Xinjiang have also occurred from time to time. There are more than 200 species of host plants in more than 30 families. Helicoverpa armigera is an important boring pest in cotton bud and boll stage, which mainly eats buds, flowers and bolls, as well as tender leaves.

Tobacco green worm commonly known as green worm, also known as tobacco nocturnal moth, belongs to the family Lepidoptera. There are 2 generations a year in Northeast and North China, 4 generations in Henan, Shandong and northern Anhui, 5 generations in Northwest China, 5 generations in Central China, and 6 generations in Southwest China. In the Huang-Huai tobacco area, the pupae overwintered in the soil with a depth of 7cm and 13 cm, and the overwintering adults appeared from late May to early June, and the peak spawning periods of the 2nd and 4th generations were from the first ten days of June to the first and middle of July, from the first ten days of July to the first ten days of August, and from early August to early September, respectively. The first generation to the third generation is mainly harmful to spring and summer tobacco, while the fourth generation is harmful to the flowers and fruits of summer tobacco, among which the second and third generation are the most harmful to tobacco.

1. Damage characteristics

The larvae eat the buds, organs, fruits and pods of the plant, as well as stems, ears and vegetable balls, and eat tender stems, leaves and buds in the early stage.

two。 Morphological characteristics

The adult Helicoverpa armigera has long 14~18mm, wingspan 30~38mm, grayish brown to yellowish brown. The front wing has a brown ring and kidney-shaped pattern. There are two brown stripes on the front vein in front of the renal pattern, the outer side of the renal pattern is a wide brown transverse band, and there are black spots between the veins in the end area. The hind wings are yellowish white to grayish brown and the tip area is brown to black. There is an inverted small hook at the end of the male moth, and the small conical horn in the male stem is large and few (about 12 pairs). The appendage of the mating capsule of the female moth is covered with small triangular thorns in addition to wrinkles. The egg is about 0.5mm in length, hemispherical, milky white, with reticular pattern. There are 1 or 2 short longitudinal edges between the two longitudinal edges, mostly bifurcated or forked, and the middle longitudinal ribs are 25-30, mostly 26-28, and the egg foramen is not obvious. The body length of mature larvae is 30~42mm, and the body color varies greatly. From light green, light red to reddish brown, black and purple, common for green type and reddish brown type. The head is yellowish brown, the topline, subtopline and superior valve line are dark longitudinal lines, the valve is white, and the abdominal toe hook is a double-ordered middle band. The lines of two anterior thoracic hairs (L1 and L2) were tangent or intersected with the lower end of the anterior thoracic valve. The surface of the body is covered with small thorns, and its base is larger. The pupa is long 17~21mm, yellowish brown. There are 7-8 rows of semicircular engraving on the back and abdomen of the fifth to seventh segments of the abdomen, and 2 spines on the buttocks.

The tobacco green worm is very similar to the cotton bollworm. The main differences are as follows: the body color of the adult is yellow, the lines on the front wings are clear, there is a brown-black line on the middle part of the brown-black broadband, and the outside is slightly concave. The male moth has no small hook at the end of the male stem, and the long conical horn of the male stem is small and numerous (about 23 groups). The female moth has only wrinkles and no small triangular thorns on the capsule appendage of the mating capsule. The eggs are slightly flat, yellowish, and the longitudinal ribs are double-ordered, mainly 1 long and 1 short, and the middle longitudinal ribs are 21-26, mostly 22-24, and the egg stomata are obvious. The connection of the two forechest hairs (L1 and L2) of the larvae is far away from the lower end of the anterior thoracic valve, and the small thorns on the body surface are shorter. The anterior segment of the pupa is slightly thicker and shorter. The valve is small and low, rarely protruding.

Prevention and cure method

The control methods of Helicoverpa armigera and Helicoverpa armigera are similar. The larvae of Helicoverpa armigera are no longer drilled after fruit decay, and chemical control must be carried out before drilling.

The main results are as follows: (1), turning the ground and killing pupae in winter and early spring to reduce the source of overwintering insects in the field.

(2) use black light, high-pressure mercury lamp, poplar branch handle or sex trap to trap and kill adults.

(3) according to the selectivity of Helicoverpa armigera to different hosts, food-loving host crops were consciously planted in the field to induce Helicoverpa armigera to lay eggs and reduce the damage to vegetable production.

(4) combined with field management, the leaves, fruits and shoots of eggs, fruits and shoots were removed with pruning and forking, increased ploughing and irrigation at pupal stage, and destroyed the normal pupation of cotton bollworm.

(5) continuous spraying of Bacillus thuringiensis Bt emulsion or HD-1 powder or Helicoverpa armigera nuclear polyhedrosis virus 3-4 days and 6-8 days after egg peak. Before the 2nd instar of the larvae, choose 5% Nongmont EC 3000 × 4000 times, 10% Nongmont EC 1500 × 2000 times, 3% Mobilang EC 1000 × 2000 times, 5% Carboxylic EC 1000 × 2000 times, 52.25% Nongdile EC 2500 × 3000 times, 5.7% Baishu EC 3000 times, 12.5% Baofu suspensions 8000Cr10000 times spray. After drilling, it is advisable to spray when the larvae come out in the morning or evening.