Hazard characteristics and control methods of walnut lifting moth
High qifu and so on
Atrijuglans hetao-hei Yang is a genus of lepidoptera, nest moth family, and erector moth family. It is named because the tibia and tarsal joint of the hind foot with an annular black burr at rest are lifted upwards to the posterior side.
1 Distribution of walnut lifting moths
Walnut lifting moth is the main fruit pest on walnut, mainly distributed in Hebei, Henan, Shandong, Shanxi, Shaanxi, Gansu, Sichuan, Guizhou and other walnut producing areas.
2 Hazard characteristics
Walnut lifting moths are mainly larval borer fruit hazards. After the larvae borer fruit, a colorless transparent gelatinous discharge appears at the moth hole, gradually becoming amber, and water droplets collect after rain. During the initial hazard period, the borer pores are linear (Figure 1) and reach deep into the kernel, causing the peel to dry shrink and turn black. The larvae feed on the green skin and form a stationary road, which is filled with insect feces and black rot in the victim area (figures 2, 3). There are 1 to 10 larvae in 1 fruit. Early fruit shedding in the first generation of larvae causes early fruit shedding (figure 4). The first generation of larvae borers in the late stage and the second and third generations of larvae borers generally do not cause fruit shedding. In the later stage of harm, walnut kernels become black and stunted, peels shrink and turn black, and internal tissues rot and deteriorate, so it is also known as "walnut black" or "black walnut", which seriously affects the yield and commodity value of walnuts, but the larvae do not turn fruit. Walnut fruit remains on branches in winter (figure 5), which is one of the important features to identify the symptoms of harm in walnut lifting moths.
Fig. 1 The larvae initially harm linear moth tracts
Fig. 2 Larvae in fruit
Fig. 3 Fruit-like after larval infestation
Fig. 4 Larval infestation causes early fruit fall
Fig. 5 Residual fruit on the tree
3 Morphological identification
3.1 Eggs
Cylindrical or oval, 0.3 to 0.5 mm long, milky white at first birth, yellowish-white in gradient, yellowish-brown in hatching.
3.2 Larvae
The hatching larvae are earthy yellow, the head is yellowish brown, and the body length is 0.5 to 1 mm; the mature larvae are yellowish white and slightly transparent, the back is pink and later turns black, the head is dark brown, covered with sparse long bristles, and the body length is 9 to 11 mm. The mouthparts, the dorsal plate of the forebrea and the thoracic foot are yellowish brown, and the gastropod toe groove is an interordinal ring, for example, the toe groove is a monophalange transverse band.
3.3 Cocoon
Oval, slightly flattened, gray-brown, 6 to 7 mm long, the initial cocoon is completely wrapped, and then there is a white slit at the wider end.
3.4 Pupae
The body is 5 to 6 mm long, and the initial pupae are pale yellow and gradually turn yellowish brown to brown.
3.5 Adults
The body is 4 to 8 mm long, the wingspan is about 12 mm long, the body is dark brown, metallic, and the abdomen is silvery white. The antennae are filamentous and densely covered with white hairs. The lower lip must be well developed, protruding forward, and curved inward in the shape of a horn. The wings are narrow and lanceolate with long marginal hairs; there are half-moon-shaped white spots at the end of the forewings, and the hindwings are brown. The feet are white, the hind feet are very long, the tibia and tarsal segments have annular black burrs, and the tibia and tarsal joints are lifted up to the side and posterior, and swing from time to time, so they are called "limb lifting moths". The female moth has a larger abdomen with a distinctly wider alternating pattern of black and white, and a darker end of the abdomen. The male moth has a thin abdomen, a narrow or inconspicuous alternating pattern in black and white, and a slightly pointed abdomen at the end of the abdomen.
4 Life history of the walnut lifting moth
Walnut erector moth occurs in 3 generations in Zhangqiu area of Shandong Province in one year, with a calendar period of about 40 days per generation; old mature larvae overwinter in the fallen fruit, at the contact between the fallen fruit and the soil surface, in the soil cracks, in the soil 1 to 2 cm, under the dead branches and leaves; the overwintering larvae begin to pupate in the cocoon from the end of April to the beginning of May; the overwintering adults first appear in mid-May and the end in mid-June; the first generation of larvae begin to hatch in late May, the beginning of June is the initial incubation period, and the end is in late June, and the larvae are harmful in walnuts for about 12 days The first generation of mature larvae begins to pupate in mid-June and ends in mid-July; the first generation of adults begins in late June and ends in late July; the second generation of larvae begins to hatch in early July and ends in late August; the second generation of adults begins in early August and ends in early September; and the third generation (overwintering) begins to hatch in mid-August and begins to overwinter in cocoons in early September (Figure 6).
5 Walnut limb moth occurrence and environmental relationship
(1) The soil moisture is large and the weeds are overgrown.
(2) Heavy occurrence occurs in the wet and humid areas of the nest and deep mountains, and the occurrence of light occurrence in the dry places and shallow mountains of the sheltered to the sun.
(3) The yin slope is heavier than the yang slope and the ditch outside the ditch.
(4) Wasteland occurs more heavily than cultivated land.
(5) The rainy and wet years of the adult feathering period occur heavily, and the dry years are lighter.
(6) Reasonable pruning, ventilation and light transmission, meticulous management of the orchard occurs lightly.
6 Walnut Lifting Moth Annual Control Resume
According to the occurrence law of walnut lifting moth, combined with local reality, a feasible and effective resume of the annual prevention and control of walnut lifting moth is formulated.
Walnut lifting moth annual control resume