The grey-white silkworm moth, also known as the hanging filarial worm, is a lepidoptera, of the family Silkworm Moth family. Distributed in Guangdong, Guangxi, Sichuan, Taiwan and other places. In South China, it harms major garden plants such as figs of small leaves, figs of maca, figs of alpine, ficus ficus, jackfruit, etc., and endangers banyan trees and figs in Taiwan. The larvae feed on the leaves and young shoots of ficus parviflora and are pests of chewing mouthparts. The hatched, early larvae feed on the leaf flesh tissue, and as they age, the larvae begin to feed along the leaf margin. When there are few insects, the leaves are incomplete, which affects the ornamental value of the ficus parviflora; when there are many insects, it will eat the leaves of the entire tree, and even lead to the wilting and death of figs.
[1] Morphological characteristics
Adult: Similar in appearance to silkworm moths, but small in size, with a body length of 8 to 9. 5 mm, wingspan 22 to 26 mm. The body color is grayish white to grayish brown, and the male moth is darker than the female moth. The forewings are tanned with dark brown spots in the middle and apical horns, slightly inverted below the apical horns, and dark spots in the middle of the outer margin. The hindwing has a light transverse band in the middle and a longitudinal grayish-brown dot on the posterior margin. The abdomen is small and rises upwards as it perches. Eggs: flattened, oval, orange-yellow at first, yellowish brown before hatching. The mature larvae are 6 to 11 mm long and darker in color, with a distinct black circular spot on each side of the dorsal longitudinal line. Pupa: 7 mm long, yellow wing buds, white belly. Cocoon: White.
[2] Occurrence law
In northern Guangdong, there are severe pest infestation periods from April to June and from September to November every year. The insect also harms other species of figs of the genus Kudzu, alpine fig, ficus and other fig species of the genus Fig. The larvae have a hanging habit of spitting silk, commonly known as hanging filariae.
[3] Prevention and control measures
1. During the wintering period of pest pupae, combined with pruning, the source of insects is removed, and the pruned branches and leaves should be burned in time.
2. During the peak period of larval hatching, spray poison with 80% dichlorvos emulsion 1000 times liquid and 90% dichlorvos 800 times liquid, all with good results.
3. Use 1000 times the liquid of the royal moth for control.