Another name
Bemisia spinosa
Form (Figure 4- 17)
Figure 4- 17 Bactrocera dorsalis
1. Male adult 2. Male reproductive organs. Female adult 4. Egg 5. Nymphs 6. Pupa 7. Pupa shell 8. Eggs are laid on leaves. victim
Adults are pale yellow, with thin wax powder and purple eyes. The female adult is 1mm in length, 0.3mm in width and 2.4mm in wing spread. The first antenna segment is the shortest, the third is the longest, and the seventh is the second. Male adult body length 1. 1mm, width 0.23mm, wings spread 2.04 mm. The antenna is the shortest in the fourth section, the longest in the seventh section and the second in the third section. The egg is 0.2 mm long and 0.07 mm wide. It was light yellow at first, then gradually turned brown, saccate, pointed at the top, dull at the base and short in handle. The pupa is light yellow at first, and then gradually becomes yellow-green, long and narrow, oval, with a length of 1.3mm and a width of 0.7 mm. There is a transverse trace in the sub-edge area, and the connection with the back plate is not obvious. There are two longitudinal lines in the center of the dorsal disc, and there are 1 pairs of thick spines on the dorsal disc, which are located at the beginning of the longitudinal lines. This feature is an important difference from Bemisia tabaci. The chest airway comb has three teeth, and the notch is not deep. There are barbed protrusions on both sides of the tubular hole. The orifice valve is flat and heart-shaped, with developed tongue, most of which are exposed. There are two tiny bristles at the end, and the tail groove is obvious, which is connected with the tubular orifice. The groove wall is thick and uneven.
Life history and habits
Bactrocera dorsalis has four generations in Chongqing 1 year, and nymph overwinters on leaves. The beginning and end of each generation: the first generation lasted for 2 months from the beginning of May to the end of June; The second generation lasted 2.5 months from early June to mid-August; The third generation lasted for 3 months from the end of July to the end of 10; The fourth generation ended from late September to mid-June of the following year, lasting nearly 8 months.
Adults emerge from cracks in the back of pupae. Pinnate holes are almost rhombic. Adults have phototaxis. Adults mate and lay eggs on the same day after emergence. Eggs are mostly laid on both sides of the main vein on the front of the leaf and attached to a short egg stalk, which looks like a banana. The newly hatched nymph is not strong in swimming. After crawling for a short time, it settles on both sides of the main vein of the leaf, and smoking is harmful, mostly on the leaf surface.
The peak periods of Bactrocera dorsalis in each generation and stage: the peak periods of eggs are in early May, late June, early August and early June10 respectively; Nymphs have four peaks 1 1 in late May, late June, early August and early October respectively. The pupal stage reached its peak in late June, early August, late September and early May of the following year (overwintering generation). The peak periods of adults are in mid-May (overwintering generation), late June, early August and late 10 respectively.
Prevention and cure method
1. Agricultural control
Strengthen cultivation management, apply sufficient fertilizer and water, and do not plant tall crops with large amount of fertilizer and water in the garden, so as not to affect light and nutrition, which is conducive to the occurrence of pests.
2. Chemical control
After the first generation of eggs are full, we choose: 25% phoxim emulsion 500- 1000 times; 40% dimethoate EC 1000 times; 40% dimethoate 10% dichlorvos EC 1000 times solution; 50% chlorpheniramine EC 500- 1000 times; 90% crystal trichlorfon 400 times solution, 10 days or so, 1 times, twice in a row.