Control Of Myzus Persicae By Using Aphidius Gifuensis Ashmaed

Myzus persicae Sulzer is one of the main pests among tobacco production of Hunan tobacco region. It usually occurs in large quantity and has damage to tobacco directly or indirectly in a long period of time. Actually, Myzus persicae Sulzer is one of the key causes of serious economic losses of tobacco production. Aphidius gifuensis Ashmead is a kind of main specific internal parasitic natural enemy of tobacco aphid. Its parasitic effect on aphid was significant with the ability to resist the growth of aphids’population effectively and can achieve significant prevention and control effect on vega aphids.In this paper, we studied the breeding condition of Myzus persicae Sulzer when transferred among different host and different amount of aphids, the inoculation situation of Aphidius gifuensis parasitic on Myzus persicae under different aphid density, carried out the study of occurrence dynamics of Myzus persicae and its main natural enemies in Hunan Liuyang tobacco zone and preliminarily studied the technology of Aphidius gifuensis’scale breeding and release control of Myzus persicae for providing a reference for in-depth study of Aphidius gifuensis parasitic on Myzus persicae and providing early stage technical support for the biological control of the Myzus persicae in scale, we draw the following main conclusions:1.Different host tobacco seeding and different aphids’ density will affect the reproduction speed of Myzus persicae. Myzus persicae were transferred to the G80, Yunyan 87 seedlings with the different number of vaccination aphids in 5,10,15,20,25,30 aphids per plant. The experimental results show that Myzus persicae which transferred on G80 tobacco seedlings were significantly faster than those transferred on Yunyan 87 tobacco seedlings. When Myzus persicae were transferred in G80 tobacco seedlings with different aphids density, the results shows that when the aphids number was 20 per plant, it can produce a greater number of aphids in a shorter period of time.2.The parasitic rates of Aphidius gifuensis were different when under different host density. When a pair of Aphidius gifuensis transferred under the host densities of 10,20,30, 40 aphids per pair, Aphidius gifuensis parasitic on Myzus persicae was significantly different, with a density of 20 we gained the highest parasitism rate, thus we recommend to transfer 20 aphids per pair in breeding Aphidius gifuensis among the scale-breeding.Double pair of Aphidius gifuensis transferred in 10,20,30,40 aphids each two pairs, Aphidius gifuensis parasitic on Myzus persicae aphids was significantly different, with a density of 30 we gaoin the highest parasitism rate, thus we recommend to transfer 20 aphids each two pairs in breeding Aphidius gifuensis among the scale-breeding.3.The alatae of Hunan Liuyang tobacco area arise migration in mid March, peaked in early May and mid June. The population dynamics of Myzus persicae showed a single peak curve, began moving into the tobacco hazards in late April, late June is the peak of aphid numbers, then decreased. Tobacco aphid’s natural enemies mainly including parasitoids and predators in two categories, among parasitoid Aphidius gifuensis is mainly, main predatory natural enemies are the ladybug, lacewings, syrphidae etc. Among all the natural enemies, the parasitoid Aphidius gifuensis occurs in large quantities and is hard to control.