Studies On The Attractancy And Toxicity Of Plant Source Chemicals To Holotrichia Parallela

The Scarab beetle (Coleoptera; Scarabaeidae) belong to invertebrates, is a kind of omnivorous pests of Coleoptera scarabaeidae, distributed all over the world. It is an important underground pests that can damage crops seriously. Duing to live in the underground the grubs is difficult to control. So control the beetles is an important way to control grubs. Taking environmental protection into account we studied on the attractancy and toxicity of plant source chemicals to Holotrichia parallela. In this article, we first investigated the local chafer in the peanut fields of Zaoyang and Yicheng. We used the Y-shaped glass tube olfactometer to test the potential activity of13kinds of plant chemicals of Holotrichia parallela, meanwhile we test the potential activity of19kinds of plant chemicals of Holotrichia parallela through field test. We also evaluated the toxicity of9kinds of plant extractions on Holotrichia parallela. Finally, we found out the best diluents and the content of the active ingredients of Nicotiana tabacum Powder. And the change of the important enzymes in grubs with time were studied with Nicotiana tabacum Powder. The results were as follows:1. The result shows that in the peanut fields of Zaoyang and Yicheng grubs are the most important underground pests. We did not find mole cricket and wireworm in the survey area. As the main pest, the density of grubs was6.67per centiare in Yicheng. After classification we found the Holotrichia parallela were dominance pest species.2. After the test of the potential activity of13kinds of plant chemicals of Holotrichia parallela by "Y" tube olfactometer we found:Component A showed the attraction to Holotrichia parallela at the dosages of10-1、10-3、10-5、10-7ul/ul (p<0.05), and the attraction is very significant at10-5ul/ul (p<0.01); Diisobutyl Phthalate showed the attraction to Holotrichia parallela at the dosages of10-、10-5ul/ul (p<0.05); Dibutyl Phthalate、L-isoleucine Methyl Ester Hrdrochloride and L-proline Methyl Easter Phdrochloride are all attractive at10-5ul/ul (p<0.01); Beta-caryophyllene showed the attraction to Holotrichia parallela at the dosages of10-1、10-3、10-5ul/ul(p<0.05); Linalool exhibited repellent action at the dosages of10-1、10-3、10-5ul/ul (p<0.01).We found compound A、Dibutyl Phthalate、L-proline Methyl Easter Phdrochloride and L-isoleucine Methyl Ester Hrdrochloride all showed attraction to Holotrichia parallela at the dosages of10-5ul/ul, and the attraction is very significant. And component A showed the strongest attraction to Holotrichia parallela at the dosages of10-5ul/ul.3. The field test show compound A is the most attractive compound. It can mostly trap16beetles one day. We found the traps hung1.5m above the ground and the traps without cap were the best for capture chafer.4. Nine plant source extracts were applied to grubs. The toxicity bioassay of9kinds of plant source extracts revealed Tripterygium wilfordii and Nicotiana tabacum presented the highest virulence to the grubs, the LC50was37.043g/L and38.081g/L respectively. Aconite Root^Xanthium sibiricum and Dregea volubilis presented a weaker virulence to the grubs, the LC50was45.428g/L、43.433g/L and42.014g/L respectively. In comparison, the other four kinds of plant source extracts show the weakest virulence to the grubs as the Fructus Toosendan presented the lowest virulence to the grubs, the LC50was87.373g/L.5. We find let Diatomite、Kaolinite、Bentonite and Talcum powder as the diluents of Nicotiana tabacum Powder all have toxic for the grubs. When let the Kaolinite as the diluents of Nicotiana tabacum Powder it presented the highest virulence to the grubs, the LC50was82.969g/kg and the Talcum presented the lowest virulence to the grubs, the LC50was113.395g/kg. Kaolinite was the best diluents and the formulation of Nicotiana tabacum Powder was9.5%.6. After treating the grubs with Nicotiana tabacum Powder under the82.969g/kg dosage, the enzymes in grubs activities changed with the processing time. The activities of GSTs content of tissue succus in grubs were repressed trending with the prolonging of treating time, whereas the activity of AchE was induced. But after treatment for36h the activity of AchE showed a downward trend.