| Lycium barbarum L. is the main cultivated varieties of economic plants inNorthwest China, and it is suitable for multipurpose tree species in forest, soilconservation and ecological forests. Aphid gosypii Glover is serious pests inwolfberry forests in Qaidam. It is difficult to control, often outbreaks in grownseasons. This pests reduced the yield of wolfberry fruit production to30%~70%, theproduct quality is dropped substantially, the value of commodities have beenaffected.In order to collect basic science and technology information for thecontrol of propagation and mischievous of Aphid gosypii Glover on Lyciumbarbarum L. in Qaidam. We took Aphids in natural and planted wolfberrywood as experimental subjects. Via observation on fixed spots, indoor cultureand chemical analyses of Aphids and wolfberry samples, we investigated thecommunity structure with five sampling method, the observation focus onbiological characteristics and population ecology of Lycium barbarum L., thenwe also conducted the toxicity indoor and Control effects in fields of a varietyof pesticides to Aphid gosypii Glover. For effective control of the qaidam foreffective control the harm of Aphid gosypii Glover in qaidam, and furtherdiscussed the biological control and comprehensive prevention and controltechnology to provide the theory basis and the scientific basis.harm,andfurther discussed the biological control and comprehensive prevention andcontrol technology to provide the theory basis and the scientific basis. Themain research results are as follows:1. Investigation of wolfberry insect community structure, there werecollected58kinds of insects in wolfberry wood in Qaidam, it is subordinate to2the outline,10yard, and2general families,29families,2subfamilies,50genera. H erbivores made up of31.03%of wolfberry wood insect community,piercing-sucking group made up of91.52%of herbivores, aphides made up of50.19%of piercing-sucking group. The dominant concentration of wolfberrypests in qaidam Qaidam are Hompteras and Acariformes. The most Homptera pest is Aphids, with Poratrioza sinica Yang et Li the second; and Acericmacrodonis is the major pest in Acariformes. There were7main types ofaphids’ natural enemy (Syrphidae, Chrysopasinic, and Chrysopa etc.)2. Life history characteristics, Aphids reproduces18generations, with overlapbetween every two generations. Aphids owerwinterings in eggs, in May of the secondyear, eggs breed into fundatrixs, and a yearly life history begans.3. Influence of temperature on aphids, the developmental thresholdtemperature of aphids nymphs is7.93℃. Between12℃and30℃, Thedevelopping rate of aphids nymphs behaves a S style response to temperature,the optimal developing temperature is21～27℃. The thermal constant foraphids is40.90DD。4. Population dynamic, yearly population dynamics express as bimodalcurve. The population dynamic of Aphids gosypii was closely related to theirmigration activity. In late June to early July, the alatae of aphids generallybegan migratory flight. Simultaneously, the population density of aphidsreaches the peak in July and Autume the sub-peak; Aphids and overwinteringeggs showed clumped distribution.5. Relationship between aphids and host plants, Aphids can affect thefruit production, leaf nutrient content and leaf trace element content ofwolfberry, which mainly caused production decline of wolfberry. Meanwhile,with the population density of aphids increasing, the meal size of theirdominant natural enemy-Chrysopasinic increased, and the number thepopulation density of Chrysopasinic increased too. When the population head ofeach star reached6.3, namely appear yield loss. The higher the population densities,the greater the yield loss, it shown a significant logarithmic correlation betweenpopulation and yield. According to production status of Lycium barbarum L. inNuomuhong, will each branch revealed to174head per red fruits, and the amounthead of each star reach to6.3head, as control criterion. The economic damagethreshold is12.24%.6. Influence of pestisides on aphids population, we found that aphidsfrom different regions（Delingha, Nuomuhong）showed diverse pesticides resistance. aphids mainly inhabit on Ning-Qi1and Ning-Qi5, ovipositmainly on Ning-Qi1and Ning-Qi7, Ning-Qi3were less significantlypredated. These imply that Ning-Qi3has the best aphids resistancecharacteristic. And1.5%nicouline and other5pesticides have upstandingaphids control effects. |
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