Study On Light Trapping Technology Against Major Underground Pests In Peanut Field

Frequoscillation pest-killing lamp as a means of green prevention and control of pests has already been produced and widely used. However, we have not known the sensitive wavelength for underground pests. Thus, the use of frequoscillation pest-killing lamp lacks pertinence. It can destroy the stability of farmland ecosystem by killing pests as well as natural enemies. On the basis of the results of preliminary experiments, we investigate the trapping effects of the selected five light resources of frequoscillation pest-killing lamp on underground pests. At the same time, we also review the effects of the five light resources on natural enemies. The purpose of the two experiments is to screen the light resource which has good trapping effect on underground pests and little killing effect on natural enemies. Furthermore, this paper analyzed the effects of three light resources of frequoscillation pest-killing lamp on antioxidant enzymes in Serica orientalis, Holotrichia parallela and Anomala corpulenta in order to preliminarily understand mechanism of phototaxis in cockchafers. The main research results are as follows:1. Insect species trapped by frequoscillation pest-killing lamps in peanut fieldThere were13orders of insects trapped by frequoscillation pest-killing lamps in peanut field from2011to2012. Among the trapped insects, the two orders (8families and30species) were underground pests, including Melolonthidae, Rutelidae, Cetoniidae, Scarabaeidae, Dynastidae, Elateridae, Gryllotalpidae and Gryllidae. The underground pests with large catches included S. orientalis (74934), H. parallela (14317), Metaboluo tumidifrons (4945), Maladera verticalis (9674) and A. corpulenta (6976). The major natural enemies included rove beetles (25309), carabid beetles (21963), ladybirds (17588), parasitic wasps (4768) and lacewings (776).2. Comparison of the trapping effects on major underground pests among five light resources of frequoscillation pest-killing lamp in peanut filedThe statistics of species and catches of underground pests showed that the trapping peak periods of Melolonthidae and Rutelidae were from late May to early July and their trapping peak dates were the same both in2011and2012. They were June9,2011and June11,2012.The trapping peak periods of Elateridae, Gryllotalpidae and Gryllidae were from late June to the end of July, from mid June to the end of July, and mid August respectively.Through comparing catches of major underground pests among five light resources of frequoscillation pest-killing lamp in peanut filed, we found that light resource III had the best trapping effect on Melolonthidae, Rutelidae and Gryllidae. Light resource V had the best trapping effect on Elateridae and light resource III came second. Light resource Ⅱ had the best trapping effect on Gryllotalpidae, and light resource III came second. Comprehensive analysis indicated that light resource III among the five light resources had the ideal trapping effect on the above major underground pests in peanut filed.3. Comparison of the trapping effects on natural enemies among five light resources of frequoscillation pest-killing lamp in peanut filedIn2011, carabid beetles, ladybirds, parasitic wasps and lacewings had the same trapping peak date (May8). The trapping peak date of rove beetles was May31. In2012, the trapping peak dates of ladybirds, rove beetles and parasitic wasps were July18, May12and April18respectively.Through comparing catches of natural enemies among five light resources of frequoscillation pest-killing lamp in peanut filed, we found that Light resource IV, II and V had the least killing effect on ladybirds, parasitic wasps and lacewings, rove beetles and carabid beetles respectively. Comprehensive analysis showed that Light resource IV among the five light resources had the least killing effect on the above natural enemies in peanut field.4. The effects of three light resources of frequoscillation pest-killing lamp on the activities of antioxidant enzymes in cockchafersThrough analyzing the activities of antioxidant enzymes in S. orientalis, H. parallela, and A. corpulenta exposed to three light resources of frequoscillation pest-killing lamp, the results showed that the total antioxidant capacity, superoxide dismutase (SOD) activity and catalase (CAT) activity in S. orientalis irradiated by light resource I, II and III were significantly lower than those under dark condition (control group). Peroxidases (POD) activity in S. orientalis exposed to light resource I was not only significantly lower than those under dark condition, but also significantly lower than those exposed to light resource II and III. Glutathione-S-transferase (GST) activity in S. orientalis irradiated by light resource II was significantly lower than those under dark condition. The activities of SOD, CAT, POD and glutathione peroxidase (GSH-PX) in H. parallela irradiated by light resource II were significantly lower than those under dark condition. However, CAT activity in A. corpulenta exposed to light resource I and III were significantly higher than those under dark condition. Moreover, malonaldehyde (MDA) contents in A. corpulenta exposed to light resource I were also significantly higher than those under dark condition.