Drosophila suzukii (Diptera: Drosophilidae) distribution modelling improves our understanding of pest range limits

Abstract

Spatial distributions models (SDM) are often used in invasive pest management to understand current and potential distribution. Using data on the well-studied spotted wing drosophila as a model, we compared distribution patterns of the range-limit with commonly applied correlative and mechanistic models. Correlative models risk underestimation whereas simple mechanistic models provide overestimated range predictions, although using both approaches for the spotted wing drosophila improved range-limit predictions. Model choice when dealing with pests is central to the accurate identification of invasive species limit range and consequently for the deployment of monitoring and early detection programs.     

Sublethal effects of four insecticides on the reproduction and wing formation of brown planthopper, Nilaparvata lugens

BACKGROUND: The brown planthopper (BPH), Nilaparvata lugens Stål, is a major rice pest in many parts of Asia. Neonicotinoids such as imidacloprid and dinotefuran are widely used for control of this pest, and resistance to these insecticides has developed in recent years. This pest has also been widely exposed to triazophos and fenvalerate, although these insecticides are not used for the control of the pest directly. Here, the effects of sublethal doses of these four insecticides on the reproduction and wing formation in BPH were examined. RESULTS: Imidacloprid and dinotefuran reduced the fecundity of BPH to 68.8% and 52.4% in macropterous families, and to 57.9% and 43.1% in brachypterous families, when compared with the untreated controls. By contrast, triazophos and fenvalerate increased fecundity. In both macropterous and brachypterous families, sublethal doses of imidacloprid and dinotefuran showed significant induction of macropterous adults. CONCLUSION: Imidacloprid and dinotefuran could reduce the fecundity of BPH to a significant extent, demonstrating further activity against this pest in addition to their direct toxicity. The significant induction of macropterous adults by sublethal doses of imidacloprid and dinotefuran is of importance in the management of this pest, particularly in the areas of predicting the size of emigrating populations and the numbers of insects likely to occur in newly colonized areas. Copyright © 2008 Society of Chemical Industry     

松毛虫赤眼蜂对三种农田常用杀虫剂的敏感性

为明确常用杀虫剂对松毛虫赤眼蜂Trichogramma dendrolimi的安全性,室内评估了高效氯氰菊酯、阿维菌素和氯虫苯甲酰胺3种药剂对其成蜂的急性毒力以及田间推荐使用剂量对赤眼蜂各发育阶段的间接影响,并模拟自然情况,测定了不同残留期的3种药剂对赤眼蜂存活和寄生能力的影响.结果表明:以LC₅₀进行评估,对松毛虫赤眼蜂毒力最高的为阿维菌素,其次是高效氯氰菊酯,氯虫苯甲酰胺毒力最小;在田间推荐使用剂量下,阿维菌素、高效氯氰菊酯和氯虫苯甲酰胺的安全系数分别为0.017、0.066和69.175;在推荐使用剂量下,氯虫苯甲酰胺处理含有不同发育阶段赤眼蜂的米蛾Corcyra cephalonica卵后,平均羽化率最高为90.43%,其次是高效氯氰菊酯为56.46%,阿维菌素仅为9.84%;接触0~7 d残留期阿维菌素的玉米叶片24 h,松毛虫赤眼蜂全部死亡,无米蛾卵被寄生,但接触3~7 d残留期氯虫苯甲酰胺的玉米叶片,赤眼蜂的死亡率和寄生米蛾卵数量与清水对照无明显差异.表明在实施释放赤眼蜂的害虫综合治理方案中,应尽量避免使用阿维菌素,而氯虫苯甲酰胺对赤眼蜂风险性极低,具有很好的相容性,可以推广使用.     

Insecticide toxic effects on Trichogramma ostriniae (Hymenoptera: Trichogrammatidae)

BACKGROUND: The parasitoid Trichogramma ostriniae (Pang and Chen) is a major natural enemy of many lepidopterans, but only a few studies have been conducted on the compatibility of biological and chemical controls. In this study, the selectivity of 30 insecticides to T. ostriniae adults was evaluated. RESULTS: Among the seven classes of chemicals tested, organophosphates and carbamates had the highest intrinsic toxicity to the wasp, with LC₅₀ values ranging from 0.032 (0.029–0.038) to 2.38 (1.91–3.15) mg AI L^?1. They are followed by phenylpyrazoles, avermectins, neonicotinoids and pyrethroids, which induce variable toxicity responses, with LC₅₀ values ranging from 0.14 (0.11–0.21) to 56.67 (48.94–67.24) mg AI L^?1, from 2.57 (1.85–4.28) to 4.48 (3.34–6.83) mg AI L^?1, from 2.48 (1.80–4.03) to 503.6 (457.6–557.5) mg AI L^?1 and from 5.44 (3.95–8.84) to 104.2 (92.48–119.7) mg AI L^?1 respectively. The insect growth regulators (IGRs) exhibited least toxicity to the parasitoid. CONCLUSION: Risk quotient analysis classifies neonicotinoids, avermectins, pyrethroids, IGRs and phenylpyrazoles (with the exception of butane‐fipronil and fipronil) as safe agents to the parasitoid, but categorises organophosphates and carbamates as slightly to moderately toxic or dangerous to T. ostriniae. Copyright © 2012 Society of Chemical Industry     

Lethal and sub-lethal effects of a novel sulfoximine insecticide,sulfoxaflor, against Asian citrus psyllid and its primary parasitoid under laboratory and field conditions

The Asian citrus psyllid, Diaphorina citri Kuwayama, is the most important international pest of citrus because it transmits the bacteria that cause huanglongbing (HLB). HLB limits citrus production globally. We evaluated the toxicity of sulfoxalor against D. citri and its parasitoid, Tamarixia radiata Waterston. Sulfoxaflor was as toxic as imidacloprid to adult D. citri. The LC₅₀ values for sulfoxaflor and imidacloprid were 8.17 and 5.7 µg AI mL^?1, respectively. The LC₅₀ of sulfoxaflor for T. radiata adults was 3.3 times greater than for D. citri adults. Treatment with sulfoxaflor resulted in reduced oviposition, development of nymphs, and emergence of adult D. citri on plants, as compared with controls. The lowest concentration that reduced adult emergence was 0.6 µg AI mL^?1. There was reduced feeding by D. citri adults on leaves treated with sulfoxaflor. The residual toxicity of sulfoxaflor was equivalent to imidacloprid. Under field conditions, formulated sulfoxaflor reduced populations of D. citri compared with untreated controls. Sulfoxaflor is a novel mode of action and is an effective tool for D. citri management.     

西藏地区豌豆彩潜蝇的发生为害及其寄生蜂种类调查

豌豆彩潜蝇Chromatomyia horticola是我国重要的潜叶蝇类蔬菜害虫,寄生蜂是其重要的天敌。2018年7月,豌豆彩潜蝇首次在西藏地区被发现。为探明西藏地区豌豆彩潜蝇的发生情况及其天敌寄生蜂种类,于2018年-2019年对西藏拉萨、林芝、山南、日喀则4个地区进行了调查采样。结果表明,豌豆彩潜蝇在西藏地区发生程度中等,为害等级达Ⅲ级。调查到被其为害的寄主植物为5科7属7种,主要嗜好菊科和豆科植物。豌豆彩潜蝇的寄生蜂种类包括3科8属12种,其中优势种为豌豆潜蝇姬小蜂Diglyphus isaea、双斑潜蝇姬小蜂Diglyphus bimaculatus和西伯利亚离颚茧蜂Dacnusa sibirica,分别占总羽化寄生蜂个体数的35.71%、28.18%和21.01%,豌豆潜蝇姬小蜂主要来自寄主植物豌豆,双斑潜蝇姬小蜂和西伯利亚离颚茧蜂的发生期最长,7月-9月均有发生。同期,我们在西藏调查发现了入侵种南美斑潜蝇Liriomyza huidobrensis,为此,本文还讨论了西藏地区豌豆彩潜蝇和南美斑潜蝇的寄生蜂种类组成差异和寄生蜂的控害特性及控害效应,以期为制定生态调控和绿色防...