Being exposed to low concentrations of pirimiphos-methyl and chlorfenapyr has detrimental effects on the mobility of Trogoderma granarium

BACKGROUND

Sublethal effects of insecticides may negatively affect several biological and behavioral traits of insects. The lethal effects of pirimiphos-methyl and chlorfenapyr have been previously showed on Trogoderma granarium, but little knowledge is available about their sublethal effects at low concentrations on both sexes. Herein, the sublethal effects of pirimiphos-methyl and chlorfenapyr on the mobility of T. granarium males and females were investigated.

RESULTS

Lethal concentration (LC) values of pirimiphos-methyl and chlorfenapyr were lower for T. granarium females than males. LC values on males were LC₁₀ = 0.000788 and 0.00139 mg active ingredient (a.i.) cm⁻², LC₃₀ = 0.00350 and 0.00535 mg a.i. cm⁻², and LC₅₀ = 0.00986 and 0.0136 mg a.i. cm⁻² for pirimiphos-methyl and chlorfenapyr respectively. LC on females were LC₁₀ = 0.000704 and 0.00110 mg a.i. cm⁻², LC₃₀ = 0.00323 and 0.00428 mg a.i. cm⁻², and LC₅₀ = 0.00925 and 0.0110 mg a.i. cm⁻² for pirimiphos-methyl and chlorfenapyr respectively. The walking duration of beetles exposed to LC₃₀ of pirimiphos-methyl was significantly lower than the individuals exposed to LC₁₀ and LC₃₀ of both insecticides and control ones. Pirimiphos-methyl LC₃₀-exposed males remained more time on their back (101.7 s) than females (46.9 s), while the latter stayed immobile longer than males (381.7 s versus 371.9 s). The highest speed was recorded for control beetles (14.17 mm s⁻¹ females vs. 12.44 mm s⁻¹ males), while the lowest speed was observed in pirimiphos-methyl LC₃₀-treated males (8.36 mm s⁻¹) and females (9.66 mm s⁻¹).

CONCLUSIONS

Overall, males and females exposed to low concentrations of pirimiphos-methyl and chlorfenapyr showed reduced motility. This knowledge can be exploited further to unlock behavioral effects of insecticides for effective pest management programs in warehouses. © 2023 Society of Chemical Industry.     

6种植物源粉剂与复配剂防治储粮害虫的效果

采用拌粮法,用艾蒿、茵陈蒿、黄花蒿、青蒿、白苞蒿、驱蚊草纯植物源粉剂,硅藻土 植物源粉剂 70%杀螟松,硅藻土 植物源粉剂对仓储害虫进行了防治研究.结果表明:植物源粉荆 硅藻土 70%杀螟松,植物源粉剂 硅藻土为效果较好的植物复配剂,经处理9个月后,防治效果均达到80%以上,未发现有仓储害虫取食小麦.纯植物源粉剂中的艾蒿、茵陈蒿和驱蚊草处理9个月后的防治效果分别为79.13%、70.86%、83.38%,与其他几种纯植物源粉剂处理及空白对照的差异均达到显著水平.     

3种常见花金龟生殖系统与生殖活动的研究

本文对山东省3种常见花金龟的生殖系统进行了解剖研究。详细描述了雌雄生殖器官的基本结构及其差异,并对其成虫的生殖活动作了观察,为深入研究奠定了坚实的基础。     

小蠹类森林害虫可持续控制的策略和方法

根据森林害虫可持续控制的理论和目标,以及小蠹类森林害虫发生的规律和特点,在总结和评价森林有害生物治理理论的基础上,提出了小蠹类重灾性森林害虫可持续控制的理论和与之相适应的行为调控、生态结构调控和种群密度治理的策略和方法.     

浅析营林技术与杨树天牛治理

危害吉林省洮南市杨、柳、榆等树种的主要蛀干害虫是天牛,笔者回顾多年来防治杨树天牛的实践,采用营林技术来治理天牛,可以实现有效抵制天牛危害。     

杭州地区蓝莓上金龟子的发生与防治

金龟子是为害蓝莓果实生产和扦插繁殖的主要害虫,对杭州地区蓝莓上的金龟子调查发现,金龟子发生种类主要为铜绿丽金龟(Anomala corpulenta Motschulsky)、东南大黑鳃金龟(Holotrichia sauteri Moser)和暗黑鳃金龟(Holotrichia parallela Motschulsky);3种金龟子在杭州地区1年均发生1代,成虫在4月初开始出现,盛发期为5月下旬至7月中旬。成虫通过取食叶片、花、果实给蓝莓果实生产和扦插繁殖造成危害。通过合理建园、春耕翻土、人工捕杀、设置防虫网,与化学防治相结合,进行综合防治,可获得较好的防治效果。     

The Effects of Agricultural Practices on Carabidae in Temperate Agroecosystems

Ground beetles (Coleoptera, Carabidae) occur in all temperate agroecosystems, and have been implicated as predators of many pests, including aphids, lepidopterous larvae, and slugs. Most are polyphagous, and some are primarily spermophagous. The species assemblage present in any particular crop is determined by multiple factors, but usually comprises a limited number of abundantly active species, which may be common to many crop types. Abiotic soil factors, especially soil type and moisture status are important in determining the species present. Crop type affects the carabid assemblage indirectly through cultivation practices and microclimatic changes. Any soil cultivation affects the carabid assemblage, but studies comparing ploughing with reduced tillage have shown varying results, according to local conditions. Pesticides, especially insecticides have a localised and short-term effect, as many carabids rapidly re-invade sprayed crops. The long-term effect of pesticide usage at a landscape scale is, however, more difficult to predict, and may have contributed to the observed decline in carabid diversity in the wider countryside. Whilst fertiliser application is generally beneficial to carabids, comparisons of conventional and organic farming systems suggest that localised short-term variations in species abundances are more important than the overall farming system used. Non-crop habitats are very important to Carabidae, as many use adjacent hedges and field margins for shelter, breeding or dispersal. But other features such as roads may act as barriers to dispersal. It is concluded that further measures need to be taken if Carabidae are to realise their potential in integrated pest management systems.     

Note: Transovarial activity of the chitin synthesis inhibitor novaluron on egg hatch and subsequent development of larvae ofTribolium castaneum

The effects of the chitin synthesis inhibitor (CSI) novaluron on egg hatch and on larval development ofTribolium castaneum (Herbst) concentrations of 1.0, 0.3, 0.2 or 0.1 ppm were tested. The effect of novaluron at low concentrations depended strongly on the exposure period. At 0.3 ppm, egg hatch ofT. castaneum was totally inhibited after 28 days; at 0.2 ppm the effect was much less but inhibition increased progressively to 66% in the 35-day experiment; at 0.1 ppm novaluron was ineffective. The viability of the larvae that hatched from the laid eggs and developed on untreated flour was also dependent on concentration of novaluron and exposure time: exposure ofT. castaneum adults to novaluron-treated flour at 0.3 ppm for 8 days, or at 0.2 ppm for 36 days, caused 100% or 97.5% mortality, respectively. At both 0.3 and 0.2 ppm, larval deaths were mainly in the first instar. Exposure ofT. castaneum adults to treated flour may serve as a good model for evaluating the effect of CSIs on internal feeders, especiallySitophilus oryzae (L.). The present study contributes to our understanding of CSI transovarial activity against internal stored product coleopterans whose larval stage develops inside the grain without contact with the toxicants. http://www.phytoparasitica.org posting Dec. 11, 2007.     

牛背梁自然保护区植物群落和针叶树小蠹虫群落物种多样性研究

对牛背梁自然保护区的山麓农田-侧柏群落(群落Ⅰ),油松-华山松-锐齿栎群落(群落Ⅱ),油松-华山松-栓皮栎群落(群落Ⅲ),油松-华山松-辽东栎群落(群落Ⅳ),巴山冷杉-落叶松群落(群落Ⅴ),红桦-牛皮桦-巴山冷杉群落(群落Ⅵ)6种类型群落的高等植物及其针叶树小蠹虫的多样性等进行研究.结果表明:在山麓灌丛群落至针阔混交林群落之间,物种多样性指数、群落均匀度指数和物种丰富度呈递增趋势;在中山针阔混交林群落与巴山冷杉和落叶松群落、红桦-牛皮桦-巴山冷杉群落之间,物种多样性指数、群落均匀度指数和物种丰富度呈下降趋势.从总体来看,森林植被的多样性程度高于灌丛和草甸,阔叶林则高于针叶林.群落优势度指数的变化规律则与之相反.不同森林群落类型中针叶树小蠹虫的多样性、均匀度和优势度研究结果表明:针叶树小蠹虫群落物种多样性指数和均匀度由高到低的排列顺序依次为:群落Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ、Ⅰ;针叶树小蠹虫群落优势度的变化趋势与之相反.不同类型的森林植物群落中,针叶树小蠹虫群落结构及多样性存在明显差异.生态环境复杂,植被丰富的中山针阔混交林群落中,针叶树小蠹虫多样性和均匀度指数均较大,但优势度指数低,小蠹虫大发生的几率较小.加强管理,促进森林生态系统的多样性和稳定性,对提高植物群落自身调控害虫种群数量具有重要意义.     

Species composition of Modellidae and Cerambycidae (Coleoptera) in a coppice woodland

A continuous sampling of canopy beetles was carried out to determine variations in the abundance, species diversity, richness, and composition of the Mordellidae and Cerambycidae in a coppice woodland. Changes in the abundance and the species richness were monitored at three heights in the forest throughout the season in 1999, using yellow and blue water pan traps. The results showed significant variations in the abundance of Mordellidae among the canopy layers, while little variation was found for Cerambycidae. The abundance, species diversity, and richness were generally greater in summer. The results showed distinct species compositions in both families among layers.