Composition and toxic, repellent and feeding deterrent activity of essential oils against the stored-grain pests Tribolium castaneum (Coleoptera: Tenebrionidae) and Sitophilus oryzae (Coleoptera: Curculionidae)

BACKGROUND: The composition and bioactivity of essential oils from Tagetes terniflora Kunth, Cymbopogon citratus Stapf. and Elyonurus muticus (Spreng) Kuntz were evaluated against stored‐grain pests. RESULTS: Fumigant and contact toxicities were observed with T. terniflora on adults of both pests. In contact toxicity, this oil was less toxic to Tribolium castaneum (Herbst). Essential oils from C. citratus and E. muticus showed contact toxicity on S. oryzae. All essential oils produced: (a) repellency on larvae and adults of T. castaneum and adults of Sitophilus oryzae (L.); (b) post‐ingestive toxicity on T. castaneum larvae and S. oryzae adults and alteration of nutritional index on T. castaneum and S. oryzae adults. Cymbopogon citratus reduced the relative growth rate and the efficiency of conversion of ingested food in T. castaneum larvae. Tagetes terniflora produced a feeding stimulant effect in T. castaneum adults. In addition, they had a feeding deterrent action against S. oryzae adults. The composition of essential oils from C. citratus and E. muticus varied only in one component. CONCLUSION: These results showed that the essential oils from T. terniflora, C. citratus and E. muticus should be studied further for their use in integrated pest management programmes for T. castaneum and S. oryzae control. Copyright © 2011 Society of Chemical Industry     

赤拟谷盗生活史参数变化的研究

对取自河南省安阳、郑州、吉林省四平和澳大利亚昆士兰州的４个赤拟谷盗 品系的生活史参数进行了研究．发现各品系的生活史参数存在很大的差异,其种群动态 变化也不同,同时认为：这些差异对实际的储粮害虫综合治理技术的实施有一定影响。     

水菖蒲活性物质β-细辛醚对赤拟谷盗的熏蒸作用

为了确定水菖蒲活性成分β-细辛醚对赤拟谷盗的熏蒸效果,采用密封熏蒸方法测定了β-细辛醚对赤拟谷盗幼虫、蛹和成虫的熏蒸作用.结果表明:β-细辛醚对赤拟谷盗3种虫态均有一定的熏蒸作用,且对赤拟谷盗低龄幼虫的熏蒸效果要比高龄幼虫明显;当β-细辛醚熏蒸浓度为200μL/L时,熏蒸48 h后蛹的校正死亡率为34.32%;β-细辛醚对赤拟谷盗成虫熏蒸120 h后的LC50为116.48μL/L.     

赤拟谷盗和杂拟谷盗体内Wolbachia的感染状况和种间传播

为明确沃尔巴克氏体(Wolbachia)在赤拟谷盗和杂拟谷盗体内的感染状况及种间水平和垂直传播情况,首先通过PCR扩增分离细胞分裂蛋白基因(fts Z)目的片段方法检测这2个近缘种拟谷盗体内是否存在Wolbachia,并将同性别或异性别的赤拟谷盗和杂拟谷盗混合饲养40 d,然后测定赤拟谷盗及其与杂拟谷盗的正反交杂种后代体内Wolbachia的感染状况。结果显示,杂拟谷盗体内存在Wolbachia,而赤拟谷盗体内不存在该菌;混合饲养后,赤拟谷盗及其与杂拟谷盗的正反杂交后代体内也均没有检测到Wolbachia的存在,未发现Wolbachia在杂拟谷盗和赤拟谷盗种间的水平和垂直传播。     

动物杂种优势两种预测方法的实验验证

本文报道的试验用实验昆虫赤拟谷盗 WT,WU,PY 和 R4个品系按 Griffing 模型Ⅰ进行完全双列杂交,验证以遗传距离和配和力效应预测蛹重、后代数杂种优势的效果。对蛹重预测排序相关两种方法均在0.5左右,对后代数预测排序相关,用遗传距离很低。     

不同光波长与光强度对赤拟谷盗趋光性影响的初步研究

研究以20nm为单位测试赤拟谷盗在300nm~800nm单色光波下的趋光性以及在固定波长下对不同光强度的反应,并设置了无光源条件下的空白处理(CK)作对照,计算趋光值。结果表明,赤拟谷盗对不同波长的光波有不同程度的趋光反应,对不同光强度的光波也有不同的反应。光波在500nm、光强度0.05Lux时赤拟谷盗对光的趋性最明显。     

Toxicity and protectant potential of Piper guineense (Piperaceae) and Senna siamea (Fabaceae) mixed with diatomaceous earth for the management of three major stored product beetle pests

There is a dearth of knowledge on the available sources of botanical products for smallholder farmers in Africa and their bioactivity against stored-product pests. Many locally available plants across Africa exhibit both promising insecticidal, medicinal activity and are nutrient rich yet remain underutilized. Laboratory studies on toxicity of powders of Senna siamea and Piper guineense alone or combined with diatomaceous earth (DE) to adult Sitophilus granarius, Tribolium castaneum and Acanthoscelides obtectus were conducted in stored grains. Adult mortality was observed up to 7 d while progeny production was recorded 6–10 weeks. Adult A. obtectus were most susceptible (LD₅₀ 0.0084% and 0.0696% wt/wt for S. siamea and P. guineense, respectively), followed by S. granarius. T. castaneum was most tolerant (LD₅₀ 0.6589% and 0.6829% wt/wt for S. siamea and P. guineense, respectively). Combination of plant powders and DE controlled the beetles faster compared to the plant powders alone. LT₅₀ ranged from 20 h to 101 h for T. castaneum exposed to 1.0% S. siamea and 1.0% DE, and 0.5% P. guineense and 1.0% DE, respectively. Botanicals caused significant reduction of F₁ adults compared to the control. The potential of using botanicals combined with DE to control stored-product insects is discussed.     

不同磷化氢抗性的赤拟谷盗亚致死浓度下生长发育比较

在室温30℃±2℃、相对湿度75％±50环境中研究了对磷化氢抗性和敏感的赤拟谷盗3个品系在磷化氢亚致死浓度下卵、幼虫和蛹的发育与死亡情况,3个赤拟谷盗品系对磷化氢的抗性系数分别为R1=1、R170=170和R247=247,研究中设定的磷化氢亚致死浓度分别为0mg／L、0．0028mg／L和0．014mg／L。主要结果为：磷化氢亚致死浓度下赤拟谷盗抗性和敏感品系的发育历期延长;亚致死浓度磷化氢熏蒸下,3个品系间幼虫发育速率差异不明显,但抗性品系卵期和蛹期的发育速率增加较敏感品系显著。在亚致死浓度下,赤拟谷盗敏感品系的卵、幼虫和蛹的死亡率增加都明显高于抗性害虫,抗性品系的存活能力明显大于敏感害虫。