Effects of temperature and yeast supplementation on the development ofTribolium castaneum (Herbst) in wholemeal and polished flour derived from four cereals in Maiduguri, Nigeria

The effects of temperature, yeast and polishing (removal of bran) on the development ofTribolium castaneurn (Herbst) in flour derived from millet, sorghum, maize and wheat were investigated for one generation in Maiduguri, Nigeria. Significantly moreT. castaneurn adults and larvae developed in flour stored at 35 °C than in flour stored at 30 °C or 40 °C; mortality of adult beetles in flour stored at 40 °C was 95 % in sorghum and maize and 100 % in millet and wheat. Addition of three levels (2.5, 5.0 and 10.0 %, w/w) of yeast to cereal flour, on average, significantly increased the population of adult and larval progenies relative to the population in yeast-free flour. Considerably higher number of adult beetles developed in wholemeal than in polished flour derived from millet.     

Effects of temperature and yeast supplementation on the development ofTribolium castaneum (Herbst) in wholemeal and polished flour derived from four cereals in Maiduguri, Nigeria

The effects of temperature, yeast and polishing (removal of bran) on the development ofTribolium castaneurn (Herbst) in flour derived from millet, sorghum, maize and wheat were investigated for one generation in Maiduguri, Nigeria. Significantly moreT. castaneurn adults and larvae developed in flour stored at 35 °C than in flour stored at 30 °C or 40 °C; mortality of adult beetles in flour stored at 40 °C was 95 % in sorghum and maize and 100 % in millet and wheat. Addition of three levels (2.5, 5.0 and 10.0 %, w/w) of yeast to cereal flour, on average, significantly increased the population of adult and larval progenies relative to the population in yeast-free flour. Considerably higher number of adult beetles developed in wholemeal than in polished flour derived from millet.     

Metabolism of a synthetic insect juvenile hormone (JH-I) during the development of Tribolium castaneum (herbst) (coleoptera,tenebrionidae)

Metabolites produced from ¹⁴C-labelled C-18 juvenile hormone (JH-I) topically applied to the flour beetle Tribolium castaneum were measured in larvae aged 21 and 28 days, pupae at four stages of development, and newly emerged and mature adults. The hormone was metabolized rapidly, in all stages examined, to form the corresponding diol-ester, acid-epoxide, and acid-diol derivatives, the diol-ester derivative being the major metabolite produced. The metabolism of JH-I was most rapid at the times of the larval/pupal and pupal/adult transformations. The differences in the rate of metabolism appeared to be correlated with changes in the production of the diol-ester derivative. Similar metabolic changes may regulate the levels of endogenous juvenile hormones during development in this species.     

The activity of some compounds extracts byAllium on stored-product insectsOryzaephilus surinamensis (L.),Sitophilus oryzae (L.) andTribolium castaneum (Herbst)

The bioactive metabolites of someAllium plants, all exhibiting interesting pharmacological activities, were tested for their attractive/repellent activity against saw-toothed grain beetle,Oryzaephilus surinamensis (L.), rice weevil,Sitophilus oryzae (L.), and rust-red flour beetle,Tribolium castaneum (Herbst), insects infesting the stored-products. The data obtained showed significant repellent effect of the thiosulfinates againstS. oryzae.     

The activity of some compounds extracts byAllium on stored-product insectsOryzaephilus surinamensis (L.),Sitophilus oryzae (L.) andTribolium castaneum (Herbst)

The bioactive metabolites of someAllium plants, all exhibiting interesting pharmacological activities, were tested for their attractive/repellent activity against saw-toothed grain beetle,Oryzaephilus surinamensis (L.), rice weevil,Sitophilus oryzae (L.), and rust-red flour beetle,Tribolium castaneum (Herbst), insects infesting the stored-products. The data obtained showed significant repellent effect of the thiosulfinates againstS. oryzae. Part 6 in the series “Chemistry of the genus Allium”.     

诱捕器类型、颜色及诱芯颜色对大豆食心虫引诱效果的影响

采用标准诱芯及合成化合物组配诱芯,比较了诱捕器的类型、颜色及诱芯颜色对大豆食心虫诱捕效果的影响。结果表明:粘胶板式(三角形、船形)和水盆式2种诱捕器类型及红色、深绿色、浅绿色、紫色、白色、黄色、棕色、蓝色8种三角板诱捕器颜色均对引诱活性无显著影响,而不同颜色诱芯对大豆食心虫的引诱效果影响较大,其中绿色诱芯引诱效果较好,显著优于蓝色、红色、灰色及橘色诱芯。因此,在田间应用时,建议优先选用绿色诱芯,并根据实际情况灵活选用不同类型的诱捕器。     

不同诱捕器和不同波段LED灯对美国白蛾的引诱效果

为提高现有诱捕器及灯光诱捕对美国白蛾Hyphantria cunea(Drury)的诱捕效果,本研究对目前应用的6种美国白蛾诱捕器进行筛选,以明确对美国白蛾诱捕效果最佳的诱捕器及LED波段;同时对美国白蛾日节律进行了观察。结果显示,桶形诱捕器对美国白蛾的诱捕效果最好,平均每个7.1头,显著高于其他诱捕器;灯光诱捕美国白蛾成虫效果最好的波段为360～365 nm;性信息素协同360～365 nm LED灯的诱捕效果显著高于其他两组;美国白蛾昼伏夜出的特性明显,试验结果表明该虫在凌晨02:00-04:00和晚上18:00-20:00的活跃度最高。本研究为性信息素诱捕器及LED灯在不同时间段进行美国白蛾监测与防治提供了技术支撑。     

Treatment of rice with diatomaceous earth and effects on the mortality of the Red flour beetle Tribolium castaneum (Herbst)

Diatomaceous earth has been demonstrated in Australia, Germany, and the USA to protect stored products from infestation by insect pests. However, application of diatomaceous earth has rarely been used in Asian countries for the protection of stored grain from insect damage. These facts and the paucity of existing data from the tropics prompted the present study of storage with diatomaceous earth. We exposed rice treated with the diatomaceous earth product Fossil Shield® to infestation by Tribolium castaneum Herbst. During the dry season, when tests were conducted, the mean temperature was 29±2°C and relative humidity was 80±3%. The population of T. castaneum in rice was significantly reduced after treatment with Fossil Shield®. Diatomaceous earth at 1g and 2g per kilogram rice reduced population growth of T. castaneum to a coefficient of 0.27, and 0.02 respectively after 42 days. Fossil Shield® at 0.5g per kilogram rice increased the mortality of T. castaneum, but did not stop population growth.     

Effects of moon phases and of various trap colors on the capture ofprays citri males in sticky traps

Field experiments with sticky traps baited with live females showed that significantly latger numbers ofP. citri males were captured during full-moon than during new- or old-moon phases. Significantly smaller numbers ofPrays citri males were captured in white sticky traps than in black, green, red, yellow or blue ones, placed during day and night in citrus groves in various areas of the country; no significant differences were noted between any of the colored traps.     

转PCD基因棉花对棉田主要病害、虫害及天敌的影响

<正>目前,利用转基因技术获得抗病品种,成为解决棉花黄萎病暴发危害的最具前景的途径之一(朱荷琴等,2011)。随着转基因抗病棉花的推广,其安全性评价已成为亟待解决的问题。中国农业科学院棉花研究所转基因课题组将细胞程序化死亡(programmed cell death,PCD)相关基因导入棉花,获得     

Gamma radiation sensitivity of larvae and adults of the red flour beetle, Tribolium castaneum Herbst

In this study, the susceptibility of larvae and adults of Tribolium castaneum (Herbst) to gamma radiation was investigated in the laboratory in Turkey. Gamma radiation was applied at 6 dose levels between 20 and 200Gy to 13–15day-old adults and at 5 dose levels between 20 and 180Gy to 18–20day-old larvae of T. castaneum. All experiments were performed in growth chambers maintained at 27±1°C and 70±5% r.h. The larvae proved to be the more susceptible stage, survival to the adult stage being prevented by exposure of the eggs to 100Gy; the adult stage was less susceptible. LD₅₀ and LD₉₉ values were determined as 19,75 and 42,97Gy for larvae and 33,21 and 64,50Gy for adult stage, respectively. It was concluded that 100Gy is the effective dose for both larval and adult stages.     

小麦中黄酮类化合物对麦长管蚜生长发育的影响

采用细SephadexLH-20葡聚糖凝胶柱从小麦叶片提取液中分离纯化得到两种黄酮类化合物，经核磁共振和紫外分光光度计吸收光谱等分析技术，鉴定出其结构为异荭草甙和异荭草甙-7-O-阿拉伯糖—葡萄糖苷。将不同浓度的两种黄酮类化合物加入麦长管蚜全纯人工饲料中饲养麦长管蚜，结果表明，分离得到的两种黄酮类化合物对麦长管蚜的生长、发育和繁殖均有明显的抑制作用。其中异荭草甙对该蚜有明显的抗生性，其抗性阈值浓度为0．02％左右。     

Characterization of fungi (Fusarium and Rhizoctonia) and oomycetes (Phytophthora and Pythium) associated with apple orchards in South Africa

Several species of fungi and oomycetes including Fusarium, Rhizoctonia, Phytophthora and Pythium have been reported as root pathogens of apple where they contribute to a phenomenon known as apple replant disease. In South Africa, little is known about specific species in these genera and their pathogenicity toward apple. Therefore, these aspects were investigated along with the development and optimization of qPCR tests for detection and quantification of the most virulent oomycete species. In eight investigated orchards, the oomycete Phythophthora cactorum was widely distributed, while nine Pythium species were differentially distributed among the orchards. Pythium irregulare was the most widely distributed and the most virulent species along with P. sylvaticum, P. vexans and Ph. cactorum. Seven binucleate Rhizoctonia anastomosis groups (AGs) were also differentially distributed among the orchards, with the majority appearing to be non-pathogenic while certain AG-I and AG-F isolates exhibited low virulence on apple. In the genus Fusarium, F. oxysporum was widely distributed, but isolates were non-pathogenic. Fusarium solani and F. avenaceum were less frequently encountered, with only some isolates having low virulence. qPCR data obtained from seedling roots inoculated with the most virulent Pythium species (P. irregulare, P. sylvaticum and P. vexans) and the genus Phytophthora were not always reproducible between trials, or isolates of the same species. In general, seedling growth inhibition was associated with the presence of a low amount of pathogen DNA (±40 fg μl⁻¹ to 2 pg μl⁻¹) in roots. Pythium irregulare, although having the lowest DNA concentrations in roots, was the only species for which a significant negative correlation was found between seedling weight and pathogen DNA concentration.     

桃小食心虫的危害及其防治研究进展

桃小食心虫是我国最严重的蛀果害虫之一,利用其性信息素进行防控,具有高效、环保及不易产生抗性等优点。天然桃小食心虫性信息素 (Z)-12-十九碳烯-9-酮与(Z)-13-二十碳烯-10-酮在昆虫体内含量极低,通过人工提取无法满足大规模防治需求。本研究以3-溴-1-丙醇为原料,经四氢吡喃基 (THP) 保护、亲核取代、Brown P2-Ni还原 (Ni(OAc)₂与NaBH₄催化氢化) 、格氏试剂加成与重铬酸吡啶鎓 (PDC) 氧化等7步反应,构建了一种高效合成桃小食心虫性信息素的方法;并首次将Brown P2-Ni还原用于桃小食心虫性信息素顺式碳碳双键的构建,总收率为5%。所构建的桃小食心虫性信息素合成方法操作简便,产品具有高度的区域选择性 (Z:E > 99:1),适用于桃小食心虫的绿色防控。

     

Effects of pyrethroids and endosulfan on fluidity of mitochondria membrane in Chilo suppressalis (Walker)

The effects of pyrethroids and endosulfan on fluidity of mitochondrial membranes from Chilo suppressalis were investigated at different temperatures by steady-state fluorescence polarization using 1,6-diphenyl-1,3,5-hexatriene (DPH) molecule as probe. The results showed that changes in DPH polarization caused by the pyrethroids tested were more at lower temperature than at higher temperature, which showed a negative temperature coefficient of the pyrethroids. On the contrary, change in DPH polarization caused by endosulfan was more at higher temperature than at lower temperature. Endosulfan displayed a positive temperature coefficient. Moreover, these effects of pyrethroids and endosulfan on changes of DPH polarization were dose-dependent in mitochondrial membranes of C. suppressalis. DPH polarization value increased in the mitochondrial membranes treated by all concentrations of pyrethroids and decreased by endosulfan, and changes caused by pyrethroids were more pronounced than by endosulfan.     

Effect of height of pheromone trap on the capture ofSpodoptera litura moths in tobacco nurseries

Experiments conducted during 1981/82 and 1983/84 in a tobacco nursery showed that the male moth catch ofSpodoptera litura F. was significantly higher in pheromone traps 2.0 m above ground level, than at lower or higher elevations.