A note on the mosquito oviposition pheromone

Mosquitoes of the genus Culex, e.g. Culex quinquefasciatus, release a volatile pheromone from their eggs that induces gravid females to oviposit around the pheromone source. Enantioselective synthesis by the Sharpless epoxidation method and chiral gas chromatography showed the major pheromone component to be (?)-(5R,6S)-6-acetoxy-5-hexadecanolide. Shortening the alkyl chain resulted in a loss of behavioural activity, whereas perfluorination of the alkyl chain or substitution of the acetoxy groups with the trifluoroacetoxy group gave active analogues. A simple large scale synthesis was devised to provide material for a fìeld trial. The pheromone, formulated in effervescent tablets, was used to concentrate oviposition in specific breeding sites where the larvae were controlled with a juvenoid-type insecticide.     

寄生蜂产卵引诱物的研究概述

寄生蜂是重要的害虫寄生性天敌,在害虫的生物防治中发挥着巨大作用。结合国际上的研究热点,对寄生蜂产卵引诱物从寄生蜂寻找寄主的3个阶段:栖境偏好、栖境定位、寄住定位等方面进行了阐述。     

Effects of sub-lethal and lethal doses of lambda-cyhalothrin on oviposition experience and host-searching behaviour of a parasitic wasp, Aphidius ervi

In many parasitoid species, the recognition of chemical signals is essential to find specific hosts. This function is often impaired by exposure to insecticides that are usually neurotoxic. The behaviour of the Hymenopterous parasitoid Aphidius ervi (Haliday) (Hymenoptera: Aphidiinae) after surviving low doses of the pyrethroid lambda-cyhalothrin was examined in laboratory conditions. The host aphid was Myzus persicae (Sulzer) (Homoptera: Aphididae) on oilseed rape. Parasitoid females were exposed by contact with dry residues of the active ingredient at a lethal dose, LD20, and a sub-lethal dose, LD0.1. In a four-armed olfactometer, untreated and inexperienced females were attracted by the odour of M. persicae-infested plants and previous oviposition experience increased the duration of the attraction response. The response of inexperienced females decreased after an exposure to LD0.1 but not to LD20. No effect was observed when females had an oviposition experience prior to the olfactometer test. The oviposition activity was significantly decreased in the LD20-treated group but not in the LD0.1-treated one. All effects disappeared within 24h. Our work shows that orientation and oviposition behaviours may be impaired by low doses of lambda-cyhalothrin, depending on the dose, the parasitoid experience and the type of behaviour.     

Inhibition of oviposition in the cattle tick Boophilus microplus by certain acaricides

Doses of ten acaricides, ranging from 2.5 to 10 μg, induced about 10-60% mortality and inhibited oviposition in engorged Boophilus microplus as well as preventing larval hatching from the eggs. The effects of the acaricides were dose dependent. The efficacy of acaricides in reducing the reproductive potential (inhibition of oviposition × inhibition of hatching/100) was in the following order: dimethoate > dioxathion > naled > diazinon > chlordimeform > carbaryl > trichlorphon > phosphamidon > gamma-HCH > fenitrothion. Most of the acaricides also retarded the oviposition cycle, delaying the peak activity by 4-8 days. The ovarian development in control ticks reached its peak between the 5th and 7th days before decreasing gradually and ceasing completely between the 16-20th days after engorgement. The protein content of the ovaries and the rate of incorporation of [¹⁴C]glycine into the tissues followed a similar pattern. Carbaryl, fenitrothion and naled inhibited these activities. Chlordimeform stimulated [¹⁴C]glycine incorporation and increased the ovarian protein content up to the 13th day before resorption of the oocytes. The eggs from treated ticks were mostly non-viable and contained more protein; those from dioxathion, carbaryl and chlordimeform treatments had a higher dry weight than the control.     

Semiochemical modulation of oviposition behaviour in the gregarious desert locust Schistocerca gregaria

Bioassays have shown that sand freshly contaminated by ovipositing females of the gregarious desert locust Schistocerca gregaria (Forskal) is more effective in inducing further oviposition from conspecifics than contaminated sand stored for three or six months, which contrasts with results obtained previously with Locusta migratoria (Reiche & Farmaire). The activity of contaminated sand correlated with the levels of three unsaturated aliphatic ketones, (Z)-6-octen-2-one, (E,E)-3,5-octadien-2-one and its geometric isomer (E,Z)-3,5-octadien-2-one present in the volatile emissions from the sand.     

黄色光对黏虫成虫产卵和寿命的影响

室内条件下研究黄色光源对黏虫成虫产卵和寿命的影响。结果表明,夜间施加黄色光照射能够使黏虫的产卵前期延长1.2d(P=0.002),产卵量减少27%(P=0.001),成虫寿命延长2.3d。可见,夜间施加黄色光照射对黏虫成虫的生物学习性有一定的影响。     

温度对智利小植绥螨发育和繁殖的影响

为了明确温度对智利小植绥螨发育和繁殖的影响,以二斑叶螨为食料,研究了16、19、22、25、28、31、34℃7个恒定温度下智利小植绥螨不同螨态的发育历期、成螨产卵动态及产卵量。结果表明,16~31℃范围内智利小植绥螨发育历期随温度的升高而缩短,34℃下发育历期较31℃有所延长。卵、幼螨、第一若螨、第二若螨、卵-成螨的发育起点温度分别为11.08、14.91、14.28、14.03和12.36℃,有效积温分别为29.69、4.94、8.96、11.72和58.33日·度。19~28℃下平均单雌产卵量较高,分别为93.60、86.90、94.25、88.95粒/头,31℃下产卵量最少,为39.25粒。16、19、22、25、28℃下平均产卵历期差异不显著,分别为20.10、22.55、19.10、19.10、21.10d,31℃下产卵历期仅为11.35d。智利小植绥螨在19~28℃下发育状态较好,繁殖力较高,说明该温度范围是智利小植绥螨生长发育和繁殖的适宜温度。     

Influence of feeding-damaged plants on the oviposition responses within a community of female moths

Competitive or facilitative interactions characterise phytophagous insect communities that utilise the same resources. These interactions are often mediated by the host plant. Plant mediation influences the oviposition choices that a community of insects, sharing the same host plant make. In this context, the oviposition choices of females within a community of lepidopteran cereal stemborers namely Busseola fusca, Sesamia calamistis and Chilo partellus were studied in plant choice-experiments under laboratory and field conditions. Gravid females of each species were presented with a choice between maize plants infested by conspecific or heterospecific larvae and uninfested maize plants. The number of eggs and egg batches laid on plants were used to quantify oviposition. Results showed that none of the three stemborer species avoided oviposition on infested maize plants. In some cases a significant preference for infested maize plants were observed. Similarly, data from field trials under natural stemborer infestation, with B. fusca as the only species, showed that the wild ovipositing moths were not avoiding infested plants. Host plant mediation may influence the incidence of multi-species infestations by stemborer species often found in the field. The potential roles of herbivore-induced and egg-deposited-induced plant volatiles in this mechanism are discussed.     

植物精油对荔枝蒂蛀虫的产卵驱避效果

在室内采用非选择性和选择性两种试验方法,测定了14种非寄主植物精油对荔枝蒂蛀虫的产卵驱避效果。结果表明,香紫苏油、肉桂油和香茅油对荔枝蒂蛀虫有很好的产卵驱避效果,其非选择性产卵驱避率(ODR_n)达90%以上;而选择性产卵驱避率(ODR_s)达80%以上。留兰香油对荔枝蒂蛀虫也有较好的产卵驱避效果,其ODR_n和ODR_s分别为89.19%和73.30%。     

半闭弯尾姬蜂羽化、交配及产卵行为观察

在22℃,相对度60%～70%的实验室条件下,研究了半闭弯尾姬蜂Diadegma semiclausum的羽化、交配与产卵行为。结果表明:半闭弯尾姬蜂蜂蛹从开始羽化到羽化结束历经4d,羽化高峰期出现在羽化的第3d,羽化数量为25头,占全部羽化数量的58.82%;第3d中羽化高峰出现在8:00～13:00,羽化数量为16.5头,占全天羽化数量的66.00%。半闭弯尾姬蜂交配过程大致分为3个阶段:准备阶段、交配阶段、结束阶段;交配后开始产卵,产卵过程大致分为寄主寻找和确定、穿刺和产卵、产卵结束和梳理。     

不同品种烟草对斜纹夜蛾生活史和产卵选择行为的影响

为探明不同品种烟草对斜纹夜蛾生活史和产卵选择行为的影响,随机选取了选育品种‘中烟100’和‘湘烟5号’,地方品种‘双管晒烟’和‘梁桥晒烟’,野生种‘八旦野生烟’和‘长花烟草’,测试斜纹夜蛾幼虫取食不同品种烟草后的生活史参数及成虫的产卵选择行为。结果表明,不同品种烟草对斜纹夜蛾的死亡率、发育历期、蛹重、蛹期、羽化率、成虫体重都有显著影响。按斜纹夜蛾的蛹重、羽化率和成虫干重从大到小对其所取食的烟草品种类型排序,依次为选育品种>地方品种>野生种;死亡率、蛹期和发育历期,从大到小依次为野生种>地方品种>选育品种。斜纹夜蛾对不同烟草品种的产卵选择偏好性存在差异,其中最偏好在选育品种上产卵,其次为地方品种,最不喜野生种。研究表明野生种烟草相对选育和地方品种而言对斜纹夜蛾抗性更高。     

黄翅绢野螟对不同植物的取食和产卵选择

为明确黄翅绢野螟Diaphania caesalis对不同植物的取食和产卵选择性, 采用叶碟法、叶面积法和室内观察等方法比较分析了黄翅绢野螟对波罗蜜(‘马来西亚1号’‘海大1号’‘四季波罗蜜’)、榴莲蜜、面包树、大果榕和桑树(‘台湾长果桑’‘粤椹大10’)的取食和产卵选择性, 取食面积及初孵幼虫取食不同植物后的存活率。结果表明, 黄翅绢野螟1～2龄幼虫对波罗蜜的取食偏好不明显, 对不同植物的取食选择率差异不大; 随着龄期的增长, 3～5龄幼虫逐渐表现出偏好取食波罗蜜。黄翅绢野螟在不同植物上的日均产卵量没有显著差异, 偏好在波罗蜜和面包树上产卵, 在‘马来西亚1号’波罗蜜上着卵量占所有供试植物上的总产卵量的22.13%。各龄幼虫对不同植物的取食量随着龄期的增加而逐渐增大, 5龄幼虫进入暴食期, 对3个波罗蜜品种、榴莲蜜、面包树和大果榕的取食量无显著差异, 但显著高于2个桑树品种。初孵幼虫取食不同植物48 h后的存活率存在显著差异, 取食‘马来西亚1号’波罗蜜存活率最高(98.51%), 取食‘台湾长果桑’存活率最低(0.37%)。综上, 黄翅绢野螟偏好选择波罗蜜属植物进行取食和产卵, 对榕属大果榕存在转移为害潜在威胁, 对桑属桑树潜在为害风险较低, 研究结果可为黄翅绢野螟在不同植物上的为害风险监测和防控提供参考。     

B型烟粉虱成虫对五种寄主植物的取食和产卵行为

为明确烟粉虱的寄主选择机制,利用刺吸电波技术(EPG)记录了B型烟粉虱在苘麻、棉花、黄瓜、甘蓝和烟草上的刺吸取食波型,并比较了烟粉虱在寄主植物上的产卵行为.研究结果表明,烟粉虱在5种寄主植物上的刺吸过程由A、B、C、E、G和np波组成,但取食不同植物的波型比例、频次及平均持续周期等指标有显著性差异.烟粉虱取食苘麻时,反映被动取食行为的E波比例和平均周期分别达83.8%和20.2min,明显高于其它寄主植物.总体上,B型烟粉虱取食5种寄主植物的适宜度为苘麻>黄瓜>棉花>烟草>甘蓝.烟粉虱在不同寄主植物上的产卵量随产卵时间延长而增加,但增加量明显低于接虫24 h的产卵量.烟粉虱对苘麻的产卵选择性显著高于棉花,但与黄瓜、甘蓝、烟草没有显著的差别.在本试验烟粉虱雌虫密度的范围内,各种寄主植物的产卵量与烟粉虱成虫密度成正相关,高密度下烟粉虱成虫在甘蓝和苘麻上的产卵量显著高于黄瓜、烟草和棉花.     

Further studies on the role of monoterpenes in pine host selection and oviposition ofThaumetopoea pityocampa

In a young mixed pine plantation (Pinus nigra andP. pinea) in central Italy, the influence of the pine needle monoterpenes (R)-(+)-limonene, (S)-(−)-limonene and (1S)-(−)-β-pinene on the oviposition activity of the pine processionary moth,Thaumetopoea pityocampa (Denis et Schiffermüller), was assessed. Two application methods were compared: spraying the trees with the substances emulsified with water, and setting up polyethylene dispensers from which the monoterpenes evaporated. During the moth’s flight period weekly treatments (at 500 mg of monoterpene /l water) were carried out and the evaporation from the polyethylene dispensers (each with 5 g of a single monoterpene) was checked on each occasion by weighing the dispensers. The GLM analysis did not uncover any difference between the methods of application or between the pine species.T. pityocampa laid a significantly (P=0.01) lower number of egg masses on the trees treated with (1S)-(−)-β-pinene than on those treated with the other substances and on the control trees. A ∼45% reduction in egg mass number was obtained on the pines treated with (1S)-(−)-β-pinene, independent of the level of infestation, method of application or pine species. (R)-(+)-limonene and (S)-(−)-limonene were not effective. http://www.phytoparasitica.org posting July 29, 2008.     

棉铃虫卵诱集植物选择试验

在新疆莎车县,对苘麻、玉米、鹰嘴豆、红花等植物对棉铃虫卵的诱集效果进行田间比较试验。结果表明:供试植物对第2代棉铃虫卵的诱集能力明显不同,累积卵量分别为:苘麻13 018粒、鹰嘴豆3 844粒、玉米2 316粒、红花160粒、棉花120粒。苘麻诱集能力最强,持续时间最长,不但可诱集第2代棉铃虫卵,而且可大量诱集第3代棉铃虫卵。     

几种染色剂对桔小实蝇产卵孔的染色效果

为寻找水果上桔小实蝇产卵情况的快速检测方法,本文测定了甲基蓝、龙胆紫、品红、曙红、藏红和刚果红等6种染色剂对水果上桔小实蝇Bactrocera dorsalis(Hendel)产卵孔的染色效果。结果表明染色剂对可疑水果进行染色,若有产卵孔,产卵孔可迅速被染色,染色率最高可达100%。筛选出甲基蓝、藏红和刚果红作为芒果、番石榴和夏橙的最适染色剂,各种染色剂在浓度为0.5%时染色效果较佳,同时对持续冷藏保存后的水果上的产卵孔仍然具有较高的染色率。