阿维菌素对广赤眼蜂(Trichogramma evanescens)不同发育阶段的毒性和实验种群动态的影响

研究了阿维菌素对广赤眼蜂不同发育阶段的毒性和实验种群动态的影响。结果表明,阿维菌素田间推荐剂量喷雾处理可显著降低米蛾卵内广赤眼蜂的羽化率;除卵期外,其它3种发育阶段经该药处理,羽化后的雌蜂寿命显著缩短,其中预蛹和蛹期处理雌蜂前翅畸形率高达43.3%～47.2%,影响程度随着其生长发育的进行呈增大趋势。根据药膜法剂量与效应测定结果,广赤眼蜂成蜂对阿维菌素比较敏感,LC50值为2.1991mg·L-1。温室盆栽试验表明,1.8%阿维菌素乳油对广赤眼蜂成蜂的持效期为10d,具有一定程度的残留毒性。广赤眼蜂的蛹经阿维菌素亚致死剂量LC35处理后,发育至成蜂,除羽化后的雌蜂产卵量显著减少外,雌蜂寿命、子代羽化率和子代性比与对照并无显著差异。生命表参数显示,LC35处理后的广赤眼蜂净增值率和世代平均历期明显地低于对照,但内禀增长率、周限增长率和种群倍增时间与对照差异不明显。可以认为阿维菌素亚致死剂量对广赤眼蜂的种群没有重要影响。

玉米螟赤眼蜂(Trichogramma ostriniae)寄主标记信息素和学习经历对产卵行为的影响

报道了标记信息素和雌蜂经历对玉米螟赤眼蜂Trichogramma ostriniae产卵行为的影响。研究结果表明,玉米螟赤眼蜂的寄主标记信息素是在其产卵过程中的收场阶段由产卵器产生的,并且标记在寄主卵表的化学物质;玉米螟赤眼蜂对标记信息素的识别不具有先天性,其必须先用产卵器插入寄生卵来检测是否被寄生,然后其触角不停地敲击,通过学习获得对标记信息素的识别能力,从而放弃了对寄生卵的选择,学习对初始放弃时间有着重要影响,改善了其对寄主搜索效率,这种学习行为是与寄主联系在一起学习的,它能根据寄主被寄生与否而对标记信息素作出反应与不反应。该研究丰富了生态学理论,为其在生防中更好的应用提供了科学依据。

Infection of Wolbachia in Trichogramma cacoeciae

Wolbachia is a symbiotic bacterium that alters reproductive behavior of numerous arthropods. It is the most advanced way to study phytogeny and classification based on sequences of the wsp gene. The presence of Wolbachia in a lab strain of the thelytokous Trichogramma cacoeciae was firstly identified based on amplification and sequencing part of the wsp gene. Aligned the resulting sequence with the published ones, the phylogenetic relationships among Wolbachia which was found in T. cacoeciae, T. dendrolimi and other insects were established. The Wolbachia that found in T. cacoeciae and in T. dendrolimi belong to the Kue group and the Pip group, respectively.

Olfactory Response of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) to Volatiles Emitted by Mungbean Plants

Intercropping maize with the prostrate variety of mungbean, Vigna radiata （L.） Wilczek which grows flat along the ground can increase parasitism of the eggs of the Asian corn borer, Ostrinia furnacalis （Guenée）, a crucial insect pest of maize in China, by Trichogramma ostriniae Pang Chen. This study investigated the behavioural responses of T. ostriniae to plant volatiles emitted from whole plants, leaves, and flowers of prostrate and erect varieties of mungbean in a 4-armed olfactometer. Female parasitiods were significantly attracted to the odours from some varieties of prostrate mungbean when the visit duration and the number of visits were considered, but were not attracted to the odours from any erect varieties. The attractive odours were shown to emanate from the leaves, rather than from the flowers of prostrate mungbean plants. These results have implications for the augmentation of Trichogramma parasitoids in bio-control of O. furnacalis and other crop pests.

The Utility of Specific Markers Based on ITS2 Sequences for Molecular Identification and Detection of Trichogramma spp.

The technology based on specific PCR amplification using internal transcribed spacer 2 of nuclear ribosomal DNA for molecular identification and detection of Trichogramma species was studied. Firstly the ITS2s of six Trichogramma species were cloned and sequenced, and the interspecific sequence variation was analyzed. Secondly the ITS2 regions of six geographical populations of T. dendrolimi were cloned and sequenced, and the intraspecific sequence identity was analyzed. The results show that the interspecific variation and intraspecific similarity of ITS2 sequences are very suitable for designation of specific primers at species-level. Screening of specific primers for T. dendrolimi leads to final sensitive and stable diagnostic primers. This system lets non-specialists can not only identify adults (males and females), but also identify eggs in parasitized hosts rapidly and accurately, which is impossible by conventional methods. Further development of this protocol can create a complete set of specific primers for different species of the whole genus Trichogramma .

Determination and evaluation on field control efficacy of Trichogramma dendrolimi against Ostrinia furnacalis

The results of evaluation on field control efficacy of Trichogramma dendrolimi against Ostrinia furnacalis showed that the correction rates of Ostrinia furnacalis egg mass parasitism were 71.75% and 73.57%,the average control effect were 65.85% and 70.24%,the restoration yield loss rates were 6.78% and 7.97%,input-output ratio at 1:27.8 and 1:33.5 in Longjiang county of Heilongjiang province in 2009 and 2010,respectively.The technology is a integration of advanced,practical,environmental safety,effective biocontrol measures,embodies the "public plant protection,green plant protection" fully,has significant economic,social and ecological benefits.

用麦蛾卵大量繁殖甘蓝夜蛾赤眼蜂(Trichogramma brassicae)

在2000年建成的麦蛾生产线基础上,经多次试验后完成了具有日生产赤眼蜂200万头生产能力的繁蜂设备,2001年最高日繁蜂量120万头。通过改进生产工艺和设备,扩大规模,提高繁蜂效率,日繁甘蓝夜蛾赤眼蜂1100万头,生产能力提高了5.5倍。生产成本比原来降低了47.3％。

Effect of Insecticides on <i>Trichogramma</i>Parasitoids Used in Biological Control against <i>Prays oleae</i>Insect Pest

This study investigated the direct effect of the insecticides deltamethrin and spinosad on three egg parasitoids species: Trichogramma oleae, T. cacoeciae and T. bourarachae. The parasitoid pupae were exposed to pesticide residues on fresh olive tree leaves at recommended concentrations (RC) at different time intervals: 3, 10, 17, 24 and 31 days after pesticide applications. Parasitism viability (% emergence from parasitized eggs) and adult emergence time (developmental time from pupa to adult emergence) were evaluated. Regarding to the International Organization of Biological Control (IOBC) guidelines, results of toxicity effects of insecticides show that: Deltamethrin was moderately harmful to all Trichogramma species at RC (Decis&reg;100 milliliters·ha&minus;1), however, spinosad was harmless to moderately harmful at RC (Tracer&reg;20 milliliters·ha&minus;1). Trichogramma species revealed differences with regard to adult emergence time and exhibited significant changes in parasitism viability with increasing time after pesticide treatment. While deltamethrin residues affected parasitism viability 31 days after the product application, spinosad displayed similar viability for almost species 24 days after the application. The usefulness of Trichogramma parasitoids used as biological control agents, in olive tree ecosystem, was discussed in integrated pest management programs for Prays oleae control when parasitoid species were exposed during pupal stage to the insecticide residue.

赤眼蜂Trichogramma sp.nr.mwanzai的寄主嗜好性试验研究

采用选择性试验与非选择性试验两种方法,对肯尼亚的一种新记录的赤眼蜂Trichogramma sp.nr. mwanzai作了寄主嗜好性的初步观察研究。结果表明:该蜂对玉米禾螟、Busseola fusca和Eldana succhrina的卵均能寄生,但最喜欢玉米禾螟的卵。对家蚕卵不能寄生。在自然条件下也不能寄生Busseola fusoa产在叶鞘下的卵。在非选择性试验中,该蜂在玉米禾螟卵和粉螟卵上的单雌产子数与子代蜂雌雄性比差异均不显著。

Assessment of Two <i>Trichogramma</i>Species with <i>Bacillus thuringiensis</i>var. krustaki for the Control of the Tomato Leafminer <i>Tuta absoluta</i>Meyrick (Lepidoptera: Gelechiidae) in Iran

In this study, we investigated the efficiency of T. brassicae and T. embryophagum in combination with bacterial suspension of B. thuringiensis against the tomato leafminer T. absoluta eggs in cage inside greenhouse (semi field) experiments. Four treatments were used (T. brassicae or T. embryophagum + T. absoluta) (T1), (B. thuringiensis + T. absoluta) (T2), (T. brassicae or T. embryophagum + B. thuringiensis + T. absoluta) (T3) and control (T4). The lowest number of T. absoluta mines (6.1, 0.5 mine per plant) were recorded in T3 for T. brassicae and T. embryophagum were significantly lower than those of all other treatments which were followed by T1 and T2, while the highest number of mines per plant (50.70) were recorded in control (T4). In addition, the parasitism rate, adults’ emergence, the number of females and adult longevity of two parasitoids were investigated. According to the obtained results, the highest parasitism rate was obtained for T. embryophagum when treated with Bt reared in the T. absoluta eggs (31.18%). However, no significant differences were detected between T. brassicae and T. embryophagum in mortality and adult emergence rates were found when they were treated with/ without Bt reared in the T. absoluta eggs in cage inside greenhouse. Also, the longevity of T. embryophagum was significantly better than T. brassicae p = 0.000. This is the first study to investigate T. embryophagum in cage inside greenhouse for parasitizing the eggs of T. absoluta and results of present study suggested that T. embryophagum with Bt could be more efficient for biocontrol of T. absoluta.

禾螟赤眼蜂Trichogramma sp.nr.mwanzai实验种群生命表

1986～1989年在国际昆虫生理生态中心的研究表明,在肯尼亚和非洲,禾螟赤眼蜂是目前记录的Chilopartellus卵的唯一的优势种寄生蜂。作者在室内研究该寄生蜂的实验种群生命表,结果表明,在35、30、25、20和15℃恒温条件下,该蜂的净生殖率R_0值依次为25.1、31.9、35.9、7.3和0; 内禀增长率rm值依次为0.4603、0.4075、0.3337、0.1101和0。在30℃和35℃时较高的R_0和r_m值表示该蜂对高温的适应性,这一特性与田间自然种群研究结果一致。对世界上某些赤眼蜂的r_m值,与本试验结果进行了比较,初步认为,肯尼亚本地产的禾螟赤眼蜂是目前最有希望的可用于Chilo partellus生物防治的优势寄生蜂。

松毛虫赤眼蜂(Trichogramma dendrolimi)几个种群间繁殖性状的杂交效果分析

应用完全双列杂交设计,对松毛虫赤眼蜂几个种群间繁殖性状的杂交效果进行了研究。通过杂种优势率的统计检验及亲本一般配合力、特殊配合力的分析,得出10个杂交组合中的最优组合为JNYT11×LT,JNYT11×XT。

Quality assessment of local Trichogramma species (Hymenoptera, Tri- chogrammatidae) to control the olive moth Prays oleae Bern. (Lepidop- tera, Yponomeutidae)

Assessment of quality of biological control agents is an important step for the success of any biocontrol program.Experiments were carried out to select candidate Trichogramma species for use in biological control of the olive moth Prays oleae Bern(Lepidoptera,Yponomeutidae).Thirteen local strains were preselected on the basis of the geographical origin and the availability from mass production of the rearing host Ephestia kuehniella ZELL.(Lepidoptera,Pyralidae) under laboratory conditions.Selection tests were focusing on acceptance and preference for P.oleae eggs.In the acceptance test,a single parasitoid female was offered P.oleae eggs on "tricho-card" for 6 hours at 25°C,70% HR and L16:D9 and assessed for parasitism after 6 days.The preference was determined by offering the choice and observing contacts with eggs of the target pest P.oleae and eggs of the host E.kuehniella.Parasitism was therefore assessed 6 days after the experiment under similar laboratory conditions.In host acceptance test,most eggs of P.oleae were parasited by strains belonging to the species T.oleae,T.bourarachae and T.cacoeciae.These strains also showed a high number of contacts with olive moth eggs in preference tests.However,a small number of T.bourarachae observed ovipositions resulted in successful parasitism.Therefore,T.oleae and T.cacoeciae were selected as candidates for further experiments.

松毛虫赤眼蜂Trichogramma dendrolimi个体发育的组织化学研究

用组织化学方法研究松毛虫赤眼蜂个体发育,在卵子时期,内部物质已有所分化,RNA 呈区域性分布,与卵子早期发育前途有关。在其胚胎发育过程中有胚外膜形成,胚盘中央的一些小颗粒是退化的消黄细胞核。幼虫阶段没有马氏管,其排泄器官为一位于中、后肠之间由八个大细胞组成的结构。马氏管芽出现于预蛹期,随后幼虫排泄器官溶解消失。幼虫阶段,碱性磷酸酶、酸性磷酸酶及脂酶主要分布于中肠、唾腺和排泄器官。蛹期以后,两种磷酸酶分布于生长中的器官芽和神经系统,酯酶分布于肠、脂肪体、卵巢和输卵管。用人工模拟卵培养的赤眼蜂和用自然寄主卵培养的同种赤眼蜂在组织化学方面未发现显著差异。

The potential of trehalose to replace insect hemolymph in artificial media for Trichogramma dendrolimi （Hymenoptera： Trichogrammatidae）

Insect additives have been shown to improve the value of artificial media for Trichogramma species, but at the same time maintain dependence on parallel cultures of host insects. In the present study, Trichogramma dendrolimi Matsumura was reared in vitro from egg to adult on artificial media with different contents of pupal hemolymph of Chinese oak silkmoth Antheraea pernyi （Guérin-Méneville） and with supplements of distilled water, or of trehalose dissolved in water or in Grace＇s insect medium. The results indicated insect hemolymph was the key component of artificial medium. Developmental parameters, including rates of parasitism, pupation, adult emergence and normal adults, and numbers of produced adults, were increased on media supplemented with trehalose even when the proportion of pupal hemolymph was reduced. Two artificial media, the first containing 30% hemolymph and 10% trehalose in water with 98.9% parasitism rate, 77.7.0% pupation rate, 77.2% emergence rate, 80.0% normal adult rate and 333 produced adults, and the second containing 25% hemolymph and 15% trehalose in Grace＇s insect medium with 97.8% parasitism rate, 91.0% pupation rate, 85.2% emergence rate, 76.1% normal adult rate and 757 produced adults, were believed to hold potential to mass produce T. dendrolimi. The use of trehalose to partially replace pupal hemolymph in artificial medium of this and other Trichogramma species may contribute to a significant reduction in their production cost and may as such help to evade problems related to short supplies of lepidopteran eggs, which currently constitute the main factitious host for the mass rearing of the parasitoids.

3种杀螨剂对松毛虫赤眼蜂和七星瓢虫的毒性风险评估

为明确30%乙螨唑悬浮剂、23%阿维菌素·乙螨唑悬浮剂和15%乙螨唑·唑螨酯悬浮剂等3种杀螨剂对松毛虫赤眼蜂和七星瓢虫的急性毒性效应和初级风险,采用试管药膜法分别测定了3种杀螨剂对松毛虫赤眼蜂和七星瓢虫的急性毒性,并预测杀螨剂在农田内外的暴露量,表征毒性风险。结果表明:3种杀螨剂对松毛虫赤眼蜂急性接触毒性LR50为0.255~63.400 g a.i./hm^(2);对七星瓢虫的急性接触毒性LR_(50-48 h)和LR_(50-16 d)分别为9.30~21.70 g a.i./hm^(2)和3.72~8.36 g a.i./hm^(2)。30%乙螨唑悬浮剂和15%乙螨唑·唑螨酯悬浮剂在农田内外对松毛虫寄生蜂的危害商值HQ均小于5,风险可接受;23%阿维菌素·乙螨唑悬浮剂在农田内外对松毛虫寄生蜂的危害商值HQ均大于5,风险不可接受;30%乙螨唑悬浮剂和23%阿维菌素·乙螨唑悬浮剂对七星瓢虫的农田内危害商值HQ均大于5,风险不可接受;15%乙螨唑·唑螨酯悬浮剂对七星瓢虫的农田内危害商值HQ均小于5,风险可接受;3种杀螨剂对七星瓢虫的农田外危害商值HQ均小于5,风险可接受。综之,2种复配杀螨剂相比单剂的毒性增大,30%乙螨唑悬浮剂和23%阿维菌素·乙螨唑悬浮剂对非靶标节肢动物的风险均不可接受,农药施用时需采用一些风险降低措施来减轻对松毛虫赤眼蜂和七星瓢虫的风险。

Quality control of the parasitoid wasp Trichogramma brassicae (Hymenoptera: Trichogrammatidae) over 45 generations of rearing on Sitotroga cerealella

Trichogramma brassicae(Bezdenko)is an important biological control agent that has been used widely against many lepidopteran pests.Commonly,colonies of Trichogramma are mass reared on factitious hosts such as Sitotroga cerealella(Olivier)over many generations.In this study,we evaluated the quality and performance of a colony of T.brassicae that had been reared for over 45 generations(G)using two-sex life table parameters and parasitism capacity.We found that female adult longevity was significantly different among sequential generations,ranging from 5.58±2.5 d(at G5)to 3.75±1.42 d(at G45).However,no significant difference was found in male adult longevity among different generations.Although female wasps survived longer until the 15th gener・ation,they allocated more days for egg laying at G5 and GIO.The highest values of gross reproductive rate(GRR),net reproductive rate(7.),intrinsic rate of increase(r),finite rate of increase(λ)and mean generation time(T)were found in G5 and GIO,which also showed significantly higher cq.No significant difference in the finite parasitism rate(co)was found among generations up to G15.These results suggest that T.brassicae wasps held under continuous laboratory rearing can be used successfully in biological control programs until the 15th generation without any loss of quality or performance.However,laboratory mass rearing colonies declined in quality after 15 generations and we suggest that they should be rejuvenated regularly by adding field-collected parasitoids periodically.

Automated detection of parasitized Cadra cautella eggs by Trichogramma bourarachae using machine vision

Cadra(Ephestia)cautella(Walker)is a moth that attacks dates from ripening stages while on tree,throughout storage,and until consumption,causing enormous qualitative and quantitative damages,resulting in economic losses.Image-processing algorithms were developed for detecting and differentiating between three Cadra egg categories based on the success of Trichogramma bourarachae(Pintureau and Babaul)parasitization.These categories were parasitized(black and dark red),unparasitized fertile unhatched(yellow),and unparasitized hatched(white)eggs.Color,light intensity,and shape information was used to develop detection algorithms.Two image processing methods were developed based on three randomly selected images and were tested on a larger validation image set of 40 images:(i)segmentation and extractions of color and morphological features followed by Watershed delineation,and is referred to as Algorithm 1(ALGO1),(ii)finding circular objects by Hough Transformation followed by convolution filtering,and is referred to as Algorithm 2(ALGO2).ALGO1 and ALGO2 achieved correct classification rates(CCRs)for parasitized eggs of 92%and 96%,respectively.Their CCRs for unhatched eggs were 48%and 94%,and for hatched eggs were 42%and 73%,respectively.Regarding parasitized eggs,both methods performed satisfactorily,but,in general,ALGO2 outperformed ALGO1.These results ensure automatic evaluation of the efficiency of biological control of Cadra cautella by the egg parasitoid Trichogramma bourarachae by quantifying the rate of parasitization.The developed detection methods can be used by producers of biocontrol agents for online monitoring of Trichogramma and similar insect natural enemies during mass production and before release against crop pests.Moreover,with few adjustments these methods can be used in similar applications such as detecting plant diseases.