Bark-Beetle Parasitoids Population Surveys Following Storm Damage in Spruce Stands in the Vosges Region (France)

This paper presents the results of a long-term study designed to follow the population dynamics of hymenopteran parasitoids associated with Ips typographus L. (Coleoptera: Scolytidae) in northeastern France (Alsace and Vosges) in spruce stands devastated by the December 1999 storms. Population densities were estimated by periodic samplings in the pre-emerging insect populations developing under the bark of attacked trees. Data were collected between July 2000 and October 2001. I. typographus population density (per m²) increased respectively by 28%, 105%, and 212% in one year in the three sites surveyed. Six hymenopteran ectoparasitoids were found: Coeloides bostrichorum Giraud and Dendrosoter middendorffi Ratzeburg (Hymenoptera: Braconidae); Rhopalicus tutela (Walker), Roptrocerus xylophagorum (Ratzeburg), Roptrocerus mirus (Walker) and Dinotiscus eupterus (Walker) (Hymenoptera: Pteromalidae). After two years, the parasitoid populations increased in terms of average density but parasitism rates remained at a relatively low level, ranging from 0% to 40%, with 60% of the trees having a parasitism rate below 5%. Data outlined the recurrent coexistence of competing parasitoid species.     

江浙野桑蚕寄生性天敌调查及群落结构分析

野桑蚕是重要的桑树害虫。作者于1985—1990年在江浙主要蚕区,进行野外采集、室内饲养其卵、幼虫、蛹共达43万余个体的寄生性天敌调查。调查中共得6种原寄生灭敌,它们是:野蚕黑卵蜂、野蚕平腹小蜂、野蚕绒茧蜂、广大腿小蜂、野蚕黑瘤姬蜂和家蚕追寄蝇。卵块寄生率0—92.22%,卵粒寄生率0—56.73%,幼虫寄生率0—77.36%,蛹寄生率0—19.57%。各寄生天敌比较,以野蚕绒茧蜂和野蚕黑卵蜂最为重要,其中后者更有应用前景。此外,并对野桑蚕寄生天敌群落结构的多样性、相似性作了分析。     

黄粉虫蛹不同处理方式对人工繁育川硬皮肿腿蜂的影响

研究乙醇和低温处理黄粉虫蛹后对繁育川硬皮肿腿蜂的影响。结果表明:有或者没有乙醇处理,不同蛹龄的黄粉虫蛹均对肿腿蜂寄生效果有明显影响。肿腿蜂对蛹龄小的黄粉虫蛹寄生效果好,但对蛹龄大的黄粉虫蛹寄生率相对低,且不能寄生未经乙醇处理过的2日龄以后的黄粉虫蛹。用75%乙醇处理蛹龄0～12 h的黄粉虫蛹2 h可以显著提高肿腿蜂的产蜂量;-6℃低温冻藏黄粉虫初蛹24 h也可显著提高肿腿蜂的寄生效果,肿腿蜂出蜂率可达65%,平均产蜂量达21头左右。由此可见,黄粉虫蛹经过75%乙醇溶液处理或低温贮藏处理后,可明显提升肿腿蜂的寄生效果。     

冷藏对不同季节采集的美洲斑潜蝇寄生蜂羽化的影响

研究了10％冷藏不同时间对天津地区不同季节采集的美洲斑潜蝇寄生蜂自然种群羽化率和羽化进度的影响。结果表明,不同季节发育的寄生蜂对10℃低温的耐受力不同,不同处理的羽化率和羽化进度有较大差异。7月份和9月中旬的寄生蜂随冷藏时间延长,羽化率显著下降;9月底、11月下旬的寄生蜂耐寒力增强,冷藏15～60d处理后羽化率无显著降低。25℃适宜条件下,7月份、9月底的寄生蜂均在20d内羽化,11月下旬、12月的寄生蜂出现羽化延迟,21～40d之间亦有羽化。9月底的寄生蜂冷藏30、45、60d处理,随冷藏时间延长,16～20d羽化比例明显增加,21～25d依次渐增;11月下旬、12月的寄生蜂冷藏处理后羽化进度加快,冷藏60d内随时间延长,10d内羽化比例明显增加。     

假眼小绿叶蝉卵缨小蜂的生物学特性研究

缨小蜂是假眼小绿叶蝉的主要卵寄生蜂,本文结合田间观察和室内实验,对缨小蜂的生物学特性进行了初步的研究。结果获知:缨小蜂成蜂的活动与温度、光照密切相关,该蜂可兼营两性生殖和孤雌生殖,但孤雌生殖未见雌性后代。在25℃条件下,缨小蜂从卵到成蜂羽化的发育历期为21.40±0.26d,以10%蜂蜜水作为补充营养能显著延长雌蜂寿命。微小裂骨缨小蜂单雌平均怀卵量36.83±0.81粒,叶蝉三棒缨小蜂单雌平均怀卵量22.33±0.48粒。同时,采用共景深成像系统拍摄了2种缨小蜂各虫态发育过程及其形态特征。     

Insect pests and beneficial arthropods population under different hedgerow intercropping systems in semiarid Kenya

Exploiting the principles of biological control of crop pests is an important management strategy for the resource-poor smallholder farmers of the tropics. The effects of nine hedgerow species on the abundance of major insect pests of beans and maize, and predatory/parasitic-arthropods were monitored over two cropping seasons and the intervening dry period. The tree/shrub species evaluated were Gliricidia sepium, Grevillea robusta, Senna siamea, Senna spectabilis, Flemingea congesta, Croton megalocarpus, Morus alba, Calliandra calothyrsus and Lantana camara. Arthropod abundance was monitored through counts of infested plants and using yellow pan and pitfall traps. Beanfly (Ophiomyia spp.) infestation was significantly higher in the presence of hedgerows (35%) than in their absence (25%). Hedgerows did not influence aphid (Aphis fabae) infestation of beans. In contrast, maize associated with hedgerows experienced significantly lower stalk borer (Busseola fusca and Chilo spp.) and aphid (Rhophalosiphum maidis) infestations than pure maize, the margin of difference being 13% and 11% respectively for the two pests. Ladybird beetles closely followed their prey, aphids, with significantly higher catches in sole cropped-plots than in hedgerow-plots and away from hedgerows. Activity of wasps was significantly greater close to hedgerows than away from them. Spider catches during maize season were 77% greater in the presence of hedgerows than in their absence, but catches during other seasons were similar between the two cropping systems. Differences among hedgerow species were not significant for most of the arthropods monitored, except that beanfly infestation was greater with Gliricidia hedgerows. The study indicates that the effect of hedgerows on pest infestations of crops and their role as refugia for predators cannot be generalized but depends on the specific arthropods.This revised version was published online in November 2005 with corrections to the Cover Date.     

竹弯茎野螟的3种新记录寄生蜂

2013年5月至2014年10月,对竹林害虫竹弯茎野螟[Crypsiptya coclesalis(Walker)]的寄生蜂及寄生率进行调查,共发现7种寄生蜂。其中3种是首次记录寄生在该种害虫的寄生蜂,即:日本棱角肿腿蜂(Goniozus japonicus Ashmead)、兰氏原绒茧蜂(Protapanteles lamborni Wilkinson)和螟黄赤眼蜂(Trichogramma chilonis Ishii)。对不同寄生蜂的寄生率调查结果表明,兰氏原绒茧蜂的寄生率最高,为45.2%,对竹弯茎野螟具有较好控制作用。同时,本文首次报道寄生于竹弯茎野螟3种寄生蜂的主要鉴别特征及其寄生生物学,并提供了形态特征图。     

Wheat (Triticum aestivum L.)‐based intercropping systems for biological pest control

Wheat (Triticum aestivum L.) is one of the most cultivated crops in temperate climates. As its pests are mainly controlled with insecticides that are harmful to the environment and human health, alternative practices such as intercropping have been studied for their potential to promote biological control. Based on the published literature, this study aimed to review the effect of wheat‐based intercropping systems on insect pests and their natural enemies. Fifty original research papers were obtained from a systematic search of the peer‐reviewed literature. Results from a vote‐counting analysis indicated that, in the majority of studies, pest abundance was significantly reduced in intercropping systems compared with pure stands. However, the occurrence of their natural enemies as well as predation and parasitism rates were not significantly increased. The country where the studies took place, the type of intercropping and the crop that was studied in the association had significant effects on these results. These findings show that intercropping is a viable practice to reduce insecticide use in wheat production systems. Nevertheless, other practices could be combined with intercropping to favour natural enemies and enhance pest control. © 2016 Society of Chemical Industry     

A survey of aphid parasitoids in Kahramanmaras,Turkey (Hymenoptera: Braconidae,Aphidiinae; and Hymenoptera: Aphelinidae)

A list of aphid parasitoids found in a survey conducted between 1999 and 2001 in Kahramanmaras Province of Turkey is presented. Nineteen taxa of aphid parasitoids were found on 30 hosts.Pauesia picta (Haliday) is reported for the first time from Turkey. Two check-lists are presented, by host aphids and by plant species. http://www.phytoparasitica.org posting April 30, 2004.     

转基因抗虫植物对昆虫天敌的影响

随着商业化种植的迅速推广,转基因作物在给人们带来经济效益的同时,其对生态环境可能带来的风险已成为关注的焦点。转基因抗虫作物在对靶标害虫有很好控制作用的同时,对捕食性天敌和寄生性天敌及其种群数量的影响是其生态安全评价的重要内容。文章从天敌个体及种群两个方面综述了转基因抗虫作物对天敌的影响。目前,大多数研究表明转基因抗虫作物在有效控制靶标害虫的同时,对昆虫天敌没有明显的不利影响,也有研究报道认为对某些天敌有一定的不良影响,除个别Bt棉田外,未发现转基因作物田中天敌种群数量受到不良影响。