Differential acquisition of chrysanthemum yellows phytoplasma by three leafhopper species

Chrysanthemum yellows (CY) phytoplasma has been transmitted with three leafhopper species: Euscelidius variegatus (Kirschbaum), Macrosteles quadripunctulatus (Kirschbaum) and Euscelis incisus (Kirschbaum): the first two species are reported as CY phytoplasma vectors for the first time. Leafhoppers were allowed to acquire the pathogen from the following source plants: Apium graveolens L., Catharanthus roseus L., Chrysanthemum carinatum Schousboe L. and C. frutescens L. DNA extracted from healthy or inoculative leafhoppers-exposed plants were analyzed by dot-blot and Southern hybridizations with a molecular probe constructed onto a fragment of European aster yellows phytoplasma DNA. The three leafhopper species were able to transmit CY phytoplasma after acquisition on chrysanthemum, but only M. quadripunctulatus and E. variegatus transmitted after feeding on periwinkle, and none acquired it from celery. All plant species tested were susceptible to CY, but while chrysanthemum and periwinkle were suitable for both inoculation and acquisition, celery did not seem to be a good source of phytoplasma for further inoculations. It is concluded that host plants influence leafhoppers' vectoring ability, possibly due to the different feeding behaviour of the insects on diverse plant species. Since CY, like several other phytoplasmas, can be transmitted by different insect species, it is likely that a close transmission specificity probably does not exist between phytoplasmas and their leafhopper vectors.     

云南大叶蝉亚科二新属二新种记述（同翅目：叶蝉科）

记述采自中国云南省叶蝉科大叶蝉亚科2新属：柄大叶蝉属Miscana,gen.nov.,盾大叶蝉属Aspidia,gen,nov.及2新种：双突柄大叶蝉Miscana biangula,sp.nov.,刀突盾大叶蝉Aspidia falcata,sp,nov。模式标本保存在西北农林科技大学昆虫博物馆。     

The effect of sulfur on biological control of the grape leafhopper, <Emphasis Type="Italic">Erythroneura elegantula</Emphasis>, by the egg parasitoid <Emphasis Type="Italic">Anagrus erythroneurae</Emphasis>

We examined the toxicity of a fungicide, sulfur, to the egg parasitoid Anagrus erythroneurae (Hymenoptera: Mymaridae) Trjapitsyn and Chiapini and the vineyard leafhopper pest Erythroneura elegantula Osborn (Homoptera: Cicadellidae) and tested whether or not the use of sulfur in the field affects biological control of E. elegantula. Using field cage bioassays, we demonstrated that sulfur is toxic to adult A. erythroneurae parasitoids, but not toxic to adult E. elegantula leafhoppers. We nonetheless found in a field experiment that sulfur produced no changes in rates of parasitism or E. elegantula egg density, and generated only a very small increase in the density of E. elegantula nymphs. These results suggest that sulfur, although toxic to A. erythroneurae, is not highly disruptive of E. elegantula biological control in vineyards. Our results suggest that simple bioassays of acute toxicity may not accurately predict the impact of agricultural chemicals on biological control.     

中国小叶蝉属栎小叶蝉种团及三新种记述（半翅目：叶蝉科：小叶蝉亚科）

对中国小叶蝉属栎小叶蝉种团研究进行了追溯。记述栎小叶蝉种团3新种:周氏小叶蝉T.choui sp.nov.,大理小叶蝉T.daliensis sp.nov.,三斑小叶蝉T.trimaculata sp.nov.及1中国新记录种:栎小叶蝉T.quercus(Fabricius,1777),并提供中国栎小叶蝉种团雄虫检索表。模式标本及观察标本存放于西北农林科技大学昆虫博物馆。     

中国殃叶蝉亚科一新属新种(半翅目,叶蝉科)

记述殃叶蝉亚科1新属新种,即拟二叉叶蝉属Paramacrosteles gen.nov.和黑斑拟二叉叶蝉Paramacrosteles nigromaculatus sp.nov..新属与二叉叶蝉属Macrosteles Fieber近似,区别点在于本属阳茎端部具4分叉.新种黑斑拟二叉叶蝉Paramacrosteles nigromaculatus sp.nov.的主要鉴别特征为:头冠前缘与中部各有1个八字形暗褐色斑纹;阳茎基部宽,端部具4分叉,长的2叉伸向前方,2短叉伸向后方.模式标本保存于贵州大学昆虫研究所.     

云南窗翅叶蝉属五新种记述(半翅目,叶蝉科,大叶蝉亚科)

记述云南窗翅叶蝉属Mileewa Distant5新种:高黎窗翅叶蝉M.gaoligongana Yang et Li,sp.nov.,突头窗翅叶蝉M.exsertocaputa Yanget Meng,sp.nov.,十刺窗翅叶蝉M.decemspina Yanget Li,sp.nov.,四刺窗翅叶蝉M.tetraspina Yang,sp.nov.和八刺窗翅叶蝉M.octospina Yang,sp.nov.。文中详细描述了新种的形态特征,提供了彩色照片,并绘制了雄性外生殖器构造图。所有研究标本均保存在贵州大学昆虫研究所(GUGC)。     

阔颈叶蝉属一新种记述(半翅目:叶蝉科)

记述阔颈叶蝉属Drabescoides 1新种,即长臂阔颈叶蝉Drabescoides longiarmus sp.nov..新种近似于圆突阔颈叶蝉Drabescoides umbonata Shang, Zhang et Shen,2003,主要区别为:本种体形稍大,翅脉色泽较深,体背、颜面黄褐色,雄虫阳茎干背面两片状脊大且显著靠拢,尾节侧瓣三角形,具2个刺突,连索干细,臂极长,两臂夹角小,阳基侧突端部"马蹄状",表面着生微齿,雌虫第7腹板后缘弧形深凹入.提供了新种的鉴别特征图.模式标本保存在贵州大学昆虫研究所.     

Engineering Enemy-free Space: An Invasive Pest that Kills its Predators

The biological invasion of the glassy-winged sharpshooter, Homalodisca coagulata, into French Polynesia presents a novel threat to Pacific Island ecosystems. Widely known as an agricultural pest because of its role as a vector of numerous lethal plant diseases, H. coagulata may pose a substantial and immediate risk to arthropod predators on invaded islands in French Polynesia. Controlled feeding experiments revealed that island spiders can be killed following predation on H. coagulata. Spider mortality appeared to result from lethal intoxication, although no form of chemical defense has been reported in H. coagulata. In the two spider species tested, approximately half of all individuals that attacked H. coagulata nymphs or adults died. As populations of this insect increase in size and range on invaded islands in French Polynesia, H. coagulata will increasingly encounter these and other arthropod predators, raising the possibility of population-level impacts on susceptible predator species. Field surveys of island spiders across nine sites on H. coagulata-invaded and H. coagulata-uninvaded islands suggest that this insect may already have adversely impacted an endemic spider on at least one island. Work is needed to identify the nature of the lethal agent harbored within H. coagulata and the taxonomic and geographic breadth of predators vulnerable to it. The generality of H. coagulata-lethality and the capacity of afflicted predator species for population-level adaptation or learned avoidance in response to this spreading pest will determine the magnitude of the threat H. coagulata poses in the South Pacific.     

Comparison of transmission abilities of four Cicadulina species vectors of maize streak virus from Nigeria

Four Cicadulina species [Cicadulina arachidis China, Cicadulina dabrowskii Webb, Cicadulina mbila (Naude), and Cicadulina storeyi China (Homoptera: Cicadellidae)] found during field surveys in 1997–1999 across five ecological zones in Nigeria were reared in screenhouses and females were used in a study to compare their abilities to transmit Maize streak virus (Geminiviridae: genus Mastrevirus) from maize to maize using the susceptible variety Pool 16. The results showed that for both acquisition access feeding periods (AAP) and inoculation access feeding periods (IAP), transmission efficiencies decreased in the following order: C. storeyi > C. mbila > C. arachidis > C. dabrowskii. The transmission efficiencies of these vectors increased with longer feeding periods, as the means of susceptible test plants that showed Mastrevirus symptoms for both acquisition and IAPs were higher for 24 and 48 h than for 1 and 2 h for all four species studied. The epidemiological implications of these differences in transmission abilities are discussed.     

中国拟隐脉叶蝉属三新种：（同翅目：叶蝉科）

本文记述叶蝉科拟隐脉叶蝉属３新种,即肛突拟隐叶蝉Ｓｏｐｈｏｎｉａ ａｎｕｓｕｈａｍａｔａ ｓｐ．ｎｏｖ,弧纹所隐脉叶蝉Ｓｏｐｈｏｎｉａ ａｒｃｕａｔａ ｓｐ．ｎｏｖ．和黑线拟隐脉叶蝉Ｓｐｐｈｏｎｉａｎｉｇｒｉｌｉｎｅａｔａ ｓｐ．ｎｏｖ。模式标本积存在贵州农学院。