Disruption of the reproductive behaviour of Scaphoideus titanus by playback of vibrational signals

Scaphoideus titanus Ball (Hemiptera: Cicadellidae: Deltocephalinae) is the vector of the grapevine disease Flavescence dorée. In S. titanus the male–female duet (MFD), based on species-specific vibrational signals, is essential for successful copulation. The female reply within a duet is a single pulse that is coupled with the male pulse with constant latency. It has been shown that a rival male can interrupt an existing duet by emitting disruptive noise signals. We tested whether the reproductive behaviour of S. titanus can be disrupted by the playback of intra-specific and synthesized vibrational signals. Tested males responded to the playback of an MFD with typical rivalry behaviour. Such behaviour includes silent search for a duetting female (satellite behaviour) and/or emission of disruptive signals. These signals were emitted either after exchange of male–female pulses or after two male pulses coupled by latency corresponding to the female response window. The onset of male disruptive signals overlapped with a female pulse. We suggest that the intruder's disruptive signals can mask the female reply and confuse courting males. Playback of disruptive vibrational signals reduced the level of male calling and interrupted an established MFD that consequently resulted in a significantly reduced number of copulations. These results indicate that the vibrational communication channel is open to interference either from abiotic environmental noise or from signals produced by sexual competitors or heterospecifics. The present study also suggests that a detailed understanding of leafhopper behaviour is essential for trying new approaches in the development of more environmentally friendly control practices.     

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.     

Ultrastructure of the spermatozoa of Psammotettix striatus (Linnaeus) and Exitianus nanus (Distant) (Hemiptera: Auchenorrhyncha: Cicadellidae: Deltocephalinae)

Previous studies of insect spermatozoa indicate that these specialized cells have undergone significant morphological evolution and exhibit traits useful for reconstructing phylogenetic relationships. Although leafhoppers (Cicadellidae) are among the largest and most economically important insect families, few comparative studies of their spermatozoa have been published. Here, the ultrastructure of mature spermatozoa of two leafhoppers Psammotettix striatus (Linnaeus) and Exitianus nanus (Distant), representing two different tribes of the largest leafhopper subfamily, Deltocephalinae, was examined by light and transmission electron microscopy. The shape and ultrastructure of spermatozoa of the two species are very similar to those of other Cicadellidae as well as other Auchenorrhyncha, comprising a conical acrosome invaginated to form a subacrosomal space, a filiform homogeneously condensed nucleus, a lamellate centriolar adjunct connecting the nucleus with the mid-piece/flagellum, a long flagellum with a 9 + 9 + 2 axoneme pattern and two symmetrical mitochondrial derivatives with an orderly array of peripheral cristae, and two drop-shaped accessory bodies. They may be distinguished by the size of the sperm, and the shape of the nucleus, accessory bodies, and paracrystalline region of mitochondrial derivatives. The fine morphology and ultrastructure of spermatozoon in P. striatus and E. nanus are illustrated, along with a brief discussion of the implications for classification and phylogenetic analyses of the subfamily.     

角顶叶蝉亚科一新属——背突叶蝉属（同翅目：叶蝉科）

记述角顶叶蝉亚科１新属－－背突叶蝉属Ｐrotensus,并记述２个新种：周氏背突叶蝉Ｐrotensus choui,sp.nov.和茎齿背突叶蝉Protensus dentatus,sp.nov.,建立１个新组合－－中国新记录种对柄背突叶蝉Protensus kiushiuensis(Vilbaste),n.comb.,列种的检索表,描述了种的外部形态特征及雄性外生殖器特征,并附主要特征图。模式标本保存在西北农林科技大学昆虫博物馆。     

中国角顶叶蝉亚科一新属六新种(同翅目:叶蝉科)

记述角顶叶蝉亚科1新属：即柔突叶蝉属Abrus gen.nov.,并记述6新种：衡山柔突叶蝉A.hengshanensis sp.nov.,短茎柔突叶蝉A.brevis sp.nov.黄芪柔突叶蝉A.huangi.sp.nov.,武夷柔突叶蝉.A.wuyiensis sp.nov,叉茎柔突叶蝉A.bifurcatus sp.nov。和锥尾柔突叶蝉A.coneus sp.nov.,列有种的检索表,描述了种的外部形态特征及雄性外生殖器特征,附有主要特征图。     

中国角顶叶蝉亚科新记录属——短叉叶蝉属Sonronius（半翅目：叶蝉科）

本文记述中国角顶叶蝉亚科新记录属短叉叶蝉属Sonronius及1个新记录种Sonronius anderi,绘制了特征图,提供了该属分种检索表及已知种名录。所有观察标本均保存于西北农林科技大学昆虫博物馆。     

中国横春叶蝉属分类研究(半翅目,叶蝉科,角顶叶蝉亚科)

对中国横春叶蝉属Hengchunia Vilbaste进行了分类研究,确认我国现知3种,其中包括1新种,平端横春叶蝉Hengchunia truncata sp.nov．,文中给出了该属全世界已知种类名录,并提供了中国已有种类的检索表。研究标本保存于西北农林科技大学昆虫博物馆。     

中国掌叶蝉属利叶蝉亚属分类研究(同翅目,叶蝉科,角顶叶蝉亚科)

对中国掌叶蝉属利叶蝉亚属进行了分类研究,我国现知4种,即横带掌叶蝉Handianus(Usuirontus)limbicosta (Jacobi)、双斑掌叶蝉H.(U.)limbfer(Matsumura)、冠斑掌叶蝉H.(U.)maculaticeps(Reuter)和条斑掌叶蝉H.(U.)ogikubonis(Matsumura),确认Usuironus quadrimaculatus Cai et Shen,1999是H.(U.)limbifer(Matsumura,1902)的新异名.文中提供了该亚属的鉴别特征和分种检索表、各种的地理分布、形态记述和特征图.     

Survival,fecundity, and body mass of Amplicephalus curtulus influenced by ‘Candidatus Phytoplasma ulmi’ (16SrV‐A) infection

The leafhopper Amplicephalus curtulus Linnavuori & DeLong (Hemiptera: Cicadellidae) can transmit ‘Candidatus Phytoplasma ulmi’ (16SrV‐A) from a native Chilean shrub, Ugni molinae Turcz. (Myrtaceae), to ryegrasses. A recent study showed that this phytoplasma reduced the total protein content and the activity of detoxifying enzymes in A. curtulus, which could also affect its vector fitness. This study evaluated the effect of ‘Ca. Phytoplasma ulmi’ on the longevity, fecundity, and body mass of A. curtulus. Both females and males were exposed to ‘Ca. Phytoplasma ulmi’‐infected plants for 96 h, whereas a control group remained unexposed. Quartiles from adult emergence to 75% (t₇₅), 50% (t₅₀), and 25% (t₂₅) survival rates were determined for each leafhopper survival distribution. The dry weight was also established at the end of the experiment. The adult lifespan of phytoplasma‐infected males and females was significantly lower than that of the uninfected leafhoppers in quartile survival distributions t₅₀ and t₂₅. The phytoplasma‐infected males and females lived 3 and 4 weeks less than uninfected ones in the last quartile, respectively. Fecundity was established by number of nymphs per female (in four periods) in phytoplasma‐infected and uninfected assays. In general, the weekly pattern of the number of nymphs per phytoplasma‐infected female was lower than that of uninfected leafhoppers; it was 37% lower at the end of the experiment. Phytoplasma‐infected females weighed significantly less (11%) than uninfected individuals. Phytoplasma‐infected males weighed 8% less than uninfected ones, but this difference was not significant. Our data indicated that ‘Ca. Phytoplasma ulmi’ negatively affected the fitness of A. curtulus, and nymphs produced by phytoplasma‐infected females varied over time, which may influence the disease dynamics in nature or in field crops.     

中国灯叶蝉属一新种记述（同翅目：叶蝉科：角顶叶蝉亚科）

灯叶蝉属Lamprotettix 隶属于角顶叶蝉亚科Deltocephalinae 圆冠叶蝉族Athysanini,由Ribaut 以Cicada octopunctata Schrank 为模式种建立。Ossiannilsson (1947) 和Ribaut (1952)确认 Lamprotettix splendidulus (Fabricius, 1803)和L. octopunctata (Schrank, 1796)是 L. nitidula (Fabricius, 1787) 的异名。该属目前仅知1种 L. nitidula (Fabricius)。本文记述采自我国云南的1新种 云南灯叶蝉L. yunnanensis, sp. nov.,至此,该属全世界已知2种,我国均有分布。新种模式标本保存在西北农林科技大学昆虫博物馆。 云南灯叶蝉Lamprotettix yunnanensis, 新种（图1～10） 　　新种与Lamprotettix nitidulus (Fabricius, 1787) 相似,但本新种尾节后背缘无三角形突起,阳茎端部仅有1对伸向体前方的突起,不同于后者。 　　正模♂,云南大理苍山,2400m,1999-Ⅺ-12,秦道正采;副模1♀,同正模。