中国四川省牧草蝗属一新种及青海湖牧草蝗雄性的发现(直翅目,网翅蝗科)

记述我国四川甘孜地区牧草蝗属l新种,褐胫牧草蝗Omocestus avellaeusitibia Zheng,Dong et Xu,sp.nov.,首次报道了青海湖牧草蝗Omocestus qinghaihuensis Zheng et Xie,2001的雄性.附有中国牧草蝗属分种检索表.新种模式标本保存于陕西师范大学动物研究所昆虫标本室.     

Testing the efficiency of three 15N-labeled nitrogen compounds for indirect labeling of grasshoppers via plants in the field

In field studies of plant–insect herbivore interactions it is often difficult to establish which herbivore has fed on a particular plant. We investigated the suitability of three different ¹⁵N‐labeled nitrogen compounds (ammonium, nitrate, and glycine) for indirect marking of three grasshopper species [Omocestus viridulus (L.), Chorthippus parallelus (Zett.), and Chorthippus biguttulus (L.) (Orthoptera: Acrididae)] through labeling their food plants in the field. In two short‐term experiments grassland plots of 1 m² were separately labeled with either one of the different nitrogen compounds. Grasshoppers were caged on three food‐plant species [Dactylis glomerata L., Holcus lanatus L. (Poaceae), and Trifolium repens L. (Fabaceae)] present in these plots for 72 h. Significantly enriched δ¹⁵N values in grasshoppers were found in all plant/grasshopper combinations. Enrichment in grasshoppers was positively correlated with the enrichment of plants and labeling with nitrate resulted in highest ¹⁵N enrichment. In a long‐term experiment, individuals of C. biguttulus were placed in a cage covering an area of 1 m² for 37 days, with sampling of grasshoppers at regular intervals. δ¹⁵N values of the grasshopper and a common food plant, D. glomerata, increased steadily over time, up to 40‐fold by the end of the experiment. Our results demonstrate that ¹⁵N‐labeling of plants is an appropriate tool for the investigation of insect–plant interactions under natural conditions.     

Grasshopper ontogeny in relation to time constraints: adaptive divergence and stasis

1. Life history theory generally predicts a trade-off between shortjuvenile development and large adult size, assuming invariant growth rates within species. This pivotal assumption has been explicitly tested in few organisms. 2. We studied ontogeny in 13 populations of Omocestus viridulus grasshoppers under common garden conditions. High-altitude populations, facing short growing seasons and thus seasonal time constraints, were found to grow at a similar rate to low altitude conspecifics. 3. Instead, high-altitude grasshoppers evolved faster development, and the correlated change in body size led to an altitudinal size cline mediating a trade-off with female fecundity. 4. An additional juvenile stage occurred in low- but not high-altitude females. This difference is probably due to the evolution of lowered critical size thresholds in high-altitude grasshoppers to accelerate development. 5. We found a strikingly lower growth rate in males than females that we interpret as the outcome of concurrent selection for protandry and small male size. 6. Within populations, large individuals developed faster than small individuals, suggesting within-population genetic variation in growth rates. 7. We provide evidence that different time constraints (seasonal, protandry selection) can lead to different evolutionary responses in intrinsic growth, and that correlations among ontogenetic traits within populations cannot generally be used to predict life history adaptation among populations. Moreover, our study illustrates that comparisons of ontogenetic patterns can shed light on the developmental basis underlying phenotypic evolution.     

新疆牧草蝗属一新种(直翅目,网翅蝗科)

记述采自新疆北部地区牧草蝗属1新种,即拟黑翅牧草蝗Omocestus peliopteroides sp.nov.。附有中国牧草蝗属分种检索表。模式标本保存于陕西师范大学动物研究所。     

湖北省牧草蝗属一新种（直翅目：蝗总科）

本记述湖北省神农架自然保护区的牧草蝗属一新种．     

青海省牧草蝗属二新种(直翅目:网翅蝗科)

记述采自青海省网翅蝗科牧草蝗属2新种,即平安牧草蝗Omocestus pinanensis sp.nov。及青海湖牧草蝗Omocestus qinghaihuensis sp.nov。模式标本保存于陕西师范大学动物研究所。     

中国蝗虫三新种及雪山雏蝗雄性记述(直翅目,网翅蝗科)

记述中国滇西北地区网翅蝗科3新种,即长翅缺背蝗Anaptygus longipennis sp.nov.、老君山牧草蝗Omocestus laojunshanensis sp.nov.、马耳山牧草蝗Omocestus maershanensis sp.nov.,另描述了雪山雏蝗Chorthippus xueshanensis Zheng et Mao的雄性.所有标本保存于大理学院生命科学与化学系.