红颈常室茧蜂蛹发育的形态特征

红颈常室茧蜂Peristenus spretus Chen et van Achterberg是一种绿盲蝽若虫的优势内寄生蜂,本研究利用超景深三维显微系统、显微镜观察了红颈常室茧蜂老熟幼虫发育特征、蛹形态特征及蛹发育后期卵巢的超微结构。结果表明:红颈常室茧蜂蛹期为12～15 d,其中雌蛹期比雄蛹期长2～3 d。根据其形态特征,可将蛹划分为预蛹期、第一蛹阶段、第二蛹阶段、第三蛹阶段。蛹期发育前9 d,蛹期组织结构开始分化形成,成蜂的外部形态基本显现,但性别难以区分;蛹期发育至10～14 d,可通过幼蜂体表颜色的变化或腹部末端的形状区分性别,在相同的适宜温度条件下,雌蜂比雄蜂颜色深,雌蜂腹部末端比较尖,有突出的产卵瓣,雄峰腹部末端钝圆,无凸起;雌蜂卵巢在化蛹后的第11天开始形成,卵巢初期的形状如细丝,此时卵巢管已开始初步分化,但卵室尚未分化;蛹发育至第12天时,卵巢管逐渐加粗,卵室开始分化;第13天时,卵巢管、卵室数量逐渐增多;第14天卵巢基部开始有少量成熟卵子产生,呈乳白色。10～12 d,雄蜂腹部末端绒毛逐渐增多,体壁变硬,逐渐角质化,虫体可活动,雄蜂胸部略带黑色,翅逐渐伸展开,整个虫体呈浅红棕色。本研究结果明确了红颈常室茧蜂蛹发育的形态变化过程,提出了蛹期雌雄区分的方法,叙述了蛹后期卵巢发育特征,为研究该蜂繁殖机理奠定了形态学基础。     

河北张家口康巴诺尔湖国家湿地公园遗鸥繁殖群新发现

2014年4月14日在张家口市康保县康巴诺尔湖国家湿地公园(东经114°35′06″~114°36′32″,北纬41°49′05″~41°50′33″)发现遗鸥(Larus relictus)3 000余只。同年7月在湖边发现新繁殖的遗鸥幼鸟觅食。2015年4月底发现遗鸥在湖心岛筑巢产卵,同年6月采用国产大疆精灵3四轴航拍飞行器航拍法及样方法统计湖心岛遗鸥种群数量,共记录遗鸥成鸟2 100余只,806巢,出壳雏鸟2 080只。此次发现属于我国遗鸥繁殖地的新发现。     

Ten polymorphic microsatellite loci for the endangered Buena Vista Lake shrew (Sorex ornatus relictus)

The ornate shrew (Sorex ornatus) is restricted to the vanishing wetlands of California, USA and Baja California, Mexico. Several subspecies of ornate shrews are considered ‘mammal species of special concern’ in California by the Department of Fish and Game, and one (Sorex ornatus relictus) has recently been listed as endangered. Populations of shrews around Buena Vista Lake have been diminished or extirpated due to habitat deterioration and human development. In order to study the patterns of genetic variation in isolated populations of Buena Vista Lake shrews, we developed 10 polymorphic microsatellite loci. There were 6–27 alleles per locus, and the loci had heterozygosity values that ranged from 20 to 80%. In addition, we screened 20 different populations of S. ornatus, eight species within two subfamilies of shrews (Soricinae and Crocidurinae), as well as in a mole (Talpidae, Neurotrichus gibbsii), to determine if these loci could be informative in other species as well.     

遗鸥研究概述

叙述自遗鸥（Larus relictus)被确认为有效物种以来30余年中世界范围内对遗鸥的主要研究结果与对遗鸥认知发展的概况,总的来讲,遗鸥作为环蒙古高原的繁殖分布,为荒漠-半荒漠生态条件下的典型鸟种,具4个相对独立的繁殖种群,取湖心岛为繁殖生境,遗鸥当年幼鸟呈辐射方式作最初扩散。而其主要越冬地和越冬种群至今尚不明了,由于气候变化造成繁殖生境的不稳定,应是导致遗鸥繁殖群呈较强动态变化的重要原因。     

Host preferences of introduced and native parasites (Hymenoptera: Braconidae) of phytophagous plant bugs (Hemiptera: Miridae) in alfalfa-grass fields in the northeastern USA

During an eight-year field study at two widely-separated locations (NJ & DE, USA), seven species of phytophagous mirid plant bugs were found in alfalfa and alfalfa-grass fields grown for animal forage. Five species of parasites were reared from these mirids. Two parasite species introduced from Europe killed significantly higher proportions of nymphs of the two important mirid pests of alfalfa than did native parasites. The introduced Peristenus digoneutis Loan parasitized an average of 31% of first and second generation tarnished plant bugs, Lygus lineolaris, a native insect; and the introduced Peristenus conradi parasitized 22% of first generation alfalfa plant bugs, Adelphocoris lineolatus, an introduced species. In addition, Peristenus pallipes significantly parasitized nymphs of Trigonotylus caelestialium (43%) and Leptopterna dolabrata (37%); both mirids are immigrant species. Because the parasite P. pallipes significantly attacked only these two non-native mirids, and is present in Europe, it also may be an accidental introduction to North America. A native wasp, Leiophron uniformis, heavily parasitized (49%) the native garden fleahopper, Halticus bractatus. A third native species, P. pseudopallipes, occasionally parasitized a few Lygus lineolaris in alfalfa at one location. Two other mirids, Stenotus binotatus and Megaloceroea recticornis, both accidently-introduced grass-feeding species, were not parasitized by native or introduced species. It is noteworthy that the effective host ranges of all the parasites in alfalfa-grass fields were limited: four of the five parasite species significantly parasitized only one of the seven mirid species, and the other parasite significantly parasitized only two mirids. Activity of the four common parasites was correlated with the mirids' host plant: three species principally parasitized alfalfa-feeding mirids, and one species principally parasitized grass-feeding mirids.     

遗鸥鄂尔多斯种群研究的最新报道*

野外工作结果表明,1993年遗鸥鄂尔多斯种群繁殖群体的数量达到90年代以来的最高值,共计1510余巢;同时桃力庙- 阿拉善湾海子对于遗鸥鄂尔多斯种群的生存具有特别重要的意义,且出现于那里的湿地鸟类集中地反映了鄂尔多斯高原荒漠型湿地鸟类群落的特点,依据《拉姆萨公约》所推荐的评判标准应考虑将该地点列入《国际重要湿地名录》。     

Comparative analysis of the reproductive biology of two Peristenus species (Hymenoptera: Braconidae), biological control agents of Lygus plant bugs (Hemiptera: Miridae)

Peristenus digoneutis Loan and Peristenus stygicus Loan, parasitoids of the European tarnished plant bug Lygus rugulipennis Poppius, are established in the United States for biological control of native North American Lygus species, and are being considered for deliberate release in Canada. High lifetime fecundity of parasitoids is considered a desirable attribute of biological control agents and therefore, an understanding of parasitoid reproductive biology is required. In the present study, the potential lifetime fecundity of both agents was compared under laboratory conditions to estimate the potential impact of Peristenus species on Lygus. Synovigenic P. digoneutis and P. stygicus females oviposited most actively in the first two weeks of their lifetime, with a maximum average daily oviposition rate after five days. The maximum number of eggs laid per day was 83 eggs for P. stygicus, and 36 eggs for P. digoneutis. P. digoneutis has an average potential lifetime fecundity of 385 ± 35 SE eggs produced over 22 ± 3 SE days. In contrast, P. stygicus females have a 50% higher mean potential lifetime fecundity reaching 782 ± 65 SE eggs over 28 ± 1 SE days. A positive correlation between lifetime fecundity and body size was found only for P. stygicus, and both species showed a significant relationship between lifetime fecundity and oviposition period. The present study demonstrates that the fecundity of P. digoneutis and P. stygicus is considerably higher than previously reported. Based on these findings, P. stygicus appears to be the most effective biological control agent for Lygus lineolaris (Palisot de Beauvois) when only fecundity is taken into consideration.     

有关棕头鸥和遗鸥两近似种的分类与分布问题研究

本文根据近几年的野外观察结果并分析有关文献资料,系统地比较研究了棕头鸥和遗鸥两近似种的分类和分布现状,直接依据野外活体形态并对照系列标本对两种鸥的成、幼鸟和雏鸟的形态及野外临别特征给出了较精确的描述,澄清了这两种鸥以往在分类上的混淆有分布认识上的错位,同时从生态－动物、地理和行为学的角度对两种鸥的现有分布和今后分布态势的演进做了分析论证。     

A survey of Lygus parasitoids in Sweden

Lygus spp. (tarnished plant bugs) are generalist herbivores and occur as pests on a wide range of crops. In the development of conservation biological control strategies for Lygus spp. in Sweden, more information is needed on the impact of different natural enemies. In this study, we determined the occurrence and the degree of parasitism on adults and nymphs of the most common Lygus species in alfalfa, barley, red clover and oilseed rape in Uppsala in Central Sweden and in Umeå in Northern Sweden. Nymphs and adults of Lygus spp. were collected by sweep netting for estimation of their parasitism level (by dissection) and identification of parasitoid species (from reared Lygus specimens). The dominant Lygus species in both locations was L. rugulipennis (75–99%). Parasitism by Phasia obesa (Tachnidae) on overwintering Lygus adults was recorded in almost every field sampled at both locations. The parasitism level was low at overwintering sites but increased in arable fields during summer. Lygus nymphs collected in Umeå were parasitised by Peristenus pallipes (Braconidae) and in Uppsala by P. relictus, P. pallipes and P. varisae. The hyperparasite Mesochorus globulator (Ichneumonidae) was recorded in Umeå.