First European record of Carassius langsdorfii from the Elbe basin

Morphological, cytogenetic and molecular genetic identification of two specimens of Carassius langsdorfii from the upper Elbe basin is given. Probably, the species was introduced by accident with commercial fish imports. Potentially, this introduced species may be of harm to native fish species.     

When is a native species invasive? Incursion of a novel predatory marsupial detected using molecular and historical data

Aim

Range expansions facilitated by humans or in response to local biotic or abiotic stressors provide the opportunity for species to occupy novel environments. Classifying the status of newly expanded populations can be difficult, particularly when the timing and nature of the range expansion are unclear. Should native species in new habitats be considered invasive pests or actively conserved? Here, we present an analytical framework applied to an Australian marsupial, the sugar glider (Petaurus breviceps), a species that preys upon on an endangered parrot in Tasmania, and whose provenance was uncertain.

Location

Tasmania, Australia.

Methods

We conducted an extensive search of historical records for sugar glider occurrences in Tasmania. Source material included museum collection data, early European expedition logs, community observation records, and peer‐reviewed and grey literature. To determine the provenance of the Tasmanian population, we sequenced two mitochondrial genes and one nuclear gene in Tasmanian animals (n = 27) and in individuals across the species' native range. We then estimated divergence times between Tasmania and southern Australian populations using phylogenetic and Bayesian analyses.

Results

We found no historical evidence of sugar gliders occurring in Tasmania prior to 1835. All Tasmanian individuals (n = 27) were genetically identical at the three genes surveyed here with those individuals being 0.125% divergent from individuals from a population in Victoria. Bayesian analysis of divergence between Tasmanian individuals and southern Australian individuals suggested a recent introduction of sugar gliders into Tasmania from southern Australia.

Main conclusions

Molecular and historical data demonstrate that Tasmanian sugar gliders are a recent, post‐European, anthropogenic introduction from mainland Victoria. This result has implications for the management of the species in relation to their impact on an endangered parrot. The analytical framework outlined here can assist environmental managers with the complex task of assessing the status of recently expanded or introduced native species.

     

Three new records of the subfamily Aphidiinae (Hymenoptera: Braconidae) from Korea

Three species of the Aphidiinae (Hymenoptera: Braconidae) are reported for the first time in Korea: Aphidius rhopalosiphi de Stefani-Perez, 1902, Aphidius uzbekistanicus Luzhetzki, 1960 and Lysiphlebus orientalis Starý and Rakhshani, 2010. Their diagnosis, photographs and host list are included.     

Factors influencing parasitism of Trichogramma dendrolimi on eggs of the Asian corn borer, Ostrinia furnacalis

Laboratory studies were made to determine the capacity of Trichogramma dendrolimi to parasitize eggs of Ostrinia furnacalis, as affected by the rearing host species, substrate of host eggs, host age, original locality of host populations, and cold storage of host eggs. Wasps reared from eggs of Antheraea pernyi showed parasitic capacity on eggs of O. furnacalis on average twice as high as that of the wasps reared from eggs of Corcyra cephalonica. When the age of O. furnacalis eggs at 26 °C increased from 0–6 h to 18–24 h, the proportion of wasps that successfully parasitized host eggs, the number of host eggs parasitized, and the rate of parasitization all decreased by >50%. The number of O. furnacalis eggs parasitized per female T. dendrolimi increased with the number of host eggs available, and reached 22.9 in a 24 h period. However, the parasitic capacity of female T. dendrolimi on eggs of O. furnacalis laid on plant leaves was similar to that of O. furnacalis eggs laid on wax paper. Levels of parasitism of O. furnacalis eggs from two widely separated localities, i.e. Changchun (43.50° N, 125.20° E) and Hangzhou (30.18° N, 120.07° E), were similar. Cold storage of O. furnacalis eggs at 4 °C for 5 days did not affect parasitization. Results obtained in this study indicate that although O. furnacalis is a less preferred and less suitable host than many other hosts, such as Dendrolimus punctatus, Actias selene ningpoane, Philosamia cynthia, A. pernyi, C. cephalonica, within the host-species range of T. dendrolimi, the parasitoid has the potential to achieve 50–60% or even higher rates of parasitization of O. furnacalis eggs in corn fields under suitable conditions, and could be used in the biological control of the pest.     

香港地区蚜虫物种多样性

蚜虫是半翅目中一类体型较小的昆虫,广布于世界各地,其中绝大部分是农林害虫。目前,国内许多地区已开展蚜虫物种多样性和区系研究,但香港地区因蚜虫研究基础薄弱,至今尚未开展过系统研究。作者研究和整理了英国自然历史博物馆和中国科学院动物研究所动物标本馆已有的香港地区蚜虫标本,并参考大量相关文献,从分类阶元、特有物种、动物地理区划和寄主植物四个方面分析了香港地区蚜虫物种多样性。研究发现香港地区已知蚜虫7科44属70种,分别占中国已知科、属、种的53.85%、16.60%和6.83%,多样性较为丰富,其中有香港地区特有种6种。香港地区在动物地理区划中位于东洋界华南区闽广沿海亚区,蚜虫物种以分布于东洋界、古北界 东洋界、东洋界 澳洲界成分为主。现记载香港地区共有蚜虫的寄主植物30科58属,其中蚜科的寄主植物最为丰富,其次为扁蚜科和斑蚜科;寄主植物中寄生蚜虫类群最多的3个科分别为:禾本科、桑科和樟科。虽然香港地区面积仅占中国总面积的万分之一,但该地区复杂的地形地貌、适宜的气候环境以及丰富的植被共同构成了有利于蚜虫生存的小生境,因此蚜虫物种多样性较高,这也是我国南方地区蚜虫物种丰富的鲜明体现。     

In-field production of parasitoids of Dysaphis plantaginea by using the rowan aphid Dysaphis sorbi as substitute host

A system was developed to provide the parasitic wasp Ephedrus persicae Froggatt (Hymenoptera: Braconidae: Aphidiinae), which attacks the rosy apple aphid Dysaphis plantaginea (Passerini) (Homoptera: Aphididae), with the alternative host Dysaphis sorbi Kaltenbach (Homoptera: Aphididae) in apple orchards. Rowan trees (Sorbus aucuparia L.) arranged along the side of an unsprayed orchard were artificially infested in late February 2002 with eggs of D. sorbi. Colonies of D. sorbi successfully developed from the introduced eggs and persisted on several trees until the end of June. The only primary parasitoid species emerging from a sample of mummified aphids collected in spring from the infested rowan trees was the braconid wasp species E. persicae. In a host-switching experiment, nymphs of D. plantaginea proved suitable for female parasitoids originating from mummified D. sorbi. A series of mummies collected from the rowan trees in early summer contained diapausing parasitoids and hyperparasitoids that only hatched in April of the following spring. These observations suggest the possibility of establishing a local population of E. persicae in apple orchards, so that D. plantaginea can be readily attacked by diapause-emerging parasitoids in early spring.     

中国钝唇姬蜂属三新种(膜翅目:姬蜂科)及二寄主新纪录(英文)

本文报道钝唇姬蜂属三新种乌钝唇姬蜂Eriborusfurvus,sp.nov.,沈阳钝唇姬蜂Eriborusshenyangensis,sp.nov.,柄钝唇姬蜂Eriborusstipitatus,sp.nov.和大螟瘦姬蜂E．terebrans（Gravenhorst）的二寄主新纪录,白杨透翅蛾ParanthrenetabaniformisRott.和青杨天牛SaperdapopulneaL．     

The role of plant chemical cues in determining host preference in the generalist aphid parasitoid Aphidius colemani

The host preference behaviour of the generalist aphid parasitoid Aphidius colemaniwas investigated using a Y-tube olfactometer. Female A. colemanishowed a preference for the host-plant complex on which they had been reared, even though the same aphid host was involved, demonstrating a host plant preference. This preference was not evident when the parasitoids were dissected from their mummies prior to adult emergence. Host plant preference exhibited during host selection appeared to be induced by chemical cues encountered on the mummy case at the time of emergence, but preferences could be changed by subsequent foraging experiences. It is concluded that plant chemical cues play a major role in determining initial preferences through a process of emergence conditioning but that learning processes, involving cues encountered during oviposition in or contact with the host, can modify these initial preferences.     

Optimization of single-strand conformation polymorphism and sequence analysis of the mitochondrial control region in Pagellus bogaraveo (Sparidae, Teleostei): rationalized tools in fish population biology

We report the isolation and sequencing of 400–550 base pairs (bp) of the mitochondrial DNA (mtDNA) control region of eight species of Sparidae (Perciformes, Teleostei). This sequence information allowed us to design specific primers to one of these species (Pagellus bogaraveo). The new set of primers was used to test a rationalized approach to study the mtDNA nucleotide variability at the intraspecific level. The single-strand conformation polymorphism (SSCP) technique was applied to detect sequence variation in two non-overlapping fragments of the control region of 32 individuals of P. bogaraveo. To assess the sensitivity of the method, the nucleotide sequence of the analysed region was determined for all the specimens. The results showed that, for one of the two fragments, SSCP analysis was able to detect 100% of the underlying genetic variability. In sharp contrast, nucleotide variation of the second DNA fragment was completely unresolved by SSCP under different experimental conditions. This suggests that the resolution power of SSCP is crucially dependent on the nature of the fragment subjected to the analysis; therefore, a preliminary test of the sensitivity of the method should be performed on each specific DNA fragment before starting a large-scale survey. A rationalized approach, combining the SSCP technique and a simplified sequencing procedure, is proposed for studying intraspecific polymorphism at the mtDNA control region in fish.     

植物挥发性物质在蚜虫寄主定位中的作用

本文综述了植物挥发性物质的化学性质、研究方法及其在蚜虫寄主定位中的作用     

Influence of the wood ant, Formica polyctena, on soil nutrient and the spruce tree growth

The effect of Formica polyctena ant nests on the distribution of soil nutrients, soil pH and the growth of Norway spruce trees was studied in the southern part of the Czech Republic. Soil nutrient content (exchangeable P, N, K and pH) and growth of mature spruce trees were measured at four distances from the nearest ant hill (0–1, 3–5, 10–50 and >200 m). Trees at all distances were visited by ants, except for those >200 m from the nearest nest. Soil pH and of P, K and NO₃ concentrations were higher near ant nests (<1 m), and pH and K at distances of 3–5 m, when compared with distances of 10–50 and >200 m from the nests, where no significant differences in these variables were detected. In contrast, tree ring analyses (1974–2004) showed that trees >200 m from the ant nests grew significantly faster than trees at other distances, followed by trees within 1 m of the nests. No growth differences were found between the growth of trees at 3–5 and 10–50 m from ant nests. We postulate that nutrient and carbohydrate removal of honeydew collected by ant‐tended aphids are slowing growth of tree. However, trees may partly compensate for this depletion by having access to a larger supply of soil nutrients near ant nests.