警惕外来危险害虫褐纹甘蔗象入侵

褐纹甘蔗象Rhabdosceluslineaticollis (Heller)在菲律宾、日本和台湾 ,严重危害椰子等棕榈科植物和甘蔗。本文对褐纹甘蔗象的分类地位、形态特征、分布、寄主、扩散与危害、生物学特性等进行简要介绍     

木瓜榕上昆虫群落结构及分布特征

对西双版纳热带雨林木瓜榕上的昆虫群落结构和分布特征进行了研究。结果表明：样地内共采集到木瓜榕树上昆虫48974号,隶属9个目,30个科,56属,70种。主要是鞘翅目、鳞翅目、膜翅目、同翅目、双翅目、等翅目、半翅目、脉翅目和缨翅目的科、属和种类。属和种以鞘翅目和膜翅目类群最丰富;个体数量是膜翅目最多, 高达68.79%, 其中56.58%是传粉类昆虫。从垂直分布规律看：种类和数量是老茎结果部位最高,占71.34%, 在青果期和熟果期表现最丰富;树冠与叶片部位次之,比率为15.68%;根部再次之(9.55%);枝杈和主干最低, 仅占3.42%。在不同季节中,雨季的种类和个体数量最高,为35.96%;干热季节次之(34.22%),干凉季节最低(29.82%)。     

不受欢迎的生物多样性：香港的外来植物物种

香港早在19世纪中叶开始就有外来植物入侵的记录,迄今为止,已发现多达238种已归化的外来或怀疑为外来的植物,其中又以薇甘菊（Mikania micrantha)、五爪金龙（Ipomoea cairica)、假臭草（Eupatorium catarium)、大黍（Panicum maximum)等最常见,外来植物最常见于受人为干扰的生境,例如荒废农田及路旁等,而较少在天然林地生境及贫瘠的灌草丛中发现,外来植物的对本地生态系统的影响主要局限于低地生境,它们常形成单优种群,减少了生境及贫瘠的灌草丛中发现,外来植物对本地生态系统的影响主要局限于低地生境,它们常形成单优种群,减少少了生境及动植物的多样性,外来动物对香港原生植物影响最大的是于20世纪70年代入侵的松树线虫（Bur-saphelenchus xylophilus)。外来的脊椎动物也有可能对香港的植物被演替产生影响,目前香港的外来植物当中,有些在大陆较少分布或没有记录,作为华南最大的港口,香港对外来物种的引入扮演着重要的角色,因此制定控制外来种在香港及华南地区的引入及传播的政策及措施非常重要。     

Genetic polymorphism in Caulerpa taxifolia (Ulvophyceae) chloroplast DNA revealed by a PCR‐based assay of the invasive Mediterranean strain

Abstract An invasive, cold‐tolerant strain of the tropical green alga Caulerpa taxifolia was introduced recently in the Mediterranean Sea and along the Californian coast. We screened 50 aquarium and open‐sea C. taxifolia specimens for the presence/absence of an intron located in the rbcL gene of chloroplast DNA. We also reanalysed a total of 229 sequences of the Internal Transcribed Spacer (ITS) of ribosomal DNA, combining previously published sequences from different studies with 68 new sequences to complement rbcL data. The introduced Mediterranean strain was found to be characterized by the absence of the rbcL intron and by the occurrence of a particular monomorphic ITS type. A PCR assay based on rbcL gene was developed to detect new introductions of the invasive strain of C. taxifolia. This rapid and inexpensive test could be useful to assist environment managers in the preservation of coastal marine ecosystems.     

In vitro insect-feeding bioassay to determine the resistance of transgenic rice plants transformed with insect resistance genes against striped stem borer (Chilo suppressalis)

Summary To determine the degree of insect resistance in transgenic plants, different bioassays are used which typically use either whole plant or small pieces of leaves or stems of transgenic plants, following culture under greenhouse conditions. An in vitro insect-feeding bioassay is presented which permits the infestation of transgenic plantlets with newly hatched larvae from the striped stem borer. The bioassay consists of the germination of rice seeds in vitro using Murashige and Skoog medium in test tubes, and then infestation of each 3–4 cm long seedling with one neonate larva obtained from surfacesterilized eggs of Chilo suppressalis. The infested in vitro plantlets are kept in culture rooms at 25°C for several days and then the seedling damage and the growth of the larvae are analyzed. Senia (japonica variety) homozygous transgenic rice plants were used for these experiments. The plants were transformed with either the cry1B or the maize proteinase inhibitor (mpi) genes. Both genes confer resistance to Chilo suppressalis. With non-transformed plants the larvae grew and developed normally, feeding on the small rice plantlets. In contrast, with cry1B plants, the neonate larvae died during the first days of the infestation. These plantlets recovered completely and developed similarly to the non-infested control plants. With transgenic plants transformed with the mpi gene, the neonate larvae did not die but grew more slowly compared with the controls. Thus, this in vitro insect-feeding bioassay is a rapid and easy method to detect the resistance of cry and mpi transgenic plants to stem borers such as Chilo suppressalis.     

The Californian urban butterfly fauna is dependent on alien plants

Abstract. Using the unusually well-documented butterfly fauna of Davis, Yolo County, California, it is shown that the mainly native species commonly observed in gardens breed mostly or entirely on alien plants, especially naturalized weeds. Over 40% of the fauna has no known native hosts in the urban–suburban environment. Were certain alien weeds to be eradicated or their abundance greatly reduced, the urban-suburban butterfly fauna would disappear. This might be regarded as an unfortunate, and perhaps intolerable, side-effect of such programs.     

Increased mortality of Acanthoscelides obtectus by alkane-grown Beauveria bassiana

The effect of alkane-growth induction of theentomopathogenic fungus Beauveria bassiana(Balsamo) Vuillemin (Deuteromycotina:Hyphomycetes), on the ability to kill the beanweevil Acanthoscelides obtectus Say(Coleoptera: Bruchidae), was tested. Adultinsects were sprayed with an 0.01% Tween 20aqueous suspension of 4 × 10⁶ conidia/ml.The performance of fungi grown in complete agarmedium containing glucose as carbon source(FS₀) was compared to that of alkane-grownfungi (FS₁) with n-hexadecane as the onlycarbon source. Mortality increased (p< 0.05) from 22 ± 4.5% to 44 ±11.4% at day 7, and from 26 ± 5.5% to 60± 7.1% 14 days after treatment withFS₀ or FS₁ respectively. The insectepicuticular hydrocarbons were analysed bycapillary gas chromatography (CGC); majorcomponents were saturated hydrocarbons, 27 to29 carbons in length. A variety ofmethyl-branched isomers of C27 were theprevailing structures, and nC27 was the majorstraight chain component. Whole insecthydrocarbons were qualitatively identical tothose of the epicuticular surface. Oleic,linoleic and palmitic acids accounted foralmost 88% of the fungal fatty acids,irrespective of the carbon source used forgrowth; however, the unsaturated/saturatedratio diminished markedly from 4.32(FS₀) to 2.47 (FS₁). These resultsindicate that alkane supplementation of culturemedia might be a tool to improve the virulenceof some mycoinsecticides.     

Adult aquatic insects: Potential contributors to riparian food webs in Australia's wet–dry tropics

Abstract Changes in the abundance and biomass of aquatic and terrestrial aerial insects with distance (mid‐stream, 0, 10–15 and 160 m) from lowland streams were examined across the dry season landscape in Kakadu National Park, northern Australia. Malaise traps and sticky intercept traps were used to sample the insects at four streams, spaced over an area of 1650 km². Malaise and intercept catches were dominated by Diptera (flies and midges), both numerically and by biomass. Chironomid midges were the most abundant taxon, making up 43.4 and 51.0% of the malaise and intercept trap catches, respectively. However, most chironomids were small (less than 3 mm body length), contributing 34.9% to intercept trap biomass, but only 5.2% in malaise traps. Ceratopogonid midges and caddisflies (Trichoptera) accounted for most of the remaining adult aquatic insects. Major terrestrial components were Diptera and Hymenoptera in malaise traps and Coleoptera and Diptera in intercept traps. The total abundance and biomass of insects were much greater over streams and along the water's edge than in riparian (10–15 m) and savanna (160 m) habitats primarily because of the presence of large numbers of adult aquatic insects. The abundance and biomass of terrestrial insects in malaise traps showed no relationship with distance, but intercept trap catches suggested slightly greater abundances over the water and at the water's edge. The great abundance of aquatic insects relative to terrestrial insects close to streams suggests that they have the potential to be an important component of the diets of riparian insectivores, and predation may be an important pathway by which aquatic nutrients and energy are moved into terrestrial food webs.     

Fine needle aspiration cytology in the work-up of mammographic and ultrasonographic findings in breast cancer screening: an attempt at differentiating in situ and invasive carcinoma.

This study evaluated the results of fine needle aspiration cytology (FNAC) from the first four years of organized mammography screening for breast cancer in Oslo, particularly our policy in differentiating in situ and invasive carcinoma. Lesions were aspirated directly, ultrasound guided, by stereotaxic device or biopsy localization plate. All lesions were aspirated by cytopathologists working with the radiologists at the breast diagnostic centre. Smears were evaluated immediately for assessment of adequacy and a preliminary diagnosis was given to the surgeon. When FNAC revealed malignancy, diagnostic terms were as follows: (1) invasive carcinoma; (2) ductal carcinoma in situ of comedo type (high nuclear grade), cannot evaluate infiltration; (3) ductal carcinoma in situ of low nuclear grade and (4) papillary tumour, cannot evaluate infiltration. There were 953 cases, 70% of which were nonpalpable. Insufficient material was obtained in 5.8%. Absolute and complete sensitivity were 81% and 91%, respectively. Specificity was 85%. There were 448 histologically proven carcinomas. 383 of these were invasive. 362 carcinomas (in situ and invasive) (80.8%) were diagnosed directly on FNAC. Distinction between invasive and in situ carcinoma was possible in 294 of 320 directly diagnosed invasive carcinomas (91.8%). PPV of a diagnosis of invasive carcinoma was 97%. Our data showed that definitive cytological diagnosis of invasive carcinoma was possible in more than 90% of fully diagnostic smears and allowed definitive primary surgery in these women.