两种防治措施下转Bt基因棉田绿盲蝽的发生与为害

2002年在河北省南皮县对2种防治措施下转Bt基因田绿盲蝽LyguslucorumMayre的发生与为害进行的系统调查表明,采用生物农药和低毒化学农药防治4次,Bt棉田绿盲蝽的发生为害较为严重,9月上旬发生高峰期种群密度为7.2头10株,显著高于防治指标,第2代绿盲蝽为害高峰期,叶片被害率为19.4%;采用当地棉农化学防治方法施用农药7次,Bt棉田绿盲蝽发生为害较轻,发生高峰期(8月中旬)种群密度为2.0头10株,第2代绿盲蝽为害高峰期,叶片被害率为4.8%。讨论指出绿盲蝽已成为转Bt基因棉生产中的重要问题,应加快绿盲蝽在转Bt基因棉田的生态调控研究。     

Evidence of population-level lateralized behaviour in giant water bugs, Belostoma flumineum Say (Heteroptera: Belostomatidae): T-maze turning is left biased

Lateralized behaviour occurs in diverse animals, but relatively few studies examine the phenomenon in invertebrates. Here we report a population-level left turn bias in the giant water bug Belostoma flumineum Say (Heteroptera: Belostomatidae) in an underwater T-maze. Individuals made significantly more left turns than right turns, including when they were naïve and first introduced to the maze. Water bugs also showed significantly longer runs of consecutive left turns than right turns (i.e. LLLLL). The length of these runs, however, did not increase with experience in the maze, suggesting that the effect is not the result of learning. There were also no differences in turning bias between male and female water bugs. The proximate mechanism(s) underlying the left turn bias is unknown, but directional cues in the environment were eliminated by rotating the maze 180° between experiments, suggesting the mechanism(s) is endogenous. To our knowledge this is the first study of lateralized behaviour in the Heteroptera or in a swimming invertebrate animal.     

草履蚧一龄若虫的发育历期与防治

在郑州通过室外埋卵观察,草履蚧Drosicha corpulenta Kuwana从1月初开始孵化,孵化后在土里等到2月初开始出土,此时日最高气温在6～8℃之间。若虫出土期约30d,2月中下旬为出土高峰期。经设置14,18,22,26和30℃5个温度梯度观察,草履蚧1龄若虫发育起点温度为7.9℃,有效积温为203.8日.度。利用树干绑缚杀虫药带防治效果达到98%以上。     

悬铃木方翅网蝽: 一种正在迅速扩张的城市外来入侵害虫

悬铃木方翅网蝽(Corythucha ciliata)是新近入侵我国城市生态系统的外来害虫, 严重危害城市行道树悬铃木(Platanus spp.), 自2002年该虫在湖南长沙首度报道以来, 已在我国11个省(直辖市)的25个城市发生, 尤其在长江流域呈现爆发态势。本文系统介绍了悬铃木方翅网蝽的生活史、生活习性、繁殖潜力等生物学特性, 以及扩散速度与方式、影响发生的主要环境因素、种群的耐寒耐热能力等生态学特性。最后, 在分析该虫的寄主及危害特点的基础上, 对其控制与管理对策进行了综述, 以为其管理提供参考。     

Colonization preference of Euschistus servus and Nezara viridula in transgenic cotton varieties,peanut, and soybean

Producers of Bt cotton, Gossypium hirsutum L. (Malvaceae), in the southeastern USA face significant losses from highly polyphagous stink bug species. These problems may be exacerbated by crop rotation practices that often result in cotton, peanut, Arachis hypogaea L., and soybean, Glycine max (L.) Merrill (both Fabaceae), growing in close proximity to one another. Because all of these crops are hosts for the major pest stink bug species in the region, we experimentally examined colonization preference of these species among the crops to clarify this aspect of their population dynamics. We planted peanut, soybean, Bt cotton, and glyphosate‐tolerant (RR) non‐Bt cotton at three sites over 3 years in replicated plots ranging from 192 to 1 323 m² and calculated odds ratios for colonization of each crop for Nezara viridula (L.) and Euschistus servus (Say) (both Hemiptera: Pentatomidae). In four of five experiments, both E. servus and N. viridula preferred soybean significantly more often than Bt cotton, non‐Bt cotton, and peanut. Neither N. viridula nor E. servus showed any preference between non‐Bt and Bt cotton in any experiment. Both species had higher numbers in Bt and non‐Bt cotton relative to peanut; this was not significant for any single experiment, but analyses across all experiments indicated that N. viridula preferred Bt and non‐Bt cotton significantly more often than peanut. Our results suggest that soybean in the landscape may function as a sink for stink bug populations relative to nearby peanut and cotton when the soybean is in the reproductive stage of development. Stink bug preference for soybean may reduce pest pressure in near‐by crops, but population increases in soybean could lead to this crop functioning as a source for later‐season pest pressure in cotton.     

Developmental response of the beneficial predator Podisus maculiventris to change in dietary ascorbic acid concentration

We report here the effects of a range of ascorbic acid concentrations (0.07, 0.3, 3.0, and 30.0 g l^?1) in artificial diets on growth rates, adult weights, fecundity, and survival over two generations of the predatory stink bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae). Overall, a dietary level of 3.0 g l^?1 gave the shortest developmental times over two generations. The likelihood of egg hatch at one ascorbic acid concentration compared to another concentration suggested that egg hatch increased as the concentration of ascorbic acid increased from 0.07 to 3.0 g l^?1 and then declined from 3.0 to 30.0 g l^?1. The combination of the maximum egg oviposition at 0.3 and 3.0 g l^?1, egg hatch at 3.0 g l^?1, and survival at 0.07 and 0.3 g l^?1 suggests an overall superior performance at a concentration between 0.3 and 3.0 g l^?1. Depletion of ascorbic acid below 3.0 g l^?1 or addition of ascorbic acid above 3.0 g l^?1 lowered the likelihood of egg hatch, which became more pronounced in the second generation. This is consistent with previously published information for phytophagous insects.     

Diversity of commensal Bacillus cereus sensu lato isolated from the common sow bug (Porcellio scaber, Isopoda)

Although Bacillus cereus sensu lato are important both from an ecological and an economical point of view, little is known about their population structure, ecology, and relationships with other organisms. In the present work, the genotypic similarity of arthropod-borne B. cereus s.l. isolates, and their symbiotic relationship with the host are assessed. Bacilli of this group were recovered from the digestive tracts of sow bugs (Porcellio scaber) collected in three closely located sites. Their genotypic diversity was investigated using pulse-field gel electrophoresis (PFGE) following the whole-genome DNA digestions with NotI and AscI, and PCR amplification of virulence genes. The majority of the sow-bug Bacillus cereus sensu stricto isolates originating from the same but also from different sites displayed identical PFGE patterns, virulence gene content and enterotoxicity, indicating strong genetic and genomic relationships. The sow-bug Bacillus mycoides/Bacillus pseudomycoides strains displayed a higher diversity. The isopod-B. cereus s.l. relationship was also evaluated using antibiotic-resistant derivatives of B. cereus s.s., B. mycoides/B. pseudomycoides and Bacillus thuringiensis reintroduced into sow bugs. Both spores and vegetative cells of B. cereus s.l. were recovered from sow bugs over a 30-day period, strongly suggesting that these bacteria are natural residents of terrestrial isopods.     

Influence of harmonic radar tag attachment on nymphal Halyomorpha halys mobility,survivorship, and detectability

The brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is a polyphagous invasive insect and currently one of the most threatening agricultural pests in the USA and globally. Nymphs are highly mobile, moving among host plants, and causing significant damage. Thus, understanding dispersal biology for all life stages is critical for the development of reliable monitoring and management programs. Here, we evaluated the influence of harmonic radar as a tool to study dispersal ecology of nymphal H. halys; we measured the impact of glues and tag attachment on survivorship and mobility in the laboratory and validated in the field that tagged and released nymphs could be tracked on baited and unbaited host and non‐host plants using harmonic radar. In the laboratory, four glues were evaluated for attaching harmonic radar tags securely to nymphs, and survivorship with attached tags was measured. There were no significant differences in survivorship or vertical and horizontal movement among nymphs with tags affixed with the glue treatments compared with the untagged control. Based on numerically greater survivorship of nymphs with tags affixed with Loctite glass glue, a field validation study of tagged nymphs released in host (apple tree) and non‐host (mowed grass) with or without H. halys pheromonal stimuli present revealed that nymphs could be successfully relocated using harmonic radar after 48 h. Among treatments, 83% of nymphs remained in baited and unbaited apple trees, 50% of nymphs remained in baited mowed grass plots, and in unbaited mowed grass plots, 17% of fifth instars, and 0% of fourth instars were retained. The absence of negative effects on mobility, survivorship, and field tracking validates that harmonic radar can be used to study dispersal ecology of nymphal H. halys.     

红火蚁蚁巢嗜蚁土蝽虫体成分及其化学防御成分鉴定

红火蚁Solenopsis invicta Buren对入侵其蚁巢的其他昆虫具有强烈的攻击性,然而时常发现嗜蚁土蝽Macroscytus sp. 成虫在红火蚁蚁巢内活动。为了明确嗜蚁土蝽成功“寄生”红火蚁蚁巢的化学机制,本研究利用GC-MS技术分析嗜蚁土蝽的表皮挥发性成分,并选取tridecane等4种主要成分对红火蚁工蚁进行触杀和熏蒸毒力测定。结果表明嗜蚁土蝽虫体挥发物共有10种化合物,包括3种醛类、3种酯类、3种正构烷烃和1种醇类,其中tridecane和(E)-2-decenyl acetate是主要成分,其相对含量为54.12%和19.32%。土蝽挥发性成分中(E)-2-decenal和(E)-2-decenyl acetate对红火蚁工蚁具有较强的触杀毒力,仅(E)-2-decenal对红火蚁表现出一定的熏蒸效果。本研究证实了嗜蚁土蝽虫体挥发性成分对红火蚁具有较强的化学防御能力,可能是其能成功寄生在红火蚁巢内的原因之一。