Repellent and toxic properties of plant oils and extracts on Cydalima perspectalis Walker (Lepidoptera: Crambidae)

Buxus plants in Europe become frequently infested by the Box tree moth, Cydalima perspectalis Walker (Lepidoptera: Crambidae) but applicable biological control methods are limited. To make a first step in preventing egg deposition on Buxus plants, seven essential oils (Carum carvi, Juniperus communis, Lavendula angustifolia, Melaleuca alternifolia, Pinus sylvestris, Rosmarinus officinalis and Thymus vulgaris), one seed oil (Sambucus nigra) and six plant extracts (Equisetum arvense, Juniperus communis, Quassia amara, Salvia officinalis, Tanacetum vulgare and Thymus vulgaris) were investigated on their potential to influence oviposition preference in the greenhouse. The four essential oils exhibiting the highest repellency values (RV = 0.61–0.94) were further assessed in laboratory leaf disc bioassays on larvae. Despite the strong repellent effect of S. nigra on female oviposition, no impact could be detected on the larvae. These were significantly susceptible to exposed leaf discs treated with T. vulgaris and M. alternifolia essential oils including feeding deterrence, survival and larval weight. T. vulgaris was the most effective oil considering both effects. The effective lethal concentration (LC₅₀) of T. vulgaris was calculated to be 1% at 72 h. Our results suggest the possibility of using essential oils to protect Buxus plants in order to reduce the overall risk for defoliation by larval feeding.     

Hagfish (cyclostomata, vertebrata): searching for the ancestral developmental plan of vertebrates

The phylogenetic position of the hagfish remains enigmatic. In contrast to molecular data that suggest monophyly of the cyclostomes, several morphological features imply a more ancestral state of this animal compared with the lampreys. To resolve this question requires an understanding of the embryology of the hagfish, especially of the neural crest. The early development of the hagfish has long remained a mystery. We collected a shallow-water-dwelling hagfish, Eptatretus burgeri, set up an aquarium tank designed to resemble its habitat, and successfully obtained several embryos. By observing the histology and expression of genes known to play fundamental roles in the neural crest, we found that the hagfish crest develops as delaminating migratory cells, as in other vertebrates. We conclude that the delaminating neural crest is a vertebrate synapomorphy that seems to have appeared from the beginning of their evolutionary history, before the splitting away of the hagfish lineage.     

Sexual behavior of the navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae)

To get a better understanding of the mating behavior of the navel orangeworm, Amyelois transitella (Walker), we developed a robust laboratory colony derived from larvae collected in Bakersfield, California and fed on dried, roasted pistachio. In the lab at 25 degrees C, most of the mating activity was observed during the last hour of the scotophase and for the first 30 min of the photophase. Female calling was characterized by the abdomen being protruded between the wings with the distal segments perpendicular to the body and exposing a pheromone gland, as well as by continuous antennation. Males approached calling females from a short distance by displaying wing fanning and antennation. When a male antennated on a calling female's abdomen, she either accepted the male and lowered the abdomen, or walked away. The accepted male made a final approach parallel to the female's body, but after coupling he rotated 180 masculine with male and female remaining in a linear, abdomen-to-abdomen position for over 3 h in average. In a possible strategy to maximize the chances of mating, the sex ratio was significantly skewed towards males in the first two days of emergence. Almost 80% of mating took place in the first two days after adult emergence, with females mating only once. About 55% of males mated only once and approximately 40% of the observed males mated twice and 5% tree times.     

A novel disease affecting the predatory mite Phytoseiulus persimilis (Acari, Phytoseiidae): evidence for the involvement of bacteria

Adult female Phytoseiulus persimilis Athias-Henriot (Acari, Phytoseiidae) of a laboratory population show drastic changes in foraging behavior, anatomy and life history compared to typical laboratory populations. We demonstrated earlier that the set of characteristic symptoms, called non-responding (NR) syndrome, is transmitted horizontally between and among predator generations via feces and debris deposited by symptomatic females. Here, we prove that bacteria present in feces and debris deposited by symptomatic females are involved in the induction of the NR-syndrome. The potential of predator products to induce the NR-syndrome was assayed by keeping healthy adult female predators during a period of 3 days on prey-infested bean leaves, which had previously been sprayed with an aqueous suspension of feces and debris. The NR-syndrome was clearly induced in those predators that had been exposed to a suspension collected from symptomatic females (incubation time 4-6 days, 93% shrunken females), whereas predators exposed to a suspension collected from non-symptomatic females did not show the NR-syndrome. Moreover, predators from the first group transmitted infectious products themselves already 5 days after the initial exposure, whereas this was not the case for the second predator group. The bioassay used in the present study is important for laboratories and companies as it can be applied for testing the presence of the novel disease in populations of P. persimilis. To investigate the involvement of bacteria in syndrome induction we (1) eliminated bacteria from a feces-and-debris suspension of symptomatic females by passing the suspension through a bacterial microfilter and (2) added the antibiotic tetracycline to a suspension of feces and debris from symptomatic females. A suspension of feces and debris collected from symptomatic females did not induce the NR-symptom after bacteria had been eliminated, whereas an untreated portion of the same suspension did so. Moreover, the NR-syndrome was induced in predators exposed to an aqueous suspension of the residues that had not passed the bacterial filter. A suspension of feces and debris collected from symptomatic females, to which the antibiotic tetracycline had been added, did not induce the NR-syndrome whereas the same suspension did induce all symptoms when no tetracycline was added. These findings prove that bacteria are involved in the induction of the NR-syndrome. The results are discussed in the context of mite pathology and biological control.     

影响二化螟种群变化的主导因素分析及其趋势的简易预测

通过对广德县1978～1994年二化螟系统调查资料的分析,表明7～10月为引起种群数量年变化的关键时期;7、8月的平均温度为引起种群年变化的主导因子。并选用7月均温,建立了年变化趋势的简易预测方法,16年回检,正确率达87．5％,2年预检,准确率为100％。     

浙江省棱角肿腿蜂属种类记述（膜翅目：肿腿蜂科：肿腿蜂亚科）

我国已知棱角肿腿蜂属 Goniozus Forster,1 856四种 ,即日本棱角肿腿蜂 G.japonicus Ashmead,1 90 4;中华棱角肿腿蜂 G.sinicus Xiao et Wu,1 987;蓬莱棱角肿腿蜂 G.hoorai Terayama,1 999和八重山棱角肿腿蜂 G.yaeyamanus Terayama,1 999。本文记述浙江省棱角肿腿蜂属 4种 ,其中除日本棱角肿腿蜂 Goniozusjaponicus Ash-mead,1 90 4为已知种外 ,其余 3个为新种 ,即 :萧氏棱角肿腿蜂 Goniozus xiaoi,sp.nov.,百山祖棱角肿腿蜂 Goniozus baishanzuensis,sp.nov.和豆卷螟棱角肿腿蜂 Go-niozus lamprosemae,sp.nov.。这样使中国棱角肿腿蜂属增加到 7种。1 .萧氏棱角肿腿蜂 Goniozus xiaoi,新种 (图 1～ 5)该新种与分布于日本和我国台湾的蓬莱棱角肿腿蜂 G.hoorai Terayama,1 999较相似 ,但新种触角第 2至 5节各节长明显大于宽 ;并胸腹节背表面后缘的横脊不完整 ,仅在并胸腹节的后侧角可见。正模 :♀ ,浙江庆元百山祖 ( 2 7.45°N,1 1 9.1 2°E) ,1 993 - -0 6,吴鸿 ,No.9452 91。副模 :1♀ ,浙江松阳 ( 2 8.2 7°N,1 1 9.2 9°E) ,1 994- -0 7,陈汉林 ,No.948481。2 .百山祖棱角肿腿蜂 Goniozus baishanzuensis,新种 (图 6～ 1 0 )本新种的触角与日本棱角肿腿蜂 Goniozusjaponicus Ashmead,1 90 4的触角     

Two New Subspecies of Herpetomonas muscarum (Leidy, 1856) Kent, 1880

SYNOPSIS. Herpetomonas muscarum muscarum n. subsp. was isolated from Musca domestica L. In culture at 20 C it assumed the opisthomastigote (up to 15%), double-flagellate and flagellate promastigote forms. At 30 C or with 4% urea added to cultures at 20 C, the proportion of opisthomastigotes was greater (up to 40%). In experimentally infected flies only transient infections, which included both opisthomastigotes and promastigotes, occurred. The promastigotes were 15–30 μ long and the kinetoplast was small and subspherical or transversely elongate. H. muscarum ingenoplastis n. subsp. was isolated from Phormia regina (Meigen). In culture at 20 C almost all individuals were double-flagellate promastigotes 20–40 μ long and less than 1% were opisthomastigotes. At 30 C or with added urea there was no increase in the proportion of opisthomastigotes and the cultures were not vigorous. In experimentally infected flies opisthomastigotes were 5–39% of the population depending on the part of the gut sampled. In all stages the kinetoplast was large (1.5–2.5 μ long) and tear-drop-shaped with the point directed posteriorly.
In artificially mixed cultures of H. m. muscarum and H. m. ingenoplastis the former predominated after a short time and eventually survived alone. A mixed culture that was about 98% H. m. muscarum was fed to Phormia regina and produced heavy pure infections of H. m. ingenoplastis , which lasted for 22 days with no indication of decline. No evidence of cyst formation was found in either subspecies.     

Mild cognitive impairment: searching for the prodrome of Alzheimer's disease

The concept of mild cognitive impairment (MCI) identifies persons who are neither cognitively normal nor demented. There is increasing evidence that MCI defines a group of persons who are at near-term risk of developing dementia and particularly Alzheimer''s disease (AD). MCI thus constitutes an attractive target population for preventive treatments of AD. MCI is associated with aging and is more prevalent than dementia. There are several clinical and biological markers that are predictive of MCI prognosis, including depressive symptoms, cognitive deficits, brain imaging and neurochemical findings. The clinician needs to be especially alert to depressive and other mood symptoms which are common in MCI and potentially treatable. Trials of current medications for prevention of MCI progression to dementia have been largely negative. There are observational data suggesting that lifestyle modifications including exercise, leisure activities, cognitive stimulation, and social activities may be effective for prevention of MCI progression. There are many novel therapies currently in trials for early AD, and if effective they may prove to be helpful in prevention of MCI progression as well.     

Factors affecting the establishment and dispersal of nymphs of Pristhesancus plagipennis Walker (Hemiptera: Reduviidae) when released onto soybean, cotton and sunflower crops

Abstract A problem with augmenting predatory bugs through mass release is the logistical difficulty of delivering nymphs onto the foliage of field crops. In this paper we examine postrelease establishment and dispersal of the nymphs of the predatory bug Pristhesancus plagipennis on soybean, cotton and sunflower in an effort to devise an appropriate strategy for field release. The effects of predator stadia and release rates on field establishment and within-crop-canopy dispersal after hand release were recorded in soybean, cotton and sunflower. Field establishment improved with the release of more-developed nymphs, with third instars providing the most appropriate compromise between field hardiness and rearing cost. Increased nymphal density at the point of release had little effect on nymphal dispersal throughout the crop canopy. The patterns of nymphal dispersal observed on the three crops suggest that crop-canopy architecture may have an effect on the ability of nymphs to spread out postrelease, as nymphs dispersed poorly in cotton and sunflower compared to soybean. To overcome poor dispersal of nymphs after release, a mechanical release method, where nymphs were mixed with vermiculite and delivered onto a target crop through a spinning disk fertiliser spreader, was tested, and provided similar nymph establishment rates and dispersal patterns as releasing nymphs individually by hand. The implications of nymph dispersal and field hardiness in regard to inundative field release techniques are discussed.     

栉眼蚤属一新种记述：蚤目：多毛蚤科

本文记述１９８９年５月在湖北省神农架林区捕获的褐家鼠体上采到的一新种跳蚤鄂西栉眼蚤Ｃｔｅｎｏｐｈｔｈａｌｍｕｓ ｅｘｉｅｎｓｉｓ ｓｐ．其形态与似种近甘肃栉眼蚤Ｃｔｅｎｏｐｈｔｈａｌｍｕｓ ｇａｎｓｕｅｎｓｉｓ Ｗｕ,Ｚｈａｎｇ ｅｔ Ｗａｎｇ,１９８２和短突栉眼蚤Ｃ．（Ｓ．）ｂｒｅｖｉｐｒｏｊｉｃｉｅｎｓ Ｌｉ ｅｔ Ｈｕａｎｇ,１９８０进行了比较。     

Oviposition and larval dispersal of the common armyworm,Mythimna convecta (Walker) (Lepidoptera: Noctuidae)

The common armyworm, Mythimna convecta (Walker), is a pest of cereal crops and pasture grasses in Australia. During autumn, egglaying in grasslands commonly occurs before plant growth commences. The possible association between oviposition and dried grasses was investigated in field studies of larval distribution in a pasture and a crop habitat, and in laboratory studies of oviposition site preferences and the mode of dispersal of newly hatched first instar larvae. A comparison of a green grass pasture with and without a component of dried grass showed that highest densities of M. convecta larvea. were found in the former. In the laboratory, egg batches were laid between plant parts in close contact, such as between the stem and leaf axil and between seeds in the seed head. The crevices in dried plant material and seed-heads were significantly more acceptable for oviposition than in green foliage. Oviposition in dried plant material enables M. convecta to rapidly colonize ephemeral grasslands immediately after rains when the neonate larvae can disperse and feed on new vegetative growth. Shortly after hatching, 93% of first instar larvae used fine silken threads for aerial dispersal in 0.5 m s^-1 air currents and 43% were blown a distance of more than 1.0 m. In the field, sticky traps caught larvae dispersing in all directions from a central source, and indicated that approximately 30% were transported 2 m after 7 days of light to medium breezes. Terminal velocities of newly hatched larvae were 20–130 cm s^-1, depending on the length of the trailing thread.     

中国辽宁蕨蝇属一新种(双翅目:花蝇科)

发现分布于我国辽宁省的花蝇科Anthomyiidae蕨蝇属Chirosia一新种:附突蕨蝇Chirosia appendiprotuberans sp.nov.。模式标本采自辽宁省本溪市,文中给出了新种的种类描述、特征图和属的隶属问题。