黄瓜新小绥螨对二斑叶螨的捕食效应研究

本文在25±1℃、相对湿度80％ ±5％和光照(L:D=16 h:8 h)条件下研究了黄瓜新小绥螨Neoseiulus cucumeris对二斑叶螨Tetranychus urticae不同螨态的捕食功能反应、捕食选择性及个体间干扰反应,以期为黄瓜新小绥螨的大田释放和利用提供理论依据.结果表明,黄瓜新小绥螨对二斑叶螨各...     

Integration of the predatory mite Neoseiulus californicus with petroleum spray oil treatments for control of Tetranychus marianae on eggplant

The red spider mite, Tetranychus marianae McGregor (Acari: Tetranychidae), a pest of several vegetable crops and perennials, is widespread in the Pacific Islands, like the Mariana Islands, where it was first reported. Recently, T. marianae has become a serious pest, particularly affecting eggplant. Efforts were therefore made to develop an integrated approach to control of T. marianae. First, indoor experiments on eggplant, Solanum melongena L. (Solanaceae), determined the optimal combination of petroleum spray oil (PSO; Volck® oil spray) with release of Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) for the management of T. marianae. Additionally, studies evaluated the viability of the predatory mites on Guam. The combination of N. californicus with PSOs produced significant control of T. marianae and did not affect the survival of N. californicus. Although dicofol and carbaryl reduced populations of T. marianae, they caused high mortality of N. californicus. Integrating PSO with N. californicus yielded better control of T. marianae than did N. californicus alone. The release of N. californicus at 200 individuals per plant reduced populations of T. marianae more than did other release rates. In addition, N. californicus was able to survive and become established after being released on Guam.     

Involvement of a corrinoid enzyme in methanogenesis from acetate in Methanosarcina barkeri

Abstract Extracts of acetate-grown Methanosarcina barkeri strain Fusaro formed methane from acetate plus ATP and form acetyl phosphate under H₂. Coenzyme A (CoA) is stimulatory. Inhibitors of methanogenesis are cyanide, propyliodide and bromoethanesulfonic acid. In cofactor-free extracts methanogenic activity from acetate was restored by addition of ATP, CoA, coenzyme M and 7-mercaptoheptanoylthreonine phosphate.
An enzyme-bound corrinoid was found to be involved in methanogenesis from acetate.     

不同温度下双尾新小绥螨对西花蓟马的捕食功能反应

为明确双尾新小绥螨Neoseiulus bicaudus各螨态对西花蓟马Frankliniella occidentalis不同龄期若虫的捕食量及不同温度对其捕食量的影响。本研究通过测定不同温度下24 h内双尾新小绥螨各螨态对不同密度西花蓟马若虫的捕食情况(西花蓟马猎物密度分别为5、10、15、20和25头/室,温度分别设置为23、26、29、32和35℃)。研究结果表明,双尾新小绥螨各螨态对猎物的捕食量随猎物密度的升高而增加。当温度为29℃,雌成螨对西花蓟马1龄若虫捕食量最高,在猎物数为25头/室时,可达4.4头/日。23~32℃内,双尾新小绥螨的雌成螨的捕食量随温度的上升而增加,到达35℃时开始降低。29~32℃双尾新小绥螨的雌成螨对西花蓟马1龄若虫的捕食量最高,可达6.7头/日,最适于其捕食。结果表明双尾新小绥螨对西花蓟马若虫的捕食功能反应类型符合Holling II模型,其对西花蓟马有较好的捕食能力,可利用于西花蓟马的生物防治。     

短时高温对加州新小绥螨发育的影响

为了探究高温逆境条件下加州新小绥螨的生存特性对其种群发育的影响,利用短时高温刺激试验,研究加州新小绥螨卵、幼螨、雌成螨在35、38、42、45 ℃等4个温度下、处理1～8 h后的孵化率、存活率、后期发育历期及繁殖的影响.结果表明: 处理温度越高,时间越长,卵和幼螨的存活率越低,其后续发育历期随处理温度升高和时间增加先缩短后延长.当温度为38 ℃,处理8 h后,卵的后续发育历期最短,为4.1 d.卵在45 ℃下处理2 h以上将不能正常孵化,而幼螨在45 ℃下处理8 h后不能存活;雌成螨产卵期和产卵量基本随温度升高先增加后降低,35 ℃处理8 h后,单雌产卵量最高,为38.9粒;38 ℃处理8 h后,单雌产卵量为36.7粒;45 ℃处理8 h后,单雌产卵量仅为14.5粒.短时高温主要影响加州新小绥螨的孵化率、存活率和后续发育历期,对雌成螨的产卵前期和存活率影响较小.     

Size,structure and nitrogen content of seeds of Fabaceae in relation to nodulation

Looking for clues to explain the low rate and unpredictability of the pollination of allogamous, epiphytic orchids in the context of the success of the orchid family in general, we compared the pollination of two miniature twig epiphytes in Mexico: Notylia barkeri, a ‘weedy’, rewarding species, and Erycina crista‐galli, a rare, deceptive species. We measured the effects of the spatial organization of the flowers and various parameters of visibility and height above the ground in relation to the spatial organization of the seed capsules (which retrospectively measures the activity of the pollinators). The spatial presentation of the flowers of E. crista‐galli explained only 5% of the distribution of the seed capsules. For N. barkeri, with compound flowers, the spatial presentation, considering individual flowers or inflorescences, explained 12% and 45% of the distribution of the seed capsules, respectively, and all other interactions between the variables were insignificant. Both the deceptive and reward strategies resulted in the production of large numbers of seeds despite a low pollination percentage (1–5%). Notylia barkeri produced 11.8 (2005–6) and 53.7 (2007–8) times more seeds in total than E. crista‐galli. Furthermore, unlike E. crista‐galli, N. barkeri responded to loss of individuals after high winds with an increased production of flowers per plant. We suggest that orchids have evolved to specialize in chance, and instead of maximizing pollinator attraction, they maximize the seed production resulting from every casual encounter. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 165 , 251–266.     

Assessing the Effects of Bt Maize on the Predatory Mite Neoseiulus cucumeris

The investigation of Neoseiulus cucumeris in the context of the ecological risk assessment of insect resistant transgenic plants is of particular interest as this omnivorous predatory mite species is commercially available and considered important for biological control. In a multitrophic feeding experiment we assessed the impact of Bt maize on the performance of N. cucumeris when offered spider mites (Tetranychus urticae) reared on Bt (Bt11, Syngenta) or non-Bt maize (near isogenic line) and Bt or non-Bt maize pollen as a food source. Various parameters including mortality, development time, oviposition rate were measured. Spider mites were used as a prey for N. cucumeris, since these herbivores are known to contain similar levels of Cry1Ab toxin, when reared on Bt maize, as those found in the transgenic leaf material. In contrast, toxin levels in pollen of this transgenic cultivar are very low. No differences in any of the parameters were found when N. cucumeris was fed with spider mites reared on Bt and non-Bt maize. Pollen was shown to be a less suitable food source for this predator as compared to spider mites. Moreover, subtle effects on female N. cucumeris (9% longer development time and 17% reduced fecundity) were measured when fed with pollen originating from Bt maize as compared to non-Bt maize pollen. Our findings indicate that the predatory mite N. cucumeris is not sensitive to the Cry1Ab toxin as no effects could be detected when offered Bt-containing spider mites, and that the effects found when fed with Bt maize pollen can be assigned to differences in nutritional quality of Bt and non-Bt maize pollen. The significance of these findings is discussed with regard to the ecological relevance for risk assessment of transgenic plants.     

猎物对巴氏钝绥螨生长发育和繁殖的影响

在(25±1)℃、90%RH以上、无光照实验条件下,以腐食酪螨和刺足根螨为猎物,研究了巴氏钝绥螨的生长发育和繁殖情况。结果表明,以腐食酪螨幼螨为猎物,巴氏钝绥螨可正常发育和繁殖,雌、雄成螨寿命分别为(34.250±1.361)和(23.950±1.606)d;以刺足根螨为猎物时,无法发育到成螨;成螨寿命明显缩短,雌、雄分别为(7.300±0.619)和(6.567±0.609)d,显著短于捕食腐食酪螨的巴氏钝绥螨,而且雌螨不能产卵。     

Review of Australian Asperoseius Chant, Euseius Wainstein, Okiseius Ehara and Phytoscutus Muma (Acari: Mesostigmata: Phytoseiidae) with a key to the genera of Australian Amblyseiinae and descriptions of two new species

Previous workers have used a conservative generic classification of the subfamily Amblyseiinae that treated most Australian Phytoseiidae as species in the genus Amblyseius Berlese. However, this lumping masks the occurrence of a number of genera recognised overseas, including some that contain important biological control agents. In this review, a key to the genera of Australian Amblyseiinae is provided and the Australian species in four amblyseiine genera are reviewed and keyed. Asperoseius Chant is represented by a single known Australian species, A. australiensis Fain and Krantz collected from a Culicoides midge in South Australia. Six species of Euseius Wainstein are recognised in Australia, including four endemics: E. dowdi (Schicha), E. elinae (Schicha), E. neovictoriensis (Schicha), and E. victoriensis (Schicha), and two Asia–Pacific species: E. noumeae (Schicha) and E. ovalis (Evans). Okiseius Ehara is represented in Australia by the previously described O. morenoi Schicha and O. domatorum (Schicha); the Asian species O. subtropicus Ehara (new record); and two new species, O. tribulation and O. cowbay described from tropical rainforest in Far North Queensland. Phytoscutus acaridophagus Collyer, a mite described from New Zealand, is reported in association with acarid mites ( Neotropacarus sp.) in Victoria and in Queensland.     

Correlation between Olfactory Responses, Dispersal Tendencies, and Life-history Traits of the Predatory Mite Neoseiulus Womersleyi (Acari: Phytoseiidae) of Eight Local Populations

To investigate the relationship between foraging behavior and life-history traits of the predatory mite Neoseiulus womersleyi, the olfactory responses, dispersal ratios from a prey patch, predation rates, fecundity, and developmental times in eight local populations of N. womersleyi were investigated. Significant differences among local populations were found in all these traits except fecundity. None of the life-history traits correlated with foraging behavior. A significant positive correlation was found only between the olfactory response and the dispersal ratio. These results suggested that predatory mites with low olfactory responses would stay in a prey patch longer than predatory mites with high olfactory responses.