16 resultados para Cecidomyiidae


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In south-eastern Queensland, Australia, sorghum planted in early spring usually escapes sorghum midge, Stenodiplosis sorghicola, attack. Experiments were conducted to better understand the role of winter diapause in the population dynamics of this pest. Emergence patterns of adult midge from diapausing larvae on the soil surface and at various depths were investigated during spring to autumn of 1987/88–1989/90. From 1987/88 to 1989/90, 89%, 65% and 98% of adult emergence, respectively, occurred during November and December. Adult emergence from larvae diapausing on the soil surface was severely reduced due to high mortality attributed to surface soil temperatures in excess of 40°C, with much of this mortality occurring between mid-September and mid-October. Emergence of adults from the soil surface was considerably delayed in the 1988/89 season compared with larvae buried at 5 or 10 cm which had similar emergence patterns for all three seasons. In 1989/90, when a 1-cm-deep treatment was included, there was a 392% increase in adult emergence from this treatment compared with deeper treatments. Some diapausing larvae on the surface did not emerge at the end of summer in only 1 year (1989/90), when 28.0% of the larvae on the surface remained in diapause, whereas only 0.8% of the buried larvae remained in diapause. We conclude that the pattern of emergence explains why spring plantings of sorghum in south-eastern Queensland usually escape sorghum midge attack.

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To quantify the role of Johnson grass, Sorghum halepense, in the population dynamics of the sorghum midge, Stenodiplosis sorghicola, patterns of flowering of Johnson grass and infestation by sorghum midge were studied in two different climatic environments in the Lockyer Valley and on the Darling Downs in south-eastern Queensland for 3 years. Parasitism levels of S. sorghicola were also recorded. In the Lockyer Valley, Johnson grass panicles were produced throughout the year but on the Darling Downs none were produced between June and September. In both areas, most panicle production occurred between November and March and infestation by S. sorghicola was the greatest during this period. The parasitism levels were between 20% and 50%. After emergence from winter diapause, one to two generations of S. sorghicola developed on S. halepense before commercial grain sorghum crops were available for infestation. Parasitoids recorded were: Aprostocetus diplosidis, Eupelmus australiensis and two species of Tetrastichus. Relationships between sorghum midge population growth rate and various environmental and population variables were investigated. Population size had a significant negative effect (P < 0.0001) on population growth rate. Mortality due to parasitism showed a significant positive density response (P < 0.0001). Temperature, rainfall, open pan evaporation, degree-days and host availability showed no significant effect on population growth rate. Given the phenology of sorghum production in south-eastern Queensland, Johnson grass provides an important bridging host, sustaining one to two generations of sorghum midge. Critical studies relating population change and build-up in sorghum to sorghum midge populations in Johnson grass are yet to be performed.

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Dentifibula nigroapicalisKolesik sp. nov., a new species of gall midge, is described whose larvae were found preying on the mangrove scale insect Aulacaspis australisBrimblecombe (Hemiptera: Coccoidea: Diaspididae). The mangrove scale was feeding on leaves of the mangrove Bruguiera gymnorrhiza (Rhizophoraceae) in Queensland. The new species is the first DentifibulaFelt known from Australia. © 2013 Australian Entomological Society.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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The purpose of this study was to evaluate the damage potential of Dasineura sp. (Diptera: Cecidomyiidae) in the pepper cultivars and show its occurrence in Piracicaba, SP. This experiment was carried out from July to November 1998. The occurrence and damages pest in the fruits were determined by weekly evaluations of pepper hybrids, 'Magali R.' larvals were collected from floral buttons and adults were collected from the incubation of buttons in humidity chamber. Healthy and infested fruits were evaluated for damages caused by pest insects. The results indicated that the damages can reach 100% in some periods of evaluation and that the production losses are significantly high with no application of insecticides. The taxonomy study was performed at National Museum of Federal University of Rio de Janeiro (UFRJ). The insect species classification will be the object of study since there is a possibility of observing a specie not described yet.

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In south-eastern Queensland, Australia, sorghum planted in early spring usually escapes sorghum midge, Stenodiplosis sorghicola, attack. Experiments were conducted to better understand the role of winter diapause in the population dynamics of this pest. Emergence patterns of adult midge from diapausing larvae on the soil surface and at various depths were investigated during spring to autumn of 1987/88-1989/90. From 1987/88 to 1989/90, 89%, 65% and 98% of adult emergence, respectively, occurred during November and December. Adult emergence from larvae diapausing on the soil surface was severely reduced due to high mortality attributed to surface soil temperatures in excess of 40 degrees C, with much of this mortality occurring between mid-September and mid-October. Emergence of adults from the soil surface was considerably delayed in the 1988/89 season compared with larvae buried at 5 or 10 cm which had similar emergence patterns for all three seasons. In 1989/90, when a 1-cm-deep treatment was included, there was a 392% increase in adult emergence from this treatment compared with deeper treatments. Some diapausing larvae on the surface did not emerge at the end of summer in only 1 year (1989/90), when 28.0% of the larvae on the surface remained in diapause, whereas only 0.8% of the buried larvae remained in diapause. We conclude that the pattern of emergence explains why spring plantings of sorghum in south-eastern Queensland usually escape sorghum midge attack.

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The saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae), has undergone a resurgence recently as a pest of cereals in Belgium and other European countries. An effective monitoring tool of saddle gall midge flights is needed to understand the enigmatic population dynamics of this pest, and to design an integrated management strategy. Therefore, volatile compounds emitted by females (alkan-2-ols and alk-2-yl butanoates) were identified, and the chirality of the emitted esters was determined to be the R absolute configuration. In field-trapping experiments, racemic non-2-yl butanoate attracted substantial numbers of H.marginata males. Thus, this compound will be useful in baited traps for monitoring seasonal flight patterns, and improving integrated management of the saddle gall midge in agricultural systems.

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Larvae of an undescribed gall midge were found feeding on leaves and stems within leaf sheaths and between leaf blades of potted plants of Cordyline fruticosa (Asparagaceae) in a production nursery in Queensland. The following varieties of the host plant were infested: Apple Blossom', Glauca', Kilauea', Negra', Pink Diamond, 'Purple Prince' and Willy's Gold'. The new species, Dasineura cordylineaeKolesik sp. nov., is described and its cytochrome oxidase unit I mitochondrial gene segment is sequenced. The new species is the first known gall midge feeding on a plant species of the genus Cordyline. Orange larvae induce oval shallow swellings on the leaf and stem tissue, which becomes necrotised during the later stage of larval feeding. Necrotic areas remain visible to the end of leaves' lives and decrease the market value of the plants. In the production nursery investigated, the lesions caused by the gall midge provided an entry for a fungal infection by Fusarium sp. inflicting further injury to plants. Larvae of the new species were preyed on by larvae of Gaurax sp. (Diptera: Chloropidae). This is the first worldwide record of Chloropidae preying on Cecidomyiidae.

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Bellyache bush (Jatropha gossypiifolia, Euphorbiaceae), a deciduous shrub introduced as an ornamental from tropical America, is a major and expanding weed of rangelands and riparian zones in northern Australia. Biological control is the most economically viable and long-term management solution for this weed. Surveys for potential biological control agents for J gossypiifolia in Mexico,Central America and the Caribbean resulted in release of the seed-feeding jewel bug Agonosoma trilineatum (Hemiptera: Scutelleridae), which failed to establish, and prioritisation of a leaf-rust Phakopsora arthuriana (Puccineales: Phakopsoraceae) for host-specificity testing, which is ongoing. With poor prospects for new agents from Mexico and Central America and the Caribbean, the search for candidate agents on J gossypiifolia shifted to localities south of the equator. Surveys were conducted on the purple-leaf form of J gossypiifolia, Jatropha excisa, Jatropha clavuligera and Jatropha curcas in Peru, Bolivia and Paraguay in 2012 and 2013. A total of 11 insect species, one mite species and the leaf-rust (P. arthuriana) were observed. These include a yet to be described leafmining moth (Stomphastis sp.) (Lepidoptera: Gracillaridae), a shoot and leaf-galling midge Prodiplosis longifila, and leaf-feeding midge Prodiplosis sp. near longifila (both Diptera:Cecidomyiidae) and an unidentified leaf-feeding moth larva (Lepidoptera: Notodontidae). The leafminer is widespread and damaging and has a field host range restricted to the genus Jatropha in Peru and Bolivia, holds the greatest promise as a biological control agent in Australia. Phakopsora arthuriana was recorded for the first time ever from Bolivia and Peru. Further exploration will be conducted in Peru and Bolivia during the wet season to confirm the field host range of collected agents,and to look for more new agents. Promising agents with field host-range restricted to Jatropha spp. will be imported into a quarantine facility in Australia for host-specificity testing.

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五味子科(Schisandraceae)隶属于木兰亚纲八角目(Illiciales),为攀缘藤本,花单性,雌雄异株或同株。近年来分子系统学的研究结果显示,一个包括八角目在内的所谓ANITA类群(Amborellaceae – Nymphaeales – Illiciales – Trimeniaceae - Austrobaileyaceae)代表了被子植物最基部的类群。这使得五味子科成为解决原始被子植物起源和演化问题的重要类群之一,而倍受关注。作为被子植物的原始类群,其繁育系统、传粉生物学和种子传播等方面的知识对于理解被子植物起源和基部各大类群之间的系统发育关系是至关重要的,而五味子科在这些方面的研究几乎还是空白。本研究选取几种代表不同雄蕊群类型的五味子科植物,对其进行传粉生物学和种子散播方式的研究,在此基础上讨论了该科植物和早期被子植物的传粉机制和种子散播机制。 1.翼梗五味子的传粉生物学 翼梗五味子是严格的雌雄异株。雄花在颜色、形状和大小上都与雌花非常相似,但是数量明显多于雌花。在开放后,雌雄花的花被片都不完全张开,把雄蕊群和雌蕊群包在其中,花被片和雄蕊群或雌蕊群之间的空隙非常狭小。翼梗五味子的花不能产热,不能散发出花香,也不分泌花蜜。翼梗五味子的传粉者只有Megommata sp.(瘿蚊科)的雌性成虫,花粉是对传粉者的唯一回报。Megommata sp.访问翼梗五味子的雄花摄取花粉作为其卵巢发育或产卵所需的额外营养,而雌花则是通过模拟雄花的形态来吸引昆虫的。绿叶五味子的传粉机制与翼梗五味子相似,也是雌花模拟雄花的形态欺骗昆虫访花。这种欺骗性传粉在基部被子植物是普遍存在的。 2.南五味子的传粉生物学 南五味子是雌雄同株。雌雄花的花被片都是黄色,子房绿色,雄蕊有黄色和红色两种颜色,开黄色雄花的和开红色雄花的植株在所研究的14个居群中都是随机分布的。南五味子的雌雄花都是在晚上开放,并能散发出强烈的花香,红色雄花、黄色雄花和雌花的花香成分非常相似,主要成分都是丁酸甲酯 (methyl butyrate)。南五味子的雌雄花还可以产生热量。南五味子的传粉者只有一种昆虫-- Megommata sp.(瘿蚊科),它们的访花时间与花香的散发时间以及花热产生的时间基本吻合,都集中在花开后的4-5小时内。在南五味子中,花香在吸引传粉者上起着决定性作用,花热可以增强花香的散发,而花色则不起作用。花粉是南五味子对Megommata sp.的唯一的回报,雌花利用与雄花相同的诱物(花香和花热)来吸引传粉者,因此南五味子的传粉系统也是一种欺骗性传粉。 3.五味子科植物的传粉系统 五味子科植物的花一般比较小,花器官多而不定,螺旋状排列。五味子科不存在风媒传粉,传粉昆虫主要是双翅目昆虫和甲虫类。翼梗五味子、南五味子、绿叶五味子只是由瘿蚊科Megommata属的一种昆虫来传粉的,表现出一种专化地传粉系统。而Schisandra glabra则有多种昆虫参与传粉,表现出泛化的传粉系统。以瘿蚊为媒介的传粉系统中,只有雄花能为昆虫提供报酬,而雌花则是通过模拟雄花来欺骗昆虫访花的。在这个欺骗性传粉系统中,味觉和视觉线索对瘿蚊都是很重要的,五味子的雌花可以通过模拟雄花的形态或者通过散发出与雄花相同的花香气味来吸引传粉者的。在泛化传粉的系统中,花粉、柱头和花被片都可作为昆虫的食物,并且S.glabra花还可以为昆虫提供栖息或交配场所。 五味子科植物的传粉模式符合“菌蚊类昆虫传粉综合征”。这个传粉综合征的特点是:植物一般具有较小的两性花或单性花、能散发强烈的花香、能够产生花热;传粉昆虫是菌蚊科、瘿蚊科和其他长角亚目的昆虫;欺骗性传粉;具有自交不亲和现象。Austrobaileyales 分支中的各类群和睡莲科植物都适合这个传粉综合征。 4.五味子科植物的种子散播 五味子的果实都是由小浆果组成的聚合果,五味子属的果实是长穗状,南五味子属的呈球形。成熟小浆果的颜色从红色到紫红色;具有中等大小的种子。翼梗五味子的果实是以小浆果为单位脱落的,整个脱落过程仅持续13天,种子是由鸟类和哺乳类散播的。异形南五味子和南五味子的聚合果虽然都是球形的,但是异形南五味子的果实和种子比南五味子大得多;它们的果实脱落和种子散播方式有很大差异,异形南五味子是整个聚合果脱落,脱落时间集中在20天内,而南五味子是以小浆果为单位脱落,脱落时间可长达4个月之久。异形南五味子的种子很可能是通过鸟类来散播的,而南五味子则没有发现有效的种子散播者。在五味子科内,果实形态总的进化趋势是由短到长,南五味子属所具有的球形聚合果很可能代表了五味子科果实的祖先性状。五味子科植物果实形状的进化可能最少要经历两个过程。在白垩纪和第三纪的交界期前后,由于气候和植被的变化,一些五味子类群的果实和种子变大;而后在第三纪,随着特化的果实散播者如鸟类和鼠类的出现,五味子科一些种类的花托在果期明显变长,球形聚合果进化成长穗状聚合果。

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The cultivation of genetically modified (GM) plants has raised several environmental concerns. One of these concerns regards non-target soil fauna organisms, which play an important role in the decomposition of organic matter and hence are largely exposed to GM plant residues. Soil fauna may be directly affected by transgene products or indirectly by pleiotropic effects such as a modified plant metabolism. Thus, ecosystem services and functioning might be affected negatively. In a litterbag experiment in the field we analysed the decomposition process and the soil fauna community involved. Therefore, we used four experimental GM wheat varieties, two with a race-specific antifungal resistance against powdery mildew (Pm3b) and two with an unspecific antifungal resistance based on the expression of chitinase and glucanase. We compared them with two non-GM isolines and six conventional cereal varieties. To elucidate the mechanisms that cause differences in plant decomposition, structural plant components (i.e. C:N ratio, lignin, cellulose, hemicellulose) were examined and soil properties, temperature and precipitation were monitored. The most frequent taxa extracted from decaying plant material were mites (Cryptostigmata, Gamasina and Uropodina), springtails (Isotomidae), annelids (Enchytraeidae) and Diptera (Cecidomyiidae larvae). Despite a single significant transgenic/month interaction for Cecidomyiidae larvae, which is probably random, we detected no impact of the GM wheat on the soil fauna community. However, soil fauna differences among conventional cereal varieties were more pronounced than between GM and non-GM wheat. While leaf residue decomposition in GM and non-GM wheat was similar, differences among conventional cereals were evident. Furthermore, sampling date and location were found to greatly influence soil fauna community and decomposition processes. The results give no indication of ecologically relevant adverse effects of antifungal GM wheat on the composition and the activity of the soil fauna community.