福建省储藏物螨类调查

对福建省２７个县、市、区的１１０个单位的储藏物进行螨类的种类、分布、危害及人出率帛样调查研究,查清了福建省储藏物螨类种类５７种,录属３个亚目,１９个科,３６个属。其中属国内瓣记录７种,常见优势螨９种,主要害螨４种。其分布广,遍布全省。危害储藏物达４５种,且较严重。     

长宁竹区竹裂爪螨生物学及楠竹害螨消长动态研究

在21℃、24℃、27℃、30℃、33℃5种不同温度条件下,用新鲜的离体楠竹叶片在室内饲养竹裂爪螨,得出该螨实验种群的主要生物学参数,应用直接最优法计算该螨的世代发育起点温度和有效积温分别为12.53℃、150.25日度,根据气象资料预测竹裂爪螨在长宁竹区年发生13－14代;每年3月下旬－4月上旬出蜇,11月份开始以雌成螨越冬。林间实际调查表明,楠竹害螨在竹区的发生与危害存在明显的春季高峰并与楠竹林的敏感生长期相吻合;降雨与高温严重影响楠竹害螨的生长发育,表现为7、8月份高温多雨季节林间害螨种群数量呈现出急剧下降。     

Mites associated with budgerigars Melopsittacus undulatus (Psittaciformes: Psittacidae) and the first report of Ornithonyssus bursa (Mesostigmata: Macronyssidae) in Mexico

Background:Hematophagous mites affect numerous bird species, causing severe injuries to the budgerigars. Some species can cause dermatitis in humans.Aims:The purpose was to morphologically identify the mites related to budgerigars (Melopsittacus undulatus) and their nests in Yucatan, Mexico.Methods:In May 2022, a private budgerigar hatchery was visited and mites were collected from the bodies of the birds and their nests. The morphological traits of the mites were confirmed by scanning electron microscopy.Results:Four of 30 birds showed severe clinical signs of mite infestation. The Budgerigars revealed lesions in the cere, nostrils, eyelids, beak, and paws. The bird’s skin showed signs of dryness and beige coloring. The birds with severe damage also presented anorexia and had deformed paws and beaks. The parasitosis was caused by the “burrowing mites,” Knemidocoptes pilae. The burrowing mites and the Grallacheles bakeri were recovered and identified from paw scabs. To eliminate mites, a topical application of Ivermectin was administered to the necks of the birds. The dose was a single, which has a residuality of 21 days. Two drops (0.115 mg/ml) of ivermectin were applied to each bird. A gradual reduction in crusted lesions due to mite mortality was noted. The “tropical fowl mite” Ornithonyssus bursa was identified in the nests, which represents the first record in Mexico.Conclusions:Three species of mites were discovered in a single budgerigar hatchery. This emphasizes the importance of deworming birds and keeping a clean environment in their cages to reduce the potential for parasitic mite infestation.     

7种药剂对苹果红蜘蛛的防治作用研究

通过试验,明确了7种药剂对苹果红蜘蛛的防治作用,为安全、合理使用和大面积推广提供一定理论依据。     

Mite-borne virus isolates from cultivated Allium species,and their classification into two new rymoviruses in the family Potyviridae

While testing several samples of onion and of vegetatively propagated garlic, sand leek and shallot from a number of countries, virus isolates with unusually flexuous particles were obtained by mite (Aceria tulipae) or sap transmissions. No aphid-borne poty-or carlavirus was transmitted by mites, and mite-borne virus isolates could not be transmitted by aphids. The mite-borne isolates did not react with antisera to aphid-borne potyviruses ofAllium spp. or with the Agdia potyvirus group monoclonal. In contrast to the mite-borne onion and garlic mosaic viruses reported in the literature, our mite-borne isolates induced no visible or only very mild symptoms inAllium spp., except isolates from shallot ‘Santé’ which caused diffuse striping. Heavily mite-infested test plants or plant samples showed streaking and malformation due to mite feeding (tangle-top). The mite-borne virus isolates could be classified with test plants and a discriminating antiserum into three groups, representing two viruses and a strain of one of them. They are tentatively named onion mite-borne latent virus (OMbLV), garlic strain of this virus (OMbLV-G), and shallot mite-borne latent virus (SMbLV). Mite transmission, length of virus particles (ca. 700 to 800 nm), and the presence of granular inclusion bodies in infected tissue indicate that the viruses belong to the mite-borne genusRymovirus of the familyPotyviridae. OMbLV from shallot and onion, and OMbLV-G from garlic and sand leek, can be assayed onChenopodium murale but differ in their natural hosts. They are very common. SMbLV, to whichC. murale does not react, was isolated from shallot originating from Asia and Russia.     

黑龙江水螨属一新种记述(蜱螨亚纲,水螨群,水螨科)

报道中国水螨属1新种刺突水螨Hydrachna tuberata sp.nov..其主要鉴别特征为:雄螨生殖域扁圆心形,雌螨生殖域桃形,均不长达EpⅣ的后中缘末端,p-Ⅱ背部具5根栓毛.     

Quantifying economic losses associated with levels of wheat streak mosaic incidence and severity in the Texas High Plains

Wheat streak mosaic (WSM), caused by the Wheat streak mosaic virus (WSMV), which is transmitted by the wheat curl mite (Aceria tosichella), is the most prevalent virus disease of wheat in the Texas High Plains. Infected plants initially exhibit mosaic symptoms, which lead to severe stunting, complete chlorosis and, in the most severe cases, eventually plant death. Wheat plants infected with WSMV have lower forage and grain yields and exhibit reduced water-use efficiency compared to non-infected plants. The disease impact on water-use efficiency raises an important issue of whether diseased fields should be irrigated as frequently as non-diseased fields. The issue becomes more relevant when energy costs and the dwindling water resources from the Ogallala Aquifer are taken into consideration. This study examined the potential economic losses due to WSM, using data collected from two fields in 2007 and 2009. A hand-held hyperspectral radiometer was used to quantify severity of WSM in multiple 1 m² plots along two transects, each stretching from the edges of the fields to their centers. Grain yield declined exponentially (R² = 0.79, P < 0.0001) with increasing disease severity, as measured by reflectance at 555 nm. For economic analysis, grain yield from each plot was used for determining cost adjustments and linked revenues in relation to WSM severity levels, which allowed calculations of potential profit reduction. The method enables one to compare losses associated with different levels of WSM severity to a baseline with little or no WSMV infection. Results show that losses from the disease are primarily an outcome of reduced revenue due to a decrease in grain yield, and, as expected, losses incurred per unit land area rapidly increase with increasing disease incidence and severity. Furthermore, producers incur additional marginal losses when irrigating fields with WSM because there is little or no return for irrigation inputs, as water-use efficiency of severely diseased wheat is drastically reduced. Results from this study are useful in estimating losses at differing levels of disease incidence and severity and represent the first step in development of an economic threshold for wheat streak mosaic.     

杨始叶螨滞育研究

杨始叶螨Ｅｏｔｅｔｒａｎｙｃｈｕｓｐｏｐｕｌｉ（Ｋｏｃｈ）是危害杨、柳科植物的重要害螨。研究结果表明，该螨以受精雌成螨滞育，为长日照（１３ｈ／ｄ以上）发育，短日照（１１ｈ／ｄ）滞育型；临界光照时间为１２ｈ／ｄ左右；光周期感应螨态为幼螨→第一若螨→第二若螨的连续２个发育阶段。在相同短日照（１０ｈ／ｄ）下，较低温度（２１℃以下）促进滞育，较高温度（２５℃）抑制滞育。     

柑桔锈螨（Phyllocoptura oleivora Ashmead）研究进展

柑桔锈螨是我国柑桔生产的重要害虫，在我国，一般每年有三个发生高峰期，造成对柑桔叶、果实的严重危害，在高温旱时危害尤为严重其发生适宜温度是２３～３２℃，最适温度是２５℃，光周期是Ｌ：Ｄ＝１２：１２，近年来已经对一些药剂如三氯杀螨醇产生了抗药性，就柑桔锈螨的发生规律、抗性和防治等进行了系统进行了叙述，并提出了综合防治措施。