Toxicity of azinphos-methyl to various development stages of the codling moth Cydia pomonella (Lepidoptera: Tortricidae)

The response to azinphos-methyl of different life-stages of the codling moth Cydia pomonella (L.) was studied. A similarity in response to azinphos-methyl (LC(50), LC(90)) was observed in neonate larvae obtained from the first and second generations of field populations. Mortality rates for neonate larvae of a field population cross-bred with a laboratory colony were lower (by a factor of 1.2-2.2) in comparison with field neonate larvae. The mortality rate of larvae from a laboratory colony exposed to artificial diet containing azinphos-methyl gradually decreased at older instars. The mortality rates of fifth-instar larvae were remarkably low when exposed to artificial diet mixed with azinphos-methyl or when topically treated with the insecticide. One- to three-day-old females were more sensitive than males of the same age, whereas the opposite was observed in 14-to 17-day-old adults. Mortality rates of 14- to 17-day-old adults were higher than those under 10 days old. No significant difference in sensitivity to the organophosphorus compound was noticed between the sexes of 7- to 10-day-old adults. Neonate larvae of the codling moth can serve as a target life-stage for various groups of pesticides, and the importance of using such a stage as a standardized methodology for monitoring resistance in the codling moth is discussed.     

基于多源Sentinel数据的县域冬小麦种植面积提取

冬小麦是我国主要的粮食作物之一,及时准确地获取冬小麦种植面积对农业政策的制定具有重要意义。以河南省扶沟县为研究区域,以多生育期Sentinel-1A和Sentinel-2A/B遥感影像为数据源,构建光谱特征、植被特征和极化特征的多生育期数据集,分析各类地物的特征曲线,采用随机森林算法对单生育期单传感器、单生育期多传感器、多生育期单传感器和多生育期多传感器的遥感影像进行精细分类,实现县域冬小麦制图。结果显示：单生育期的雷达影像无法满足制图要求,拔节期的总体精度最高,仅为62.9%,多生育期雷达影像分类精度达到81.9%,基本满足制图要求;单生育期的光学影像和融合影像在成熟期的精度最高,总体精度分别为93.4%和95.1%,Kappa系数分别为92.4%和94.8%,可以绘制较为精准的冬小麦分布图;多生育期融合影像绘制的扶沟县2019年冬小麦空间分布图,总体精度为96.8%,结果最优。研究结果表明融合的多生育期遥感影像可以为县域冬小麦种植面积的提取提供技术依据。     

不同生长阶段斑节对虾消化酶活性变化

通过对斑节对虾不同生长阶段蛋白酶、脂肪酶及淀粉酶活性变化的分析,探讨了斑节对虾在生长过程中对蛋白质、脂肪和碳水化合物的消化利用。结果表明,根据消化酶活性,可将斑节对虾生长分为两个阶段。第1阶段,在体长10～12.5 cm阶段之前,随着个体的增大蛋白酶和脂肪酶活性不断升高;第2阶段,在12.5 cm之后,蛋白酶和脂肪酶活性呈现出一定程度的下降。肝胰腺、胃、肠3种不同消化器官的消化酶活性在不同生长期也不一致,大致上蛋白酶活性从高到低依次为:肝胰腺>胃>肠;脂肪酶活性:肠>肝胰腺>胃;淀粉酶活性:肠>胃>肝胰腺。     

Morphological characterization and notes on the life cycle of a newly discovered variant of Loma salmonae (Putz, Hoffman & Dunbar) from a natural infection of chinook salmon, Oncorhynchus tshawytscha (Walbaum)

Two variants of Loma salmonae occur in net-pen reared chinook salmon, Oncorhynchus tshawytscha. The typical variant (OA) has a host specificity for salmonids of the genus Oncorhynchus whereas the atypical variant (SV) has a host specificity for brook trout, Salvelinus fontinalis, and in this study, the ultrastructure of the two are compared. In fish at 8 weeks post-exposure xenomas of the SV variant have a very high proportion of mature spores compared with other developmental stages, while in xenomas of the OA variant there are fewer spores and many other developmental stages. Spores of the SV variant had up to 20 turns of their polar tube whereas those of the OA variant only had 17. Furthermore, the spores of the SV variant were significantly larger than those of the OA variant. The sporophorous vesicle for both variants appears to form around a sporogonial plasmodia, which results in many spores developing within the vesicle.     

不同时期接种AM 真菌对大棚黄瓜产量及品质的影响

研究不同时期接种丛枝菌根真菌根内球囊菌（Glomus intraradices,GI）对大棚土壤栽培黄瓜植株生长、产量及营
养品质的影响。结果表明：黄瓜不同时期接种GI 对其生长均有促进作用,与不接菌的对照相比,播种时接菌和移栽时接菌处理使黄瓜的单株产量分别提高54%、34%;播种时接菌处理的黄瓜叶片的叶绿素含量比对照显著提高了14.7%～17.7%;播种时接菌和移栽时接菌的黄瓜硝酸盐含量较对照分别下降了9.4% 和15.0%,总糖含量分别比对照提高了8.9% 和7.1%;移栽时接菌处理的黄瓜粗蛋白含量比对照提高了4.6%;播种时接菌和移栽时接菌显著提高了黄瓜VC 含量。表明接种GI 对黄瓜生长和产量品质具有一定的改善作用。     

Life cycle of Caligus rogercresseyi, (Copepoda: Caligidae) parasite of Chilean reared salmonids

Caligus rogercresseyi, [Contrib. Zool. 69 (2000) 137] is the only caligid known to affect the salmon industry in Southern Chile. Economic losses due to reduced fish quality, cost of chemical treatment and outbreaks of other diseases such as the Piscirickettsiosis occur. The life cycle of C. rogercresseyi is described in rainbow trout reared in seawater tanks from observations made under natural conditions of light and temperature between January 1997 and April 1998. Fish were infected with laboratory-cultured larvae obtained from ovigerous females. Rainbow trout were periodically slaughtered for parasite collection and identification. C. rogercresseyi life cycle includes the following stages: two nauplius, one copepodid, four chalimus and the adult. No preadult stage was observed. Timing of the different stages of development was directly dependent on water temperature. The maturation of the eggs or the time for a complete life cycle took place at 45 days in July at 10.3 °C, 31–32 days in April at 12.4 and 12.8 °C, respectively, and at 26 days in November at 15.2 °C. In January, at 16.7 °C, only the appearance of first eggs were observed at 18 days. A simple degree–day (dd) model is proposed for each developmental stage between 4 and 17 °C, where the development rate is a linear function of the average temperature of water. Using this degree–day model, the proportion of fourth stage chalimus was maximum at 172 dd of effective temperature, adult males at 193 degree–days, adult females at 208 dd. The minimum temperature threshold is at 4.2 °C where there is no development of the parasite. The appearance of first eggs occurred at 231 dd and the first pigmented eggs at 277 dd. The temperature-independent degree–days value allowed to predict the timing of C. rogercresseyi life cycle at any temperature within the evaluated range.     

Pathogenicity of white spot syndrome virus on postlarvae and juveniles of Penaeus (Litopenaeus) vannamei

White Spot Syndrome Virus (WSSV) has decimated the shrimp aquaculture around the world. Breeding efforts to generate resistant stocks are necessary but there is a lack of basic information on challenge test strategies focused on genetic selection. Infection routes and developmental stages were evaluated on Penaeus vannamei as a first step in a strategy to select white spot virus (WSSV)-resistant stocks. Mortalities could not be induced before the PL30 stage. The impact of infection by immersion and blended tissue was intermediate on mortalities when compared to the minced tissue treatment on PL30. Blended and minced tissue treatments produced the highest mortalities on PL40 while immersion was intermediate. A general tendency towards higher susceptibility associated with older stages was detected. Additionally, juveniles of 1 g average weight from three local breeding programs were challenged. There were no differences in survival between the programs, although two of them derived their progenies from survivors of strong WSSV events. The implications of these results to the WSSV epidemiological characteristics and breeding programs are discussed.     

吉林省玉米穗期害虫种类及发生情况分析

吉林省是玉米生产大省,为明确吉林省玉米穗期害虫种类、分布及发生情况,2013～2016年对吉林省9个地市,42个县(市/区),累计409个地点的玉米穗期害虫进行系统调查,为玉米穗期害虫的监测预警和制定合理防治策略提供科学依据。调查发现,吉林省玉米穗期有27种有害生物,隶属于3个纲,7个目,18个科。亚洲玉米螟、双斑长跗萤叶甲、叶螨和蚜虫的有虫田率均在80%以上,百株虫量和危害级别较高,是吉林省玉米的主要害虫。美洲黍潜叶蝇、古毒蛾、大青叶蝉、梨剑纹夜蛾、赤角盲蝽、白星花金龟等有虫田率在20%以下,且百株虫量<1头,尚未玉米生产造成威胁。此外,迁飞性害虫黏虫也是玉米穗期重要害虫,棉铃虫是潜在的玉米穗期重要害虫。     

QTLs for Waterlogging Tolerance at Germination and Seedling Stages in Population of Recombinant Inbred Lines Derived from a Cross Between Synthetic and Cultivated Wheat Genotypes

Waterlogging is a widespread limiting factor for wheat production throughout the world. To identify quantitative trait loci （QTLs） associated with waterlogging tolerance at early stages of growth, survival rate （SR）, germination rate index （GRI）, leaf chlorophyll content index （CCI）, root length index （RLI）, plant height index （PHI）, root dry weight index （RDWI）, shoot dry weight index （SDWI）, and total dry weight index （DWI） were assessed using the International Triticeae Mapping Initiative （ITMI） population W7984/Opata85. Significant and positive correlations were detected for all traits in this population except RLI. A total of 32 QTLs were associated with waterlogging tolerance on all chromosomes except 3A, 3D, 4B, 5A, 5D, 6A, and 6D. Some of the QTLs explained large proportions of the phenotypic variance. One of these is the QTL for GRI on 7A, which explained 23.92% of the phenotypic variation. Of them, 22 alleles from the synthetic hexaploid wheat W7984 contributed positively. These results suggested that synthetic hexaploid wheat W7984 is an important genetic resource for waterlogging tolerance in wheat. These alleles conferring waterlogging tolerance at early stages of growth in wheat could be utilized in wheat breeding for improving waterlogging tolerance.     

白桦次生林4个林龄0～30cm土层水源涵养功能比较

以小兴安岭地区白桦次生林4个林龄为研究对象,对其凋落物持水量、土壤贮水性能、土壤特性等进行研究.试验表明：4个林龄凋落物的蓄积量和最大持水量是70 a为最低,40 a为最大;土壤非毛管孔隙度在各林龄间变化呈波动性,30 a白桦次生林0～30 cm土层非毛管孔隙最小,不利于水分下渗,40 a白桦次生林0～ 30 cm土层非毛管孔隙最大,有利于降水的下渗,土壤水源涵养功能大小排序为40 a（3 276.820 t·hm-2）＜30 a（3 434.626 t·hm-2）＜50 a（3 525.015 t·hm-2）＜70 a（3 629.445 t·hm-2）.