Cloning of Partial Sodium Channel Gene From Strains of Fenvalerate-Resistant and Susceptible Cotton Aphid(Aphis gossypii Glover)

The strain of fenvalerate-resistant cotton aphids was selected using fenvalerate insecticide in the laboratory, the resistance factor of the strain was 199.54. Three degenerate primers were designed and used to perform PCR amplification. A cDNA encoding partial sodium channel gene was cloned from the fenvalerate-resistant and -susceptible strains. There were two nucleotide acid differences between fenvalerate-resistant strain and -susceptible strain, resulting in an amino acid mutation, Met→Leu. It is predicted that the mutation is related to the cotton aphid resistance to fenvalerate.

Demographic parameters of cotton aphid, Aphis gossypii Glover （Homoptera： Aphididae） on five cotton cultivars

Life table parameters of the cotton aphid, Aphis gossypii Glover, were estimated on five cotton cultivars （‘ Sealand＇ ,‘Siokra＇ ,＇ Vararnin＇ ,‘ Bakhtegan＇ and ‘ Sahel＇ ）. Demographic parameters of the cotton aphid were assessed at 27.5 ± 1 ℃, 65% ＋ 10% RH and a photoperiod of 14：10 （L： D）h. The shortest developmental time for the nymphal stages was 5.5 days on ‘Siokra＇ and the longest was 6.1 days on‘ Sealand＇. The highest offspring per female was 29.6 on ‘Sahel＇ and the lowest was 15.3 on ‘Sealand＇. The rm values varied from 0.272 on ‘Sealand＇ to 0.382 （day^-1） on ‘Varamin＇. Jackknife estimates of the A. gossypii parameters on these cultivars indicated the greatest developmental rate and fecundity on ‘ Varamin＇ and the poorest on ‘ Sealand＇ cultivar.

Biological mechanism of controlling cotton aphid (Homoptera: aphididae) by the marginal alfalfa zone surrounding cotton field

At the beginning stage of cotton aphids (Aphis gossypii Glover) invading the cotton field, large numbers of insects have accumulated in the marginal alfalfa (Medicago sativa L.) zone surrounding it. They are 6.94 times (excluded natural enemies) as many as the aphids in cotton field. Most of these insects are Therioaphid maculata (Buckton), and occur in fields 10-15 d earlier than cotton aphids. Consequently, abundant natural enemies have bred in alfalfa zone when cotton aphids increase rapidly in cotton fields in the middle of June in Xinhe County, Xinjiang Autonomous Region. The total number of the major natural enemies, including Coccinellids, Chrysopids and Syphid flies in alfalfa zone, is 13.65 times that in cotton field within the same acreage of fields. At this period, it is very effective to force the natural enemies from the alfalfa zone into the nearby cotton field to control the rapid increase of cotton aphid population by cutting the alfalfa stands.

The biotypes and host shifts of cotton-melon aphids Aphis gossypii in northern China

Aphis gossypfi is a globally distributed species and therefore has a highly variable life cycle. Populations of A. gossypii in northern China exhibit greater genotypic diversity and a broader host range, yet the details of life cycles of different biotypes is still unclear. In this study, the Cytb and 16S gene regions of A. gossypfi collected from 5 common summer hosts and 4 primary hosts were analyzed. A total of 57 haplotypes were obtained from 1 046 individual A. gossyp# sequences. The sequence included 44 variable sites, 27 of which were parsimony informative sites and 17 of which were singleton variable sites. The most frequent 3 haplotypes were found in 896 individuals, representing a total of 85.7% of all individuals and 36 haplotypes were found in 1 individual. A neighbor-joining tree was constructed using 21 haplotypes that were found in more than 2 individuals. Considering the individual host plant, 5 biotypes were identified. Type 1 corresponded exactly to the cucurbit host-race and the other 4 biotypes were found as cotton host-races. Type 3 was the most abundant biotype in cotton fields in northern China.

2种蚜虫取食诱导棉花对棉长管蚜与棉蚜取食行为的影响

为研究棉长管蚜Acyrthosiphon gossypii与棉蚜Aphis gossypii对蚜虫取食诱导棉花的取食适应性,揭示取食诱导下两种蚜虫的取食竞争机制,采用刺探电位图谱技术(electrical penetration graph, EPG)测定在健康棉花、棉长管蚜或棉蚜诱导的棉花上取食6 h的棉长管蚜和棉蚜的16个重要参数,比较两种蚜虫的取食行为。研究发现:1)取食健康棉花时,棉蚜在木质部(G波)的取食持续总时间长于棉长管蚜,棉蚜在木质部的取食能力大于棉长管蚜,但二者在韧皮部的取食能力相差不大。2)取食棉长管蚜诱导的棉花时,棉蚜取食韧皮部(E2波)持续的总时间为(2 531.33±60.86)s,显著大于棉长管蚜E2波持续总时间[(2 196.00±98.91)s];取食棉蚜诱导的棉花时,棉蚜取食韧皮部、木质部持续的总时间显著长于棉长管蚜(P<0.05),说明棉蚜对于棉蚜诱导棉花的取食耐受性大于棉长管蚜。棉蚜对两种蚜虫取食诱导棉花的适应性更强,更易在竞争中取得优势。棉长管蚜与棉蚜取食棉长管蚜或棉蚜诱导棉花的F波持续总时间长于健康棉花,说明经取食诱导的棉花具有一定的抗虫性。

Insights into wing dimorphism in worldwide agricultural pest and hostalternating aphid Aphis gossypii

Background:The worldwide pest Aphis gossypii has three-winged morphs in its life cycle,namely,winged parthenogenetic female(WPF),winged gynopara(GP),and winged male,which are all produced by a wingless parthenogenetic female(WLPF).Most studies on A.gossypii have focused on WPF,while few have investigated GP and male.The shared molecular mechanism underlying the wing differentiation in the three wing morphs of A.gossypii remains unknown.The wing differentiation of WPF was explored in a previous study.Herein,GP and male were induced indoors.The characters of the body,internal genitals,wing veins,and fecundity of GP and male were compared with those of WPF or WLPF.Compared with WLPF,the shared and separate differentially expressed genes(DEGs)were identified in these three-wing morphs.Results:Newly-born nymphs reared in short photoperiod condition(8 L:16D,18°C)exclusively produced gynoparae(GPe)and males in adulthood successively,in which the sex ratio was GP biased.A total of 14 GPe and 9 males were produced by one mother aphid.Compared with WLPF,the three-wing morphs exhibited similar morphology and wing vein patterns but were obviously discriminated in the length of fore-and underwings,reproductive system,and fecundity.A total of 37090 annotated unigenes were obtained from libraries constructed using the four morphs via RNA sequencing(RNA-Seq).In addition,10867 and 19334 DEGs were identified in the pairwise comparison of GP versus WLPF and male versus WLPF,respectively.Compared with WLPF,the winged morphs demonstrated 2335 shared DEGs(1658 upregulated and 677 downregulated).The 1658 shared upregulated DEGs were enriched in multiple signaling pathways,including insulin,FoxO,MAPK,starch and sucrose metabolism,fatty acid biosynthesis,and degradation,suggesting their key roles in the regulation of wing plasticity in the cotton aphid.Forty-four genes that spanned the range of differential expression were chosen to validate statistical analysis based on RNA-Seq through the reverse transcription quantitative real time polymerase chain reaction(RT-qPCR).The comparison concurred with the expression pattern(either up-or downregulated)and supported the accuracy and reliability of RNA-Seq.Finally,the potential roles of DEGs related to the insulin signaling pathway in wing dimorphism were discussed in the cotton aphid.Conclusions:The present study established an efficiently standardized protocol for GP and male induction in cotton aphid by transferring newly-born nymphs to short photoperiod conditions(8 L:16D,18°C).The external morphological characters,especially wing vein patterns,were similar among WPFs,GPe,and males.However,their reproductive organs were strikingly different.Compared with WLPF,shared(2335)and exclusively(1470 in WLPF,2419 in GP,10774 male)expressed genes were identified in the three-wing morphs through RNA-Seq,and several signaling pathways that are potentially involved in their wing differentiation were obtained,including insulin signaling,starch and sucrose metabolism.

棉花蚜虫防治药剂筛选

[目的]有效防治棉花蚜虫虫害。[方法]选择5种常用杀虫剂,在棉花苗期,采用叶面喷施的方法,进行田间防效比较。[结果]通过比较不同药剂的防治效果,25%高效氯氟氰菊酯·啶虫脒乳油225 g/hm2效果最好,防效可达96%以上。[结论] 25%高效氯氟氰菊酯·啶虫脒乳油的防效明显高于另外4种药剂,可在棉花生产中推广应用。

Weed and insect control affected by mixing insecticides with glyphosate in cotton

Field studies were conducted in 2012 and 2013 to evaluate weed and insect control efficacy with glyphosate at 1 230 g ai（active ingredient） ha^（-1） and the insecticides acephate（728 g ai ha^（-1））,carbosulfan（135 g ai ha^（-1））,endosulfan（683 g ai ha^（-1））,imidacloprid（32 g ai ha^（-1））,or lambda-cyhalothrin（23 g ai ha^（-1））,as well as glyphosate tank-mixed with these insecticides.Four of the most common weeds in cotton,common purslane,false daisy,goosegrass,and lambsquarters,were manually sown in the cotton field and treated with glyphosate alone or in combination with insecticides.Glyphosate efficacy,based on visual estimates of control and weed fresh weight at 21 d after treatment（DAT）,was unaffected by the addition of insecticides.Four weeds were controlled by 93-97%and 86-100%（visual rating） and reduced weed fresh biomass by98-99%and 96-100%with glyphosate alone and its combination with insecticides,respectively.Addition of glyphosate to acephate improved cotton aphid control compared with acephate alone.However,addition of glyphosate to carbosulfan,endosulfan,imidacloprid,or lambda-cyhalothrin did not affect the aphid control when compared with the insecticide alone treatments.These results indicate that cotton producers could potentially integrate weed and insect management strategies by choosing suitable insecticide mixing partners with glyphosate,thereby reducing the application costs without sacrificing the efficacy of the glyphosate or the insecticides.

播期对黄河流域棉花苗蚜种群动态和棉花产量的影响

【目的】研究播期对棉花苗蚜种群动态和棉花产量的影响。【方法】于我国冀南棉区研究4月16日、4月26日和5月6日三个播期对棉花出苗、苗期蚜虫种群动态及棉花产量相关参数的影响。【结果】随着播期的推迟,棉花出苗率呈增高趋势,4月26日和5月6日播种处理的棉花出苗率显著高于4月16日。4月16日和4月26日播种处理的棉田苗蚜均出现了明显的发生高峰和蚜量快速下降过程,而5月6日播种的处理,苗蚜始终未出现明显高峰。随着播期的推迟,棉花单行产量也从3.94 kg(4月16日)增至5.46 kg(5月6日),表现出明显增产。【结论】适当推迟播期能起到保苗、减轻早期蚜害和保证产量的效果。

新疆地区喷施纳米农药防治棉蚜效果试验

为明确纳米农药在新疆地区对棉蚜的防治效果,2022年在新疆石河子地区开展纳米农药防治棉蚜试验,比较不同处理1次施药后不同时间的防效。结果表明:纳米农药对新疆地区棉蚜防效有较大差异,最高防效可达85.0%以上,较常规药剂减少农药使用量11.1%~27.3%,但需根据不同地区(棉田)棉蚜种群的抗性特点进行组合配方施药,从而达到农药减量增效的目的。

甘草带对棉田多异瓢虫种群发生与控害的调控功能

【目的】阐明田埂甘草(Glycyrrhiza uralensis)种植带对棉田多异瓢虫(Hippodamia variegata)种群发生与控害能力的影响,为合理利用甘草带促进棉田蚜虫生物防治提供理论基础。【方法】在新疆库尔勒采用田间种群系统调查法研究甘草带及对照棉田(无甘草带)和距甘草带不同距离(1 m、5 m、10 m、20 m)棉花上蚜虫和多异瓢虫的种群动态,通过罩笼评估法评价甘草带对棉田蚜虫种群相对增长倍数和多异瓢虫控蚜功能的影响。【结果】6月上中旬,田埂甘草带上高密度的棉黑蚜(Aphis atrata)能够保育大量的多异瓢虫,是邻近棉田多异瓢虫种群的重要源库。6月下旬至7月中旬,多异瓢虫在棉田大量发生;6月中旬至7月下旬,距甘草带1 m、5 m、10 m、20 m的棉田中多异瓢虫与蚜虫的益害比均不同程度地高于对照棉田,其中6月17日距甘草带1 m处棉田益害比最高为2.502 9。罩笼天敌隔离处理研究发现,罩笼后7 d和14 d罩笼组棉花上蚜虫种群相对增长倍数均显著高于对应的非罩笼组;罩笼后14 d,田埂有甘草带棉田多异瓢虫对棉蚜的控害指数显著高于无甘草带棉田。【结论】田埂甘草带能有效增加棉田多异瓢虫种群数量并提高益害比,对棉田多异瓢虫的控蚜功能具有重要的调控作用。

基于YOLOv8网络的棉蚜图像识别算法及软件系统设计

为解决在棉蚜种群预测与防治科研工作中人工计数难度大、效率低的问题,提出一种基于YOLO神经网络的棉蚜图像识别算法并集成为软件。首先,连续15 d使用手机拍摄人工接种的棉蚜图像,选择清晰的50张图像将其裁剪为6个子图像,再使用LabelImg软件进行人工标注得到训练集和测试集。然后,选择YOLOv5和YOLOv8系列的10种模型,训练参数设置相同(批次大小32,迭代100轮,初始学习率0.01,周期学习率0.01),使用AutoDL平台的服务器进行训练。最后,对训练好的模型进行测试,其中YOLOv8l模型综合性能表现最佳,mAP50达到了0.926。为了给用户提供方便易用的人机软件,使用PYQT5开发了软件的前端,实现了棉蚜图片的读取、计数、结果可视化和导出为Excel等功能。软件的后端采用了“拆分—检测—合并”的图像处理方式,保障了YOLO模型对小目标的检测效果。经过测试,该软件对于死棉蚜与活棉蚜计数的平均精度为0.945,展现出与人工计数相当的精度,具有较好的实用价值。该研究为棉蚜防治相关科研人员提供了一种智能化检测工具,也可为无人农场等场景中的精准作业提供关键作业信息。

基于铷元素标记技术分析多异瓢虫在甘草带与棉田间的迁移范围

【目的】研究铷元素标记技术分析多异瓢虫在甘草带与邻近棉田间的迁移范围,丰富铷(Rb)元素标记技术在昆虫迁移扩散的作用。【方法】在室内利用铷元素标记技术检测多异瓢虫体内的铷元素滞留期;在田间利用铷元素标记技术,研究多异瓢虫从甘草带向棉田的迁移范围。【结果】铷元素在多异瓢虫成虫体内滞留期为15 d左右;多异瓢虫成虫和幼虫从甘草向棉田的转移范围有所不同;成虫的铷元素检出率0~15 m>30~50 m>15~30 m>50~100 m。【结论】铷元素标记技术可以在田间有效的跟踪多异瓢虫成虫和幼虫的迁移范围。

助剂对植保无人机喷施纳米农药理化性质和防治棉田蚜虫效果的影响

【目的】用植保无人机在棉田喷施纳米农药防治棉花蚜虫,探讨助剂对药液理化性质、抗蒸发性能、雾滴沉积分布及对纳米农药防治效果(防效)的影响。【方法】于室内利用动态光散射仪、自动界面张力仪、BP100张力计、接触角仪、超景深拍照系统等测定了添加3种助剂(优若派、杰效丰、Aero-mate 320)后8%(质量分数,下同)烯啶虫胺·呋虫胺纳米农药推荐使用剂量(1200 g·hm-2)减量20%的溶液的理化性质及抗蒸发性能,并结合植保无人机田间喷雾试验研究了助剂对雾滴在棉花冠层的沉积分布及农药对棉蚜防效的影响。【结果】在减少20%用量的纳米农药药液中添加体积分数为0.1%的优若派、0.1%的杰效丰和0.6%的Aero-mate 320助剂可以改善药液理化性质。其中:溶液的静态表面张力由36.43 mN·m^(-1)下降至31.82~34.99 mN·m^(-1);340 s后接触角减小到12.25°~14.85°,降低了22.97%~36.46%;润湿面积增加18.34%~33.57%;药液的蒸发抑制率达27.72%~73.40%;田间喷雾试验结果显示,棉花上部和下部冠层的雾滴直径中值由122.4μm和106.7μm分别增大至154.3μm和148.5μm;施药后7 d,纳米农药减量20%处理的防效为47.6%,而添加3种助剂的处理对蚜虫的防效分别提高至63.2%、65.0%和73.3%,与植保无人机喷施纳米农药常规用量防效(71.8%)和人工背负式喷雾器喷施相同成分常规农药的防效(74.9%)相当。【结论】在纳米农药减量20%用量的情况下,添加3种助剂有助于改善药液理化性质,增加润湿面积,减少雾滴蒸发和飘移,提高药剂对棉蚜的防效。

含氟均三嗪类化合物的合成及生物活性

以灭蝇胺为先导化合物,通过中间体衍生化法合成了8个未知和1个已知的含氟均三嗪类化合物,对所合成的目标化合物进行1H NMR、13C NMR、HRMS表征,确定了所有目标化合物的结构,并进行了杀虫活性测试,测试结果表明,对于棉蚜幼虫,试验浓度为5 mg/L时Ⅰ-3c杀棉蚜率能够达到95%,Ⅰ-3d也能达到85%,同时Ⅰ-3c与Ⅰ-3d对红蜘蛛也有一定的活性,在10 mg/L时,化合物Ⅰ-3c与Ⅰ-3的活性分别为96%和90%。作为杀虫剂具有一定的发展潜力。

不同生境下棉蚜虫情信息的时空分布特征

为明确棉蚜在不同生境下的数量变化及时空分布规律,本试验通过盆栽和田间试验2种生境条件对棉蚜数量在棉株上的分布特征进行探究,同时测定了叶片的叶绿素含量,并对棉蚜数量和叶绿素含量进行了相关性分析。结果表明,田间试验条件下的蚜虫数量呈现先增加后缓慢降低直至消失的趋势,蚜虫数量于6月上旬出现,高峰期集中在6月下旬,之后急剧下降,且主要分布在下层叶片;盆栽试验中,棉蚜数量会随着时间的延长而增加,蚜虫集中分布在棉株的中、下层叶片。2种生境下,叶片的叶绿素a、叶绿素b和叶绿素总含量的变化趋势基本一致,整体呈现出先增高后降低的趋势,并且幼嫩叶片的叶绿素a、叶绿素b和叶绿素总含量高于先出叶。通过相关分析发现,单叶棉蚜数量达到一定值时,与叶绿素a、叶绿素b含量呈极显著正相关性,表明棉蚜数量达到一定程度时可以促使叶片色素含量增加。棉蚜除品种外,在可控的环境中,棉蚜数量会持续上升;在不可控的环境中,高峰期过后会自动消亡。

Hap4型棉蚜取食西葫芦后的寄主适应性变化

棉蚜寄主间转移是常见的现象,在寄主转移过程中的寄主适应能力转变是其重要的生物学特性。为了解棉蚜取食西葫芦不同世代后,对其他寄主适应能力的转变,探究取食经历对棉蚜寄主适应性变化的影响,本试验利用寄主转接试验,将采自棉花上的Hap4型棉蚜转接到西葫芦上,分别测定取食西葫芦不同世代后,对棉花、黄瓜和西葫芦的适应能力。结果显示,随着取食西葫芦代数的增加,Hap4型棉蚜对原寄主棉花的适应性逐渐降低。Hap4型棉蚜取食西葫芦一代后就对黄瓜有良好的寄主适应性,并呈现较为稳定的趋势。Hap4型棉蚜对西葫芦的寄主适应性随着在西葫芦上取食代数的增加而降低,但强于在原寄主上的寄主适应性。除此之外,本试验也发现取食西葫芦后的Hap4型棉蚜的寄主适应性表现为黄瓜>西葫芦>棉花。植食性昆虫的取食经历影响其寄主适应能力,Hap4型是棉蚜主要的生物型之一,其取食经历直接影响其寄主适应性,研究结果为生产中作物布局及棉蚜的生态调控技术应用提供理论基础。