转基因品种非目标害虫需早期防治

在害虫复合种群发生初期进行防治,才能使棉花良好生长发育。复合种群中的主要害虫是蓟马,也包括蚜虫和螨类。在为害棉花前,蓟马种群已在转主寄主植物上生存,待转主寄主死亡,蓟马就成群迁移到棉苗上,通过刺吸式口器为害棉苗的顶芽和第二到第四真叶。蓟马为害引起叶片...     

新疆棉蓟马发生为害及其防治

棉蓟马 ( Thrips tapaci L.)又称烟蓟马、葱蓟马。过去为新疆棉花苗期的主要害虫 ,在隐蔽施药等措施的应用下 ,使棉蓟马的为害逐年减轻 ,已成为次要害虫。但近年由于产业结构的调整 ,蔬菜等作物面积的增加 ,为棉蓟马的发生创造了良好的条件 ,使其在个别地区有发生加重的趋势。为防止棉蓟马重新给新疆棉花生产带来不良影响 ,现将棉蓟马的主要特征、发生、为害及防治措施简述如下。1形态特征棉蓟马成虫体长 1 .0～ 1 .3mm,宽约 0 .3mm,黄褐色。复眼紫红色 ,单眼间鬃在单眼连线之外。触角短 ,7节 ,第 3、 4节端部有“U”形感觉锥 ,第 5节端部…     

烟蓟马对甜叶菊的危害与防治

调查了临泽县甜叶菊育苗大棚内的蓟马种类和危害特点.结果表明:为害甜叶菊的蓟马为烟蓟马.在3个月的育苗期内,2月上旬到中旬,未发现烟蓟马为害;2月下旬株虫头数较少,仅为2头,3月上旬烟蓟马的株虫头数上升为3,甜叶菊的受害率达16％,4月下旬株虫头数明显增加到28,甜叶菊受害率猛增到83％.因此,3月下旬到4月下旬是烟蓟马发生的高峰期,3月上旬到3月中旬是防治烟蓟马的最佳时期.     

白色板涂油诱杀棉蓟马初见成效

棉蓟马又名烟蓟马、葱蓟马,是棉田的苗期虫害之一。目前,防治棉蓟马因使用化学农药,产生了一定的抗药性,防治效果大大降低。近几年来,我们从实践中发现棉蓟马有趋向白色的习性。经试验采用白色板涂油诱杀的方法,获得了可喜的成效。现将方法与结果简介如下:     

豆黄蓟马的识别与综合防治

豆黄蓟马（Thps nigropilosusuzel）是大豆主要害虫之一，严重发生时造成大豆减产20％～25％以上。介绍了豆黄蓟马为害症状、识别特征、发生规律，生产中可行的防治措施。     

2001年周口市棉田蓟马暴发原因及防治措施

棉蓟马又名烟蓟马、葱蓟马,主要为害棉花、烟草、葱蒜、瓜类等植物.前几年,蓟马在周口市仅局部地区发生,且为害时间短,仅限于苗期为害.近年来随着作物布局的变化,温室大棚作物种植,抗虫棉大面积推广应用,棉蓟马为害面积逐年扩大,为害程度加重.     

盆栽榕树蓟马的发生与防控药剂配方筛选

以福建漳州盆栽榕树种植示范基地为观测和实验点,调查鉴定蓟马的种类、为害过程和发生规律,选择测定阿维菌素+啶虫咪、速灭威+啶虫咪和毒死蜱+啶虫咪等3组配方药剂对榕树蓟马的防控效果,筛选确定防控榕树蓟马的最佳配方药剂及田间使用浓度。结果表明:对盆栽榕树造成为害的主要是榕管蓟马;速灭威+啶虫咪4∶1配比对榕管蓟马防治效果最理想,药后3～10 d的防治效果均在93.48%以上,无药害产生,性价比最好,是防治榕管蓟马的最佳配方药剂,田间推荐使用500～1 500倍液。     

漳州地区榕树蓟马为害及田间防控药剂药效评判

以漳州地区盆栽榕树种植示范基地为观测点,调查了榕树蓟马的为害情况,评判了6种药剂对榕树蓟马的田间防治效果。结果表明：盆栽榕树易受榕树蓟马危害,锉吸嫩叶、幼芽和当年生的老叶,造成盆栽榕树生长受阻。6%乙基多杀菌素悬浮剂防治效果最好,可长时间将虫口密度抑制在较低的水平,是防治榕树蓟马的首选药剂;52.25%毒死蜱.氯氰菊酯乳油和20%丁硫克百威乳油的速效性和总体防治效果均较好,也是防治榕树蓟马较好的药剂;3%啶虫咪乳油和48%毒死蜱乳油可作为防治榕树蓟马辅助药剂;4%阿维菌素乳油在田间应酌情考虑少用。6种药剂均未对盆栽榕树产生药害。     

茶黄蓟马的发生与防治

根据几年来的调查、研究，现就茶黄蓟马的为害症状，发生规律及防治措施小结如下。     

香蕉蓟马在花蕾期发生为害动态及精准化学防控研究

为了解香蕉蓟马(Thrips hawaiiensis Morgan)的最佳防控时机,评价精准喷雾的防治效果,本研究开展了最佳诱捕效果粘虫色板的筛选,在花蕾期监测蓟马迁入动态,调查蓟马在果穗上的为害分布,评价不同施药时机的防效,以期找到最佳防控方法。结果表明:在竞争和非竞争条件下,较白色和黄色,蓝色粘虫板的诱捕效果最好;蓟马迁入动态为植株现蕾后成虫大量迁入,呈逐渐增加趋势,花蕾向地弯垂后至第8梳苞片打开期间达高峰,色板上诱捕的蓟马数量最大,达290头;果穗上所有果梳均受到为害,并随着果穗生长呈逐渐加重趋势,最末端第7果梳的为害最严重,为害症状的黑点数为207个;在植株刚现蕾和花蕾向地弯垂时,对花蕾和果穗喷雾,2次施药的间隔期为5 d,对整个果穗有较好保护作用。香蕉蓟马的最佳防治时间为刚现蕾和花蕾向地弯垂的生育期。定向精准用药能够有效防控蓟马、保护果皮外观,实现蕉园农药减量施用,为香蕉产业提质增效提供技术依据。     

Investigation into the apparent failure of chemical control for management of western flower thrips, Frankliniella occidentalis (Pergande), on plums in the Western Cape Province of South Africa

Western flower thrips (WFT), Frankliniella occidentalis (Pergande), causes russetting, pansy spot and silvering damage on plums. Despite routine insecticide applications for thrips control, some plum producers report economic losses due to pansy spot damage, pits and holes that render fruit unfit for export. Six commercial plum orchards in two climatic regions in the Western Cape Province, South Africa, were monitored to determine (1) why current management practices based on monitoring and insecticide applications failed to prevent damage in some orchards, and (2) whether WFT is responsible for pitting damage. Western flower thrips was the dominant thrips species in all orchards, though low numbers of Frankliniella schultzei Trybom also occurred. Blue sticky traps were more efficient for monitoring WFT and F. schultzei than yellow traps. Insecticide applications early in bloom and unfavourable weather conditions for thrips flight contributed to very low numbers of WFT on sticky traps during the flowering and fruit set periods. Flower dissections, however, revealed varying levels of oviposition damage to ovaries and fruitlets. Dissections confirmed that WFT enter flowers to lay eggs in the ovaries and other flower parts before petals are fully open. No consistent significant relationship between sticky trap counts and WFT oviposition damage to plums were found, therefore no treatment threshold level could be recommended. Insecticide applications during bloom limited thrips feeding damage, but were too late to prevent oviposition damage. Some oviposition sites developed into typical pansy spots, whilst others formed holes or pits that increased in size as the fruit matured. After insecticide applications ended, and as air temperature increased, WFT populations increased. Weeds and wild vegetation in and around orchards provide a continuous source of potential infestation for as long as the fruit remains attractive and vulnerable to WFT. As oviposition damage by WFT can occur before flowers open, and because of the risk to pollinators when insecticides are applied during flowering, a purely chemical control strategy does not appear to be feasible. A new approach to WFT management is required.     

Seasonal timing of neonicotinoid and organophosphate trunk injections to optimize the management of avocado thrips in California avocado groves

The timing of trunk injections of the organophosphate, acephate, and two systemic neonicotinoids, imidacloprid and dinotefuran, was evaluated in field trials for the management of avocado thrips. Following treatments, leaves were sampled over a 6-month period to determine the period of efficacy for each insecticide. The efficacy of acephate was determined using bioassays. Imidacloprid and dinotefuran residues in leaves were quantified by ELISA to determine the window of efficacy for these treatments based on previously determined biological dose response data. In addition, residues in fruit were quantified to determine whether trunk injection of insecticides might present a greater risk for contaminating fruit than traditional application methods. The timing of trunk injection treatments significantly impacted the uptake of imidacloprid and dinotefuran, with mid- and late-leaf flush periods proving more effective in terms of rate of uptake and degree of persistence at threshold levels. Acephate was mobilized very rapidly and gave good control of thrips in bioassays; however, residues of acephate, and its insecticidal metabolite methamidophos, were detected in the fruit for up to 4 weeks after injection. Imidacloprid was most effective when injected during the mid-flush period, which allowed levels to establish within the trees over a period of time when thrips would be actively feeding on young leaf tissue. The establishment of dinotefuran in trees was very rapid following trunk injection. However, its use was compromised by the inability of the chemical to reach effective concentrations for thrips control. Residues of dinotefuran were detected in fruit sampled from one tree, but the levels were below typical MRLs for other crops treated with this insecticide. Imidacloprid was not detected in any fruit sampled from trees in which imidacloprid had established in leaf tissue at concentrations that were toxic to avocado thrips. Overall, trunk injection of imidacloprid could be a viable option for avocado thrips control. However, residues of acephate in fruit may preclude its use because of the requirement for increased pre-harvest intervals. Dinotefuran injections may also be useful due to the rapid uptake and establishment within the canopy; however, it will be necessary to determine whether higher doses of dinotefuran can deliver the required levels of insecticide necessary for thrips control, without contaminating the fruit with residues.     

Estimating the level of fruit scarring by citrus thrips from temperature conditions prior to the end of bloom

In this study, we develop and validate multiple regression models to estimate the degree of fruit scarring by citrus thrips, Scirtothrips citri (Moulton), from heat and chill degree days. Regression coefficients indicate that cool weather during early March (2 March–16 March) and warm weather during bloom are associated with high levels of thrips scarring. The biological mechanisms leading to the temperature-fruit scarring relationships are unknown. An economic analysis suggests that using model predictions may increase the average financial return per hectare and reduce the number of insecticide treatments applied against citrus thrips.     

Effect of cyantraniliprole on feeding behavior and virus transmission of Frankliniella fusca and Frankliniella occidentalis (Thysanoptera: Thripidae) on Capsicum annuum

The anthranilic diamide insecticide cyantraniliprole was previously shown to reduce transmission of Tomato spotted wilt virus (TSWV) to pepper, Capsicum annuum, by Frankliniella fusca but not Frankliniella occidentalis. This study examines the effects of cyantraniliprole and imidacloprid on thrips feeding using electrical penetration graphing (EPG), and on TSWV transmission in field cage studies. Some antifeedant responses were observed in the EPG studies when thrips fed on cyantraniliprole- and imidacloprid-treated plants; however, these responses were variable between species and among the 2, 6, and 10 day post-treatment time intervals during which feeding behavior was observed. Cyantraniliprole significantly reduced the probability of TSWV infection when spread by F. fusca in field-grown pepper when viruliferous thrips were released 7 days but not when released at 14 days after the insecticide treatment in one of 2 field trials. In the second trial cyantraniliprole significantly reduced the probability of infection when F. fusca were released 14 days but not 7 days after treatment. In both years, imidacloprid prevented or significantly reduced transmission of TSWV by F. fusca in field-grown pepper when viruliferous thrips were released 7 days and 14 after treatment. In one of two years, cyantraniliprole significantly reduced the incidence of TSWV in field-grown pepper that was spread by F. occidentalis when viruliferous thrips were released 7 days after the insecticide treatment, but not 14 days after the treatment. Imidacloprid did not reduce the incidence of TSWV in field-grown pepper when viruliferous F. occidentalis were released. Although these studies demonstrate that probing behavior of these thrips species is altered on cyantraniliprole-treated pepper plants, results of field cage studies did not consistently show a reduction in incidence of TSWV-infected plants.     

豆大蓟马对12种杀虫剂的敏感性测定

室内采用叶管药膜法测定12种杀虫剂对豆大蓟马(Megalurothrips usitatus)成虫和若虫的毒力。结果表明,供试药剂中除杀虫环和拟除虫菊酯类杀虫剂对豆大蓟马各虫态的毒力较低外,其他药剂均对豆大蓟马具有较高的毒力。毒力测定分析结果表明,供试药剂对豆大蓟马若虫的毒力不同程度上均大于成虫,且对成虫的毒力又以对雄成虫的毒力大于雌成虫。综合来看,乙基多杀菌素、甲维盐、噻虫胺、啶虫脒、阿维菌素和噻虫啉等药剂对豆大蓟马毒力较大,可推荐作为田间防治药剂。     

Effects of new field resistant cultivars and in-furrow applications of phorate insecticide on tomato spotted wilt of peanut

Field experiments were conducted at Tifton, Georgia from 2008 to 2014 to determine the effects of new peanut (Arachis hypogaea) cultivars and in-furrow applications of phorate insecticide on severity of tomato spotted wilt (TSW) caused by Tomato spotted wilt virus. Several cultivars, including Florida-07, Georgia-06G, Georgia-07W, Georgia Greener, and Tifguard, had final incidence of TSW that were less than that of Georgia Green. In-furrow applications of phorate insecticide reduced incidence of TSW in Georgia Green in three experiments in which that cultivar was included. In-furrow application of phorate insecticide reduced incidence of TSW in most cases where incidence in nontreated plots was 10% or higher. Cultivars Georganic, and Georgia-10T, had final incidence of TSW that was lower than that of Georgia-06G, or Florida-07 within nontreated plots across 2011–2012. Georgia-10T and Georgia-12Y had final incidence that was lower than that of Georgia-06G, Georgia-07W, Georgia-09B and Georgia Greener across insecticide treatments in 2013. In-furrow application of phorate increased yields across cultivars in 2008–2009, and increased yield of Georgia-09B in 2010. In most other cases, phorate had no significant effect on yield. With higher levels of field resistance in most of these cultivars, especially those such as Georgia-12Y, benefits from use of phorate insecticide for TSW suppression were small, and typically did not result in yield increase. Based on these results, several of these cultivars should allow greater flexibility for insecticide choice for thrips management without increasing the risk of losses to TSW.     

蓟马复合种在芒果植株上的空间分布和理论抽样

为弄清蓟马在芒果植株上的空间分布格局,确定芒果蓟马监测及防控的抽样技术和方法,分别于芒果嫩梢期和扬花期,调查芒果植株不同冠层蓟马虫数。结果表明：不同地区芒果园蓟马的为害程度差异较大。芒果植株不同冠层均有蓟马分布为害,芒果花期取中、下层花穗,嫩梢期取中、上层叶片能较准确反应出植株的受害情况。芒果蓟马的分布型受种群密度的影响,密度低时为均匀分布,密度高时为聚集分布;聚集程度随密度升高而增大,个体间相互吸引。利用聚集均数分析聚集原因,发现芒果蓟马的聚集主要是由蓟马自身的习性和环境共同作用引起的。应用Iwao理论抽样原理,建立了芒果扬花期及嫩梢期的抽样模型：N =（8.8543/m +0.2098）t ²/D ²和N = (1.8462/m +0.1513)t ²/D ²。     

Seed flavonoids and anthocyanins as markers of enhanced plant defence in nodulated cowpea (Vigna unguiculata L. Walp.)

Insect pests are a major constraint to cowpea production in Africa. Therefore the aim of this study was to identify cowpea material that exhibit greater pest resistance and grain yield for evaluation by farmers. About 45 cowpea genotypes were assayed for flavonoids and anthocyanins with the objective of quantifying the levels of these phenolics in seed extracts as markers for effective plant defence. The results revealed significant differences in the concentration of flavonoids and anthocyanins in seed extract. Farmer varieties such as Sanzie, Bensogla and Omondaw exhibited much higher levels of phenolics compared with improved genotypes like ITH98-46, TVu1509 and IT93K-452-1. When planted in the field in Ghana and Tanzania, the genotypes that had high concentrations of flavonoids and anthocyanins in seed extracts (e.g. Bensogla, Omondaw and IT86D-2075) showed relatively lower infestation by thrips, pod-sucking bugs, aphids and alcidodes. Providing minimum protection with insecticide spray further showed that, genotypes with low infestation by thrips and pod-sucking bugs produced more grain yield without spraying, an indication of their natural resistance to these insect pests. Furthermore, farmer-selected varieties such as Sanzie, Bensogla, and Omondaw produced more grain yield without protection than their improved counterparts. These results showed that the higher the concentration of flavonoids and anthocyanins in cowpea seed extracts, the lower the insect pest incidence on seedlings raised from those seeds. Correlation analysis further confirmed a direct relationship between high flavonoids/anthocyanins in seed extracts and enhanced insect pest.     

Relative abundance and damage of some insect pests of wheat under different tillage practices in rice–wheat cropping in India

Tillage changes the physical and chemical properties of soil and can also inhibit or enhance useful and harmful fauna. In agriculture, different tillage technologies are being tried to enhance crop productivity, but little concrete information seems to exist on their effects on pest abundance and damage. To address this lack of information, sowing of wheat was investigated under different tillage systems. In order to monitor pest abundance and damage in altered tillage systems, the present studies on the relative abundance and damage due to insect pests viz. pink stem borer (PSB, Sesamia inferens Walker), termites (Microtermes obesi Holmgren and Odontotermes obesus Rambur) and root aphid (Rhopalosiphum rufiabdominalis Sasaki) were undertaken in a rice–wheat cropping system during 2010–11 and 2011–12. Pest abundance and damage was monitored in four tillage systems i.e. conventional tillage (CT), zero tillage (ZT), ZT + mulch and rotary tillage (RT) under insecticide protected and unprotected conditions. The application of insecticide did not affect root aphid incidence or termite damage. However, significant differences in PSB damage in insecticide protected (0.9%) and unprotected (1.2%) conditions were observed. The investigations demonstrated that in CT, damage by PSB (0.6%) was minimum; however termite damage (2.2%) was maximum as compared to all other tillage conditions. In ZT, PSB damage (1.4%) was maximum and root aphid incidence (3.1 aphids/tiller) was minimum in comparison to other tillage conditions. ZT + mulch resulted in inter-mediate insect pest incidence/damage; however, RT was the least effective practice which showed relatively high incidence/damage of these three insects (1.2% PSB damage, 1.9% termite damage and 5.1 aphids/tiller). The insecticide × tillage interaction indicated that insecticide application is needed only in ZT and RT for PSB management.     

Screening of the susceptibility of newly released genotypes of potato to thrips infestation under field conditions in northwest Iran

Use of host plant resistance is an essential component of integrated management of Thrips tabaci Lindeman. The present research was designed to screen five commercial cultivars of potato, namely Agria, Kondor, Morene, Diamant and Savalan, and two breeding lines 397082-2 and Khavaran for their susceptibility to thrips infestation and for their mean relative plant growth rate (MRGR) and crop yield in an experimental field (not frected with insecticides) and a control field (chlorpyrifos frected) in the Ardabil region of Iran in 2011 and 2012. Thrips populations were assessed by visual inspection on potato leaves. At harvest time, the percentage of leaf area damaged by thrips infestation was assessed on leaves of the tested genotypes. All adults of phytophagous thrips collected in the experimental field were T. tabaci. In both years the mean numbers of thrips adults and larvae were lowest on Savalan cultivar among the tested genotypes. The mean damage index was also lowest on Savalan in both years and the MRGR and the mean yield were greatest in Savalan in the control field. Moreover, in thrips-infested plants, the lowest percentage of MRGR loss and the lowest percentage of yield reduction were observed in Savalan (3.7% and 5.8%, respectively). Of the genotypes tested, Savalan is the most resistant host and has potential for use in the sustainable management of T. tabaci on potato.