Trapping whiteflies? A comparison of greenhouse whitefly (Trialeurodes vaporariorum) responses to trap crops and yellow sticky traps

BACKGROUND: Greenhouse whiteflies, Trialeurodes vaporariorum (Westwood), are notorious pests that, through the reduction of crop yields and excretion of honeydew, cause significant economic losses for sweet pepper (Capsicum annuum L.) growers. Chemical and biological controls are the two most common forms of whitefly management in greenhouses. Consequently, insecticide resistance and inadequate control have rejuvenated interest in alternative tactics. In the present study, whitefly responses to trap crops (eggplant and squash) and yellow sticky traps were compared in order to identify the most effective traps for dispersing and resident adults. RESULTS: Results indicated that yellow sticky traps were most effective at trapping adult whiteflies. Significantly more dispersing whiteflies were recorded on eggplant than on squash trap crops. None of the traps significantly reduced adult populations on the main crops (peppers) compared with the control. However, yellow sticky traps did significantly reduce oviposition on peppers. CONCLUSIONS: Adult whiteflies were most effectively trapped on yellow sticky traps followed by eggplant trap crops. Further study of whitefly trapping using visual cues may enhance trapping management. Specifically, research combining yellow sticky traps with other control strategies is recommended. Copyright © 2011 Society of Chemical Industry     

Potential for a sticky trap monitoring system for the diamondback moth (Lepidoptera: Yponomeutidae) on cabbages in Indonesia

Experiments on the development of a sticky trap monitoring system for the diamondback moth, Plutella xylostella (L.), were carried out in six cabbage fields (two in each of three villages) in North Sulawesi, Indonesia. This region is characterized by small, closely‐situated, fields. Yellow cardboard traps with a sticky upper surface were placed 10 cm below the crop canopy, four traps per field, and were maintained throughout the 1991 growing season. Larvae were sampled weekly in quadrats centred around each trap. One village where continuous cabbage growing occurred had higher P. xylostella populations than the other two villages, where growing is discontinuous. Although the relationship between trap catches and larval populations for individual fields was weak, the relationship between catches in all fields pooled and larval populations 2 weeks later was very strong, suggesting that a region‐wide predictive system would be feasible. An increase in larval numbers as distance from the traps increased further suggests that sticky traps may have potential for use in mass trapping.     

Dispersion patterns and sampling plans for the pea aphid,Acyrthosiphon pisum (Harris), on grass pea,Lathyrus sativus L.

From 2009/2010 to 2010/2011, flight patterns and spatial distribution of pea aphids were studied in northwestern Ethiopia. Yellow traps were used and legume fields sampled. Trap catches varied between years (lower in 2009/2010 than in 2010/2011), locations and months in the growing season. At Woreta, peaks were observed in January (20–70 per trap) and at Wondata in October and November (60–80 per trap). Also, pea aphid numbers were more on fallow land than on other land-use systems (a maximum of 41,000 in December 2010/2011 and 25,000 in January 2009/2010 per 100 plants). Taylor's power law coefficients, i.e., b values, were significantly greater than 1 on grass peas planted after fallow; the corresponding r² values ranged between 0.87 and 0.94. Coefficients were inconsistent on grass peas planted after teff and undersown in maize. The optimum sample size n (number of yellow traps) required in relation to the mean densities of the pea aphid was more or less the same for the three levels of accuracy (D = 0.2, 0.3 and 0.5). At D = 0.5, numerical sample size curves showed 10 traps as mean number of aphids per trap approached 4 or 5, which is practical and affordable. Some additional work at more locations may be required to validate these sampling plans before wider use.     

黄色黏虫板在3种果园对蚜虫及其天敌的诱集作用

为减少黄色黏虫板(简称黄板)对果园害虫天敌的影响,明确黄板在果园中的使用方法,于2014年5月4日至9月30日在山西省太谷县的苹果、梨、桃园中进行了黄板诱集蚜虫及其天敌的动态调查。结果表明:在3种果园黄板可以诱集8目32科的昆虫,主要类群为蚜虫、叶蝉、瓢虫、食蚜蝇、草蛉和蚜茧蜂等。在苹果园和桃园中诱蚜量呈双峰谷线状,在梨园中呈三峰状;各果园寄生性天敌的数量变化趋势与蚜虫一致且有跟随效应,但苹果园和梨园诱集的捕食性天敌均在8月下旬至8月底出现高峰期,而桃园中捕食性天敌水平一直较高。3个果园在花期至幼果期即5月4日至6月22日益害比最小,苹果园仅为1:202.8,而在其它时段的益害比均大于1:150,甚至最高可达1:19.4,表明在果园中使用黄板的害处大于益处,建议在果园中慎用黄板诱蚜。     

Virus vector aphid activity and seed potato tuber virus infection in Hungary

An aphid and virus survey was conducted from 1993 and 1999 on the eastern lowlands in Hungary. Aphid flight was monitored with two yellow pan traps placed on the edge and in the middle of seed potato fields. From 1993 and 1997, aphid flight was monitored with a Rothamsted type suction trap. The aphid and virus survey was continued in four different regions of Hungary in 2000. Aphid flight activity recorded by the suction trap and the yellow pan traps was different. Cumulative vector intensity based on yellow pan trap catches revealed a greater variation between years than among the different locations. In 4years out of 8, aphid flight was less intensive and quality seed potato was harvested regardless of the production site. Cumulative vector intensity is a good means to forecast the time of haulm destruction in seed potatoes.     

Virus vector aphid activity and seed potato tuber virus infection in Hungary

An aphid and virus survey was conducted from 1993 and 1999 on the eastern lowlands in Hungary. Aphid flight was monitored with two yellow pan traps placed on the edge and in the middle of seed potato fields. From 1993 and 1997, aphid flight was monitored with a Rothamsted type suction trap. The aphid and virus survey was continued in four different regions of Hungary in 2000. Aphid flight activity recorded by the suction trap and the yellow pan traps was different. Cumulative vector intensity based on yellow pan trap catches revealed a greater variation between years than among the different locations. In 4years out of 8, aphid flight was less intensive and quality seed potato was harvested regardless of the production site. Cumulative vector intensity is a good means to forecast the time of haulm destruction in seed potatoes.     

诱杀球对橘大实蝇诱捕效果的研究

为开发一种新型的橘大实蝇诱捕器,研究了不同颜色、直径的诱杀球和不同颜色的粘虫板对橘大实蝇的诱集效果。结果表明,绿色诱杀球的诱杀数量显著大于黄色和黄绿色诱杀球(P0.05);诱杀球上橘大实蝇的诱集数量,随诱杀球直径的增大而显著增加,但在直径7cm以上时,诱杀球的诱集数量增速变缓,其中以直径7cm的绿色诱杀球生产成本和诱集效果最佳;诱杀球能显著提高黄板对橘大实蝇的诱集效果(P0.05)。     

青岛地区暗黑鳃金龟性信息素鉴定及田间应用技术

为深入了解国内暗黑鳃金龟Holotrichia parallela Motschulsky种群的性信息素组分及其田间引诱效果,采用气质联用技术对其雌性信息素进行了分离鉴定,利用标记-回捕技术测试了5 h内暗黑鳃金龟的扩散距离,并在此基础上测试了诱捕器颜色、离地高度、密度、单诱芯性信息素含量等对田间诱虫效果的影响。结果表明：L-异亮氨酸甲酯和（R）-（-）-芳樟醇为国内青岛种群暗黑鳃金龟雌虫性信息素的主要组分,两者含量比为7：1;暗黑鳃金龟5 h扩散距离可达400 m以上,平均扩散距离为55.9 m,扩散距离在20~60 m的个体占总虫数的77.5%;黄色诱捕器对该虫的引诱效果显著优于黑色和绿色;诱捕器离地2 m引诱到的试虫数目显著高于1、1.5、2.5和3 m;单个诱芯性信息素含量360 mg引诱效果最好,显著高于180 mg及以下浓度;诱捕器间隔20~60 m防治效果较好,结合使用成本和试虫扩散距离,间距60 m最优。     

不同颜色色板对梨园昆虫的诱集效应

为筛选对梨园害虫诱集效果较好的粘虫板,选用黄色、红色、绿色、紫色、蓝色、灰色、白色和黑色8种颜色的粘虫板对梨园内昆虫进行诱集。结果显示,黄色粘虫板的诱集效果最好,诱集害虫种类8科10种,对中国梨木虱和小绿叶蝉的诱集效果较好;其次为绿色粘虫板,诱集昆虫种类7科7种,对中国梨木虱和小绿叶蝉也表现出较好的诱集效果。半翅目昆虫的趋色性较强,诱集数量最多,适合选择色板诱集防治。黄板和绿板对梨园天敌有一定影响,在梨园使用时应适时适量选择性使用。本研究为利用粘虫板在梨园进行害虫防治提供了理论依据。     

A method for monitoringBemisia tabaci and timing spray applications against the pest in cotton fields in israel

A method for monitoring tobacco whitefly [Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae)] populations was developed and used for timing spray applications against this pest in cotton. It was found to be successful in tests in eight commercial cotton fields. A trap composed of a yellow plastic plate (15 × 20 cm) smeared on the upper side with a thin layer of glue, was attached to an iron pole which held the plate in a horizontal position above the plants. The traps were placed 400 m apart along the periphery of the field. The sticky plates were changed weekly and the adult whiteflies were counted. When the mean weekly catch per trap reached ~ 100–200 adults, spray applications were carried out. Following this treatment,B. tabaci populations remained low and sooty mould did not develop on the lint.     

Olfactory and visual responses of the longlegged chafer Hoplia spectabilis Medvedev (Coleoptera: Scarabaeidae) in Qinghai Province, China

BACKGROUND: Monitoring traps and control methods are needed for the long‐legged chafer, Hoplia spectabilis Medvedev, which has recently reached outbreak numbers in pastureland of Qinghai Province, China. RESULTS: Field trapping experiments, using cross‐pane funnel (barrier) traps, showed that H. spectabilis adults were not significantly attracted to branches of the host plant Dasiphora fructicosa (L.) Rydb. However, beetles were slightly attracted to similar host plant branches infested by conspecific beetles, possibly owing to weakly attractive volatiles, primarily (Z)‐3‐hexenyl acetate, released from beetle‐damaged host leaves. This compound was weakly attractive when released from traps. However, H. spectabilis beetles showed strong visual responses to yellow‐ or white‐painted trap panes, with weaker responses to blue, red or green panes, and least response to black panes. Black traps at 0.2–1.5 m above ground intercepted significantly more beetles than traps at 2.5 m. The mean flight height based on trap catches was 0.88 m (SD = 0.76), yielding an effective flight layer of 1.9 m. Flight response of beetles to colored barrier traps occurred between 10:00 and 18:00, and peaked between 12:00‐14:00, when daily temperatures reached their maximum. CONCLUSION: Unbaited yellow or white cross‐pane funnel traps are recommended for both monitoring and mass‐trapping programs against this economically and ecologically important scarab beetle. Copyright © 2010 Society of Chemical Industry     

Catching Ips duplicatus (Sahlberg) (Coleoptera: Scolytidae) with pheromone‐baited traps: optimal trap type,colour, height and distance to infestation

BACKGROUND: Field trapping experiments were carried out to evaluate effective trap characteristics for maximising Ips duplicatus (Sahlberg) catches in pheromone‐baited traps in China. RESULTS: Window‐slot and cross‐barrier traps had significantly higher catches than multiple‐funnel traps. The colour of window‐slot traps showed a significant effect on catches, with dark colours (black and red) being more effective than light colours, especially white and yellow. Window‐slot traps at a 1.5–2.0 m level caught more beetles than those at either ground level (0–0.5 m) or at 3.5–4.0 m. Ips duplicatus can be attracted to pheromone‐baited traps over a distance of > 100 m from the forest edge in an open grassy field. There was a strong diurnal pattern of flight activity, with catches on window‐slot traps occurring during the daytime with one broad peak at mid‐ to late afternoon. The seasonal flight activity of I. duplicatus as monitored by pheromone‐baited window‐slot traps during 2007–2008 indicated that three major flight peaks occurred in early June, late June–early July and late July respectively, suggesting the existence of a potential second generation. CONCLUSION: The optimal trap characteristics will improve the performance of pheromone‐baited traps as a critical monitoring or mass‐trapping tool to combat outbreaks of this pest species. Copyright © 2009 Society of Chemical Industry     

不同色板和引诱剂对设施蔬菜主要害虫的诱杀效果

为了发挥物理防治技术的作用,降低农药用量,本文探讨了不同色板和诱芯对设施蔬菜主要害虫的控制作用和使用技术。结果表明,在种植辣椒、番茄和黄瓜的温室,普通黄板和烟粉虱诱芯黄板对烟粉虱均具有较好的诱杀效果,2种色板诱杀烟粉虱的数量无显著差异;蓝板无明显诱杀作用。第6周,普通黄板对烟粉虱的诱杀量高于烟粉虱诱芯黄板,且差异显著(P0.05),表明烟粉虱对黄色的趋性更强。针对温室害虫蓟马,普通蓝板的诱虫量显著高于普通黄板和烟粉虱诱芯黄板,表明蓟马对蓝色的趋性更强。因而,在烟粉虱和蓟马混合发生的温室中,推荐黄板和蓝板的联合使用同时治理两种害虫。     

Estimation of fly population density of Bactrocera oleae in olive groves of Crete

Population density of adults of Bactrocera oleae (Gmelin) (Diptera: Tephritidae) was obtained from olive trees during a two-year study by means of two different methods, namely, knock down by an insecticide applied as a fog (‘sondage’) and trap captures (of yellow sticky panels and McPhail traps baited with ammonium). First it was concluded that yellow sticky panel traps give a poor representation of the olive fruit fly population density of the olive grove. Yellow panel trap captures were significantly lower than McPhail’s (September) and than the actual population of B. oleae as recorded in olive tree canopy (August of 2008). When only McPhail captures were compared to the olive fruit fly population in the tree canopy, B. oleae captures in McPhail traps represented only a small percentage of the population that was recorded in the olive tree canopy (July and August of 2009). It was estimated that traps captured only 0.5% of the flies present within a radius of 20 m in the studied field (which consists of approximately 25 trees). However, during autumn (September), low trap captures of B. oleae can occur even when the fly population in the field is near zero.     

正交试验法研究黄板对3种温室西葫芦害虫的诱杀作用

应用正交试验法研究了黄板悬挂高度、黄板形状、黄板距温室出口距离、黄板距北墙距离4个因素对黄板诱杀3种温室西葫芦害虫的影响。结果表明:4个因素对诱杀温室白粉虱都具有显著、极显著影响,黄板悬挂高度和黄板距出口距离对诱杀美洲斑潜蝇有显著影响;黄板距北墙距离对诱杀有翅瓜蚜具有极显著影响。黄板诱杀害虫的4因素组合为黄板高出植株0.2 m、平板形、距出口91 m、距北墙距离0.7 m时诱杀虫量最大。     

Effect of Weather Conditions on Frit Fly (Oscinella frit, Diptera: Chloropidae) Activity and Infestation Levels in Spring Wheat in Central Germany

Effects of temperature, rainfall and solar radiation on frit fly (Oscinella frit) population and infestation level were evaluated in two wheat varieties in central Germany during 2008?C2010. The effect colour of water traps (blue, white and yellow) -used in population determination- on their efficiency was also evaluated. Strong correlation was found between weather parameters and trap catches (R² between 0.8 and 0.98). Infestation percents were calculated by counting the infested plants at different growth stages 10?C30. The weather conditions in 2008 and 2009 were drier, warmer and sunnier than 2010, which affected trap catches as well infestation percents. There was a positive correlation between blue trap catches and solar radiation and negative correlation with white and yellow traps. Infestation percents were higher in 2008 & 2009 than in 2010; although trap catches were higher in 2010 than 2008 & 2009, because weather conditions affected adult negatively ovipositon and newly larvae survival in 2010. The results indicate that weather can play a precise role in frit fly activity and its infestation levels.     

Screening sticky traps under low magnification for adult Bemisia tabaci (Gennadius), Trialeurodes vaporariorum (Westwood) and Aleyrodes spp. (Hemiptera: Sternorrhyncha: Aleyrodidae)

Whiteflies are commonly transported in international plant trade, accounting for 25% of arthropods found in association with imported plant material in England and Wales between 1996 and 2006. Several species are of quarantine significance and rapid, accurate identifications are essential in order for phytosanitary services to decide upon appropriate action. Whitefly taxonomy is based on the puparium, but these are often difficult to detect when present at low densities. Adults are more conspicuous and are readily caught on yellow sticky traps. Screening traps under low magnification for adult Bemisia tabaci , Trialeurodes vaporariorum and Aleyrodes spp. using pigmentation characters was evaluated; 5151 adults were examined on 238 traps and their identity predicted. Twenty-one percent of the adults were slide mounted and examined under high magnification to check their identity. The overall accuracy of the initial whitefly species prediction under low magnification was 98%. The speed and reliability of detecting adult B. tabaci on sticky traps was greatly improved and the number of adults requiring slide preparation reduced (by an average of 46% per trap) resulting in significant financial savings, compared to randomly selecting adults for slide mounting. Protocols are presented for removing adults from traps and making microscope-slide preparations.     

Verbena as a trap crop to suppress thrips-transmitted Tomato spotted wilt virus in chrysanthemums

The effect of verbena as a trap crop on the occurrence of western flower thrips, Frankliniella occidentalis, and the incidence of Tomato spotted wilt virus (TSWV) in chrysanthemums were investigated. Verbena cvs. Pink Parfait and/or Fancy Parfait were cultivated alongside chrysanthemum cv. Jimba in a greenhouse in the proportion of 17%–25% of the chrysanthemum plants. Verbena plants attracted vector thrips, reducing western flower thrips colonization of chrysanthemum until flower bud initiation, and markedly suppressing TSWV incidence on chrysanthemums until flowering. Significant quantities of linalool oxide pyran were produced by the flower of cv. Fancy Parfait; and the ratio of cis-linalool oxide pyran, an attractant for vector thrips, to the trans-type was approximately 1 : 5. Our results suggest that cultivation of verbena as a trap crop may be useful in integrated pest management programs as a control for thrips-transmitted TSWV in chrysanthemums.     

Field evaluation of synthetic sex pheromone traps for the cocoa mirid Sahlbergella singularis (Hemiptera: Miridae)

BACKGROUND: Field trapping experiments were conducted to evaluate the attractiveness of five different pheromone blends as well as the impact of trap design on attractiveness towards cocoa mirids, Sahlbergella singularis Hagl. and Distantiella theobroma (Dist.), in Cameroon. RESULTS: A total of 361 adults of S. singularis (359 males and two females) were caught. The highest numbers of mirids were found in traps with pheromone blends that combined a monoester and a diester, compared with traps with the diester or the monoester individually and control traps with no pheromone. Rectangular traps caught significantly more mirids compared with delta traps. The mean number of 5.1 mirids trap^?1 year^?1 caught in rectangular traps was significantly higher compared with the 1.8 mirids trap^?1 year^?1 for the delta traps. CONCLUSION: The data revealed that rectangular traps containing pheromone blends combining both the monoester and the diester have a good potential to lure and trap adult males of S. singularis on cocoa farms. The pheromone blends used were specific for S. singularis, and the use of pheromone traps appears to be a promising strategy for incorporation into integrated pest management strategies for the monitoring or even the control of S. singularis in cocoa plantations. Copyright © 2011 Society of Chemical Industry     

北方规模种植果园昆虫种类调查及虫害防治——以黑龙江省宝清县为例

采用食诱法、陷阱法、网捕法和夜间灯诱法4种方法,在不同时间段对调查地昆虫进行采样调查。调查结果表明:在调查地发现昆虫101种属于42科,11目。通过调查结果进行分析,可采用合理种植与生态环境调节、生物农药、以虫治虫的手段,使规模种植果园发展成为无机绿色果园。