Blue LED trap and commercial lure improve western flower thrips (Frankliniella occidentalis) monitoring in cucumber crops

Blue sticky traps contribute substantially to monitoring the western flower thrips, Frankliniella occidentalis Pergande (Thysanoptera: Thripidae), in greenhouses. Although sticky traps can detect the initial presence of thrips reliably, an estimation of the actual thrips density in the crop by counting number of thrips on the traps is often not accurate. To overcome this issue, we compared blue sticky traps and newly developed sticky LED-enlightened traps in combination with the commercial thrips kairomone Lurem-TR under commercial growing conditions. Therefore, an experiment was conducted in cucumber, Cucumis sativus L. (Cucurbitaceae), crop stands in greenhouse cabins investigating the correlation between thrips caught on (LED) traps and the thrips density in the crop for an accurate and reliable thrips monitoring. Additionally, experiments aiming to understand underlying mechanisms of thrips orientation towards traps in different scenarios were conducted under controlled conditions. Results show that thrips catches on sticky LED enlightened coloured traps correlated strongly positive with number of thrips in the crop, especially at low thrips population densities. Adding Lurem to this trap type further improved accuracy of the correlation in the greenhouse cabin experiment. Moreover, LED traps with and without Lurem were more attractive towards thrips in small follow-up experiments compared to standard blue sticky traps. The results are discussed in the context of general orientation of thrips and its behaviour towards visual and olfactory cues when considering different scenarios. Our study shows the successful integration of blue LEDs into an existing trapping system and underlines the advantages compared with standard sticky plates. In conclusion, sticky LED enlightened coloured traps have a potential as an improved thrips monitoring device that might improve pest management decisions

Применение цветовых клеевых ловушек против огуречного комарика в защищенном грунте

In the article the data on colour sticky traps for cucumber midge control in the protected ground are presented. For cucumber midge imago the most attractive are yellow colour sticky traps: the pest number in yellow colour traps is 1,3-1,5 times higher than in blue colour traps. Cucumber midge imago are attracted by traps along the whole height of a plant, but their maximum number becomes sticky at a distance of 40 cm from soil and subsoil surface

First report and population dynamics of the Tobacco Thrips, Thrips parvispinus (Karny) (Thysanoptera: Thripidae) on ridged gourd, Luffa acutangula (L.) Roxy in selected export fields in southern Ghana

Thrips attack several crops causing considerable economic damage. To prevent this damage, sticky traps can be used to monitor their population for the timely execution of management interventions. Ridged gourd or turia (Luffa acutangula (L.) Roxy) is an important Asian vegetable exported regularly to the European Union market from Ghana. However, this vegetable has been intercepted severally at the point of entry because of thrips infestation. The current study is aimed at identifying and monitoring thrips population on turia using blue and yellow sticky traps in six export vegetable production sites in Ghana for two consecutive seasons and three trapping periods. The results showed that Thrips parvispinus (Karny) (Thysanoptera: Thripidae) was the commonest and only species of thrips found attacking turia. The highest and lowest mean number of thrips were recorded from the blue and yellow sticky traps during the dry and the late part of the major rainy seasons, respectively. Thrips population build-up was observed to reach its peak at the flowering stage of the crop. This is the first report of T. parvispinus in Ghana. The implications of this finding on the export of turia to the EU market has been discussed

Can mass trapping reduce thrips damage and is it economically viable?: management of the western flower thrips in strawberry

The western flower thrips Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is a cosmopolitan, polyphagous insect pest that causes bronzing to fruit of strawberry (Fragaria x ananassa). The main aim of this study was to test whether mass trapping could reduce damage and to predict whether this approach would be economically viable. In semi-protected strawberry crops, mass trapping of F. occidentalis using blue sticky roller traps reduced adult thrips numbers per flower by 61% and fruit bronzing by 55%. The addition of the F. occidentalis aggregation pheromone, neryl (S)-2-methylbutanoate, to the traps doubled the trap catch, reduced adult thrips numbers per flower by 73% and fruit bronzing by 68%. The factors affecting trapping efficiency through the season are discussed. Damage that would result in downgrading of fruit to a cheaper price occurred when bronzing affected about 10% of the red fruit surface. Cost-benefit analysis using this threshold showed that mass trapping of thrips using blue sticky roller traps can be cost-effective in high-value crops. The addition of blue sticky roller traps to an integrated pest management programme maintained thrips numbers below the damage threshold and increased grower returns by a conservative estimate of £2.2k per hectare. Further work is required to develop the F. occidentalis aggregation pheromone for mass trapping and to determine the best timing for trap deployment. Mass trapping of thrips is likely to be cost-effective in other countries and other high-value crops affected by F. occidentalis damage, such as cucumber and cut flowers

Visual Responses of Adult Asian Citrus Psyllid (Hemiptera: Liviidae) to Colored Sticky Traps on Citrus Trees

The effects of five differently-colored sticky traps in capturing adult Diaphorina citri were evaluated in citrus orchards. Trap catches of D. citri were monitored fortnightly on blue, green, red, white and yellow sticky cards placed on three citrus varieties during D. citri active flight period from April to July in south Texas. Evaluation of mean trap catches of each color by repeated measures analysis of variance produced three separate groups: yellow traps caught significantly more D. citri adults than the other four traps; red and green traps caught significantly more D. citri than blue and white traps, which were not significantly different. Although the number of adult psyllid captured on all trap types significantly increased with time during the trapping period, the performance of traps did not change with time. Trap catches were also significantly influenced by the citrus species; traps placed on lemon trees captured more D. citri than those placed on sweet orange and grapefruit, suggesting that plant preference exhibited by D. citri may influence the performance of traps. The ratio of trap reflectance between the 680 to 700 nm and the 450 nm was significantly correlated with total trap catches in all host species studied. Thus, this index was a good indicator of the attractiveness of adult D. citri to colored traps. Additionally, we compared the reflectance values of young versus mature flush shoots of the three host plants used in this study as related to densities of D. citri recorded in colored traps. We discussed the importance of visual cues in the host finding behavior of adult D. citri

Мониторинг огуречного комарика в защищенном грунте.

В статье приведены многолетние экспериментальные данные о применении цветовых клеевых ловушек против огуречного комарика в защищенном грунте. Для имаго огуречного комарика наи-более аттрактивны ловушки желтого цвета: численность вредителя на ловушках желтого цвета в 1,3-1,5 раз выше, чем на ловушках голубого цвета. Имаго огуречного комарика привлекаются ловушками по всей высоте растения, однако максимальное их количество улавливается на расстоянии до 40 см от поверхности почвогрунта. = In the article the data on color sticky traps for cucumber midge control in the protected ground are presented. For cucumber midge imago the most attractive are yellow color sticky traps: the pest number in yellow color traps is 1,3-1,5 times higher than in blue color traps. Cucumber midge imago isattracted by traps along the whole height of a plant, but their maximum number becomes sticky at a distance of 40 cm from soil and subsoil surface

Local and landscape effects of field margins on aerially dispersing beneficial insects and spiders

Field margins were implemented in UK agri-environment schemes with the aim to increase farmland biodiversity. Recently aerially dispersing aphid enemies have been shown to provide the majority of aphid control in winter wheat fields but there is a lack of research conducted on the aerial predator guild. This thesis examines the effect field margins have on aphid predators at the single field scale, the landscape scale and, using results from a marking study, examines the direct use of a pollen and nectar rich field margin by Episyrphus balteatus. At the single field scale, field margins had a positive effect of the numbers of Cantharidae, Empididae, Linyphiidae and Tachyporus spp. in fields with sown margins compared to those without during wheat growth and total aphid predator numbers were significantly higher in fields with margin surrounds in early May but not later in the year. At the landscape scale, results from twelve winter wheat fields with varying densities of surrounding field margins showed predatory Tachyporus spp. to exhibit a positive correlation at scales above 500m radius and Cantharidae to exhibit a negative correlation at local scales. Implications for field margins exerting both positive and negative influences on the presence of aerially dispersing aphid predators in winter wheat fields are discussed. A marking study using rubidium chloride proved direct utilisation of a pollen and nectar rich field margin by the Syrphid Episyrphus balteatus, and the traps used in this study also highlighted the association in distributions between Empididae and cereal aphids. Overall it was concluded that the presence of field margins does have an effect on the spatial and temporal distributions of some aerially dispersing aphid predators, but the response of each predator group varies depending on numerous interlinking components of their life history and directions for future research are discussed