A diagnostic real-time PCR assay for the rapid identification of the tomato-potato psyllid, Bactericera cockerelli (Sulc, 1909) and development of a psyllid barcoding database

The accurate and rapid identification of insect pests is an important step in the prevention and control of outbreaks in areas that are otherwise pest free. The potato-tomato psyllid Bactericera cockerelli (Sulc, 1909) is the main vector of 'Candidatus Liberibacter solanacearum' on potato and tomato crops in North America and New Zealand; and is considered a threat for introduction in Europe and other pest-free regions. This study describes the design and validation of the first species-specific TaqMan probe-based real-time PCR assay, targeting the ITS2 gene region of B. cockerelli. The assay detected B. cockerelli genomic DNA from adults, immatures, and eggs, with 100% accuracy. This assay also detected DNA from cloned plasmids containing the ITS2 region of B. cockerelli with 100% accuracy. The assay showed 0% false positives when tested on genomic and cloned DNA from 73 other psyllid species collected from across Europe, New Zealand, Mexico and the USA. This included 8 other species in the Bactericera genus and the main vectors of 'Candidatus Liberibacter solanacearum' worldwide. The limit of detection for this assay at optimum conditions was 0.000001ng DNA (similar to 200 copies) of ITS2 DNA which equates to around a 1:10000 dilution of DNA from one single adult specimen. This assay is the first real-time PCR based method for accurate, robust, sensitive and specific identification of B. cockerelli from all life stages. It can be used as a surveillance and monitoring tool to further study this important crop pest and to aid the prevention of outbreaks, or to prevent their spread after establishment in new areas

Suction-trap catches partially predict infestations of the grain aphid Sitobion avenae in winter wheat fields

Effective pest monitoring programmes are needed for providing reliable advice on when pest populations require active management. We studied whether suction-trap catches of the grain aphid Sitobion avenae during the period 1989-2009 can be used to predict field infestations of this aphid in Swedish winter wheat fields. We found that suction-trap catches of S.avenae until the time of crop heading (GS51) were significantly related to both number of aphids per tiller (R-2=0.69 at GS 59 and R-2=0.27 at GS 69) and proportion of fields with infestations above economic threshold (R-2=0.49 at GS 59 and R-2=0.40 at GS 69). This effect was consistent across Swedish regions and years. This information could be used by advisory services and farmers to decide whether field inspection to estimate the profitability of insecticide treatment at heading is needed. To improve the predictive ability further, suction-trap catches could be combined with weather data and information about biological control potential in different landscapes

25 Risk Assessments for Pests and Diseases of Field Crops, especially Forecasting and Warning Systems

Ecosystem Health and Sustainable Agricultur

Predicting the effects of climate change on the latency period of wheat leaf rust in western Poland

Leaf rust caused by Puccinia recondita f. sp. tritici belongs to the most important diseases of wheat worldwide. The progress of the disease is highly dependent on meteorological conditions. One of the parameters affecting the disease progress is latency period driven mostly by temperature. Examination of the influence of predicted temperature changes on the monthly sum of the daily latency period expressed as rate (MSLPR) in western Poland was the aim of our study. Experiments in quasi-natural conditions were performed with the aim of validating models describing the influence of temperature on leaf rust latency period in two wheat varieties, Turnia and Ostroga. Both models used for assessment of latency period duration on cv. Turnia and cv. Ostroga performed well. The influence of climate changes on leaf rust latency period was then simulated using meteorological data from three weather stations located in western Poland and virtual data obtained after transformation of the recorded data to reflect a temperature changes under RCP2.6 and RCP8.5 scenarios according to giss_e2_r climate model. The study shows that without mitigation of greenhouse gas emission latency period of wheat leaf rust is going to decrease which may result in increase of wheat leaf rust incidence