Semiochemicals of Rhagoletis Fruit Flies: Potential for Integrated Pest Management

Worldwide economic losses associated with Rhagoletis fruit flies (Diptera: Tephritidae) require an effective means of control. Most conventional insecticides used to control fruit flies have been banned, and fruit producers are seeking new economical fruit fly control options. Bait stations can be a suitable alternative, provided they are affordable, effective and pest-specific. Semiochemicals are important for fruit flies to locate their host fruit and to reproduce. They could therefore be good candidates to improve existing bait stations. In this literature review, we summarize the available data on Rhagoletis semiochemicals, including the pheromones and allelochemicals used for host location. Then, we present some field applications of semiochemicals that have been successful at Rhagoletis fly control and discuss potential semiochemical-based control strategies.Développement d'une méthode de lutte alternative contre la mouche du brou du noyer, Rhagoletis complet

Semiochemicals to control the Walnut husk fly Rhagoletis completa

Most European walnut producers have to deal with the recent introduction of the Walnut Husk Fly, Rhagoletis completa (Diptera, Tephritidae), that causes severe economic losses, especially in biological productions. In orchards where R. completa is present and uncontrolled, losses in walnut yields can reach up to 80%. As a consequence, there is a need for developing environment-friendly methods of control. In this research, we evaluated the efficiency of two different semiochemical blends to trap R. completa in walnut orchards. The first semiochemical blend consisted in walnut fruit volatiles, previously collected and identified from two walnut varieties. The second semiochemical blend was made of the putative male sex pheromone, made of two lactones, and previously collected from R. completa males. In field both semiochemical blends were associated with yellow sticky traps. The assays were conducted in France, in a total of 53 orchards, in 2015, 2016 and 2017. The first blend (made of fruit kairomones) was highly attractive for both male and female R. completa in a laboratory assay, but did not enhance the number of fly captures in the field. On the other hand, sticky traps associated with the putative sex pheromone captured up to 10 times more fruit flies each week during the entire season. The total number of captured flies was also more important than with a mass trapping system baited with food attractant. These field results are promising for R. completa monitoring and mass trapping

Walnut husk fly, Rhagoletis completa (Diptera: Tephritidae), invades Europe: invasion potential and control strategies

Rhagoletis completa Cresson (Diptera: Tephritidae) is native to North America and invaded Western Europe in the late 1980s, causing important damage to its principal host, walnut (Juglans spp.). In this review, we summarize the important elements of R. completa’s biology, phytosanitary status and methods used in Europe for its control, and then present the main conclusions associated with a completed risk analysis performed in 2014 to evaluate the dispersion and establishment potential of R. completa in Europe. The walnut husk fly was initially identified in Switzerland (1988) and Italy (1991), from where it spread to at least seven additional countries: France, Spain, Germany, Austria, Croatia, Slovenia and Hungary. R. completa has not reached the limits of its potential distribution. The main dissemination pathways within Europe include: (1) natural adult dissemination; (2) adult hitchhiker behaviour; and, to a lesser extent, (3) transportation of larvae in fresh fruits. R. completa host plants are widely distributed in Europe, either as isolated wild trees or in orchards, favouring the probability of fly establishment in currently fly-free areas. In addition, the European territories where Juglans species are present share biogeographic similarities. In orchards where R. completa is present and uncontrolled, 100% of walnut trees can be infested, causing losses in walnut yields of up to 80%. The negative effect is low (<10% yield loss) under phytosanitary control, although additional costs must also be considered to support specific monitoring for R. completa. The information presented here underlines a strong need for better walnut husk fly monitoring across European countries, as well as for increasing efforts to develop biological methods to control this emerging pest

Improving the Monitoring of the Walnut Husk Fly (Diptera: Tephritidae) Using Male-Produced Lactones

peer reviewedIt is important to monitor fruit flies (Diptera: Tephritidae) efficiently to implement sustainable means of control. Attractants are often used to increase the efficiency of sticky traps deployed in orchards to monitor Lepidopterans, but remains to be developed to monitor fruit flies. Rhagoletis completa Cresson (Diptera: Tephritidae) is an invasive species in the walnut orchards of Europe, and is commonly monitored with yellow sticky traps. In this study, we collected the volatile compounds released by male and female R. completa, and identified two lactones released exclusively by males. We then formulated both lactones in long-lasting volatile dispensers, and we quantified their release rate over a 26-d period. Finally, during the entire period when female flies are present in the field, we compared the efficiency of the conventional monitoring method using unbaited yellow sticky traps with yellow sticky traps associated with a dispenser releasing both male-produced lactones. These assays were conducted in 54 walnut orchards in France, in 2017. The number of fruit flies caught with sticky traps associated with lactones dispensers was increased by up to 10 times each week. Lactone-baited traps also allowed earlier detection in the season. These field results are promising for R. completa monitoring. A complete chiral identification of these lactones should be performed along with a clarification of their role in the sexual communication of R. completa

Surgery and postoperative radiation therapy in primary retroperitoneal sarcomas: Experience of the cancer centre Alexis-Vautrin

National audiencePURPOSE: Surgical resection remains the standard treatment for patients with resectable retroperitoneal sarcomas. The aim of this study was to retrospectively analyse the outcomes of patients with primary retroperitoneal sarcoma. PATIENTS AND METHODS: We analysed data of 50 patients with primary retroperitoneal sarcoma who underwent curative-intent resection from 1975 to 2008. External beam radiotherapy and chemotherapy were delivered postoperatively. Demographics, surgical, pathological variables and chemo/radiation therapy were analysed as prognosis factors. RESULTS: There were 22 males and 28 females (mean age 54±13years). Surgery required visceral resections in 30 patients. There were 16 leiomyosarcomas, 25 liposarcomas and eight other sub-types. Twenty-one patients had clear surgical margins. Twenty-eight patients received postoperative external beam radiotherapy (median 45Gy) and 15 received chemotherapy. At the end of the follow-up (median 55months), local recurrence occurred in 39% (n=14) among R0/R1 resection group (n=36). Postoperative external beam radiotherapy tends to increase the time of local recurrence from surgery (27 vs. 13months, P=0.05). The overall survival rates were 81%, 55% and 46% at 1, 3 and 5years, respectively. Although R0 resection (P=0.01), well tumour differentiation (P=0.004) and postoperative external beam radiotherapy (P=0.02) significantly influenced overall survival in univariate analysis, only R0 resection was an independent prognostic factor in a multivariate analysis. CONCLUSION: We confirm the pre-eminence of radical surgery with negative margins as major prognostic factor and the benefit of postoperative radiotherapy