Bait sprays against the European cherry fruit fly Rhagoletis cerasi: Status Quo & Perspectives

Bait spray experiments against Rhagoletis cerasi were carried out in 2005 to 2007. The main principle of this method is to use food (e.g. sugar and proteins) as baits for the flies with small amounts of insecticides, which is applied on parts of the cherry tree. Main focus was aimed at laboratory and field cage experiments using the commercial GF-120 Naturalyte Fruit Fly BaitTM with the insecticide spinosad, which is registered against North American cherry fruit fly species in the US and Canada. Furthermore, additional bait spray formulations as alternatives to GF-120 were used to define the right food bait quality for a high attractiveness and low reproduction ability. Beyond, the negative effect on reproduction of flies for azadirachtin (neem) was shown. During this project, promising results, e.g. efficacies up to 99 % with infestation rates below the infestation threshold were obtained. From 2008 on, other insecticides, like azadirachtin (neem) and pyrethrine in an appropriate food bait mixture will be used. Questions like efficacy, adequate concentrations, persistence, rainfastness and practicability in commercial cherry orchards will be answered

Invertebrate and vertebrate pests: Biology and management

[No abstract available

Effects of photoperiod and relative humidity on diapause termination and post-winter development of Rhagoletis cerasi pupae

The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a univoltine species that undergoes obligatory summer-winter diapause at pupal stage in the soil (2-5 cm) beneath host trees. To study the effects of photoperiod and relative humidity on diapause termination and post-winter developmental duration of R. cerasi, pupae collected from Dossenheim (Germany) were exposed to different photoperiod or relative humidity regimes during a chilling period ranging from 2 to 8.5 months. Specifically, pupae were exposed to four photoperiod regimes: (a) light conditions (24L:00D), (b) dark conditions (00L:24D), (c) short photoperiod (08L:16D) and (d) long photoperiod (16L:08D), as well as to three relative humidity regimes: (a) low (40% RH), (b) medium (60% RH) and (c) high (70-80% RH). Data revealed that relative humidity is not a significant predictor of diapause termination, but it affects the post-winter developmental period. Higher relative humidity promotes post-winter pupae development. On the other hand, photoperiod significantly affected both diapause termination and post-winter development of R. cerasi pupae. Light conditions (24L:00D) accelerate adult emergence, particularly for females. Regardless of the photoperiod (24L:00D, 00L:24D, 08L:16D), rates of adult emergence were high (>75%) for chilling intervals longer than 6.5 months. Nonetheless, exposure to a long day photoperiod (16L:08D), during chilling, dramatically reduced the proportion of adult emergence following 6 months exposure to chilling. Our findings broaden the understanding of factors regulating diapause responses in European cherry fruit fly, local adaptation and synchronization of adult emergence with the ripening period of major hosts. Copyright © The Author(s), 2020. Published by Cambridge University Press