Rhagoletis cerasi: Oviposition Reduction Effects of Oil Products.

Claudia Daniel

doi:10.3390/insects5020319

Abstract

The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is a highly destructive pest. Methods to control it are limited and alternatives are needed. Observations of cherry fruit flies suggest that females exert much effort to penetrate cherries at color change stage (from green to yellow) for oviposition. Therefore, the question arose as to whether a physical barrier on the fruit surface could reduce oviposition. The effects of different commercial horticultural oil products on R. cerasi oviposition were evaluated in a series of laboratory, semi-field and field experiments. In the laboratory experiments, the rate of successful oviposition on fruits treated with 0.25% v/v of the rapeseed oil product Telmion was significantly reduced by 90% compared to the untreated control. In semi-field experiments, deposits of 1% of rapeseed, mineral and paraffinic oil significantly reduced oviposition for up to 3 days. Semi-field experiments indicated that the oil products lose efficacy within 3 to 6 days after application due to degradation. Although treatments with the rapeseed oil product Telmion reduced infestation rates in an on-farm field experiment, the infested fruit clearly exceeded the level of market tolerance of 2%. Further research is needed to assess whether combinations of oil products, higher application rates and different formulations might improve field efficacy.

Highlights

The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is a major pest of sweet cherries
Semi-field experiments indicated that the oil products lose efficacy within 3 to 6 days after application due to degradation
Treatments with the rapeseed oil product Telmion reduced infestation rates in an on-farm field experiment, the infested fruit clearly exceeded the level of market tolerance of 2%

Summary

Introduction

The European cherry fruit fly, Rhagoletis cerasi (L.) (Diptera: Tephritidae), is a major pest of sweet cherries. R. cerasi is univoltine and overwinters as pupae in the soil [1]. The adult flies emerge in May and June [2,3] and begin to lay eggs about ten days after emergence [4,5]. The larvae develop inside the Insects 2014, 5 cherries [6]. Up to 100% of fruit can be infested [7]. The low market tolerance for infested fruit is the principal reason for preventive insecticide treatments. The legal phase-out of insecticides threatens cherry production in Europe. A biocontrol strategy using the entomopathogenic fungus Beauveria bassiana in an oil-based, sprayable formulation

Methods

Results

Conclusion