Development and implementation of early detection tools and effective management strategies for invasive non-European and other selected fruit fly species of economic importance (FLY DETECT)

Insects of the family Tephritidae (Diptera) exert a huge economic impact on fruit and vegetable production worldwide because of direct damage on fruit and vegetable commodities and quarantine regulations. These species are also known as true fruit flies. Within the FLY DETECT project, focus was given on species of tephritid fruit flies that are key pests to a large number of crops in the Mediterranean region, such as Ceratitis capitata (Mediterranean fruit fly, Medfly), or are considered as important invasive species, such as Bactrocera zonata (Peach Fruit Fly, PFF), Bactrocera dorsalis complex (Oriental Fruit Fly, OFF), and Myiopardalis pardalina (Melon Fruit Fly, MFF). These species, which are already present in some parts of Europe (e.g. Medfly), or that are a threat as they may become established in the Mediterranean basin (e.g. PFF), pose a risk to the horticultural crops and agriculture of Central and Southern Europe, and are considered quarantine pests for most European countries (cf. EPPO Alert List, A1 or A2 Lists). The pests under study have substantial interceptions in EUROPHYT database each year.

Early detection of the presence of these species in new areas as well as during the season when adults appear is of utmost importance for successful management. For fruit flies, detection is based on the use of specific traps with appropriate lures that attract males or females. There are several traps and attractants combinations that can be used for detection and monitoring of fruit flies. A literature review for traps and attractants revealed a number of trap options and attractants that are being used to trap either male or females or both sexes.

One of the targeted species within FLY DETECT, the Mediterranean fruit fly, has lately expanded its distribution northwards. In northern Italy for example it has become a major pest for apples, jeopardizing the integrated pest management scheme for codling moth. Monitoring activities that took place during the project in Austria and Bulgaria shows that medfly population is present each year in Vienna, while scattered catches occurred in Bulgaria in orchards and warehouses although established overwintering population was not confirmed. Nevertheless, the repeated trap catches in northern areas suggest that there is a constant pressure for northward expansion of the species.

Infestation by tephritid fruit flies can be undetectable during harvest, storage and transport to the point of use, thus, destructive sampling in a large proportion of the commodity is often required. It is known that infested fruits emit specific volatile compounds. The profile of volatiles emitted could be used for the development of technology intense methods of rapid detection of infested fruits. Within FLY DETECT we determined infestation-specific volatile compounds-indicators by headspace- solid phase micro extraction- gas chromatography- mass spectrometry (HS-SPME-GC-MS) in order to develop a rapid, reliable and cost effective method aiming to reduce the time required for a reliable inspection.