The genus Epitrix (Coleoptera: Chrysomelidae) comprises approximately 180 species which are polyphagous and mainly associated with solanaceous plants. The North American flea beetle, Epitrix tuberis, is the most damaging species to potato. While the adults chew the leaves and create shotgun holes, the larvae feed on the roots and tubers causing fine superficial tunnels that lower the quality of the tubers. E. cucumeris and E. papa, a new species initially misidentified as E. similaris, have been distributed in Portugal. The former has also been found in Spain. Due to the establishment and damage caused by these two species several other exotic potato damaging Epitrix species, viz. E. cucumeris, E. similaris and E. subcrinita attained a quarantine status for the EU. Knowledge on the occurrence of Epitrix species is a prerequisite for developing monitoring programs and control measures to prevent the introduction and establishment of these exotic insects in Belgium. Therefore, this research aimed to (1) investigate the occurrence of native and exotic Epitrix species and related potato flea beetles in Belgian potato fields, (2) develop morphological and molecular identification tools for native and exotic Epitrix species and lookalike genera, and (3) assess the establishment potential of these exotic insects in Belgium. Monitoring was performed during the period 2015-2016 in Belgian fields planted with potatoes or other crops and/or contaminated with wild Solanaceae (e.g. Solanum nigrum and Datura stramonium). Potato importing and packaging companies were also monitored. E. pubescens and E. atropae were the only native species recorded but they did not cause damage to potato. These species are linked to their hosts, S. nigrum and Atropa belladonna, respectively. Although no exotic species were detected, imported tubers with damage symptoms were found at importing companies. An identification key, based on distinct characteristics, e.g. antennae, legs and elytra, was developed to distinguish Epitrix from similar beetles. Aphthona spp. and Longitarsus spp. were the most abundant lookalike flea beetles, followed by Psylliodes spp., Phyllotreta spp., Chaetocnema spp. and Altica spp. The shape and size of different parts of the female and male genitalia were the main features for identification of Epitrix species. Epitrix larvae were difficult to identify morphologically. The restriction fragment length polymorphism (RFLP) using a restriction enzyme, AluI distinguished larvae, pupae and adults of native Epitrix species from those of exotic ones. Introduction and establishment risk maps were also generated for exotic species. Although exotic species were not detected during this study, there is a risk of their introduction into Belgium because potatoes are being imported from regions in Europe where exotic Epitrix spp. occur.
Key words- Coleoptera: Chrysomelidae, occurrence, potatoes, molecular identification, exotic insects.
|Titel||69th International Symposium on Crop Protection|
|Publicatiestatus||Gepubliceerd - 23-mei-2017|