Epitrix similaris and Epitrix cucumeris in Portugal: damage patterns in potato and suitability of potential host plants for reproduction

Abstract

The potato flea beetle species Epitrix similaris and Epitrix cucumeris were identified in mainland Portugal in 2009. This was the first finding of the species E. similaris in the EPPO region, and the first report of the species E. cucumeris, established in the Atlantic Islands of Azores (Portugal) for three decades, in the mainland EPPO zone. Preliminary information on the damage patterns caused by E. similaris and E. cucumeris on potato and their host plant preferences is provided. Leaf feeding by the adults causes the characteristic shot-hole pattern common to flea beetles. The larvae of both species develop on the root system and cause damage to the tubers. In field experiments, tuber damage by E. similaris presented three patterns: superficial tracks (serpentines), black splinters, and shallow holes. In the laboratory E. cucumeris was observed to be able to feed on very small immature tubers, causing serpentines and holes as well. However, in some cases it developed exclusively on roots. The adults of both Epitrix species hardly fed and reproduced on sweet pepper plants but fed and reproduced on the remaining five solanaceous plants tested (aubergine, Datura stramonium, tomato, potato and Solanum nigrum). E. similaris produced a much higher number of progeny on potato and on S. nigrum than on the other host plants. E. cucumeris produced more offspring on S. nigrum than on the other host-plants.

Pest survey card on Epitrix cucumeris, Epitrix papa, Epitrix subcrinita and Epitrix tuberis

“…Under experimental conditions, E. cucumeris can complete its life cycle on aubergine, tomato, Datura stramonium, potato and Solanum nigrum, with the latter two species raising more offspring than the other four (Boavida et al, 2013). Under experimental conditions, E. cucumeris can complete its life cycle on aubergine, tomato, Datura stramonium, potato and Solanum nigrum, with the latter two species raising more offspring than the other four (Boavida et al, 2013).…”

“…Adults of all four Epitrix species mainly feed on the upper surface of leaves of host plants -and less often on the lower surface -and produce typical shot-like holes with a 1-1.5 mm diameter on these leaves (Boavida et al, 2013;EPPO, 2017) (Figure 10). …”

“…Especially, S. nigrum is reported as a suitable host plant on which E. papa and E. cucumeris are able to produce large numbers of offspring (Boavida et al, 2013). Especially, S. nigrum is reported as a suitable host plant on which E. papa and E. cucumeris are able to produce large numbers of offspring (Boavida et al, 2013).…”

“…In the EU, this crop is of high economic value (Figure 1.7). In addition, given that under experimental conditions S. nigrum and potato are equally suitable host plants for E. papa and S. nigrum is a better host plant than potato for Epitrix cucumeris (Boavida et al, 2013), this weed species is a target for surveillance as well. (2010) indicates that some authors (e.g.…”

Epitrix pubescens can cause damage to potato (Solanum tuberosum)

“…Two species of Epitrix flea beetles (Coleoptera: Chrysomelidae) native to North America (Epitrix cucumeris and E. similaris) have recently been found in mainland Portugal causing damage to potatoes (Boavida & Germain, 2009). The type of symptoms observed were shothole lesions on leaves caused by adult beetles and corky lesions on the tuber skin caused by larval tunnelling (Boavida et al, 2013). Damage to leaves may reduce tuber yield, but tuber damage is more important because the crop may be rendered unmarketable.…”