Introduction of Vaccinium pests in Italy: Dasineura oxycoccana and aphids
Vaccinium corymbosum (highbush blueberry - a North American species) has been introduced into Italy in 1963, and is now grown on 104.5 ha (of which 58 ha are located in Piemonte). In Europe, V. corymbosum is essentially cultivated in Germany, France, Netherlands, Poland and Romania. Other cultivated Vaccinium of North American origin are V. ashei (rabbit eye blueberry) and V. macrocarpa (cranberry). In 1996, unusual damage on a few V. corymbosum crops and in a nursery specialized in the production of V. corymbosum and V. ashei was reported in Piemonte, and the presence of Dasineura oxycoccana (Diptera, Cecidomyiidae) was observed. D. oxycoccana (cranberry tip worm or cranberry midge) is a north American pest of Vaccinium. Eggs are laid near the young buds. Larvae of D. oxycoccana feed inside vegetative meristems and cause leaf distortion, blackening and death of young buds. Serious attacks on vegetative parts can affect the next season's harvest, as infested bushes develop fewer blossoms. Larvae then pupate in the soil. Several overlapping generations can be observed per year. So far, only damage on vegetative parts has been observed in Italy (as in north-eastern USA). However, another type of damage is observed in south-eastern USA (e.g. in Florida) as larvae appearing earlier in the year can attack flowering buds (20-80 % of the buds can be destroyed). This is the first report of D. oxycoccana in Italy and in Europe.
It is also interesting to note that in Piemonte during studies made in 1997 on V. corymbosum in the province of Cuneo, and in a nursery in the province of Torino (producing V. corymbosum, V. ashi and V. angustifolium (lowbush blueberry) and Vaccinium hybrids) that the following 'new' aphid species were identified (Barbagallo et al., 1998).
- Ericaphis scammelii: present in several states in USA and Canada, introduced into the Netherlands and UK (reported there under the name Fimbriaphis fimbriata ssp. pernettyae, which is considered as a synonym). It is a new species for Italy.
- Illinoia azaleae: originates from North America, considered as sub-cosmopolitan. Previously reported in Italy on protected azalea. It is noted that another species Illinoia pepperi is a vector of blueberry shoestring sobemovirus which does not occur in Italy.
- Aulacorthum circumflexum: already present in Italy and other European countries but on other host plants.
Barbagallo, S.; Bosio, G.; Brussino, G.; Scarpelli, F. (1998) [Aphids infesting cultivated blueberries and cranberries in Italy.]
Informatore Fitopatologico, no.10, 65-71.
Bosio, G.; Bogetti, C.; Brussino, G.; Gremo, F.; Scarpelli, F. (1998) [Dasineura oxycoccana, a new pest of blueberry (Vaccinium corymbosum) in Italy.]
Informatore Fitopatologico, no.11, 36-41.