In recent years, Lake Trasimeno (Central Italy) has been affected by massive chironomid swarms that have been a serious nuisance to inhabitants and tourists. The introduction of ‘tofo lamps’, to divert chironomid midges from inhabited areas, has exploited the natural attraction that these insects have for artificial light. These tofo lamps had a high white light intensity (450 W) and were equipped with an external net that imitates the fish net, called ‘tofo’. The attractive efficiency of such lamps was tested in the summers of 2007, 2008 and 2009 by monitoring these devices in areas on eastern (S. Feliciano) and western (Castiglione del Lago) sides of Lake Trasimeno. The most attracted taxa included the species causing a serious nuisance, i.e. the large-sized Chironomus plumosus, and the small-sized Tanypus punctipennis and Procladius sp. In summer, massive swarms of the last two taxa preceded those of C. plumosus. Female chironomids were much more attracted than were males by the artificial white light, with a sex ratio much lower than 1. In addition, the percentage of gravid females of C. plumosus was higher than that of females not carrying eggs. Artificial lights were confirmed as effective in diverting the pestiferous chironomids, a feature that should be carefully considered in order to limit the nuisance from these insects and to avoid spreading insecticides in natural environments.
Artificial light device for attracting pestiferous chironomids (Diptera): A case study at Lake Trasimeno (Central Italy)
GORETTI, Enzo;DI VEROLI, ALESSANDRA;GAINO, Elda Rosa
2011
Abstract
In recent years, Lake Trasimeno (Central Italy) has been affected by massive chironomid swarms that have been a serious nuisance to inhabitants and tourists. The introduction of ‘tofo lamps’, to divert chironomid midges from inhabited areas, has exploited the natural attraction that these insects have for artificial light. These tofo lamps had a high white light intensity (450 W) and were equipped with an external net that imitates the fish net, called ‘tofo’. The attractive efficiency of such lamps was tested in the summers of 2007, 2008 and 2009 by monitoring these devices in areas on eastern (S. Feliciano) and western (Castiglione del Lago) sides of Lake Trasimeno. The most attracted taxa included the species causing a serious nuisance, i.e. the large-sized Chironomus plumosus, and the small-sized Tanypus punctipennis and Procladius sp. In summer, massive swarms of the last two taxa preceded those of C. plumosus. Female chironomids were much more attracted than were males by the artificial white light, with a sex ratio much lower than 1. In addition, the percentage of gravid females of C. plumosus was higher than that of females not carrying eggs. Artificial lights were confirmed as effective in diverting the pestiferous chironomids, a feature that should be carefully considered in order to limit the nuisance from these insects and to avoid spreading insecticides in natural environments.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
