ATTRACTION OF CHIRONOMUS-SALINARIUS (DIPTERA, CHIRONOMIDAE) TO ARTIFICIAL-LIGHT ON AN ISLAND IN THE SALTWATER LAGOON OF VENICE, ITALY

The attraction of adult Chironomus salinarius to incandescent 3-W lamp s of 7 different colors used in CDC traps was studied on a small islan d in the lagoon of Venice, Italy. An ANOVA indicated that the lamp typ e was a highly significant (P < 0.01) factor associated with differenc es in light trap catch (28% of total variation), as well as catch per lux (18% of total variation). The white lamp attracted higher numbers of adults than the other 6 color lamps, Yellow was the second most pre ferred, and red was the least attractive. There was a strong linear re lationship (r = 0.93) between the catch and light intensity, which sug gested that intensity was the primary factor influencing catch. Howeve r, catch per unit brightness (lux) tended to be inversely proportional to the peak wavelength associated with the lamp color (e.g., the viol et lamp had the highest catch/lux, and the red lamp had the lowest). T he corresponding regression model, Catch = 49 + [(48,013/lambda) - 63] . L, in which the slope associated with light intensity in lux (L) is inversely proportional to the peak wavelength in nm (lambda) explaine d 97% of the variation among lamp catch means. Manipulating light inte nsity and color could be useful to divert adult C. salinarius populati ons from midge-affected areas for control purposes.