Efficacy of different ovitraps and binomial sampling in Aedes albopictus surveillance activity

The efficacy of plastic, glass, and metal ovitraps has been compared in the Desenzano del Garda (Northern Italy) urban area, infested by Aedes albopictus since 1993. Plastic and glass ovitraps gave similar results while metal ovitraps collected a significantly lower number of eggs (-56 and -59%, respectively). The reason may be related to the different internal color of the metal trap with respect to plastic and glass ones. Utilizing the Gerrard and Chiang binomial model we obtained a high r2 for all 3 ovitrap types (plastic, 0.96; glass, 0.87; metal, 0.79) indicating a good fitting of the observed data to the model. According to the desired level of precision for the estimated population, the number of each type of ovitrap required is calculated. Validation of the model in a different area of northern Italy gave positive results. The simple observation of oviposition strips for presence or absence of Ae. albopictus eggs could be adopted in surveillance programs, thus allowing considerable labor saving.