216 - Improved and modified traps for surveillance and control of mosquitoes

Although Malaise-Traps are highly effective and unbiased in catching mosquitoes they are rarely used in surveys or experimental studies. To increase catches, we suggest several new practical modifications of Malaise-Traps.  

Trials were conducted in urban and rural settings in Mali, West Africa, the main targets were mosquitoes of the Anopheles gambiae complex and Culex species. 

Observations with night-vision equipment showed that mosquitoes are often readily entering the net constructions but they seldom get caught in the passive collecting containers. 

Catches were significantly increased when the regular containers were replaced by battery powered suction devices (as used in CDC-Traps). Best results were obtained if the suction device was combined inside a 40cm long dark plastic tube with LED UV light diodes. The UV-ligh,t which was visible in the tube, was directed to throw light only in a perimeter of 20cm of the net and thus it affected only mosquitoes which were already inside the net. Anopheline catches increased up to 15 X and Culex catches up to 11 X with different types of Malaise-Traps and suction heads. The modified Malaise traps outperformed by far the conventional CDC-UV traps, both in rural and especially urban settings. Additionally, Malaise traps caught significantly more blood fed females which are often scarce or absent in UV-CDC traps.