Efficacy of commercial mosquito traps in capturing phlebotomine sand flies (Diptera: Psychodidae) in EgyptArchived

Hoel DF 1, Kline DL 2, Hogsette JA 2, Bernier UR 2, El-Hossary SS 3, Hanafi HA 3, Watany N 3, Fawaz EY 3, Furman BD 3, Obenauer PJ 3, Szumlas DE 4 Journal of Medical Entomology  2010 Nov; 47(6):1179-84. 

Four types of commercial mosquito control traps, the Mosquito Magnet Pro (MMP), the Sentinel 360 (S360), the BG-Sentinel (BGS), and the Mega-Catch Ultra (MCU), were compared with a standard Centers for Disease Control and Prevention (CDC) light trap for efficacy in collecting phlebotomine sand flies (Diptera: Psychodidae) in a small farming village in the Nile River Valley 10 km north of Aswan, Egypt. Each trap was baited with either carbon dioxide (CO2) from combustion of butane gas (MMP), dry ice (CDC and BGS traps), light (MCU and S360), or dry ice and light (CDC). Traps were rotated through five sites in a 5 x 5 Latin square design, repeated four times during the height of the sand fly season (June, August, and September 2007) at a site where 94% of sand flies in past collections were Phlebotomus papatasi (Scopoli). A total of 6,440 sand flies was collected, of which 6,037 (93.7%) were P. papatasi. Of the CO2-baited traps, the BGS trap collected twice as many P. papatasi as the MMP and CDC light traps, and at least three times more P. papatasi than the light-only MCU and S360 traps (P < 0.05). Mean numbers (+/- SE) of P. papatasi captured per trap night were as follows: BGS 142.1 (+/- 45.8) > MMP 56.8 (+/- 9.0) > CDC 52.3 (+/- 6.1) > MCU 38.2 (+/- 6.4) > S360 12.6 (+/- 1.8). Results indicate that several types of commercial traps are suitable substitutes for the CDC light trap in sand fly surveillance programs.

VBORNET comment: 2010-02-04

Sticky traps have generally been used for determining the sand fly species composition of an area, sampling randomly the species where they are set as they have no specific attractiveness. CDC light traps attract better phototropic sand flies and previous studies revealed that their effective range was less than 5 meters (Wheeler et al. 1996, Comparison of sticky-traps and CDC light-traps for sampling phlebotomine sandflies entering houses in Venezuela. Med Vet Entomol 10: 295-29). Although the results obtained from both CDC light traps and CO2-baited traps may not be reliable with respect to human–vector contact, in terms of trapping efficiency these two trapping methods appeared so far to be the most productive for both estimating the abundance of sand flies and the species composition in a study area. Commercial mosquito control traps have been developed for the residential homeowner and have gained wide acceptance for use as tools to reduce backyard mosquito populations. Beside, trap-out programs to reduce biting fly populations to a tolerable level have recently been explored using commercial mosquito traps. Some success has been achieved recently in several field studies. For instance, in Iraq, MMP traps collected over 600,000 sand flies during high season, an extraordinarily high number compared to traditional CDC light traps (Blow et al. 2007, Challenges of effective vector control: Operation Iraqi Freedom 05-07. U.S. Army Med Dep J: 46-53). Such results suggest that commercial mosquito traps might be good candidates for inclusion into integrated sand fly control programs in desert settings. They might also be employed to provide superior surveillance results commonly used traps (i.e., sticky traps or CDC light traps).

The purpose of this study was to assess whether each of four commercial mosquito traps examined in the study could catch a larger number and greater variety of sand flies than the CDC light trap. Results indicate that these commercial traps are suitable substitutes to the CDC light trap in sand fly surveillance programs. In particular, authors have showed two important results: 1) CO2-baited traps catch higher numbers of sand flies than light traps without CO2; CO2-baited unlighted traps (BGS and MMP) show to be the most efficient for sampling P. papatasi. 2) The BGS trap offers P. papatasi a large, visually attractive, unlighted target; another advantage is that it is setup directly on the ground, where sand flies are likely to rest during the day and from where they begin to forage for blood meals during the night. The results of this study suggest that BGS and MMP traps are worth using as sand fly surveillance tools and might be useful in an integrated sand fly control program.

References:

1. Medical Entomology Collaborations, Navy Marine Corps Public Health Center Detachment, United States        Department of Agriculture-Agricultural Research Service, Gainesville, FL 32608, USA. David.Hoel@ars.usda.gov
2. United States Department of Agriculture—Agricultural Research Service, Center for Medical, Agricultural, and Veterinary Entomology, 1600 SW 23rd Drive, Gainesville, FL 32608.
3. United States Naval Medical Research Unit No. 3, Cairo, Egypt.
4. Centers for Disease Control and Prevention, 4770 Buford Highway NE, Mail Stop F-22, Atlanta, GA 30341-3724.