Field responses of Anopheles gambiae complex (Diptera: Culicidae) in Liberia using yeast-generated carbon dioxide and synthetic lure-baited light traps.

Malaria infection is a serious public health problem throughout Liberia, but vector surveillance is limited or nonexistent in remote regions of the country. To better understand the spatial and temporal distribution of malaria vectors in Liberia and to support vector and malaria activities of the Liberian Ministry of Health, a study was conducted to determine the efficacy of light traps baited with a synthetic lure and CO2 for capturing Anopheles gambiae sensu lato (Giles). Traps with a ultraviolet, light-emitting diode, and incandescent lights baited with a synthetic skin lure and CO2 combinations were evaluated at four field sites in three counties of Liberia for five consecutive nights every 8 wk during 2011. In total, 4,788 mosquitoes representing 56 species from nine genera were collected throughout the 30-wk study; An. gambiae s. l. comprised 32% and of the148 An. gambiae s. s. collected, 85% were of the S form. A greater percentage of An. gambiae s. l. were collected in ultraviolet traps baited with a synthetic lure and CO2 compared with any other trap configuration. The influence of trap configuration on conclusions from surveillance efforts, specifically with regards to An. gambiae is discussed.

The potential distribution of Phlebotomus papatasi (Diptera: Psychodidae) in Libya based on ecological niche model.

The increased cases of cutaneous leishmaniasis vectored by Phlebotomus papatasi (Scopoli) in Libya have driven considerable effort to develop a predictive model for the potential geographical distribution of this disease. We collected adult P. papatasi from 17 sites in Musrata and Yefern regions of Libya using four different attraction traps. Our trap results and literature records describing the distribution of P. papatasi were incorporated into a MaxEnt algorithm prediction model that used 22 environmental variables. The model showed a high performance (AUC = 0.992 and 0.990 for training and test data, respectively). High suitability for P. papatasi was predicted to be largely confined to the coast at altitudes <600 m. Regions south of 300 degrees N latitude were calculated as unsuitable for this species. Jackknife analysis identified precipitation as having the most significant predictive power, while temperature and elevation variables were less influential. The National Leishmaniasis Control Program in Libya may find this information useful in their efforts to control zoonotic cutaneous leishmaniasis. Existing records are strongly biased toward a few geographical regions, and therefore, further sand fly collections are warranted that should include documentation of such factors as soil texture and humidity, land cover, and normalized difference vegetation index (NDVI) data to increase the model's predictive power.

Efficacy of light and nonlighted carbon dioxide-baited traps for adult sand fly (Diptera: Psychodidae) surveillance in three counties of Mesrata, Libya.

ABSTRACT. Sand flies are important vectors of cutaneous leishmaniasis, especially along coastal towns of northwestern Libya where an estimated 20,000 cases have occurred from 2004 to 2009. Host-seeking traps are an important tool for sampling sand fly populations and surveying the incidence of Leishmania major and L. tropica within a given population. We evaluated the capture efficiency of CO2-baited BG-Sentinel, Centers for Disease Control and Prevention (CDC) light, CDC ultraviolet light, and nonbaited CO2 CDC light traps in 3 coastal townships during June, August, September, and November 2010. A total of 3,248 sand flies, representing 8 species from 2 genera, were collected; most sand flies were identified as either Phlebotomus papatasi or P. longicuspis. Three of the traps captured significantly more sand flies compared to the BG-Sentinel baited with CO2 (P < 0.001). Three of 456 DNA pools extracted from sand flies were positive for Leishmania DNA, indicating a minimum estimated infection rate of 0.83% and 0.47% for P. papatasi and P. longicuspis, respectively.