[Show abstract][Hide abstract] ABSTRACT: Stomoxys flies are mechanical vectors of pathogens present in the blood and skin of their animal hosts, especially livestock, but occasionally humans. In livestock, their direct effects are disturbance, skin lesions, reduction of food intake, stress, blood loss, and a global immunosuppressive effect. They also induce the gathering of animals for mutual protection; meanwhile they favor development of pathogens in the hosts and their transmission. Their indirect effect is the mechanical transmission of pathogens. In case of interrupted feeding, Stomoxys can re-start their blood meal on another host. When injecting saliva prior to blood-sucking, they can inoculate some infected blood remaining on their mouthparts. Beside this immediate transmission, it was observed that Stomoxys may keep some blood in their crop, which offers a friendly environment for pathogens that could be regurgitated during the next blood meal; thus a delayed transmission by Stomoxys seems possible. Such a mechanism has a considerable epidemiological impact since it allows inter-herd transmission of pathogens. Equine infectious anemia, African swine fever, West Nile, and Rift Valley viruses are known to be transmitted by Stomoxys, while others are suspected. Rickettsia (Anaplasma, Coxiella), other bacteria and parasites (Trypanosoma spp., Besnoitia spp.) are also transmitted by Stomoxys. Finally, Stomoxys was also found to act as an intermediate host of the helminth Habronema microstoma and may be involved in the transmission of some Onchocerca and Dirofilaria species. Being cosmopolite, Stomoxys calcitrans might have a worldwide and greater impact than previously thought on animal and human pathogen transmission.
[Show abstract][Hide abstract] ABSTRACT: Stomoxyine flies (Stomoxys spp.) were collected in 10 localities of Thailand using the Vavoua traps. These localities represented four major ecological settings, as follows: small local dairy farms, large industrial dairy farms, a national park, and one elephant conservation area. Three species of stable flies were identified in the following proportions: Stomoxys calcitrans (91.5%), Stomoxys indicus (7.9%), and Stomoxys sitiens (0.6%). The number of flies collected differed significantly among collection sites (chi2 = 360.15, df=3, P < 0.05). The greatest number of stomoxyine flies was captured in dairy farms. Seasonal and daily activity of S. calcitrans was observed during a 1-yr period at two selected locations (Dairy Farming Promotion Organization of Thailand and Khao Kheow Open Zoo). S. calcitrans was more abundant during the rainy season (March-September), but was not associated with the total rainfall (r2 = 0.0002, P > 0.05). Peak of daily flight activity of males S. calcitrans was at 1000 and 1600 h, whereas females showed an increase of activity all along the day until 1600 h. A better understanding of stomoxyine fly behavior related to patterns of daily activity will facilitate and improve the efficiency of fly control measures in private and government sectors.
Journal of Medical Entomology 09/2010; 47(5):791-7. · 1.86 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Starch gel electrophoresis of isozymes was used to estimate gene flow among nine populations of Stomoxys calcitrans (L.) (Diptera: Muscidae) from Thailand. Of the 13 putative loci, nine polymorphic loci were detected. Limited genetic differentiation among populations was observed (F(ST) = 0.060). The highest level of polymorphism was observed in flies from eastern Trat and northern Chiang Mai provinces (69.2%), whereas the lowest level of polymorphism was seen in flies from central Saraburi Province (23.1%). Gene flow between populations varied from 3.27 to 27.53 reproductive migrants per generation. Among the nine populations sampled, no correlation was seen between genetic and geographical distances showing that sampled S. calcitrans fit closely in the same cluster taxa. The electrophoresis of ten isozymes shows a genetic homogeneity of S. calcitrans populations at the scale of Thailand.
Journal of Economic Entomology 06/2010; 103(3):1012-8. · 1.60 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Adult mosquitoes in the Anopheles maculatus group were surveyed from different regions of Thailand and five different species were morphologically identified, including Anopheles maculatus, Anopheles sawadwongporni, Anopheles notanandai, Anopheles dravidicus, and Anopheles willmori. Blood-feeding activity and host preference of two species, Anopheles maculatus and Anopheles sawadwongporni, were observed during a one-year period at Pu Teuy Village, Sai Yok District, Kanchanaburi Province, west-central Thailand. Both species were more prevalent during the wetter period of the year and each had a greater predilection to feed on cattle than humans. Primary feeding activity occurred between 20:00-23:00 and a smaller peak at 01:00-03:00. Findings are discussed relative to the importance of these two vectors for malaria transmission in Pu Teuy.
Journal of Vector Ecology 06/2009; 34(1):62-9. · 1.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Behavioral responses of 2 wild-caught populations of Anopheles maculatus (Theobald) and Anopheles sawadwongporni Rattanarithikul and Green to operational field doses of DDT (2 g/m2) and permethrin (0.5 g/m2) were characterized using an excito-repellency test system. Both test populations, collected from animal quarters at Ban Pu Teuy, Sai Yok District, Kanchanaburi Province, western Thailand, were found completely susceptible to DDT and permethrin. Specimens from 2 test populations quickly escaped from direct contact with treated surfaces from 2 insecticides compared with paired controls. Noncontact repellency response to DDT was significantly pronounced in An. sawadwongporni (P < 0.05) and comparatively weak in An. maculatus, but it was statistically greater than individually paired controls (P < 0.05). We conclude that contact irritancy is a major behavioral response of both field populations when exposed directly to DDT and permethrin, whereas noncontact repellency to DDT also produced a significant escape response in An. sawadwongporni.
Journal of the American Mosquito Control Association 12/2006; 22(4):689-98. · 0.76 Impact Factor