The Mosquito Book: An awareness and activities manual promoting ecological management of urban mosquitoes

This manual is the 2005 second edition edited by Ed Boles. It provides environmental knowledge and detailed ecology of mosquitoes that encourages all to bring environmental education into their homes and environment helping to reduce mosquito breeding habits. It is designed to educate you on the different types of mosquitoes and their effects and diseases which can be transmitted to humans.

Filariasis in Amerindians of Western Guyana with observations on transmission of Mansonella ozzardi by a Similium species of the amazonicum group

In order to conduct experimental infection studies on Mansonella ozzardi in local haematophagos Diptera, volunteers infected with this parasite were identified during a microfilaria survey of four Amerindian villages in the Pakaraima Mountains of Western Guyana, near the Brazilian border. M. ozzardi microfilariae were detected in blood smears from 8-21 percent of persons examined. They were also found in skin snips from 8/73 persons all of whom were positive by blood smear examination. No Onchocerca volvulus microfilariae were detected. Dipetalonema perstans infections were found in three of four villages but prevalence rates were only 1-8 percent. Man-baited catches of haematophagous Diptera made at the onset of the dry season in one of the villages yielded only three Simulium species. After the flies were engorged on infected volunteers, M. ozzardi larvae developed to the infective stage in 6-7 days in the most abundant species, a member of the Simulium amazonicum group. Man-biting rates of up to 156 per 15-minute period were recorded for this species in midday collections along riverbanks near one of the villages. Developing filariae, including infective larvae of M. ozzardi, were also found in wild-caught flies. It was concluded that this Simulium species is a vector of M. ozzardi in the study area (Summary)

Preliminary trials using abate to control Kabowra flies in the Rupununi, Guyana - abstract

Control of Simulium (called Kabowras in Guyana) black flies is usually directed to the larvae which breed in fast flowing waters. The purpose of the project was to determine the effectiveness of Abate Insecticide 200E in controlling Simulium sp., in a selected river in the Rupununi Savannah, Guyana. Two bioassays were carried out on the San Jose River near Lethem, Rupununi to determine the effective distance of Abate 200E at a concentration of 0.3 ppm during August, 1979 along a 2.4 km and 3.5 km stretch of the river. River discharge rates were calculated at a point of injection of the Abate. The volume of Abate required to give a concentration of 0.3 ppm when dispensed over approximatelty thirty minutes at the measured discharge was dripped into the stream. Counts of larvae on marked vegetation were made at several points before injection of Abate and four and nineteen hours after injection. The results of the first bioassay over 2.4 km showed at 57.8 percent drop in larvae four hours after injection of larvicide and a 99.3 percent drop within nineteen hours. Larval mortality was 97 percent at 2.4 km. Larval counts after the second Abate application two weeks later at 3.5 km showed a 52.8 percent drop after four hours and 96.1 percent after nineteen hours. Larval mortality was 100 percent at 2.7 km and 9.3 percent at 3.5 km. Larval counts were very low during the subsequent four weeks. Abate 200E at a concentration of 0.3 ppn was found to be effective in killing Simulium larvae over a distance of 3.5 km with a mortality of 93 percent nineteen hours after injection of larvicide. These trials should continue using lower concentrations of the larvicide (AU)

The black fly (simulium) problem in the Rupununi Savannahs, Guyana - abstract

Simulium black flies (called Kabowras in Guyana) are not known to carry diseases in Guyana, but they become a serious nuisance at certain times of the year in the Rupununi Savannahs. The present project was designed to study the bionomics of the nuisance species. Of about 20 species of black flies known from Guyana, 2 are serious manbiters; Simulium incrustatum and S. sanguineum s.l. The former appears in large numbers near small creeks and rivers, while the latter seems to be associated with larger rivers such as the Takutu and Rupununi. Peak densities of the two species appear at the height of the rainy season, but drop rapidly at the onset of the dry season. A peak biting rate of 928 flies per man hour was recorded for S. incrustatum and 764 flies per man hour for S. sanguineum s.l. Data obtained so far indicate that the two species tend to stay near river banks rather than the open savannahs. Both species are diurnal; none were collected after dark. For S. incrustatum there are early morning and late afternoon peaks. S. sanguineum s.l. peaks towards mid-morning and declines in the afternoon. The diurnal activities can be affected by rainfall and cloudy conditions. S. incrustatum shows no marked preference for humans or animals, but S. sanguineum s.l. shows a marked preference for livestock, dividing its attention almost equally between a cow and a horse during a comparative study. Because of their high biting rates these flies are serious pests, sufficient to discourage people from settling and developing the area. Further, their attacks on cattle may cause severe blood loss, annoyance and subsequent loss of weight resulting in financial loss to farmers (AU)