Use of Sleeve Nets to Improve Survival of the Boisduval Silkworm, Anaphe panda, in the Kakamega Forest of Western Kenya

Prospects for development of a wild silk industry in Africa would be improved if silkworm survival during mass production could be improved. A study on the survival of the Boisduval silkworm, Anaphe panda (Boisduval) (Lepidoptera: Thaumetopoeidae) was conducted with and without protection by net sleeves in two different forest habitats (natural and modified) in the Kakamega forest of western Kenya. Overall, cohort survival was significantly higher (P < 0.001) in the natural than in the modified forest, but larval survival was improved over three-fold by protection with net sleeves in both habitat types. In the modified forest, only 16.8% of unprotected larvae survived to the pupal stage and formed cocoons, whereas 62.3% survived in the same environment when they were protected with net sleeves. In the natural forest, 20.4% of unprotected larvae survived, whereas 67.7% survived in net sleeves. There was also a significant effect of season; cohorts of larvae that eclosed in the wet season had significantly lower survival than those eclosing in the dry season (P = 0.02). Sources of mortality appeared to be natural enemies (parasites, predators and diseases) and climatic factors

Biology of the Wild Silkmoth Anaphe panda (Boisduval) in the Kakamega Forest of Western Kenya

A study on the life cycle of the silkmoth Anaphe panda (Boisduval) was conducted in two different habitats of the Kakamega Forest in western Kenya: Ikuywa, an indigenous forest, and Isecheno, a mixed indigenous forest. Eggs were laid in clusters, and the incubation period ranged from 40 to 45 days. Larvae fed on Bridelia micrantha (Hochst) and passed through seven instars. The developmental period took between 83 to 86 days in the dry season and 112 to118 days in the rainy season. The pupal period ranged between 158 and 178 days in the rainy season and, on the other hand, between 107 and 138 days in the dry season. But the later caught up in development with those that formed earlier. Moths emerged from mid-October until mid-May. Longevity of adult Anaphe panda moths took between 4 and 6 days, but generally females seemed to live longer than males. The moth also seems to have higher lifespan in the indigenous forest compared to the mixed indigenous forest

Livestock Owner\'s Perception On Trypanosomosis And Associated Treatment On The Adamaoua Plateau In Cameroon Ten Years After Tsetse Eradication

Ten years after the tsetse eradication campaign, a survey using a structured questionnaire was conducted on the Adamaoua plateau in Cameroon to obtain qualitative and quantitative information from cattle owners about mains frequent bovines diseases, the use of trypanocidal drugs and insecticides pour-on to control trypanosomosis in cattle. Trypanosomosis was the main frequent and lethal disease. Buffer zone cattle owners used preferably isometamidium chloride rather than diminazene aceturate, whereas those of tsetse-free and tsetse-infested valley used the two trypanocides especially to treat disease episodes were perceived to be trypanosomosis. Pyrethoids was the main pour-on used to control trypanosomosis in the three zones. They were generally obtained from veterinary chemist and market, and breeders themselves administered slightly more than ¾ of them. Study suggests to extension workers the improvement of the use of veterinary products.Dix ans après la campagne d\'éradication des glossines, des enquêtes ont été menées sur le plateau de l\'Adamaoua au Cameroun pour recueillir auprès des éleveurs du bétail des informations qualitatives et quantitatives au sujet des principales maladies bovines, l\'usage des trypanocides et insecticides «pour-on» pour contrôler la trypanosomose chez le bétail. La trypanosomose était la maladie la plus fréquente et la plus mortelle. Les éleveurs de la zone tampon utilisaient plus le chlorure d\'isométamidium que l\'acéturate de diminazène, alors que ceux de la zone assainie et infestée utilisaient en même temps les deux trypanocides pour traiter des épisodes de maladie qu\'ils percevaient être la trypanosomose. Les insecticides à base de pyrèthre étaient les principaux «pour-on» utilisés pour contrôler la trypanosomose dans les trois zones. Ces produits étaient achetés auprès des pharmacies vétérinaires et du marché local, et les trois-quarts de ces produits étaient administrés par les éleveurs euxmêmes. L\'étude suggère aux agents de vulgarisation l\'amélioration de l\'usage de produits vétérinaires.Bulletin of Animal Health and Production in Africa Vol. 54 (4) 2006: pp. 260-27

Comparison of the infection rate of tsetse, Glossina morsitans morsitans, fed in vitro or in vivo

Studies were made of infection rates of trypanosomes in the tsetse fly Glossina morsitans morsitans Westwood (Diptera: Glossinidae) when maintained in vivo (rabbits) or in vitro on high quality, gamma-irradiated, sterile defibrinated bovine blood, obtained from the Entomology Unit of the International Atomic Energy Agency (IAEA). For both Trypanosoma congolense Broden and T. b. brucei Plimmer & Bradford, in vitro maintenance significantly reduced the proportion of flies that developed mature metacyclic trypanosome infections

Parasitological prevalence of bovine trypanosomosis in Faro and Deo division Cameroon, Ten years after the tse-tse eradication campaign

Dix ans après la campagne d'éradication des glossines, une enquête transversale visant à déterminer la prévalence de la trypanosomose et l’identification des espèces de trypanosome en présence a été effectuée dans le département du Faro & Deo, plateau de l’Adamaoua, Nord Cameroun. Au total, 302 bovins adultes ont été examinés dans vingt localités différentes appartenant soit à la zone assainie, tampon ou infestée. Les techniques de diagnostic utilisées consistaient en un examen de la couche leucocytaire sur fond noir, un examen d’un frottis mince colore et une évaluation de l’hématocrite. La prévalence totale de la trypanosomose bovine était de 14,6%, mais variait significativement par zone. Elle était élevée en zone infestée 35.1% et basse dans la zone assainie (4.3%) et tampon (5.3%); et aucune différence significative (P =0.051 > 0.05) n’été observé entre la zone tampon et le plateau. Parmi les animaux positifs, 43.2%, 13.6%, 9.1%, 13.6% et 20.5% étaient causes par Trypanosoma congolense, Trypanosoma vivax, Trypanosoma brucei, et des infections mixtes (T. congolense et T. vivax) et (T. congolense, T. brucei et T. vivax) respectivement. L’hématocrite des animaux positifs et négatifs allait de 16 à 40 pour cent et de 15 à 46 pour cent, respectivement. L’hématocrite moyen des animaux négatifs (29,6±5.7%) était significativement plus élevé que l’hématocrite moyen des animaux positifs (26,9±6.4%) (P = 0.003 < 0.05). Vu le risque de trypanosomose sur le plateau, une stratégie de contrôle appropriée est fortement recommandée.Ten years after the tsetse eradication campaign, a cross sectional survey to determine the prevalence of trypanosomosis and identifying the species of trypanosomes infecting cattle was conducted in the Adamaoua plateau, North Cameroon. A total of 302 adult cattle were examined at twenty different localities. Field examination of the buffy coat, stained thin blood film examination and packed cell volume (PCV) evaluation were thediagnostic techniques used. The overall prevalence of bovine trypanosomosis was 14.6%. However, the prevalence differed significantly between zones. It was higher in the valley (35.1%) and lower in the buffer zone and the plateau (5.3% and 4.3% respectively); no significant difference (P = 0.051) was found between the buffer zone and plateau. Among the positive animals, 43.2%, 13.6%, 9.1%, 13.6% and 20.5% werefrom Trypanosoma congolense, T. vivax , T. brucei and mixed infection (T. congolense & T. vivax) and (T. congolense, T. brucei & T. vivax), respectively. The mean PCV of positive and negative animals ranged between 16 - 40 % and 15 - 46%, respectively. The mean PCV of negative animals (29.6±5.7%) was significantly higher than the mean PCV of positive animals (26.9±6.4%) (P < 0.05). Because of the risk of trypanosomosis on the plateau, appropriate control strategies need to be put in place urgently

Prevalence and incidence of bovine trypanosomosis on the Adamaoua plateau in Cameroon 10 years after the tsetse eradication campaign

Between March 2004 and February 2005, the monthly incidence of trypanosome infections was measured in cattle from nine sentinel herds in the Adamaoua province of Cameroon. Three herds of 20 cattle each were kept on the plateau which has been cleared from tsetse flies about 10 years ago, three other herds were grazing in the tsetse infested valley whereas the last three were herded in the buffer zone. The cross-sectional study showed that the initial trypanosomosis prevalence was 1.8, 5.2 and 2.0% on the plateau, in the buffer zone and the valley, respectively. During the longitudinal study, the trypanosomosis incidence was high in the valley (3.7-20%) and the buffer zone (1.8-13.4%), whereas it was significantly lower (0-2.1%) on the plateau. Tsetse flies, mainly Glossina morsitans submorsitans and a few G. tachinoides, were caught in the valley and the buffer zone, but none on the plateau. The data indicate a low trypanosomosis risk on the plateau. Further entomological studies, however, are required to clarify the origin of the trypanosome infections on the plateau

Protecting cows in small holder farms in East Africa from tsetse flies by mimicking the odor profile of a non-host bovid

<div><p>Background</p><p>For the first time, differential attraction of pathogen vectors to vertebrate animals is investigated for novel repellents which when applied to preferred host animals turn them into non-hosts thereby providing a new paradigm for innovative vector control. For effectively controlling tsetse flies (<i>Glossina</i> spp.), vectors of African trypanosomosis, causing nagana, repellents more powerful than plant derived, from a non-host animal the waterbuck, <i>Kobus ellipsiprymnus defassa</i>, have recently been identified. Here we investigate these repellents in the field to protect cattle from nagana by making cattle as unattractive as the buck.</p><p>Methodology/Principal findings</p><p>To dispense the waterbuck repellents comprising guaiacol, geranylacetone, pentanoic acid and δ-octalactone, (patent application) we developed an innovative collar-mounted release system for individual cattle. We tested protecting cattle, under natural tsetse challenge, from tsetse transmitted nagana in a large field trial comprising 1,100 cattle with repellent collars in Kenya for 24 months. The collars provided substantial protection to livestock from trypanosome infection by reducing disease levels >80%. Protected cattle were healthier, showed significantly reduced disease levels, higher packed cell volume and significantly increased weight. Collars >60% reduced trypanocide use, 72.7% increase in ownership of oxen per household and enhanced traction power (protected animals ploughed 66% more land than unprotected). Land under cultivation increased by 73.4%. Increase in traction power of protected animals reduced by 69.1% acres tilled by hand per household per ploughing season. Improved food security and household income from very high acceptance of collars (99%) motivated the farmers to form a registered community based organization promoting collars for integrated tsetse control and their commercialization.</p><p>Conclusion/Significance</p><p>Clear demonstration that repellents from un-preferred hosts prevent contact between host and vector, thereby preventing disease transmission: a new paradigm for vector control. Evidence that deploying water buck repellents converts cattle into non-hosts for tsetse flies—<i>‘cows in waterbuck clothing’</i>.</p></div

Repellent dispenser developed to deliver waterbuck repellent compounds for cattle.

<p>(a) Dispenser with protective shield and (b) without protective shield to show tubing from which the repellent compounds are released and (c) a cow with a repellent collar.</p