Multiple Trypanosoma infections are common amongst Glossina species in the new farming areas of Rufiji district, Tanzania

<p>Abstract</p> <p>Background</p> <p>Tsetse flies and trypanosomiasis are among several factors that constrain livestock development in Tanzania. Over the years Rufiji District was excluded from livestock production owing to tsetse fly infestation, however, a few years ago there was an influx of livestock following evictions aimed at conserving the Usangu wetlands.</p> <p>Methods</p> <p>A study was conducted to determine the efficiency of available traps for catching tsetse flies, <it>Glossina </it>species infesting the area, their infection rates and <it>Trypanosoma </it>species circulating in the area. Trapping was conducted during the semi dry season for a total of 30 days (ten days each month) during the onset of the dry season of May - July 2009. Harvested flies after every 24 hours were dissected and examined under a light microscope for trypanosome infections and whole fly DNA was extracted from 82 flies and analyzed for trypanosomes by polymerase chain reaction (PCR) using different sets of primers.</p> <p>Results</p> <p>The proportions of total tsetse catches per trap were in the following decreasing order S3 (33%), H-Trap (27%), Pyramidal (19%), sticky panel (11%) and biconical trap (10%). Of the 1200 trapped flies, 75.6% were identified as <it>Glossina pallidipes</it>, 11.7% <it>as G. brevipalpis</it>, 9.6% as <it>G. austeni </it>and 3.0% <it>G. morsitans morsitans</it>. Dissections revealed the overall infection rate of 6.6% (13/197). Whole DNA was extracted from 82 tsetse flies and the prevalence of trypanosomes circulating in the area in descending order was 92.7% (76/82) for <it>T. simiae</it>; 70.7% (58/82) for <it>T. brucei </it>types; 48.8% (40/82) for the <it>T. vivax </it>types and 32.9% (27/82) for the <it>T. congolense </it>types as determined by PCR. All trypanosome types were found in all tsetse species analysed except for the <it>T. congolense </it>types, which were absent in <it>G. m. morsitans</it>. None of the <it>T. brucei </it>positive samples contained human infective trypanosomes by SRA - PCR test</p> <p>Conclusion</p> <p>All tsetse species found in Rufiji are biologically important in the transmission of animal trypanosomiasis and the absence of <it>T. congolense </it>in <it>G. m. morsitans </it>could be a matter of chance only. Therefore, plans for control should consider all tsetse species.</p

Occurrence of Nosema species in honey bee colonies in Kenya

Honey bees (Apis mellifera) provide critical pollination services and livelihood for small-holder farmers in Kenya, thus contributing to nutrition and food security. While honey bee colonies in North America and Europe are in decline due to parasites and pathogens, little is known about the status and effects of the honey bee pathogens and pests on the honey bee populations in Africa. A nationwide survey was conducted in 2012/2013 across eight agro-ecological zones to assess the  presence of Nosema microsporidia and quantify the levels of infection. Nosema microsporidia occurred throughout the eight ecological zones. Infection levels were negatively correlated with altitude, suggesting that environmental factors may play a role in the honey bee host-pathogen interactions. Infections levels were higher in the coastal region than in the interior. There was no evidence of colony size reduction in areas where the Nosema microsporidia was in abundant. The results suggest that Nosema could be an exotic pathogen and may have been recently introduced in Kenya and is spreading to all ecological zones. However, its impact onhoney bee populations is not yet known. This study thus provides baseline data for further detailed survey and analysis of the impact of this pathogen to the Kenyan honey bee colonies with a view of establishing any form of resistance mechanisms of the Kenyan honey bee colonies compared to the European honey bee colonies.Key Words: Honey bee, Nosema, Keny

Resistance of the predacious mite, euseius kenyae (acari: phytoseiidae) to chlorpyrifos (dursban &reg;) in kenyan coffee farms

This study was carried out to assess whether the predacious phytoseiid mite, Euseius kenyae (Swirski and Ragusa), commonly found in major&nbsp; coffee growing regions in Kenya has developed resistance to Chlorpyrifos. Mite populations were collected from coffee farms harbouring E. kenyae and where Chlorpyrifos or other organophosphates were sprayed to manage the primary coffee insect pests. The mites collected were reared in mass in the laboratory for bioassays. The findings showed that under coffee agro-ecosystems, levels of resistance existed among the populations of E. kenyae after their exposure to Chlorpyrifos or other organophosphates. The population of E. kenyae from a coffee farm (C44) was most susceptible to Chlorpyrifos with LC50 = 0.044 that was below the lowest concentration of 0.1875 ml per litre of water which was tested. The E. kenyae from coffee farms (C1, C4, C7, C37, C25 and C119) had&nbsp; resistance ratios more than ten times that of C44. The coffee farms (C2, C12, C19, C116, C31, C50 and C72) had populations of E. kenyae&nbsp; susceptible to Chlorpyrifos at concentration of 0.75 ml per litre of water which is the field recommended rate for control of insect pests in coffee. The population of E. kenyae from C7 was resistant to the highest field rate of 200% (1.5 ml per litre of water) with LC50 of 1.716 and resistance ratio of 39 times. The existence of resistance populations of E. kenyae is an aspect that needs to be considered in the integrated pest control strategies against coffee insect pests

Abundance and diversity of soil mites (Acari) along a gradient of land use types in Taita Taveta, Kenya

The abundance and diversity of soil mites was monitored along a gradient of land use types (LUTs) during the wet seasons in soils of Taita Taveta, Kenya. Sampling of mites from soils was carried out in eight LUTs which included maize-based system (Zea mays), coffee (Coffea Arabica), horticulture, napier grass (Pennisetum purpureum), fallow, pine (Pinus patula), cypress (Cypressus lusitanica), natural forest. LUT significantly influenced abundance, richness and diversity of the soil mites. During the short rains the diversity of soil mites increased in the order napier < maize-based system < horticulture < coffee < fallow < natural forest < pine forest < cypress plantation while the long rains season abundance increased in the order maize-based system < coffee < horticulture < napier < natural forest < fallow < pine forest < cypress forest. Higher abundance, richness and diversity of the mites was observed in the less disturbed forest ecosystems unlike the agro-ecosystems, which are often disturbed with intensive cultivation A total of 37 families were recorded with 20 oribatid families, 10 mesostigmatid families and 7 prostigmatid families. The families that ranked highest in abundance across the LUT were Scheloribatidae, Oppidae (Oribatida) and Rhodacaridae (Mesostigmata). LUT influenced significantly (