Dawit Kidane

Background: Cutaneous leishmaniasis (CL), caused by Leishmania aethiopica and transmitted by Phlebotomus longipes, is endemic in northern Ethiopia. However, sand fly fauna are poorly documented in the northern Tigray region. High-altitude CL cases have also been observed, but their local acquisition is uncertain. To identify the faunal composition and explore the spatial distribution of Phlebotomus longipes and other potential CL vectors, cross-sectional surveys were conducted in ten villages (average altitude range: 2411 – 3186 meters) with confirmed CL cases across four endemic districts of the region.Results: Totally, 1477 sand flies (52% males & 48% females) comprising five species of Phlebotomus (37.9%) and six species of Sergentomyia (62.1%) were identified morphologically. The Phlebotomus species included Phlebotomus longipes (72.7%) and three potential vectors: Phlebotomus arabicus (17.7%), Phlebotomus sergenti (5.9%), and Phlebotomus guggisbergi (2.0%); the latter is a new record for Ethiopia. Phlebotomus longipes prevailed in every village and predominated in caves (42.5%), animal sheds (28.3%), and bedrooms (15.2%). Phlebotomus longipes and three low-to-mid altitude Sergentomyia species were found at elevations reaching 3186 meters, setting a new altitude record for Ethiopia. Phlebotomus arabicus was also found up to 3045 meters in hyrax habitats.Conclusion: This study revealed that the risk of CL in Tigray reaches up to 3200 meters. Phlebotomus longipes habitats suggest the potential for domestic and peri-domestic transmission of CL. Further research is needed to determine if the new high-altitude presence of Phlebotomus longipes and the other sand fly species is due to climate change or other factors.

Human–carnivore conflict (HWC) is an increasing conservation and livelihood challenge worldwide, particularly in rural areas where communities depend

Rodent species belonging to the Arvicanthis genus cause substantial field and postharvest losses in many African countries, where management still relies mainly on lethal control methods. Hormonal fertility control may provide a complementary strategy for reducing rodent population growth. We investigated the antifertility effects of bait containing quinestrol, a synthetic estrogen, levonorgestrel, a synthetic progestogen, and their combination at 10, 50, and 100 ppm in the Nile grass rat (Arvicanthis niloticus). These compounds suppress fertility by disrupting normal reproductive endocrine function. Adult male and female animals were exposed to treated bait under laboratory conditions, and reproductive responses were evaluated through measurements of bait intake, body weight change, reproductive organ weights, sperm count, sperm motility, pregnancy rate, and litter size. Quinestrol and combined treatments significantly reduced male reproductive organ weights and impaired sperm quality. Female reproductive organ weights were generally unaffected, although uterine edema occurred at higher concentrations. Quinestrol at 50 ppm completely inhibited pregnancy in treated females, regardless of the male mating partner. In addition, untreated females paired with treated males exhibited lower pregnancy rates and reduced litter sizes. Our findings demonstrate the potential of hormonal fertility control as a complementary strategy for sustainable rodent pest management in Africa. Future studies should focus on improving bait intake, field evaluation, and determining the duration and reversibility of contraceptive effects.

Nowledge on honeybee flora is very crucial to identify diversity of honeybee plant species and their contribution in improving beekeeping. The study was conducted to identify the honeybee flora diversity, floral calendar, their nectar and pollen contribution in Welkait district, Tigray region. Moreover, the study addressed the honeybee practices by the local beekeepers. A semi-structured questionnaire interview, focus group discussions and field observation were used to gather the data. Hundred fifty two purposefully selected local beekeepers were approached for this interview. Results revealed that 106 honeybee plant species belonging to 46 families, 27.4% of them from lowlands, 34.9% from midland and 37.7% from both agroecological zones were collected and identified. Among the honeybee plant species, 44.3% were herbs, 39.6% were trees, 16.1% were shrubs. This study demonstrated that people have a rich knowledge of honeybee flora of the Welkait that could strengthen beekeeping practices of the region via natural conservation for sustainable use and development.

Successful biological control of the whitefly Bemisia tabaci involves the mass rearing of biocontrol agents in large numbers for field release. Cold storage of the biocontrol agents is often necessary to provide a sufficient number of biocontrol agents during an eventual pest outbreak. In this study, the fitness of two whitefly parasitoids Encarsia sophia Girault and Dodd (Hymenoptera: Aphelinidae) and Eretmocerus hayati Zolnerowich and Rose (Hymenoptera: Aphelinidae) was evaluated under fluctuating cold storage temperatures. The emergence rate of old pupae of either species was not affected when stored at 12, 10, 8 and 6 °C for 1 week. Cold storage had no effect on the longevity of the emerging adult En. sophia except young pupae stored at 4 °C, while Er. hayati was negatively affected after 2 weeks of storage time at all temperatures. Parasitism by adults emerging from older pupae stored at 12 °C for 1 week was equivalent to the control. Combined with the results for the emergence time, we suggest that the old pupal stage of En. sophia and Er. hayati could be stored at 12 and 10 °C, respectively (transferred every 22 h to 26 ± 1 °C for 2 h), for 1 week, with no or little adverse effect.

The abundance and microhabitat use of rodents were investigated in four different habitats: two rain-fed crop fields with differing stone bund density, an irrigated field and bushland. A total of 444 individual small mammals belonging to six rodent and one shrew species were recorded in trapping grids and line transects. Of these, 230 individuals (52%) belonged to three pest rodent species of crop fields in northern Ethiopia: Stenocephalemys albipes (65%), Mastomys awashensis (25%) and Arvicanthis niloticus (10%). Population abundance of the three species was higher in the early dry season compared to the rainy season. While the bushland was significantly (p < 0.05) favoured by S. albipes and M. awashensis in both seasons, the irrigated field was preferred by Arvicanthis niloticus in the early dry season. In the early dry season, the microhabitat use of A. niloticus was strongly associated with the type of ground cover (herb) (R2adj = 0.152, P < 0.01). While M. awashensis was associated with vegetation density (R2adj = 0.13, P < 0.01), S. albipes was associated with vegetation cover (R2adj = 0.102, P < 0.001). The findings indicate that co-occurring pest rodent species prefer different microhabitats. Understanding their co-occurrence particularly in crop fields is vital for crop protection as they are known serious agricultural pests in northern Ethiopia.

This study evaluated the potential of two aphelinid parasitoids, Encarsia sophia (Girault & Dodd) and Eretmocerus hayati (Zolnerowich & Rose) to control the sweetpotato whitefly Bemisia tabaci, (Gennadius) using a banker plant system over two consecutive years. The parasitism rates of both parasitoids on a tomato (Solanum lycopersicum L.) crop were determined using melon, Cucumis melo L. (Cucurbitaceae) and castor bean, Ricinus communis L. (Euphorbiaceae), as banker plants, respectively. The emergence rates of Er. hayati and En. sophia parasitoids from parasitised whiteflies on both banker plants exceeded 90% and 85%, respectively, which is 17–20 percentage points higher than that on the pupal card under field cage conditions. Parasitism (%) on banker plants was significantly higher for both parasitoids in the third week after release as compared to adult releases in the first year, reaching 15.2 ± 1.3 and 24.0 ± 1.4% for En. sophia and Er. hayati, respectively. However, no significant difference in parasitism (%) was observed between banker plant and pupal card release treatments in the second year. The combined release of the two parasitoids during the second year clearly showed a continuous increase in parasitism, which was higher than parasitism in the single parasitoid-release treatments by the 4th week after release. Whitefly populations were significantly lower in all parasitoid-release treatments than in the no-release control by 4–6 weeks into the study period in the second year, while no other significant differences were observed between treatments in either year. This study found that both banker plants efficiently supported populations of both parasitoids and improved their emergence compared to the pupal card.