Seasonal Prevalence and Host Preference of Some Medically Important Aedes Species of Doon Valley, India

In the recent past, several outbreaks of mosquito-borne diseases in Dehradun city make it necessary for a comprehensive understanding of man-vector contacts, disease transmission and determination of appropriate resting sites for adult mosquitoes. The study was conducted within the periphery of Dehradun city in Doon valley, Uttarakhand state, India consisting of eight (08) locations namely Sahaspur, Premnagar, Raipur, Karanpur, Sahastradhara, Dudhli, Doiwala and Rani Pokhri with the objective to analyze and assess the seasonal prevalence and host choice of the mosquitoes with special reference to Aedes species. Among the eight locations of the current study, Raipur registered the highest mosquito abundance (17%) trailed by Sahaspur (16%) and Karanpur (15%). A low abundance of mosquitoes was registered conjointly from Doiwala and Rani Pokhri areas (9% from each area). In these areas, the profile plots of the 2-way ANOVA displayed the highest variation for the data collected from human habitations followed by bovine sheds, whereas the lowest recorded variation was from the poultry. With regards to seasonal prevalence, the highest mosquito abundance was registered during the monsoon followed by the post-monsoon. In provender analysis, a total of 1912 blood meals were collected for antibody test among which 1851 were found positive, with the highest reaction with human antisera (57.75%), followed by bovine antisera (21.34%) and pigs antisera (4.97%). Ae. aegyptihad the highest Anthropophilic Index (A.I.) with 68.78%, followed by Ae. albopictus (64.89%) and Ae. vittatus (55.55%). However, Human Blood Predominance (H.B.P.) and Pure Human Blood Pervasiveness (P.H.B.P.) were found highest for Ae. albopictus with values 0.43 and 0.44 respectively. The results also show the seasonal prevalence and feeding habits of these vectors. This study would be helpful in formulating season-wise strategies for the control of Aedes vector mosquitoes in different eco-epidemiological situations.

Seasonal Variation on the Incidence and Severity of Major Folia Diseases of Cassava in Sierra Leone

A diagnostic survey was conducted in the rainy and dry seasons from 2014 to 2015 to determine the incidence and severity of major diseases of cassava in Sierra Leone. At least three chiefdoms and five villages per district were targeted. The survey was carried out in fourteen districts of the country with geo references using a GPS. On the spot assessment was conducted in all fields. Prevalence, severity and incidence were calculated. The most dominant diseases included the cassava mosaic disease and the cassava bacterial blight. The prevalence of cassava mosaic disease was high with 69.1% and 61.5% in the rainy season and dry season, respectively. The prevalence of cassava bacterial blight was 100% and 92% in the rainy season and dry season, respectively. Diseases of less importance included white spot and brown spot diseases as well as cassava anthracnose disease. The study provides bases for the deployment of improved varieties and provides information on the seasonal prevalence, incidence and severity of cassava diseases in Sierra Leone.

Prevalence of Visceral Schistosomiasis in Cattle Slaughtered in North-Eastern Region of Bangladesh

A cross sectional study was conducted to estimate the prevalence and identify possible risk factors (season, sex) of Schistosoma in three north-eastern districts of Bangladesh namely Mymensingh, Sunamganj, Kishoreganj. Mesenteric sample of cattle from different slaughter houses were collected and examined for helminths which were identified as Schistosoma on accordance with Soulbsy, 1965. Total 67 (55.83%) out of 120 randomly selected samples were found positive for schistosomiasis. Cattle of Kishoreganj were mostly infected (67.50%), followed by Sunamganj (55.00%) and Mymensingh (45.00%). Regarding seasonal prevalence, samples collected during winter (63.33%) were more infected than summer (48.33%). Moreover, 58.69% of male and 46.42% of female were found infected. In conclusion, relatively high prevalence was recorded in the study areas based on the results obtained. Hence, control measures against schistosomiasis must be designed. Res. Agric., Livest. Fish.8(1): 165-169, April 2021

Seasonal prevalence of Asian honeybee ectoparasitic mite Varroa destructor Anderson and Trueman, 2000 in Madanpokhara Apiaries, Palpa, Nepal

The present study highlights the prevalence and seasonal variation of Varroa destructor Anderson and Trueman, 2000 in Apis cerana colonies at two apiaries (site-I and site-II) in Madanpokhara, Palpa district, Nepal. Altogether 498 varroa mites were collected from February to October 2017. The highest and lowest number of varroa mites were observed in March and September, respectively. The mites were observed higher in brood cells (54.84% and 52.51%) and lower in adult bees (10.39% and 9.59%) in site-I and site-II, respectively. The inner hive and outer temperature in site-I and II were ranged from 30°C to 34°C and 24°C to 32.4°C, 30°C to 33.5°C and 25.1°C to 32.3°C, respectively. Similarly, inner and outer hive humidity ranged from 41% to 61% and 40% to 68%, 40% to 60% and 41% to 65% at site-I and II respectively, differed significantly and correlated positively with mite population. Concern for honeybee health and conservation along with Nepali apiculture are also discussed in this paper.