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To embark on an anti-vectorial fight against mechanical vectors of animal trypanosomosis, investigations were undertaken in order to determine the abundance, species diversity and daily activity of tabanids in a cattle ranch in Gabon. The nzi and vavoua traps were used to catch tabanids in three divisions of this ranch. In this study, 616 tabanids were captured: 349 (56.66%) in Division 1, 226 (36.69%) in Division 2 and 41 (6.66%) in Division 3. In the first Division, T. taeniola was the most abundant species with an Apparent Density (ADT) of 2.2, followed by H. pluvialis (ADT = 1.05). In the second Division, H. pluvialis was most abundant with ADT of 1.6, followed by T. taeniola (ADT = 0.38). In the last Division, the most abundant species was H. pluvialis (ADT = 0.15). Comparing the relative abundance of catches with sites (Divisions), we realized that there was no statistically significant difference in catches with trapping sites. It was noticed that Division 3 recorded the highest diversity index values. We realized that the nzi trap recorded higher tabanid catches than the vavoua trap. The diurnal activity rhythm of the most frequent species encountered slightly differed with prospection sites.

Foot-and-mouth disease (FMD) is an economically important viral disease of domestic animals and wildlife. High circulation occurs during outbreaks but little is known about the current transmission dynamics in sedentary cattle and sheep herds. To investigate on this, samples from cattle and sheep located in the Vina Division of the Adamawa region of Cameroon, during FMD outbreaks were collected. Non-Structural Protein (NSP) and antigen detecting/serotyping FMD ELISAs were used for sample screening. The NSP serological data of cattle was used to estimate transmission parameters in catalytic and reverse catalytic models. The Akaike’s Information Criteria (AIC) revealed the reverse catalytic model as the most parsimonious for the NSP serological data and was used to estimate the force of infection (FOI), the rate of waning immunity and to estimate historic periods of sustained transmission. Four serological types of FMD notably O, A, SAT 1 and SAT 2 were identified from cattle vesicular epithelia tissues. Seroprevalence findings revealed 65.14% and 15.71% FMDV antibodies in cattle and sheep respectively with highest prevalence in both populations occurring in Mbidjoro. The FOI (λ) in sedentary herds was constant; the rate of waning immunity (ω) was 0.32 meaning cattle are generally immune for 3.12 years post natural infection. The reproductive number (Rt) was 7.33, meaning approximately 87% of cattle always need to be effectively immunized to prevent outbreaks. Therefore, FMD circulates in sedentary cattle and sheep populations in the study area with four serological types detected in cattle.

The aim of the study was to determine the abundance and diurnal activity rhythm of Stomoxyinae at the Ivindo National park and its environs, 14 Vavoua traps were set-up during the rainy season (25th Sept-5th Oct and 21st Oct-9th Nov 2018), in two habitats: the forest, a part of the Ivindo National Park (INP) and village-Town. In the Village-Town habitat, 62141 Stomoxys were caught and regrouped under five species notably 36502 S. omega (58.74%), 24045 S. n. niger (38.69%), 1312 S. xanthomelas (2.11%), 265 S. n. bilineatus (0.43%) and 17 S. calcitrans (0.03%). At the INP, 4645 Stomoxys were caught and regrouped under four species notably 2364 S. n. niger (50.89%), 2153 S. omega (46.35%), 114 S. xanthomelas (2.45%) and 14 S. n. bilineatus (0.30%). Stomoxys were more abundant in the village (517.84 s/t/d) as compared to the INP (44.24 s/t/d). There was a statistically significant difference (P

Stable flies (Stomoxys spp.) are common pests of livestock in the peri-urban rangelands of Vina Division of the Adamawa Plateau. No documented information is available on their diurnal dynamics in relation to physiological age and landscape. The main aim of this study was to determine the trap apparent density (ADT) of Stomoxys and associate it to their diurnal activity rhythm and landscape. Vavoua traps (n=12) were used for Stomoxys collection. Trapping was carried out for seven days i.e. three days consecutively in August and four days consecutively in October, 2016. Three traps were pitched in each of the three biotopes (river, cattle corral and gallery forest) of the four study sites (Galim, Mbidjoro, Velambai and Soukourwo). All female Stomoxys captured underwent ovarian dissection for the determination of their physiological ages (parous or nulliparous). A total of 218 Stomoxys were caught and identified into four species (S. niger niger, S. omega, S. calcitrans, and S. xanthomelas) with an overall ADT of 2.59 flies per trap per day and Stomoxys niger niger (1.13 s.n.n. per trap per day) recorded the highest ADT. Species richness was study site dependent. Higher catches of females 113 (51.83%) were made than that of their male 105 (48.17%) counterparts. Galim recorded the highest Stomoxys apparent density (4.90) as compared to other sites with a statistically significant difference (P

There is need for a simple, cheap and efficient collection and control tool for the different stable fly-species in hyper-infested foci. The efficacy of a modified unbaited Vavoua trap (MVT) was compared with an unbaited Nzi as a standard. Each trap model was pitched either inside or outside the cattle overnight pen with rotation taking place after four days for eight days in September 2018 in Ngaoundere. Fly collection was made every 24 hours and sorted using standard identification keys. In total, 2105 hematophagous flies were caught and constituted of 1417 S. niger (89 S.n/t/d), 124 S. calcitrans (8 S.c/t/d), 562 Musca spp. (25m/t/d) and 2 Chrysops distinctipennis (0.1 Cd/t/d). The overall mean catches with the MVT (50.96±57.16) was higher than with the Nzi (27.43±27.73), with no statistically significant difference (t=0.9, df=46.0, P=0.37). Higher mean catches were recorded outside the overnight cattle pen (47.79±55.27) than inside (39.83±55.40) with no statistically significant difference (t=0.5, df=46.0, P=0.62). Stable flies and tabanids were mostly caught outside the overnight stable, while Musca spp. were highly caught inside. Humidity and wind speed were the main drivers of the abundance of the flies caught and from the Pearson’s correlation test, there was a negative and significant correlation between the two meteorological parameters (r=-0.29, P=0.04). The MVT can serve as a simple and efficient tool for the survey and control of stable flies in the Adamawa plateau and elsewhere.

The rangelands of the Vina Division on the Adamawa Plateau are densely infested with Stomoxyinae, but little is known about their species composition and ecology. A trap-transect survey was carried out in three villages: Galim, Mbidjoro, and Velambai, using Nzi (n = 3), Vavoua (n = 3), and Biconical (n = 3) traps, all baited with octenol. Three traps of each trap type were set in each of the study villages, and collections were carried out daily. In total, 3,762 Stomoxys spp. were collected from October 2016 to June 2017 and identified using standard keys into five species: Stomoxys niger niger, S. calcitrans, S. niger bilineatus, S. omega, and S. xanthomelas. Galim recorded the highest apparent density of stomoxyines (30 stomoxyines/trap/day) with a statistically significant difference (p<0.05). The Vavoua trap was an ideal tool for Stomoxyinae collection. Stomoxyines abundantly occurred at the end of the dry season (March 2017) and beginning of the rainy season (May 2017). The monthly rainfall positively influenced monthly ADTs of Stomoxyinae. Their diurnal biting activity was bimodal in the rainy season and unimodal in the dry season. The daily activity peak was between 14 h and 16 h with a mean temperature of 31°C, a mean wind speed of 1.5 m/s, and a mean humidity of 50%. The daily trap catch was positively influenced by temperature and wind speed but negatively influenced by rainfall and air humidity. Weather variables influenced Stomoxys spp. monthly and daily ADTs.