Apparent Densities of Stomoxys species (Diptera, Muscidae) of different Physiological Ages caught with Vavoua Trap differ With Landscape and trapping period

Abstract

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<0.05). The proportion of parous 87 (59.30%) was higher than that of their nulliparous 46 (40.71%) counterparts. Parity differed with landscape and capture periods. S. n. niger was the most frequent in all biotopes and Galim recorded the highest ADT. The population of female flies was made up of adults (parous) with a bimodal diurnal activity rhythm whereas males had a unimodal activity rhythm.