International audience | Susceptibility of two French strains of stable flies Stomoxys calcitrans (L.) to six insecticides was assayed, using an exposure technique (1-hour contact) with treated filter papers. Three replicates per insecticide, per concentration (10 concentrations per insecticide), per fly strain (ENVT, Cabanac) and fly category (blood-engorged - non-blood-engorged) were performed using a total of 14,400 adult flies in this trial. The LD50 and LD90 are higher for the blood-engorged flies than the non-blood-engorged flies for both strains of S. calcitrans. The LD90 (mg/m(2)) of the engorged flies for both strains were respectively: cypermethrin (637.9, 54.9), deltamethrin (264.3, 28.1), fenvalerate (2392.5, 125.1), lambda-cyhalothrin (118.2, 41.3), permethrin (353.7, 88.1), and phoxim (194, 226.8). Phoxim, which has not been used in the ENVT for several years, showed the same susceptibility for both strains. The LD90 values obtained for the Cabanac strain (organic farm) were 1 to 4 times lower than the recommended doses of all five pyrethroids. For the ENVT strain (blood-engorged flies), the LD90 was 7.1 and 22.6 times over the recommended doses of both deltamethrin and fenvalerate respectively, which are commonly used insecticides on this site.

Trypanosomiasis positive cases were reported in Sahom Farm Retreatin Gopeng, Perak; with multispecies livestock animals. Nzi and Vavoua traps were applied to survey the population of biting flies; stable flies (Muscidae: Stomoxyinae) and horse flies (Tabanidae)as the vector for surra. Results indicated the presence of Trypanosomiasis infection diagnosed by buffy coat examination, thinblood stained smears and serological test (Surra Sero K-Set test) and identification of its insect vectors. The presence of bothbiting flies provides the missing link between the occurrence of the disease and host or environmental factors precipitatingthe disease. Besides trypanosomiasis in cattle, other parasitic infections were also recorded with heavy infections for liver fluke (Fasciola gigantica ova) and coccidia oocysts. Therefore, some control measures are recommended to eradicate the vectors and to treat infected animals in order to prevent the dissemination ofthe trypanosmiasis.

This study was conducted during June 2016 to May 2017, to determine the morphological characteristics of stable fly Stomoxys calcitrans L. ,and studying some ecological aspects. These studies of stable flies are being conducted for the first time in Iraq.The morphological diagnosis of Stomoxys calcitrans: Frontal vitta with black pollinose, yellow around ocellar triangle, parafrontalia golden, parafacialia grayish black. Thorax gray to yellowish pollinose, Pleura yellow; sternites dark brown to black, Legs black, Wing tinged smoky-brown. Abdomen gray to yellowish; dorsum with four brownish pollinose spots, at least 3 abdominal segments with a single median spot basally and pair of spots at apex of each segment. Female identical to male in color and structure except for wider frontal vitta, frontal triangle with golden pollinosity extending almost to frontal ridge, setae on head somewhat stouter than in male, Interocular space wide in females, narrower in males by about half the distance of separation in females. A total of 470 flies were collected in this study. The results showed, some variations of monthly abundance were determined during the study period, four different climatic seasons. In general, stable flies were found to be more abundant in the moderate climates period of the year. April was the highest abundance with 18.7%, while, no presence recorded in January and December. Some observations showed that stable flies were found in the field in different periods of the day, beginning from 06:00 to 18:00 hr.,but these are periods that are considered the peak of its presence of other seasons during the year. Both sexes of S. calcitrans showed the same peak of activity in the day108 nearly. The field observations showed that Stomoxys calcitrans adults attack many economic and domesticated animals in Basrah province.Cattle are the most, followed by buffaloes, dogs, horses, cats, camels, donkeys than sheep, goats and rabbits

To determine their capacity to host Brucella abortus, face flies were examined 1 to 120 hours after feeding on broth containing bacteria and bovine erythrocytes. Brucella abortus was cultured in large numbers from whole flies for 12 hours after feeding, but not after 72 hours. Histologic analysis showed that brucellae were rapidly taken into the midgut, sequestered from erythrocytes, transiently stored, and shed in the feces; there was no evidence of bacterial replication within epithelial cells. Immunoperoxidase and immunogold techniques revealed that most brucellae in the gut were confined to the lumen by the peritrophic membrane, that brucellae were degraded in secondary lysosomes of midgut epithelial cells, and that intact brucellae passed into connective tissues surrounding the midgut. Bacterial excretion without midgut replication is consistent with transient, but not long-term, insect transmission in nature.