UNASSIGNED: The face @entity238 (Musca autumnalis De Geer) and horn @entity238 ( @entity14454 irritans ([L.])) were studied at the southern edge of the face @entity238 's North American range, examining southern California geographic distribution, seasonal activity on @entity291 and in dung, and diapause. Face flies were common only at Pomona (34  03'N, 117  48'W). Other irrigated pastures, even those only slightly inland from Pomona, were probably too warm for face flies, due to a steep west (cooler) to east (warmer) temperature gradient. Horn flies were abundant at all sites. Adult densities on @entity291 , adults emerging from dung pats, and prevalence of @entity238 -positive pats were assessed for both @entity238 species throughout a year at Pomona. Summer adult horn @entity238 densities of 500-2,000 flies per @entity291 , or face @entity238 densities of 3-10 flies per face, were common. Summer prevalence of face @entity238 -positive pats and horn @entity238 -positive pats was about 20-40% and 30-70%, respectively. Face @entity238 adults diapaused from late October until late March and early April. Horn flies probably diapaused as pupae from late October or early November to early-mid March, although some emerged in winter. Experimental cohorts of October-emerging adult face flies were held in a representative overwintering site. They exhibited hypertrophied fat body and undeveloped oocytes, which are characteristics of diapause, and survived until the following spring. The dominant diapause cues in face and horn flies are probably photoperiod and temperature. Despite warm winter temperatures that would permit activity of both species, and despite relatively long winter day lengths, face flies and most horn flies still diapaused at this latitude.

Seasonality and Diapause of Musca autumnalis (Diptera: Muscidae) at its Southern Limits in North America, With Observations on XXXX irritans (Diptera: Muscidae).

@entity14454 :: ('MESH:D012553', 'Disease') :: ['Haematobia'] @entity291 :: ('9913', 'Species') :: ['cow', 'cattle'] @entity238 :: ('7227', 'Species') :: ['fly']
@entity14454 :: (MESH:D012553,Disease) :: ['Haematobia']
