BITING FLIES 2 99 



just above the root of the antennae). If the halteres are covered by a scale (squama) 

 we have calyptrate Cyclorrhapha; if not, acalyptrate. These squamae are large 

 enough in the calyptrate species to even conceal the halteres when the fly is looked 

 at from above. 3. Pupipara: the larvae are extruded ready to begin the pupal state. 



The males of flies where the two compound eyes come together above the antennae 

 are referred to as holoptic, if more or less widely separated as dichoptic. Ocelli are 

 three single eyes usually, when present, situated in the triangular space between the 

 compound eyes in the front (the space separating the compound eyes). 



In studying the biting flies it is very important to recognize the anterior, small, 

 or mid-cross vein. This short transverse rib or vein is the key to wing venation. 

 Beneath it is the discal cell and it bounds the first posterior cell internally or basally. 

 It is also of great value in differentiating Culicidae. The character of the antennae 

 should also be noted carefully. The study of the bristles about head, thorax, and 

 abdomen (chaetotaxy) is more difficult. Anyone taking up the study of flies should 

 carefully note the wings, etc., of Musca domestica. By putting a few house flies 

 on moist horse manure in a gauze-covered bottle the entire metamorphosis may be 

 observed. 



Tabanidae. 



This is the family of horseflies, gadflies, breeze flies or green-headed flies. It 

 is the most numerous family of the Diptera there being more than 1000 species. 

 The females are blood suckers; the males live on flowers and plant juices. The eyes 

 are usually very brilliant in color, and in the male make up the greater part of the 

 head. 



They belong to the suborder Orthorrhapha and in the group of short antennae 

 flies (Brachycera). Five posterior cells are always present. 



The antennae consist of three segments. No arista. The epipharynx is tube 

 like, the hypopharynx has a groove and both are awl shaped. The pair of maxillae 

 are serrated and the mandibles lancet like. They have rather coarse maxillary 

 palps. The labellae are prominent at the extremity of the fleshy labium. They are 

 thick set flies and rarely show color. The body of the larva has eleven segments 

 with a small but distinct head. The eggs are deposited in masses on the leaves or 

 stems of plants about marshy places. The larva is carnivorous. 



Tabanus autiunnalis. Is about 3/4 of an inch long; it is dark in color, and has 

 four longitudinal bands on the thorax. The last joint of the antennae has a crescentic 

 notch. The wings do not overlap. 



Hsematopota pluvialis. In the Haematopota there is no crescentic antennal 

 notch, and the wings overlap. The abdomen is narrower than in Tabanus. The 

 brimp, one of the Haematopota, bites man severely. 



Pangonia beckeri. The genus Pangonia is characterized by a very long, slender, 

 and more or less horizontal proboscis. 



Chrysops dispar. Chrysops has three ocelli, in this respect differing from the 

 genera Tabanus and Haematopota. The wings are widely separated and spotted. 

 The antennae of Chrysops are especially long and slender. Chrysops and Haemato- 

 pota produce the greatest amount of pain from their bites. The Tabanidae are not 

 implicated as intermediate hosts in the transmission of disease. By their bites, 



