Tabanidae 4° 5 



Family tabanidae 



METHODS FOR COLLECTING AND REARING HORSEFLIES 



H. H. Schwardt, University of Arkansas 



COLLECTING ADULT TABANIDAE 



CATTLE in a partly wooded pasture near a pond or sluggish water 

 course are likely to be annoyed by horseflies during the appropriate 

 season. An afternoon of collecting from animals so located is usually 

 fruitful. Small isolated ponds, especially if full of aquatic vegetation, 

 attract adult horseflies which come to drink or to oviposit. Such places 

 are frequented by males as well as females, the former often perching in 

 numbers on the vegetation. Sweeping of grasses, sedges, or flags about 

 such ponds often results in the capture of male specimens. Light colored 

 surfaces such as the sides of concrete culverts, or small isolated white 

 buildings, often attract numbers of adult Tabanidae. Horseflies are 

 seen in greatest numbers on hot sunny days when there is little motion 

 of the air. 



COLLECTING IMMATURE STAGES 



Horsefly larvae inhabit a wide variety of situations. They may be 

 found in greatest number in the mud banks of ponds or slow-flowing 

 streams. They are usually within two feet of the water and seldom 

 deeper in the mud than four inches. Banks composed of loose soil 

 containing some fine gravel or sand usually yield more larvae than those 

 composed of clay. Larvae of Tabanus annulatus apparently live only in 

 decaying logs or in decayed portions of living trees. They have been 

 collected in numbers from such places. Larvae of T. jronto and T. lineola 

 have been taken in soil of average moisture content and well removed 

 from water. Larvae of T. sulcijrons, T. melanocerous, and T. trimacula- 

 tus have been taken under logs on marshy ground. Since egg masses of 

 T. lasiophthalmus and T. benedictus have been found over fairly dry 

 ground it is possible that larvae of these species are partially terrestrial. 

 Larvae of T. atratus and T. lineola have been found in large numbers 

 among floating algae in swamps, stagnant ponds, and the irrigation 

 ditches serving rice fields. Larvae of Goniops chrysocoma inhabit the 

 top inch of soil under a heavy blanket of leaves. Occasional individuals 

 are found under rocks or logs. For collecting various species of larvae 

 from mud, a sieve i ft. square and 2 in. deep made of a wooden 

 frame, covered on one side with 16 mesh screen wire, has been found the 

 most efficient equipment. A handful of mud from the larval habitat 

 is placed in the sieve and spread out in a thin layer. The sieve is then 

 moved up and down slowly in the water until the mud is washed through, 



