FAMILY PSYCHODIDAE 177 



lamp chimney is partially immersed in the water, horizontally and in the 

 direction of the current, and the leaf or twig to which the larvae are 

 attached is then passed into the chimney ; the water flows through the 

 chimney, so that the larvae remain under natural conditions ; when they 

 pupate the ends of the chimney should be covered with fine netting, 

 which will prevent the flies from escaping. 



FAMILY PSYCHODIDAE 



Small to minute moth-like gnats with narrow depressed heads ; frons 

 wide in both sexes ; ocelli wanting. Antennae long, as long as the thorax 

 and head together, with a beaded appearance, and thickly covered with 

 hairs ; each antenna is usually composed of sixteen segments, the two basal 

 ones being short and cylindrical. , Palpi recurved, covered with hairs and 

 scales, and consisting of from four to five segments. Proboscis very short, 

 or as long as the head. Thorax raised, arched, and covered with dense 

 hairs ; scutellum rounded. Abdomen cylindrical, composed of from eight 

 to ten segments ; male genitalia prominent, consisting of two or three 

 Pairs of appendages ; in the female the ovipositor may be prominent or 

 concealed within the last segment. Legs stumpy, or very long and 

 slender, covered with hairs and scales ; claws small. Wings large, oval 

 or lanceolate in shape, covered with hairs or scales, when at rest either 

 held in an arched manner over the abdomen, or in an upright position ; 

 the margin is fringed with hairs. The costal vein is continuous round 

 the wing ; the other veins are well marked, and are almost all longi- 

 tudinal and hidden by hairs or scales. Subcostal vein very short. The 

 second long vein arises near the origin of the first, and may be 

 forked either once or twice ; the front vein, which is often spoken of as 

 the second division of the second vein, is considered by some to be 

 a branch of the third vein. In any case there appear to be either one or 

 two simple longitudinal veins between the second and fourth. The vein 

 (3rd) just anterior to the posterior forked vein (4th) nearly always 

 terminates at or near the tip of the wing. The fifth and sixth 

 longitudinal veins end at the border of the wing, and the seventh, 

 if present, is always short. The cross-veins are very indistinct, and 

 are situated in the basal half of the wing. The supernumerary and the 

 mid-cross veins, situated at the base of the third long vein are the 

 most prominent. The eggs of the Psychodidae are laid in damp earth, 

 where there is green algal matter. The larvae are cylindrical, the last 

 segment often ending in a short stiff stigmatic tube. The pupa 

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