387 

 Wirth and Stone: Diptera 



Fig. 14:9. Psychodidae. a, Pen'coma sp., female; b-c, Psychoda 

 sp.: b, pupa; c, larva (a. Smart, 1948; b,c, Quote 1955). 



The immature stages of the Psychodidae have the 

 following characteristics: 



Egg. — Pale or dark brown in color; oval; usually without 

 prominent reticulations or other conspicuous markings. 



Larva (fig. 14:9c).— Elongate cylindrical, except Maruina 

 (fig. 14:10c) which is onisciform, flattened ventrally, with 

 eight ventral suckers (fig. 14:106). Head and mouth parts 

 complete, head nonretractile, except Sycorax; mandibles 

 toothed, opposed, usually with long setae, leaflike struc- 

 tures, and serrate bristles; epicranial suture U-shaped, 

 conspicuous; antenna small, domelike or composed of 

 several small rods, or long and three-segmented. Thoracic 

 and abdominal segments usually divided secondarily into 

 annuli, ordinarily two for each thoracic and first abdominal 

 segment and three for abdominal segments two to seven, 

 some or all annuli with tergal plates. Respiration amphi- 

 pneustic, anterior spiracles borne on apex of domelike 

 protuberance on thorax; posterior spiracle at apex of siphon 

 or located dorsal ly on terminal abdominal segment. 



Pupa. — Body cylindrical (fig. 14:96) or flattened ven- 

 trally (fig. 14:10a); head, legs, and wing distinct, closely 

 applied to body; tips of legs not extending beyond apices 

 of wing covers; respiratory horn present on prothorax, 

 usually elongate and slender, exterior surface with double 

 row of pits extending from tip to base or near base, pits 

 connected to inner chamber by lateral channels. Abdominal 

 segments with variously shaped spines and marginal 

 fringes. Terminal segment elongate, roughly rectangular 

 in lateral outline. 



The larvae of psychodids are easily recognized 

 because the body segments are secondarily divided 



Fig. 14:10. Maruina sp. a, pupa; b, ventral suckers of larva; 

 c, larva (Quate 1955). 



into two or three annuli. The commoner species gen- 

 erally bear a tergal plate on each annulus. The pupae 

 are less easily separated from other Nematocera, 

 and at present generic pupal characters are not 

 available. 



With the exception of Maruina, Phlebotomus, and 

 possibly Trichomyia, North American psychodids are 

 semiaquatic, living under very moist or semiliquid 

 conditions or rarely, in open water. Common habitats 

 include moist, decaying vegetable matter of many 

 types, heavily saturated mud and sand at stream 

 margins, and moss and algae floating on still or 

 slow-moving streams or growing in water-splash areas. 

 The pupae can withstand drier conditions, although 

 they do not appear to prefer these, but they have 

 been found intermixed with larvae in very moist 

 situations. 



Keys to the North American Genera of Aquatic Psychodidae 

 Adults 



1. Only 1 longitudinal vein between the 2 forked veins 

 Maruina Mueller 



— Two longitudinal veins between the 2 forked veins 

 (fig. 14:9a) 2 



2. Antenna with 14 to 16 segments, the last ones dimin- 

 utive and often united to each other. Psychoda Latreille 



— Antenna with 15 to 16 segments, the last ones not 

 diminutive or united to each other 3 



3. Flagellar segments barrel-shaped or fusiform without 

 very pronounced basal bulb Pericoma Walker 



— Flagellar segments with notable basal bulb, often more 

 bulging on one side, and with a distinct distal neck 



Telmatoscopus Eaton 



