264 



differentiating characters see key to pupae of Nematocera and descrip- 

 tions of families. 



Imago. — Mouth parts sometimes fitted for piercing, rarely abort- 

 ed ; palpi sometimes remarkably long; antennae from 9- to 15-jointed, 

 often with long plumes or with whorls of hairs ; ocelli absent or pres- 

 ent. Thorax without complete, well-defined suture. Wings without 

 discal cell; surface often haired or scaled; costa, in all except 

 Blepharoceridae, encircling wing, in the latter the field of wing has 

 numerous longitudinal and transverse creases which give it the appear- 

 ance of having a secondary venation. Legs very slender except in 

 Psychodidae; in the latter and in most Culicidae, with conspicuous 

 hairs or scales. 



Family PSYCHODIDAE 



r'AMii.Y characte:rs 



Larva. — Head complete; antennae protuberant; mandibles op- 

 posed, toothed, sometimes with long, fringed outer processes ; labium 

 usually serrate on anterior margin. Prothorax with distinct spiracles, 

 sometimes protuberant ; thoracic and first abdominal segments with a 

 slight central transverse constriction, giving them a biannulate appear- 

 ance, remaining abdominal segments, except the apical one, triannu- 

 late; some of the abdominal segments usually with a chitinized dorsal 

 plate upon each of the annuli ; in some cases all the segments of thorax 

 and abdomen have such plates, some of those on thorax being inter- 

 rupted longitudinally in center to facilitate the rupturing of the skin 

 for the exclusion of the pupa ; apical abdominal segment usually more 

 or less elongated, particularly in the species without or with very few 

 dorsal plates, in the form of a tapering tube, chitinized, the pair of 

 tracheal spiracles opening close together at its apex, generally with 4 

 protuberances which are fringed with soft hairs ; surface of body with 

 moderately long bristly hairs, variously arranged in the different spe- 

 cies. 



Pupa. — Prothoracic spiracles elevated, stalk-like ; head parts, legs, 

 and wings distinct, closely adherent to body ; fore tarsi overlying mid 

 pair, the latter overlying hind pair; apices of hind legs not projecting 

 beyond apices of wings. Dorsal appearance of body in Maiiriua oval 

 in outline, without a distinct break at base of abdomen ; the dorso- 

 ventral elevation very slight, so that the pupa appears somewhat in the 

 form of an oval scale (onisciform) without projecting spines or 

 bristles on dorsum. In Pericoma and PsycJwda the pupa is much like 

 that of a small tipulid, but the legs are very much shorter and the 

 wings are differently shaped. 



