78 NORTH AMERICAN DIPTERA 



Family Psychodidae — The Moth Flies 



Thickly haired, small iiies, rarely exceeding 5 mm. in length, the 

 wings clothed with hairs or scales and folded roof-like over the back. 



Head small; ocelli absent. Antenna usually as long as the head 

 and thorax together, the segments usually bead-like and sometimes so 

 densely haired as to appear very thick; composed of from twelve to 

 sixteen segments, the basal segments usually short and cylindrical. 

 Proboscis usually short but more or less elongate and rigid in Flehoto- 

 mus; palpi composed of four segments, hairy. Thorax without trans- 

 verse suture, not very convex; scutellum rounded. Abdomen rather 

 cylindrical, composed of six to eight segments; male genitalia prominent, 

 the female ovipositor usually projecting. Wings large, ovate, often 

 pointed, when at rest lying roof -like over the abdomen, the base being 

 bent at more than a right angle, the veins and border densely haired, 

 the integument often with hairs or scales; veins strong, usually con- 

 cealed by the dense hair; crossveins restricted to the basal third of the 

 wing; two or three of the veins furcate. Legs rather short, elongate 

 in Flehotomus and usually thickly haired. 



The adults occur commonly in shady places in the vicinity of 

 water and may often be found in large numbers on dense foliage in 

 swamps, where they crawl about on the under surface of leaves, occa- 

 sionally alighting on the upper surface after a short flight. I have seen 

 them in thousands on tree-trunks after a heavy rain and they are not 

 rare on logs and fallen trees where they walk about in a peculiar, jerky 

 manner or remain perfectly still. One or more species of PsycJwda 

 breeds in drain pipes and they often cause uneasiness by appearing in 

 the bath room. Their presence should incite interest rather than fear 

 as the larvae survive hot water and soap alike, and do no harm. The 

 adults are not common in collections, chiefly because they are so easily 

 damaged. The hairs brush off and they become useless unless unusual 

 care is taken of the specimens. No recent revision of the family has 

 appeared and the synonymy is badly mixed and is not to be trusted. 

 The male genitalia offer excellent characters. There are dozens of species 

 and the family offers an excellent opportiuiity for a thorougli, mono- 

 graphic work. 



In America two diseases are known to he carried by species of 

 Flehotoimis. The disease known as Verruga Peruviana, Oroi/a Fever 

 or Carrion's Disease lias been found only in narrow valleys on the 

 western slopes of the Peruvian Andes. Verruga is said not to be serious 

 but Oroj/a Fever (Carrion's Disease), the malignant form, is re- 

 sponsible for many deaths annually. Loeal Leishmaniasis or Fspundia 



