(/KCIDOMYID/I*:. 



ORTHOERHAPHA. 



1. CECIDOMYIDiE. 



Small, slender flies with broad wings, and long antennae and 

 feet. Head small ; eyes round or reniform, sometimes holop- 

 tic; ocelli usually wanting; antenute long, cylindrical or bead- 

 like, composed of a large number of joints — ten to thirty-six ; 

 in many species the joints beaded or petiolate and verticillate, 

 especially in the S; proboscis short, elongated in one genus 

 only; palpi usually with four joints. Thorax ovate; more or 

 less convex, without transverse suture; abdomen composed of 

 eight segments; hypopygium composed of a pair of projecting 

 booklets ; ovipositor sometimes much elongated. Legs long 

 and slender ; coxae not very long ; tibias without terminal 

 spurs ; the first joint of tarsi sometimes very short. Wings 

 large, usually hairy, narrowed at the root, without alula ; at 

 the most with five, usually with but three, longitudinal veins, 

 viz : the first, the third, and the fifth ; the fourth and the sixth 

 sometimes present ; the humeral cross-vein indistinct, or want- 

 ing; costal vein enclosing the entire wing; veins all w^eak ; 

 the fifth usually furcate ; anterior cross-vein very near the 

 root of the wing, often appearing as the beginning of the third 

 vein, the real origin of the third vein having the appearance 

 of a short cross-vein ; only one basal cell present. 



The family Cecidomyidse includes a very large number of 

 frail, delicate, often very minute flies, but is of the greatest 

 interest to the biologist as well as the economic entomologist. 

 At present about 600 or 700 species are known. 



The egg of tlie Cecidomyidae is somewhat elongated, rounded 

 at both ends, orange yellow or white in color. The time re- 

 quired for hatching is very variable and depends upon the 

 weather, sometimes requiring a very few hours, but more gen- 

 erally a few days or even weeks. The larval food is almost 



