514 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



reflections; trophi reddish-black, dwarfed; antennoe black, with light yellowish- 

 brown pubescence in front. Thorax above intense black, velvety, with a bluish 

 luster; under side grayish. Legs reddish, with black tarsi; wings hj^aline, veins and 

 base bluish-white. Abdomen above black, with posterior margins of segments edged 

 with gray; under side of segments 2 and 3 light reddish-gray, the others blackish 

 with gray posterior margins. Sexual organs black. Thorax and abdomen very 

 sparsely clothed with white pubescence. • 



Described from three bred specimens. 



Larva. — (Plate VII, Fig. 3.) Length when full-grown 5. 5""" to 7°"°. Normal shape 

 and general appearance. Differs from S. pecuarum by the much more irregular 

 markings of segments and head, A majority of the larvae possess one or two lateral 

 spots on club-shaped posterior third of body. Head lacks the regular arrangement 

 of spots and lines, which become confused; the two black spots on each side pres- 

 ent.'^ Antennce (Plate VII, Fig. 3a) uniformly pale, much longer than in pecuarum, 

 slender and 3-jointed; first ;joint almost twice as long as joints 2 and 3 together, and 

 a little bent; at base three times and at tip twice as thick as second joint, which is 

 nearly uniform in width, tapering but very slightly towards tip; joint 3 small and 

 pointed, about one-fifth as long as joint 2. Mentum (Plate VII, Fig. 4) similar to 

 that of S. pecuarum, but distinguished by a flatter apex, by the possession of three erect 

 bristles on each side, starting from round pores, which decrease in size towards base; 

 a fourth very small bristle close to base and in line with the bristles above; the sides 

 of mentum have on each side four sharp teeth. Lahrum and labium not different 

 from those of pecuarum. Mandibles (Plate VII, Fig. 35 and 3c) possess but seven 

 teeth in first row; the three first nearly uniform in length; teeth 4 to 7 gradually 

 decrease in length; tooth 4 much the longest of all; the two teeth in second row 

 similar to those of pecuarum. Maxillce and maxillary palpus also similar. Fans 

 similar, but the hairs lining the inside of the scythe-shaped rays are thicker and 

 nearer together. Proleg more slender; last joint bearing a crown of hooks, usually 

 bent suddenly toward head. Tip of abdomen similar to that oi pecuarum. Breath- 

 ing organs (Plate VII, Fig. 5) quite different; the three main trunks branch each 

 six times, and the branches enter the trunk from both sides. Full-grown larvse 

 show also tlie newly formed coiled breathing tubes of the pupae through their skin. 



Described from many specimens. 



Pupa. — (Plate VII, Fig. 6.) Average length, 3.5°^™. Shape and coloration as in 



5. pecuarum. The thoracic filaments consist only of the six original rays, which do 

 not branch. Upon dorsal surface of the posterior margins of abdominal joints 4 

 and 5 is a row of eight anteriorly curved hooks similar to those of pecuarum, but 

 none on joint 3; anterior margins of joint 9 and of subjoint with a continuous row 

 of smaller anteriorly curved hooks; joints 7 and 8 imarmed dorsally ; ventrally joints 



6, 7, and 8 have each four minor hooks. 



Cocoon. — (Plate VII, Fig. 6.) Length, 3.5™™. Neater than that of any other 

 species known to me, being formed of fine threads, lined with gelatinous ones. The 

 web is quite dense, uniform, with well-defined, sometimes thickened rims. The 

 cocoon is always securely fastened singly to leaf or stick, and even if many are 

 fastened upon the same leaf they do not crowd each other. It fits snugly about the 

 pupa, which is so securely anchored inside as to be with difficulty extricated. . 



REMEDIES TRIED AND PROPOSED AGAINST THE LARV^. 



The results of a number of different experiments with insecticides 

 upon the larvae of the Buffalo Gnats made by Mr. Lugger during the 

 early spring indicates that it is nearly if not quite impossible to re- 

 duce their numbers by killing them in the streams. To attempt to do 

 so when all these streams are swollen, and frequently from 10 to 20 

 yards wide and half as deep, would be sheer waste of time. When the 

 water is very low and much more sluggish in its motion, thus bring- 

 ing the chemicals in contact with the larvae, an application of them 

 might be more effective. Great caution must be used in any efforts 

 in this direction, however, as both man and beast are in many local- 

 ities entirely dependent upon these streams for their water supply and 

 the introduction of ])oisonous substances might cause much trouble. 



Some of the exjieriments were made by conlining the larvse in glass 

 tubes and submitting them to a current of water to which the fol- 

 lowing decoctions and solutions had been added, viz : China berries, 

 salt, lime, sulphur, tar water, kerosene emulsion^ and carbon-bisul- 



