68 Kansas Academy of Science. 



"The insects seemed to have preferred a small stump or projection to 

 one of large size, and also such as was exposed to the full sweep of 

 the current to one protected. Obstructions partly protected from the 

 full force of the current showed but a slight infestation. Again, in 

 the willow brakes, which are also subject to overflow, this same prefer- 

 ence was observed, but, on the other hand, few pupa cases were found 

 on the small willows that have smooth bark. A heavy infestation had oc- 

 curred on the larger willows having rough bark which afforded the best 

 m.aterial for inducing oviposition and for the young larvie to attach their 

 silken threads. A cottonwood brake, therefore, showed a heavier infesta- 

 tion than did a willow brake. 



"The bridges spanning the bayou had their pillars covered with the 

 empty pupa cases of the last brood, which also coated the braces of these 

 pillars to a height of two feet above the water level at this time. The 

 current of the stream had produced a strong parallel sweep along the 

 brace boards as well as a strong vertical sweep against the upright pil- 

 lars. 



"On Tuesday, March 20, I went down stream from headquarters for a 

 distance of two miles, engaging in similar inspections as were made on the 

 previous day and obtaining the same results. I observed on this trip 

 that on small sand-bars in mid stream, where they had been left dry by 

 the fall of high water, cottonwoods, etc., showed less numbers of pupa 

 cases than did the stumps and other projections in mid stream. 



"A large cypress brake whose trees measured about six feet in circum- 

 ference showed almost no pupa cases. These brakes were also subject to 

 overflow. From this point down stream, I returned and again visited the 

 'Government raft,' thinking that the warm midday sun and the cessation 

 of the wind might have brought about some new developments. But there 

 v/as no sign of the insects whatever about the raft or in the swamps bor- 

 dering the bayou where they were said to have been most abundant dur- 

 ing the outbreaks. In fact, at this time, there were cattle ranging in 

 these swamps unmolested by any insects, and I carefully ?wept over these 

 swamps in the hope of capturing some adults in the grass where they 

 could find protection from the wind, but this search proved in vain. 



"On Wednesday, March 21, I walked to Rambin bayou, a distance of 

 two miles from headquarters. This bayou is thought by some persons to 

 be one of the chief breeding places of the gnats. It never rises so high as 

 does Bayou Pierre, and it is believed that the flat, swampy areas along the 

 bayou, which are protected from winds, furnish ideal breeding places. 

 This bayou aff'orded just such conditions as these, and I spent a whole day 

 investigating it. The stream was inspected after the manner pursued on 

 Bayou Pierre, as were also the surrounding swamps, but not a single 

 trace of a former brood was obtained in the stream or in the swamps 

 which were swept over and over again. 



"All of the deductions in this report are necessarily based upon the 

 traces of the last brood of gnats, as none could be found at the time of 

 my investigation, nor had any been seen for a period of three weeks; there- 

 fore, the only thing to do was to study the conditions of the streams 

 and swamps and then use the traces of the last brood as a clue to some 

 of the habits of the insect in question. 



"Some reports obtained from the planters of the Bayou Pierre section 

 will be of interest. The planters report that as yet the gnats had not 

 appeared in very great numbers. Only a few specimens had been ob- 

 served. This brood is said to have occurred about three weeks before my 

 investigation. Last year, about the first of March, during very high water, 

 the gnats were very abundant along the lowlands of Bayou Pierre as well 

 as in the pine woods along its banks. 



"Many horses and mules were killed in the outbreak and one man 

 states that he lost three mules from the attacks of the gnats, on March 8, 

 1905. From all reports, it appears that the gnats made their worst at- 

 tacks on stock during the hours of early morning and late evening. The 

 outbreaks usually lasted from a week to ten days. 



