67 



some of these are known as ant lions. ^Many of these larvae 

 excavated their pitfalls under the station building and many 

 small insects were preyed upon by them. The adults were taken 

 connnonly while sweeping with a net in tall grass. 



Several species of the large robber flies are common and it 

 is pleasant to watch their cunning w^ays. They do not appear 

 to have as much choice in taking their food as the wasp. They 

 station themselves on the ground or on a leaf or in some other 

 place and remain motionless until some insect comes near 

 ei.ough for them to make an attempt at capturing it, when they 

 are ofl:' like a dart and in full pursuit before the chosen victim 

 i^ hardly aware of their presence. They do not attend their 

 young as the wasps do, so the insects taken are used as food for 

 themselves. ^lembers of the order Odonata are known as mos- 

 quito hawks, and the name is an appropriate one, especially 

 for some of the larger species. Their food is not entirely mos- 

 quitoes it is true, but there are times at Cameron when a large 

 percentage is made up of these pests. Of the eighteen species 

 taken, Anax Junius is perhaps of most importance on account 

 of its abundance, but the others are worthy of consideration, 

 even the smallest of theni. While the large species are fee-ding 

 0:1 the wing the small ones are flying from ,one perch to another 

 along the edges of pools and ponds feeding on such small insects 

 ab they can procure. ]\I/osquitoes just emerged are not active 

 on the wing and are easily captured by such small species as 

 belong to genera Lestes, Ischnura and Enallagma. 



Ischnura prognata is an insect worth mentioning here be- 

 ef use it is considered as a very rare species. Hagen described the 

 male from a specimen which was taken in Virginia. The female 

 was not described until two years ago when Williamson procured 

 specimens near Nashville, Tennessee. His description is pub- 

 lished in Entomological News for September, 1903. Over twenty 

 specimens of this species were taken at Cameron in a single day, 

 tut, although I looked for it several .times thereafter, no more 

 were taken. On the day when specimens were collected the wind 

 was blowing from the south and all were found on the leward 

 side of the laboratory. It is a very weak flyer but on account 

 of its color is verv hard to see among the green foliage. Para- 



