ARTHROPODA 



2 l i 



spread, measure from ten to thirteen and a half centimeters 

 from tip to tip. The larva is better known perhaps than the 

 adult fly; it is much used by anglers for bait under the name of 



FlG. 211. i/, Myrmeleon formicarius ; an adult ant-lion; b, the larva. (From Claus and 



Sedgwick's Text-book.) 



"dobson." The larvae are aquatic and abundant under stones 

 in swiftly flowing- brooks ; they attain a length of seven and a 

 half centimeters, are carnivorous in habit, feeding on the larvae 

 of other insects, and they lead this 

 aquatic life for about three years. 

 Then they come out of the water, 

 pass into the pupal stage, and in 

 the course of a 

 few weeks become 

 adult insects. 



The adult ant- 

 lions (Fig. 21 1 )are 

 graceful insects, 

 somewhat resem- 

 bling the dragon 



flies ; their larvae, to which the popular name 

 is particularly applied, are conspicuous because 

 of the little pitfalls they dig in the sand for 

 catching their prey. The larva lies buried at 

 the bottom of this pit with its jaws projecting, 

 and when an ant or similar animal steps on the 

 edge of the hole, the sand giving way it falls 

 into the jaws of the ant-lion. The scorpion flies 

 (Fig. 212) are so called because of the peculiar shape of the pos- 

 terior part of the abdomen in the male ; this is not unlike the cor- 

 responding region in a scorpion, but is not provided with a sting. 



Fir,. 212. Panorpa communis, tf, a 

 scorpion fly. ( From Ludwig-Leunis" 

 Synopsis der Thierkunde.) 



213. A caddice- 

 fly larva, partly pro- 

 truding from its case. 



m Ludwig-Leu- 

 nis' Synopsis der 

 Thierkunde. 1 



