PARASITES OF SPIDERS AND THEIR EGGS. ' 53 



cause of such a situation, he found an ichneumon fly walking cautiously 

 down the thread towards its victim. AVhen close to the spider she touched 

 it with her antennae, whereat Drassus dropped a few inches lower. 

 Method This movement gave better opportunity to see the ovipositing of 

 Dositine- *^® parasitic egg. The fly, having apparently ascertained that 

 she had found a suitable subject, turned round and walked back- 

 wards until close to the spider, where she paused a few moments, and 

 then deposited her egg on its abdomen close to the cephalothorax. 



Mr. Bignell boxed both insect host and aranead guest, and took them 

 home. Two days afterwards the egg had hatched, and the larva was about 

 one line in lengtli. A day or two thereafter both larva and spider were 

 found dead. The strangest fact in the above story is that the spider would 

 permit the fly to thus approach it without attack. The insect would seem 

 to have been within its power, yet it forebore to strike. Was it made 

 inactive by fear? By what spell did the mother parasite procure this rare 

 exemption ? 



The same gentleman, while beating for larvae of Lepidoptera, found an 

 Orbweaver, Epeira cucurbitina Clerck, which had been attacked by an ex- 

 ternal parasite. This lay like a sack across its guest's 

 back, reminding one of a miller's man carrying a ^«^£s^3Ec5Biliii?e^> 



bag of flour. It was taken May 22d (1882), and on . 



the 24th it was full fed. On the 2od it was figured pig- «■ Parasitic larva of 

 and described (Fig. 40), and foumi to have no legs, " ^^^ 



but in place thereof had sucking discs, two on the second segment and 

 four on the third and fourth. Six of these occupied the usual 



A Para- place of the legs of larvae ; the other four were half covered with 



site 



T the skinfold usually seen on lepidopterous larvae. On its back 



were tubercles, the first on the fourth segment, the others on 

 the seven following ones ; each tubercle was surmounted with two rings of 

 booklets, with three or four in the centre. These served the larva to sus- 

 pend itself from the round snare while feeding on its victim, and to hold 

 on to the web after it was consumed. When all the juices of the spider's 

 body had been extracted the legs and empty skin were allowed to fall down. 



The larva then commenced to make itself a cocoon which was finished 

 by the third day, during which time the tubercles performed a prominent 

 role, having to do the work of the claspers of an ordinary caterpillar. 

 When a tentacle, attached to the silken cord, had to be removed, the 

 booklets were withdrawn into the tentacle, which at once became disen- 

 gaged and ready to make another attachment. 



The anal segment often played an important part by being brought 

 round to the assistance of the mouth ; this act was first seen while the 

 larva was feeding, and its purpose was to disengage some adhering portion 

 of the spider from its jaws. Afterwards it was frequently used while 

 spinning to unite the silk to some narrow part of the cocoon, where the 



