82 Psyche [June 



there being from five to nine placed on each side over every distance 

 equal to its length. These threads are at times opposite each other 

 but are more often somewhat alternate. 



As the larva moves forward, the mucus tube collapses behind its 

 posterior end and remains as a flat, glistening trail. This trail is 

 more or less broken and ragged in places; sometimes the anchoring 

 threads break and sometimes the empty tube breaks as the larva 

 travels in and out and over and around obstructions, etc., in its 

 path. In fixing its mooring threads and building or adding to its 

 transparent covering the larva moves its head in a quick, jerky 

 fashion and altogether can glide along fairly rapidly. Excrement, 

 particles of fungus and other foreign matter which adhere to the 

 tube as the larva works in the fungus remain stationary and the 

 larva simply slides under them. 



Sometimes, but apparently not often, the larva reverses its for- 

 ward motion and slides backward for a short distance filling the 

 collapsed portion of the tube again. When it reaches its desired 

 position, it bites through the portion covering its head and starts 

 off in a new direction. If, in its forward movement, it has mis- 

 placed its mooring threads, it bites through them thus releasing 

 the anterior part of its tube. In this manner it travels over and 

 in the fungus feeding as it goes. 



Before pupating, larvae under observation anchored their tubes 

 in spaces between pieces of fungi in the cage using quite a few more 

 supporting threads for this operation than they used in anchoring 

 their tubes while moving and so placing them that the tube and 

 later the pupa was suspended in a network and did not touch any 

 part of the fungus. These threads were not numerous or close 

 enough, however, to even slightly resemble a loosely built cocoon. 



According to Ferris^ the larva of Sciophila unimacidata moves in 

 a similar way. An interesting account of the habits of this species, 

 which Ferris found associated with the fungus Polypoms versicolor, 

 together with descriptions and figures of the larva and pupa is given 

 in his paper, "Note pour servir a I'histoire de la Sciophila uni- 

 rnacw/afa Macq."^ 



lAnn. Soc. Ent. France 2; 7; p. 341-50, 1849. 

 2 Loc.cit. 



