Vol. Xxix] ENTOMOLOGICAL NEWS. 265 



were not directed to them by their motion. This covering 

 usually consists of desquamated particles from the plant 

 roots, which, becoming attached to the hairs of the larvae, 

 causes them to resemble small pieces of decayed vegetable 

 fibre. This is especially true of larvae found in small land- 

 locked pools at the side of a river, where the water is usually 

 stagnant. 



The young larvae that emerged from eggs deposited by fe- 

 males in confinement rarely lived longer than twenty-four 

 hours and never seemed to take any food. 



Although we have not been able to study the development 

 of the larvae under natural conditions, it is nevertheless quite 

 manifest from laboratory observations that they develop very 

 slowly. Young larvae that have been removed from their en- 

 vironment and placed in breeding jars containing Pistia plants 

 readily attached themselves but never lived longer than eight 

 days, showed no appreciable increase in size and did not pu- 

 pate. Large larvae that were apparently mature and ready to 

 pupate also readily attached themselves to the plants when 

 placed under these conditions, but they also seemed to be 

 rather short-lived when confined in breeding jars. Usually 

 those that failed to pupate within seven or eight days after 

 being placed in the jars died before pupation. A few lived 

 for longer periods of time and succeeded in reaching the pupal 

 stage. One full grown larva attached to a plant lived in a jar 

 for nineteen days and then pupated. In confinement they 

 seem to thrive better in water that is stagnant and quite foul 

 with vegetable debris than in clean fresh water. Naturally 

 this is clue in part to the increased food supply found in the 

 water containing the extraneous matter. 



When placed in a dish containing no plant life the larvae 

 are capable of living for a few days as free living larvae, 

 somewhat similar to those of Cnlc.v. They hang head down- 

 ward with the air-tube at the surface of the water, going back 

 and forth from the bottom to the surface to feed and breathe. 

 Very often they will hang from the surface for long ;>eriod> 

 of time and they also seem to be capable of remaining at the 



