310 Phylum Arthropoda 



they produce healthy bugs. Five species of Microvelia and two species 

 of Velia have been successfully reared on a straight diet of cockroaches. 

 Several specimens of Curicta have been carried from the 3rd instar to 

 the adult on this diet while adult Nepa, Curicta, Ranatra, Velia, and 

 Microvelia have been kept through the winter. 



Immediately upon hatching the nymphs are large enough to make a 

 meal for Microvelia or Velia, while those a week or two old serve nicely 

 for the larger waterbugs. If one has access to a place infested with cock- 

 roaches it is a simple matter to catch nymphs. A space on the floor is 

 cleared, a few bits of food placed there and covered with a piece of 

 cardboard or beaverboard. After the lights have been turned off a few 

 minutes they may be turned on, the cardboard lifted, and dozens of the 

 nymphs killed or crippled with a fly swatter. The clean floor makes 

 them readily visible and they are easily picked up with a forceps. Often 

 they will come in numbers while the lights are on and even during the 

 day. The scattering of food particles or even sprinkling of water on the 

 floor will attract them. They may also be trapped by placing a heavy 

 paper funnel in a deep bottle, but specimens caught in this manner are 

 unsatisfactory for they get wet and for that reason sink through the 

 surface film of the water. Microvelia and Velia will catch living organ- 

 isms beneath the surface film, but they do not care for flies, cockroaches, 

 or other similar food that does not rest upon the surface. Because of this 

 it is preferable to kill the nymphs just before feeding time. If placed on 

 their backs they are not likely to sink and in this position the parts easiest 

 to pierce are uppermost. 



To insure a continuous supply of food, adult cockroaches bearing egg- 

 cases may be trapped and the cases removed to containers with damp 

 blotting paper or other damp material on the bottom. Corked bottles 

 or glass containers with rather tight-fitting lids will serve the purpose. 

 Upon hatching the nymphs may be reared by giving them a piece of 

 apple every few days. 



j. g. N. 



VELIA WATSONI* 



FIFTH-STAGE nymphs and adults of Velia watsoni, taken among the 

 roots of smartweed and other weeds and grasses on the moist banks 

 of pools in the bed of a small stream, were placed in tin boxes with damp 

 vegetation. Little trouble was experienced in keeping the bugs in cap- 

 tivity and in rearing them. 



Mating in captivity has taken place during every month of the year, 

 but has been more frequent during the warmer part of the season. 



♦Abstracted from an article in Canad. Ent. 57:107, 1925, by William E. Hoffmann, 

 Lingnan University. 



