Mesovcliidae 305 



available. However, later a change was made to the larvae of Tribolium 

 confiisum, the confused flour beetle. This insect proved to be a very 

 satisfactory food supply for Reduvius, since it could be reared in any 

 numbers desired, and in a short time, on common flour. The greatest 

 objection to its use was that occasionally a larva would crawl upon 

 and kill or cripple a molting Reduvius. 



M. E. D. 



Family mesoveliidae 



HOW TO REAR MESOVELIA 



C. H. Hoffmann, U. S. Bureau of Entomology and Plant Quarantine 



A DULTS were collected and divided according to species, after which 

 l\ they were isolated in finger bowls containing lake water and several 

 pieces of decayed cat-tail leaf available for oviposition. The water was 

 changed daily. Fruit flies or houseflies served as food. When a large 

 number of eggs were laid in the stem provided, it was then removed to 

 a petri dish and given a number that corresponded with that on a card. 

 Permanent data were, of course, kept on cards. An eye dropper was 

 used to change the water in the egg containers, and a dropper or two 

 full of water was sufficient for the daily change. 



The little nymphs that hatched out were isolated in small stender 

 dishes 1 inch deep and 2 inches in diameter and in some other stenders 

 slightly larger. In the case of individual rearings, each stender was 

 supplied with a single dropper full of water, a small piece of white card, 

 and two adult fruit flies for food. The card served as a support for 

 the small nymphs, and, being white, did not interfere in the search for 

 molted skins. The bugs flourished with a daily change of water and a 

 fresh supply of food every other day, the remains of the previous 

 feeding being removed at this time. 



It is often difficult to find the newly hatched bugs, because they cling 

 to the surface of the cat-tail stem. In changing the water of the egg 

 cages daily, therefore, the fresh water was squirted directly on the 

 surface of the stem and the young washed off into the clear water. These 

 were then easily transferred to stenders by tilting the petri dish and 

 placing the tip of a pair of curved forceps under the nymph, thus lifting 

 it out together with a drop of water. Mass rearing in finger bowls was 

 tried and found to be satisfactory. All rearings were carried on in a 

 room which maintained a temperature of approximately 24 C. 



Houseflies served as good food but scarcity during the winter neces- 

 sitated the finding of a food supply plentiful enough to care for many 



