PREDACEOUS HEMIPTERA, 



395 



upon other insects. The first stumbling block met with, in 

 attempting to raise these insects, was the provision of a 

 suitable breeding-cage, and many attempts made, both dur- 

 ing 1894 and 1895, to breed them in confinement in boxes, 

 jars, etc., gave only negative results. With the establish- 

 ment of an insectary at Maiden and increased facilities for 

 out-door experimentation, in June, 1895, other attempts 

 were made to construct a cage in which one might rear 

 these insects under the nearest possible approach to natural 

 conditions. After several experiments a breeding-cage was 

 devised which gave the desired result (Plate 61, Fig. 10). 

 This consists of a fine wire gauze, semi-ellipse, fastened 

 tightly at the sides to a small tree trunk, and closed at the 

 bottom by a tight-fitting wooden base, the cage, on the 

 whole, being quite similar to those used in rearing the pre- 

 daceous beetles. The top is covered by a piece of cloth, 

 held firmly in place by a rubber band, wdiile a small wooden 

 hoop is placed around the inside of the top of the cage, in 

 order to prevent the band from pulling the cage out of 

 shape. The cages used are twelve inches in height by 

 four inches in width, the maximum distance of the outer 

 part from the tree being five inches. In cages like the one 

 described the bugs Avere fed on Lepidopterous larv?e and 

 reared through their diff'erent stages. For many careful 

 notes on the feeding habits of these insects I am indebted 

 to Mr. H. L. Frost, who assisted me in the work. In 

 these cages we were able to successfully carry specimens of 

 P. serieventris through all their transformations.^ 



Life History of P. serieventris TIM. 

 The Egg. — The eggs have been found deposited in small 

 clusters on the bark of trees, cn leaves and on the burlap 

 bands. When first laid they are of a glistening, whitish- 

 gray color, but this soon changes to a bronze, which grows 

 darker as the embryo develops, up to within about a day 

 previous to hatching. At that time the eggs grow lighter 

 in color, possibly due to the entrance of air into the shell. 

 Each egg-cluster contains from ten to thirty eggs, t^vo or 

 three clusters being laid by each female. The eggs (Plate 



