60 THE GYPSY MOTH APPENDIX. 



DlPLODUS LURIDUS * (Stal). 



The members of the group of insects to which this species 

 belongs possess such marked predaceous habits that they 

 have received the very appropriate name of "assassin 

 bugs. " The species under consideration is one of the most 

 rapacious of our predaceous bugs, and, while occurring in 

 but limited numbers, its great activity and almost abnormal 

 appetite render it a formidable enemy to several forms of 

 insect life. 



On May 12, 1896, I took a nearly full-grown nymph in 

 the act of feeding upon a partly grown tent caterpillar. 

 An inspection of the tree in the vicinity of the web showed 

 several other nymphs engaged in the work of destroying 

 the caterpillars. The nymphs did not enter the webs of 

 this caterpillar, as do some of our predaceous Pentatoniids, 

 but devoted their attentions to such larvae as were more or 

 less isolated and at some distance from the web. One of 

 these nymphs was reared upon tent caterpillars until May 

 18, when it assumed the mature form. 



Later in the season several imagoes of this species were 

 found attacking gypsy moth larvae, as well as those of 

 CUxiocampa amerieana. From a female confined in a breed- 

 ing cage with a male imago from June 5 to 10 I obtained 

 June 12 a cluster of thirty-four eggs, which were laid in a 

 compact mass (Plate 2, Fig. 1) shaped like the frustum 

 of a cone. | The eggs were closely cemented together and 

 to the surface on which they were deposited, and could only 

 be separated with difficulty. The eggs (Plate 2, Fig. 2) 

 may be described as follows : 



Length, 1.9 mm. ; width at base, .4 mm. ; at top, .3 mm. ; 

 somewhat curved, widest and rounded at the base, truncate 

 at the top. The eggs forming the outer layer are of a 

 burnt sienna color, those on the inside being of a pale 

 amber. The upper end of the eggs is of a pale yellowish 

 color, and bears immediately within the circumference a 



* For the identification of the species I am indebted to the kindness of Prof. P. 

 R. rhler. 



t Mr. Robert A. Cooley, assistant entomologist, Massachusetts Hatch Experiment 

 Station, informs me that he has found the eggs of this insect attached to the under 

 surface of leaves of Ostrya virginica and Betula lenta. 



