ANNALS 



OF 



The Entomological Society of America 



Volume VI DECEMBER, 1913 Number 4 



THE EXTERNAL ANATOMY OF THE SQUASH BUG, 

 ANASA TRISTIS DE G:' 



' By Daniel G. Tower, B. S. 



Amherst, Massachusetts. 



INTRODUCTION 



In writing this article the chief aim is to endeavor to supply 

 a reference work on the external morphological characters of a 

 typical Heteropterous insect. For this reason the common 

 squash bug has been selected as it is widely distributed, well 

 known as a pest, and is readily obtainable for study. 



In order to make the paper as complete as possible the 

 morphologists' and systematists' terms have both been used, 

 except in referring to the wing venation (the systematists' terms 

 being lacking in the fore-wing and the morphologists' in the 

 hind wing). 



At this point I wish to express my gratitude to Dr. H. T. 

 Fernald and Dr. G. C. Crampton for their many helpful sug- 

 gestions and assistance in preparing this paper. 



ANATOMY 



Head 

 The sclerites of the head capsule of the squash bug are 

 solidly fused together making it impossible to do more than to 

 describe the general regions of which the head is composed. Of 

 these the occiput (occ), (PI. LV, f . 1.) lies behind the ocelli (oc) and 

 forms the posterior portion of the head surrounding the occipital 

 foramen. It is marke(i off by a shallow transverse groove, from 



* Contribution from the Entomological Laboratory, Massachusetts Agricul- 

 tural College. 



427 



