MORPHOLOGY OF THE BARK-BEETLES OF THE 

 GENUS GNATHOTRICHUS EICHH. 



By KARL E. SCHEDL 



CONTENTS 



PAGE 



Introduction 2 



Abstracts of the literature up to date 3 



A. The genus 3 



B. Gnathotrichns materiarhis Fitch 6 



C. Gnathotr'tchns retusns Lee 11 



D. Gnathotrichus sulcatus Lee 13 



Synonyma 14 



Common names 15 



The chitinous skeleton of the adult 15 



General appearance, vestiture, color and size 15 



The head 19 



The appendages of the head 22 



The antennae 22 



The mouthparts 24 



The thorax 30 



The prothorax 31 



The mesothorax 34 



The metathorax 36 



The abdomen 41 



The spiracles 45 



The legs 45 



The wings • 49 



Mesathoracic wings or elytra 49 



Metathoracic wings or hind wings 53 



The male reproductive organs 57 



The female reproductive organs 63 



The alimentary canal ()4 



The larvae 65 



The chitinous skeleton 70 



The head 70 



Tiie appendages of the head 7;^ 



The antennae 7S 



The mouthparts 7Ji 



The thorax 77 



The abdomen 77 



The spiracles 78 



The thoracic and abdominal setae 78 



Tlie alimentary canal 80 



Tlie pupae 81 



The head 83 



The thorax 83 



The abdomen 84 



Smithsonian Miscellaneous Collections, Vol. 82, No. 10 



I 



