MORPHOLOGY OF THE BARK-BEETLES OF THE 

 GENUS GNATHOTRICHUS EICHH. 



By KARL E. SCHEDL 



CONTENTS 



PAGE 



I ntroduction 2 



Abstracts of the literature up to date 3 



A. The genus 3 



B. Gtiathotrichus iiiatcriariiis Fitch 6 



C. Gnathofrichxts rctitsus Lee 11 



D. GnatJwtrichus 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 2i 



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 64 



The larvae 65 



The chitinous skeleton 70 



The head 70 



The appendages of the head 7i 



The antennae 7i 



The mouthparts 7i 



The thorax 77 



The abdomen 77 



The spiracles 78 



The thoracic and abdominal setae 78 



The alimentary canal 80 



The pupae 81 



The head 83 



The thorax 83 



The abdomen 84 



Smithsonian Miscellaneous Collections, Vol. 82, No. 10 



I 



