THE OTTAWA NATURALIST 



VOL. XXV. OTTAWA, JANUARY, 1912 No. 10 



POPULAR ENTOMOLOGY. 



The Engraver Beetles (Family Ipid^;). 



By J. M. Swaine, Assistant Entomologist, Division of 

 Entomology C.E.F., Ottawa. 



Beetles of the Family Ipidse have been described from almost 

 every portion of this continent from Mexico to Alaska, and will 

 probably be found wherever their food-plants occur. Many 

 species are described from the West Indies, and a very large 

 number from Central and South America, and from Europe. 

 Many are known from Japan, Australia, Ceylon, South Africa 

 and elsewhere. A few species seem almost world-wide in dis- 

 tribution; others are known only from small regions. A number 

 of species, e.g. , Eccoptogaster rugulosus and Xyleborus dispar, have 

 been introduced into America from Europe. 



The North American members of the family Ipidas are 

 usually somewhat elongate and cylindric in form, and brown 

 or black in colour. They vary from one to a little over eight 

 millimeters in length. Crypturgus pusillus is one of the smallest 

 species, and Dendroctonus valens probably the largest. The legs 

 are rather small and weak, as becomes their habits. The anten- 

 nae are short and geniculate, with an extremely large club, which 

 is usually annulated. The vast majority of the Ipidae cut their 

 breeding tunnels in the bark or wood of trees or shrubs. The 

 chief North American exceptions are referred to below. 



Their burrows are of great interest, and often of remark- 

 able regularity and beauty. Those of many species are 

 so characteritsic that it is often easy to determine which 

 species has been at work from an examination of the tunnels and 

 galleries alone. 



A large portion of our North American species infest conif- 

 erous trees, the pines and spruces being especially subject to 

 attack. Of deciduous trees, the oak, beech and hickory suffer 

 severely, and there is scarcely a northern tree but serves as 

 food-plant for one or more species of this family. As a rule 



