3 6 4 



COLLEGE ZOOLOGY 



SUBORDER 8. RHYNCHOPHORA. (SNOUT-BEETLES, Fig. 304.) 



- The RHYNCHOPHORA are the curculios, weevils, bill-bugs, and 



snout-beetles. The front of the head is prolonged into a beak 



or snout, with the mouth-parts at the end. Weevils (Fig. 304, A) 



attack many varieties of 

 fruits, nuts, and grain. 

 The bark-beetles (ScoLY- 

 TID^E) are the most de- 

 structive of all insects 

 to forest trees, their 

 depredations reaching 

 a total of probably 

 $100,000,000 annually. 

 The genera Dendroc- 



tonus (Fig. 304, B) and 



Tomicus are the most 

 FIG. 304. Order COLEOPTERA. A, cotton- no torious 

 boll weevil. B, southern pine beetle, Dendroc- 

 tonus frontalis. (A, from Farmer's Bui. 189; Order IQ. Hymenop- 



D'ep?A gr ", PkinS ' BU1 ' 83> Bur ' Ent " "' S ' tera " - SAW-FLIES, 



GALL-FLIES, ICHNEU- 

 MON-FLIES, ANTS, BEES, WASPS (Figs. 305-312). Insects 

 possessing four membranous wings with few veins; first ab- 

 dominal segment fused or partly fused with thorax; mouth-parts 

 both mandibulate and suctorial; female with an ovipositor; 

 metamorphosis complete. 



There are about seventy-five hundred species of HYMENOP- 

 TERA inhabiting North America. They may be grouped into 

 suborders, superfamilies, families, subfamilies, etc., but because 

 of the limited space that can be devoted to them in this book, 

 only a few of the most important families will be considered; 

 these are the saw-flies (TENTHREDINID^E), the chalcid- flies 

 (CHALCIDID.E), the gall-flies (CYNIPID.E), the ichneumon- flies 

 (ICHNEUMONID^E), the bees (Apnxs), the solitary wasps (Eu- 

 MENID.E), the social wasps (VESPID^E), the digger-wasps 

 and the ants (FORMICIDJE). 



