HOW TO KNOW THE IMMATURE INSECTS 



119b. 9th abdominal tergum without a pair of cerci and without an 

 unpaired spine 120 



120a. 10th adbominal segment in front of anus provided with a pair 

 of cushioned and adjacent lobes separated by a median, lon- 

 gitudinal groove often marked at the anterior end by a small 

 transverse sclerome. (See Figs. 326 and 330) 121 



120b. 10th abdominal segment in front of onus without a pair of soft/ 

 oval lobes separated by a longitudinal groove. 

 (See Fig. 333) 125 



121a. Head protracted; mandible dentate -. . . 122 



121b. Head retracted; mandible not dentate 123 



122a. Thoracic spiracle pushed forward to the anterior margin of pro- 

 thorax. Fig. 326 Family PTINIDAE 



About 550 species have been describ- 

 ed. The larvae are scarabaeoid form 

 and feed upon dead and dried animal 

 and vegetable matter. The storehouse 

 beetle, Gibbium psylloides (Czempin- 

 ski), is a most destructive species to 

 stored products. Several species are 

 reported as inguilines in ants' nests. 



Fig. 326. Niptus sp. 



122b. Thoracic spiracle not reaching, anterior margin of prothorax. 



Fig. 327 Family ANOBIIDAE 



There are around 1,200 described 

 species. The larvae are scarabaeoid 

 form, very small, and living in dead 

 and usually well-seasoned hard woods. 

 Many feed on animal and plant pro- 

 ducts. The furniture beetle, Anobium 

 striatum Olivier, the cigarette beetle, 

 Lasioderma seriicorne (Fab.) and the 

 drugstore beetle, Stegobium pamceum 

 (L.) are serious pests. 



Fig. 327. Nevermonnia dor- 



catomoides Fisher. (Redrawn 

 from Boving & Craighead) 



119 



