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includes twelve American States and two provinces of Canada. 

 It probably attacks all species of pine in the Canadian and 

 transitional zones, and also black spruce, Norway spruce, Abies 

 menziesii and larch. Normally only dying or recently dead trees 

 are attacked. The beetles have never been seen in flight or 

 leaving a tree, but are probably attracted by the resinous odour of 

 injured trees. Infestation may be very severe, 125 to 150 beetles 

 having been found in a white pine log 7 feet long and about 4 inches 

 in diameter. The upper part of the tree, where the bark is not too 

 thick, or the larger limbs are usually selected for attack. The entrance 

 hole is perfectly round and is usually made by the male closely followed 

 by a female ; when the sap-wood is reached a chamber is excavated, 

 between it and the outer bark, where pairing takes place. 



From this chamber the female makes a longitudinal, primary gallery 

 from 4 to 6 inches long. The egg-laying period extends from 25 to 35 

 days, and at a temperature of 69° F. the eggs take about 5 days to 

 hatch. The larvae on emerging burrow into the cambium at right 

 angles to the primary gallery. In cases of severe infestation, the larval 

 galleries form a mass of interwinding mines. The pupal period lasts 

 about 5 days. The adult beetle remains in the pupal chamber 4 or 5 

 days and then works in the cambium some time before emerging. 

 At Ithaca two generations have been recorded ; under favourable 

 conditions a third is possible. The beetles of the late brood gradually 

 become dormant as winter sets in and remain in the bark. 



Wet seasons are detrimental to the development of the larvae and 

 cause the beetle to be attacked in all stages by fungi. Predaceous 

 enemies include the Clerid beetles, TTianasimus dnbius, F., and Enoclerus 

 quadriguttatus, Oliv., a Histerid, Cylistix cylindrica, Payk., the Staphy 

 linids, Xantholinus ce'phalus, Say, Quedius laevigatus, Gyll., and 

 Homolota sp., a Tenebrionid, Hypophloeus parallelus, Melsh., and 

 probably also the Clerids, Trichodes simulator and Clems quadriguttatus, 

 Oliv. The following species have been taken in burrows, but may only 

 be associates : the Histerid, Platysoma coarctatum, Lee, the Curcu- 

 lionids, Dryophthorus corticalis, Say, and Cossonus sp., the Cucujid, 

 Brontes dubius, F., the Eucnemid, Deltometopus amoenicornis, Say, 

 the Staphy linid, Anthophagus {Geodromicus) strictus, Fair., and an 

 Anthocorid bug, Dufouriellus ater, Dufour. Mites and Nematodes 

 have been found on the beetles, but the efiect of their presence is not 

 known. Black carpenter ants readily devour the beetles. Parasites 

 include : Hymenoptera, Roptrocerus eccoptogaster, Ratz., Spaihius sp., 

 Microbracon sp. and a Chalcid ; Diptera, an Agromyzid and 

 Phyllomyza sp. 



Removal of the bark will cause the death of all pupae and larvae, 

 and if done carefully, will destroy a great nimiber of adults and thus 

 lessen the severity of future attacks. The attacks may also be pre- 

 vented by placing the newly felled logs in water. The following 

 beetles are often found in the part of the tree infested by Ips-pini : 

 Monochamus {MonoJiamynus) scutellatus, Say, Rhagium lineatum, Oliv., 

 Pytho americanus, Kirby, Ips longidens, Swaine, Pityogenes sp., and a 

 Buprestid. In other parts of the tree the following may be found in 

 addition : Ips caelatus, Eich., /. calligraphus, Germ., Gnathotrichus 

 materiarius, Fitch, Hylastes {Hylurgops) 2nnifex, Fitch, and Mono- 

 chamus {Monohammus) confusor, Kirby. 



