6 



States several other parasites have been reared from or with it.^ In 

 addition, three or four predaceous insects^ have been detected under 

 circumstances to indicate that they hved upon the liark-beetle larvse. 

 Some idea of the vahie of these parasites in lielping to restrain the 

 excessive multiplication of their host nvay he had when it is stated that 

 in a case tliat recentl.y came under the writer's observation at Wash- 

 ington, 92 parasites were reared from infested twigs, against 72 beetles. 

 All but two individuals of the parasites were Ghiropachys colon (tig. 4). 



REMEDIES. 



Borers are among the most troublesome insects with which the fruit- 

 tree grower has to deal, and the present species is, perhaps, the most 



dilficult one to control by ordinary measures. 

 The time-worn remedy of cutting borers from 

 the tree, valual)le for large forms, and still 

 practiced against many species, is useless 

 against the fruit-tree bark-beetle. Prevent- 

 ive measures that may be successfully used 

 against other boring species are also ineffec- 

 tual. The main diliiculties in the way of 

 treating this species are its minute size, its 

 . , ,, , .„ , ,. , extreme abundance, and the tact that it is 



larged (author s illustratKiiii. ' 



not restricted to any portion of a tree, and 

 that oviposit ion occ^ui'S i)racticall3' throughout the entire season. 



Clean culture a prime requisite. — Foremost among the requisites is 

 clean cultural practice ; in fact, little of really substantial benefit can 

 be accomplished without it. Brushwood and other remnants of 

 orchards, as has already been shown, are t(io frequently left to serve as 

 centers of infestation to sound trees. As soon as infested trees are 

 seen to be actually drying, it is practicallj^ useless to do anything to 

 save them. Trees may recover from slight attacks, and the fruit-grower 

 must use judgment in discriminating l)etween what will recuperate and 

 what are beyond hope of recovery, and should cut out and burn the 

 dying and dead growth as often as detected. 



For the peiiect protection of one kind of fruit tree all other kinds 

 which are permanentl3^ injured must be destroyed. If, for any reason, 

 such measure l)e neglected during the sunnner, the injured growth 

 should at least be burned before the following spring, as by such 

 means all the hibernating insects will be destroyed. 



' Ghiropachys colon Linn., Raphitelus maculatus Walk., Eurytoma hicolor 

 Walsh, Kiiryto)na (rassinemn Asbni., Heydenin tmica Cook, Hemiteles scolyti 

 Aslini., ridtyynrlnis (?) scolyti Aslini., Tctrfistlchus scolyti Ashm. (secondary), 

 and two or more new species of Enpelmus. 



- FJiyllohfrniis dislocatus Say, Clems ichneuntoneus Fab., TlKiiiasiniits sp., 

 unknown clerid larva, llltizojthrums hipunctatus Say. The American species 

 have mostly been reported by Dr. A. T). Hopkins and the writer. 



