18 FIFTH REPORT OF THE ENTOMOLOGICAL COMMISSION. 



Coleopterous enemies of borers. — Besides woodpeckers aud other birds 

 which pick insects out of bark, and thus do great benefit to forestry, 

 and besides ichneumon and Chalcid parasites of borers, there are many 

 carnivorous grubs which prey upon the borers. 



Among the external though less known enemies belonging to the 

 order of beetles, which Perris enumerates from his extended observa- 

 tions on their habits, are a large number which live under the bark of 

 trees. I quote his accounts of them, premising thac we have similar 

 insects with like habits in this country ; and though the list of scientific 

 names seems formidable, yet there are no common names for them. I 

 use nearly his own words, with occasional interpolations of English 

 names. 



Wheu one of the Scolytids injurious to pines (the Bostriclms stenographus) lays its 

 eggs under tlie barli, the Platysoma oblongiun introduces itself by the hole which has 

 given entrance to the first named insect ; it lays its eggs in the gallery of the Bostri- 

 chus, and from those eggs are born the carnivorous larvae which devour those of the 

 wood-eating beetles. Other beetles conduct themselves in the same manner in war- 

 ring against other Scolyti. The larvae or grubs of Plegaderiis disclsus destroy the 

 young of Crt/pturgus pusillus ; another wood-eating beetle, the Auloniiim sulcatum, is 

 the deadly enemy of Scolytus destructor, so formidable a foe to shade trees ; Aulotiium 

 bicolor attacks Bostrichus laricis ; Colydium bicolor preys upon the Bostrichus of the 

 larch; Colydium elongatum on Platypus cylindrus ; Bhizophagus depressus on Blastopha- 

 gus piniperda and B. minor ; LwmophUeus hypobori on Hypoborus ficus ; Hypophlceus 

 pinion Bostrichus stenographus ; and finally Hypophlceus linearis on Bostrichus bidens. 

 Who will not be struck by these antagonisms ? Who will not admire this infallibility 

 of instinct which causes these insects to discover the tree attacked, aud perceive 

 among the species wh ich the tree conceals the victim which has been assigned to 

 them ? 



Other beetles exhibit the same sagacity. The larvae of several Elaterids (wire- 

 worms) and those of Clerus mutillarius and C. formicarius make war on those of some 

 longicorn beetles of the oak, the elm, alder bush, and the pine. The Opilus mollis 

 and 0. domesticus are the enemies of the borers which mine our floors and ceilings ; the 

 Cylidrus albofasciatus and the Tillus unifasciatus prey on Sinoxylon sexdentatum and on 

 Xylopertha sinuata, which seek the diseased branches of the vine and those of several 

 trees; the Tarsostenus univitlatus AttackH the Lyctus canaliculatus, injuring our timber 

 works ; while the Trogosita mauritanica destroys the grain moth. 



In an article in the American Naturalist (xvi, 823) on inquiline wood- 

 borers, or those which usually take up their residence in mines or gal- 

 leries made by true wood-borers, Mr. E. A. Schwarz finds that the com- 

 mon Plati/pus compositus may itself bore in the thick bark of pine 



ments from Australia were received at Los Angeles by Dr. D. W. Coquillet, another 

 of the agents of the division." » » » 



The people of California are enthusiastic over the grand success of this effort, and 

 the Vedalia is spreading with remarkable rapidity and clearing the trees in its wake. 

 Prof. W. A. Henry, director of the Wisconsin Experiment Station, in a recent report 

 to the Department of Agriculture writes: 



"A word in relation to the grand work of the Department in the introduction of 

 this one predaceous insect. Without dnubt it is the best stroke ever made by the 

 Agricultural Department at Washington. Doubtless other oftbrts have been pro- 

 ductive of greater good, but they were of such character that the people could not 

 clearly see and appreciate the benefits, so that the Departmeut did not receive the 

 credit it deserved. Here is the finest illustration possible of the value of the Depart- 

 ment to give people aid in time of distress. And the distress was very great indeed." 



