. Annual report of the Regents. y parasite in the lunate long sting,Thalessa lunator Fabr. This beneficial insect is of great aid inkeeping the Tremex under control. In the trunk of one smallelm I found the remains of 13 ovipositors. In their efforts toreach the numerous borers in the tree, the females had driventheir long ovipositors so far into the wood that they were unableto withdraw them. Another insect which infests debilitated elms is known as theelm borer, Saperda tridentata Olivier. The larvae of this beetlerun their burrows under the bark and in the sap wood of the 20 NEW YORK STATE
. Annual report of the Regents. y parasite in the lunate long sting,Thalessa lunator Fabr. This beneficial insect is of great aid inkeeping the Tremex under control. In the trunk of one smallelm I found the remains of 13 ovipositors. In their efforts toreach the numerous borers in the tree, the females had driventheir long ovipositors so far into the wood that they were unableto withdraw them. Another insect which infests debilitated elms is known as theelm borer, Saperda tridentata Olivier. The larvae of this beetlerun their burrows under the bark and in the sap wood of the 20 NEW YORK STATE MUSEUM trunk, not many penetrating to a greater depth than an burrows may become so thick as to girdle trees two orthree feet in diameter. An infested elm may be recognized bythe patches of unhealthy bark—in case of a bad infestation largepieces become loose and scale off easily. The beetle is usuallyless than J inch long, and of a dull slate color, with the thoraxand wing covers margined with dull orange (fig. 6).. Fig. 6.—Saperda tridsntata (twice natural size)NATURAL. ENEMIES OF ELM-LEAF BEETLE. The natural checks which serve so well, to keep thousands ofinsects under control which otherwise would be very destructive,are unable to reduce the numbers of this beetle to a relativelyharmless figure. One of the more important natural agents isthe fungus, Sporotrichum entomopMliim Peck, which has beenobserved developing on many beetles in this city. Like the dis-ease of the chinch-bug, caused by the allied fungus, SporotHeliumgldhulifei^um Speg., the one attacking the elm-leaf beetle requiresmoist atmosphere for its development. Beetles in close breedingjars or those found under the bark of trees and similar dampplaces succumbed readily to the disease. On account of the cli-matic conditions not being ordinarily favorable to the rapidgrowth of this fungus, it has a relatively slight value as a naturalcheck upon the elm-leaf beetle. Several insects are known to prey e
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