^2 NEW YORK STATE MUSEUM 



This giant hornet is hairy, black, with dark, yellowish orange 

 markings, the posterior extremity being mostly yellowish orange. 

 It is about an inch long. Gillanders records injury by this insect 

 in England to the young stems of ash, alder and elm, while Judeich 

 and Nitsche, writing of German conditions, report it as stripping the 

 bark from alder, linden, lilac, various willows, poplar, horse-chestnut, 

 larch and oak. 



The injury to the living twigs is usually very irregular in char- 

 acter and generally inflicted early in June or during July. It is 

 caused by the hornets gnawing away the bark down to the sapwood, 

 attacking twigs half an inch in diameter or less. The denuded 

 area may be mostly on one side of the twig and extend for lo to 12 

 inches, or it may be much more irregular and girdle the twig in 

 several places. In the latter instance the portion beyond the 

 affected part ultimately dies; in any event there is more or less 

 disfiguration. The tissues removed are doubtless used in the con- 

 struction of the paper nests, though some European authorities 

 hold that the main purpose of this attack is to obtain the sap flowing 

 from the wounds. 



The life history of this species is very similar to that of our native 

 Vespa maculata Linn., except that the nests are rarely 

 found hanging free, being more generally built within cavities in 

 a tree, in confined places in buildings, as between rafters and 

 underground. The nests in trees may consist of a series of combs 

 occupying the entire cavity, entrance to which is usually gained 

 through a small opening. The underground nests are entered by 

 a broad gallery which, turning up slightly at its extremity, gives 

 access to the lower portion of the nest. The " paper " used in 

 construction of the nest is considerably darker than that made 

 by Vespa maculata. 



Control measures. Ordinarily we would not expect serious 

 injury to follow attacks by these hornets and, taken as a whole, 

 it is probable that they are more beneficial than injurious. The 

 damage to specimen trees in lawns and parks is certainly annoying 

 and can be prevented only by reducing the number of the hornets 

 or by applications of protective materials to the trees. The Euro- 

 pean authorities mentioned above suggest trapping the hornets by 

 the use of long-necked flasks containing sweetened water. It is 

 also practical to trace the insect, especially in early niorning or on 

 cool days, and thus locate the nest, which may be destroyed by 

 the use of burning sulphur or carbon bisulfid, depending upon its 

 location. This can be best done in the early evening, and great 



