29 



Eckstein (K.). Beitrage zur Kenntnis des Hausbocks, Hylotrupes 

 bajulns, L. [Contributions to the Knowledge of H. bajulus.] — 

 Zeitschr. f. Forst -u. Jagdwes., lii, 1920, pp. 65-89. (Abstract in 

 Centralbl. Bakt., Parasit. n. Infcktionskr., Jena, lite Abt., Hi, 

 no. 4-8, 21st October 1920, pp. 136-137.) 



Hylotrupes bajulns, L., infests the timber of conifers ; its presence 

 in that of deciduous trees is not yet proved. It is usually found in 

 beams, less often in furniture. The larvae destroy the wood so 

 thoroughly as to threaten the very existence of the buildings involved. 

 The flight period of the beetles extends from mid-June to the end of 

 August. The eggs are deposited singly in cracks. The mines extend 

 in the sapwood up to just beneath the surface, a skin about | mm. thick 

 being left, and the interior of the beam being rendered spongy in 

 appearance. Pupation takes place in a larval mine. The larvae are 

 long-lived, the adults appearing from 3 to 11 years after oviposition. 

 The adults remain for 5-7 months in the wood before their flight 

 period, death occurring about 14 days later. Painting with carbohneum 

 is a useful protective measure. 



Burke (H. E.). U.S. Bur. Entom. The Pacific Oak Twig-girdler.— //. 



Econ. Entom., Concord, N.H., xiii, no. 5, October 1920, pp. 379- 

 384. 



The Buprestid, Agrilus angelicas, Horn, causes serious damage to 

 oaks {Querciis agrifolia) in California. It also attacks interior live oak 

 {Q. wislizeni), leather oak (Q. durata), canyon hve oak {Q. chrysolepis), 

 mesa oak {Q. engelmanni), Cahfornia black oak {Q. californica) and tan 

 oak {Q. densiflora). It is found from a few feet above sea-level to an 

 altitude of 6,000 ft. The eggs are generally laid singly on the smooth 

 bark of the twig near the end of the last year's growth at the end of 

 June or beginning of July. They hatch in from two to three weeks, 

 and the larvae begin boring under the bark. The complete life-cycle 

 requires about two years. By the middle of the first winter the mine 

 extends down the small twigs for about one to three inches. Some of 

 the larvae may reach the wood, whilst others still remain in the bark. 

 Mining is continued in the following spring and summer, the length 

 of the burrow being increased to from 6 to 12 inches. The winter is 

 parsed in the centre of the branch. In the succeeding spring the burrow 

 is lengthened by an inch or two, after which the larva turns and 

 retreats for several inches before entering the wood to form the pupal 

 cell, usually about the middle of May. The adults remain for several 

 days in the pupal cell before emerging in Maj' and June. 



The natural enemies of this beetle include the following Hymeno- 

 pterous parasites: — Cryptohelcostizus rufigaster, Cushm., Cryptoidens 

 fasciatiis, Ashm., Doryctes macuUpennis, Rohw., Callihormiiis sp., 

 Ptinobins agrili, Rohw., reared from the larvae, Metapelma spectabilis, 

 Westw., which may be a hyperparasite, TetrasticJnis anthracimts, 

 Ashm., of which as many as 17 larvae have been found in one larval 

 host, and Dinotus agrili, Rohw. 



The remedial measures advocated include pruning about April 

 before the beetles emerge. These prunings should be placed in a box 

 or barrel covered with a 16 mesh wire screen to permit the escape of 

 the parasites. Poison and contact sprays exercise a certain amount 

 of check by poisoning the beetles as they feed, but not sufiicient to 

 warrant their use against this beetle only. 



