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Kemner (N.A.). De ekonomiskt viktiga vedgnagande Anobierna. 



[The wood-boring Anobiiduo of economic importance.] Medd. 

 frdn Centralanst. for Jordbruksfdrsok, no. 109^ Stockholm, Entom. 

 Avdeln. no. 19, 1915, 43 pp., 33 figs. 



The following species are of economic importance in Sweden : — 

 Anobium striatum, OUv., Anohiiun pertinax, L., Xestobium rufovillosuni^ 

 de G., Ernohius mollis, L., and Ptilinus pectinieornis, L. After a descrip- 

 tion of their larvae and pupae, with a key to the former, the author 

 reviews the literature and subsequently gives an account of the different 

 species, based chiefly on his own researches. 



Anobium striatum, Oliv., attacks especially pine and fir trees, but 

 also birch, beech and alder, avoiding oak and ash on account of their 

 harder wood. It prefers wood in houses and seldom attacks timber 

 exposed to weather and wind. Swarming takes place in June or July. 

 The eggs hatch in two weeks, and the tunnels are at first only 1-3 mm. 

 wide and follow the annual rings, though in trees with more homo- 

 geneous wood, such as birch and alder, they are more irregular. When 

 the larva is full grown, they are 1*5-2 mm. wide ; the pupal chamber 

 is excavated close to, and parallel with the surface of the wood. After 

 a pupal period of a fortnight, the imago appears. There is only one 

 generation a year, individuals sometimes requiring two years to 

 complete their cycle. Anobium pertinax, L., is not of the same 

 importance as the preceding spe3ies. It attacks pine and fir, as well 

 as the softer wood of deciduous trees. The eggs are laid singly, and 

 the tunnels of the full-grown larvae are 3 mm. wide and often occur 

 so closely together that larger ones are formed. The pupal chamber 

 is generally perpendicular to the surface of the wood and measures 

 3"5 by 9 mm. Pupation takes place in summer, but the imago hibernates 

 in the pupal chamber and emerges the following spring. 



Xestobium mfovillosum, de G. {tesselatuyn, F.) seems to prefer oak 

 trees and occurs both in decayed trees and in houses, chiefly attacking 

 timber, less often, furniture. Swarming takes place in June, the eggs 

 being laid in crevices of the wood or in the exterior part of previous 

 tunnels. These, in the case of a full-grown larva are from 3"5 to 4 mm. 

 wide and are generally parallel to the longitudinal axis of the tree. 

 A generation probably requires two years, sometimes possibly three. 



Ernobius mollis, L., differs from the fore-going species in that 

 its tunnels are excavated between the wood and the bark. It 

 ranks next to Anobium striatum as the most common species in Sweden. 

 Its attacks are confined to pines and firs, and only those from which 

 the bark has been partially removed. Swarming takes place during 

 the whole summer, and the eggs are laid in crevices of the bark. The 

 larva wanders about on the bark in order to find a place suitable for 

 entering. The tunnels are at first only O'o mm. wide, soon widening 

 to 35 mm. They are comparatively short, measuring only 6 or 7 mm. 

 in length. The pupal chamber is 3 by 8 mm. and is situated close to 

 the surface and parallel to it. A generation requires probably one 

 year, but from eggs laid early in the spring a second generation 

 apparently develops, the majority of the larvae, however, hibernating. 



Ptilinus pectinieornis, L., is comparatively rare in Sweden, but 

 occurs in houses as well as in forests. 



