BIRCH INSECTS. 45 



BIRCH. 



(Betula spp. Family Betulacese.) 



Ornamental deciduous trees or shrubs grown chiefly for their bright green handsome 

 foliage. There are many species occurring in North America, Europe, north and 

 central Asia. Propagated from seed and readily transplanted. The bark and wood 

 are of value in the arts and crafts, and some species yield a sap used as a beverage. 

 The bark of B. papynfera is used in raaldng canoes and for tanning leather. 



A. BETTER KNOWN BIRCH PESTS LIKELY TO 

 BE IMPORTED. 



Eriophyes rurtls Cai. 

 (Birch Blister Mite. Eriophyidae; Acarina.) 



Hosts: Betula alba, B. pubescens, B. odorata. ^ 



Injury: Causes gall-like swellings of the buds. Ulti- 

 mately kills a tree. 



Description and biology: A four-legged blister mite 

 which forms gall-like swellings of the buds. Very easy 

 to introduce on nursery stock. 



Distribution: Europe, England (especially severe 

 around London). 



SoRAUEK, P. Handbuch der Pflanzenkrankheiten, 3d 

 edit. vol. 3, 1913, p. 117, 118. fig. 93. 



Magdalls carbonaria Linnaeus. 



(Birch Twig Weevil. Curculionidae; Coleoptera.) 



Hosts: Corylus avellana L., Prunus domestica L., 

 Betula alba L., Juglans regia L., Pinus. 



Injury: Breeds in young twigs. Fig. 27.-Mole cricket, Qryllo- 



Description and biology: Weevil similar to the com- talpa. (Kurdjumov.) 



mon MagdaUs species of this country. The eggs are laid in small dead or injured 

 twigs. Larva feeds in medullary canal^of twigs. Pupates in tunnel. Adults 

 feed on foliage. 



Distribution: Europe. 

 Bargagli, p. Rassegna Biologica Rincofori Europei, 1883-1887, p. 194. 



B. OTHER IMPORTANT BIRCH PESTS. 



. ^._..^ HEMIPTERA. 



Aphididse. 



Glyphina betulx Kaltenbach, a plant louse; Germany; attacks leaves and twigs. 



Coccidse: 



Armored — 



Chionaspis saZicis Linnaeus; Europe. 



Unarmored — 



Lccanium ciliatum Douglas; Europe. 



Lecanium coryli Linnaeus; Europe. 



Lecanium pulchrum Marchal; Eiu-ope; Betula verrucosa. 



Pulvinaria betulx Linnaeus; Europe; Betula alba. 



ORTHOPTERA. 

 Gryllotalpidse. 



'-^Gryllotalpa gryllotalpa Linnaeus; Europe, New Jersey; injures roots, young shoots, and Rerminatine 

 seed. (Seete.xt, fig. 27.) 



