INSECTS INJURIOUS TO THE APPLE AND PEAR 525 



one inch long, and usually rests in the curved position shown in 

 Fig. 453. The larva becomes full grown in a single year and in 

 the South may pupate in November, but in the North does not 

 pupate until the next spring, when it remains as a pupa about 

 three weeks. The beetle emerges through an elliptical exit hole, 

 in contrast to the round hole of the round-headed borer. 



Control. As this beetle is everywhere present, injury may 

 always be expected if trees are not kept in a healthy condition, 

 but if the orchard is well cared for it seldom suffers much damage. 

 The same measures for preventing oviposition as suggested for 

 the previous species are advised, but the repellant washes must 

 be applied higher on the trunks and should extend to the lower 

 branches as high as can be reached. 



The Oyster-shell Scale * 



Not infrequently young apple and pear trees are encrusted and 

 killed by the Oyster-shell Scale, as are young poplars and maples. 

 It is probably our most com- 

 mon scale insect, being al- 

 most always found on apple 

 trees, on which it works on 

 the bark or the twigs and 

 trunk, reproducing even on 

 old trunks, where the scales 

 will be found under the loose 

 bark and are undoubtedly 

 a factor in causing the bark 

 to slough off. All of the 

 common orchard trees are 

 occasionally infested but 

 rarely injured, as are also 

 maple, poplar, horse-chest- 

 nut, willow and lilac. 

 Quaintance and Sasscer give 

 a list of over 100 trees, 

 shrubs, and plants upon 

 which the scales have been 

 found. The species is a cos- 

 mopolitan one, having been 



FIG. 454. The oyster-shell scale (Lepid- 

 osaphes ulmi Linn.): a, female scales on 

 twig; 6, female scales from above; c, 

 same from below showing eggs; d, male 

 scale enlarged. (After Howard.) 



* Lepidosaphes ulmi Linn. Family Coccidce. See Quaintance and Sasscer, 

 Farmers' Bulletin 723, U S. Dept. Agr., and references there givea 



