CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 32 1 



Round-headed Apple-tree Borer (Saperda Candida Fab.). — This 

 beetle is a common native pest of the mountain ash, apple, quince 

 and pear in orchards east of the Rocky Mountains (Fig. 209). 



Adult. — A pretty beetle, ^-^ inch long, with long grey antennae; 

 head and under side of body silvery white, upper surface light yellow- 

 ish-brown and with two longitudinal white stripes extending through 

 thorax and wing-covers; legs grey. Appears mostly in May, June 

 and July, usually in day-time. 



Eggs. — Embedded singly in incisions in the bark, near the base of 

 the trunk, and covered with gummy substance; pale rust-brown, oval, 

 }i inch long; hatch in 2-3 weeks. A female may deposit 15-30 eggs. 



Larva. — Full-grown larva is a yellowish fleshy cylindrical legless 



Fig. 209. — Round-headed apple-tree borer: a, b, larvae; c, female beetle; d, pupa. 

 (Chittenden, Cir. 32, Bur. Ent., U. S. D. A.) 



grub, ^^ to 1 3-^ inch long; head small and dark; body tapering from the 

 thorax backward. Matures in 3 years. Works in bark and sap- 

 wood the first year forming broad, irregular, circular galleries beneath 

 the outer bark; bores deeper in the second year, and in the third year 

 bores upward into the solid wood and outward to the bark, and in May 

 of the fourth year transforms to a pupa, the winter being spent in the 

 pupal chamber. 



Pz^/ja.^Lighter than larva, with transverse rows of minute spines 

 on the back. Duration about 3 weeks. 



Control. — Probe or cut out grubs in fall; apply a carbolic alkaline 



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