312 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



THE CYPRESS TWIG-BORER 221 

 /'////; osinus crintatus Leconte (Family Ipiclae) 



Description. — The beetles are light or dark brown in color, with 

 darker head and prothorax. They are short, robust and quite small, 



averaging about g% 

 inch in length and 

 half as much in 

 width. 



Life History. — It 

 is supposed that nor- 

 111 ally the adults 

 breed in dead or un- 

 healthy trees and 

 only occasionally 

 rind their way to 

 living tissue. 230 The 

 larval stage is passed 

 usually in dead or 

 decaying wood. Dur- 

 ing the spring and 

 summer the beetles 

 bore into the smaller 

 twigs of the cypress, 

 usually in the axils or 

 forks, and so nearly 

 sever the twigs that 

 they either break off 

 at the burrow or the 

 tip dies. In this way 

 trees and hedges are 



Fig. 306.— Tree in neglected apricot orchard killed by the Sometimes rendered 



shot-hole borer or fruit-tree bark-beetle, Eccoptogaster „ _ „ - „ r, . ■% ■, 



rugulosus (Ratz.). Such a dead tree is an excellent breed- " u * i 8 " I 1 V a 11 (I 



ing place for this pest. (Original) greatly injured. 



They also burrow into unhealthy or dead trees, where the succeeding 

 broods are reared. 



Nature of Work. — The work consists in the making 

 of shallow burrows two or three times the length of 

 the beetle in the smaller twigs, causing many of them 

 to break at the burrow and die. The beetles are 

 usually found within the burrow and make the cause 

 of the injury apparent at once. Dead or dying trees 

 are normally attacked, but they often extend their 

 work to perfectly healthy trees, and repeatedly attack 

 the twigs of the latter. 



Distribution. — This species is common throughout 

 the southern and central parts of the State. 



Food Plants.— Monterey cypress is injured most by the beetle, but 

 the coast redwood is also reported as a host. 231 



"Another species, Phlcrosinus <ltiiti<tn.s Say, about the same size but usually lighter 

 lor, works only mi the California juniper in the state 

 tnseel Life. v. p. 262, 1893. 

 ''■Hi. X". 21, Bur. Ent., CJ. S. Dept. Agric, p. 7. ] son, 



Fig. 307. — Adult 

 of the s li o t-ho 1 e 

 borer or fruit-tree 

 bark-beetle, Eccop- 

 togaster rugulosus 

 (Ratz.). Enlarged 

 five times. ( Orig- 

 inal) 



