U38 



[NJURIOUS AND BENEFICIAL INSECTS ()K CALIFORNIA. 



Distribution.' x — This beetle occurs throughout the central and south- 

 ern parts of the Stale, having been recorded from Riverside, San Ber- 

 nardino, Los Angeles, and San Diego counties by II. C. Fall, from San 

 Joaquin County by Geo. P. Wei don and from Imperial County by 

 Dr. B. C. Van" Dyke. 



Food Plants. — Mesqi lit (Prosopis juliflora) is reported by Van 

 Dyke as a native host. The beetle has also been reared from apricot, 

 fig, grape, pear and orange. In most case3 dead and not living wood 

 was reported infested. 139 



Control.— Control measures are difficult for such a pest and should 

 be applied only when injury warrants, which is very rarely the case. 

 Orchard trees should be kept as healthy as possible, all native trees 

 serving as breeding places destroyed and infested branches pruned 

 out and burned. 



THE BRANCH AND TWIG-BORER" 

 Polycaon confertus Leconte 14 ' (Family Bostrychidaj) 



(Fig. 2:>7) 



Description. — The beetle is slender, black with brown wing covers 

 and from | to § inch long. The head is as wide as the prothorax, 



w h i c h is noticeably 

 narrower than the rest 

 of the body. 



Life History.— 

 According to Dr. E. ('. 

 Van Dyke, the eggs are 

 laid in various dead 

 woods, such as grape, 

 acacia, certain brush 

 woods, etc. The larva 1 

 develop in them, grad- 

 ually tunneling t h e 

 wood in all directions, 

 as is the case with the 

 powder post beetles, 

 and the adults emerge 

 in the early summer. 

 When the beetles have 

 once infested the wood 

 they continue to breed 

 there for many suc- 

 ceeding generations, or until all of the nutritious parts have been con- 

 sumed. When they attack the dead twigs of the grape they cause the 

 "die back" to extend further and further into healthy tissue, and thus 

 often do considerable damage. 



Pig. 227. — The branch and twig-borer, Poli/caon 

 confertus Bee. Adult male and female and their work 

 mi olive twigs. (Anthill's illustration, Mo. Bui. Cal. 

 I fort. Com. » 



'"Fall, H. C, True. Cal. A, -.id. S.i.. Vlll. p. 134, 1901. 



Mo. Bui. Cal. Hint. Com., II, P. 684, 1913. 

 "•Mo. Bui. Cal. Hurt. Cum.. II. 684, 1913. 

 "Ah.. Bui. Cal. Hurt. Com.. II, pp. r,N7-. r ,N9, 191::. 



"'J'iiI ycaon stoutii Bee. is much larger ami entirely black. It also occurs generally 

 throughout the stale anil attacks the almond, eucalyptus, maul nak and coast live oak. 



