12 BULLETIN 1107, U, S. DEPARTMENT OF AGRICULTURE. 



dence, Hillsborough, Hollister, Lamoine, Los Gatos, Monterey, Nord- 

 hoff, Palo Alto, Placerville, Salinas, San Jose, Santa Cruz, Shingle 

 Springs, Tuolumne, Vade, and Watsonville in Calif ornia, and Ashland 

 and Hood Eiver, Oreg. Others record it from Cisco, Fort Tejon, Los 

 Angeles, Orange, Pomona, Sacramento, San Nicolas Island, Sonoma, 

 and Sylvania in California. The range in elevation is also great, 

 being from 50 to 5,300 feet, 



FOOD PLANTS. 



The principal food plants of the cable beetle are the various species 

 of oak. Of these the California live oak {Querent agrifolia) and the 

 black oak {Q. calif ornica) appear to be the most important, but heavy 

 infestations have been found in the blue oak {Q. douglasii) , the white 

 oak {Q. lobata)^ the huckleberry oak {Q. chrysolepis) ^ and the tan 

 oak {Q. densifiora). 



Besides the oaks, the writers have found infestations in the wood 

 of the elm {Uhiius campestris) , the bigleaf or Oregon maple {Acer 

 macro p hyllu?n) , the California laurel {Umbellularia calif ornica), 

 the sweet cherry {Prunus avium), the gum {Eucalyptus sp.), and the 

 wattle {Acacia sp.). In addition to these, Coquillett {63) records 

 the orange and rose as food plants. 



ASSOCIATED INSECTS. 



The borers commonly associated with the cable beetle in the oaks 

 are the three roundheads, Xylotrechus nauticus Mann,, Neoclytus 

 conjunctus Lee, and Phymatodes nitidus Lee, and the powder-post 

 beetle Lyctus pla/nicoUis Lee, The larval work of the cable beetle 

 usually can be distinguished from the work of the other species be- 

 cause the mines are smaller, circular, and finer than those of the 

 roundheads and larger and coarser than those of Lyctus. (PL VII, 

 Fig. 4.) Lyctus also works only in the sap wood. Sometimes the 

 larger powder-post beetles, Polycaon stoutii Lee. and P. confertus 

 Lee, occur with the cable beetle. The only associate found in the elm 

 is the roundhead Xylotrechus nauticus. In the California laurel the 

 common species is the anobiid Ptilinus ramicornis Casey, and the 

 cable beetle occurs only in small numbers. The work of the anobiid 

 can be distinguished by the smaller size of the larval mines. The 

 buprestid Chrysohothris femorata Oliv, has been reared from infested 

 live-oak wood, 



PREDATORY AND PARASITIC ENEMIES. 



The predatory and parasitic enemies of the cable beetle do not ap- 

 pear to be very common. One clerid, Monophylla calif ornica Fall, is 

 predatory, and one histerid, Teretri/as sp., may be. The clerid larvae 

 are found in the mines of Scobicia and of the associated Lyctus plani- 

 collis. The adult clerids emerge and fly during July and August. 



