INSECT ENEMIES OF WESTERN FORESTS 23 



larvae of L. cupressana (Kearf.) bore in the green-cone clusters 

 of Monterey and other cypress in California. (See p. 53.) 



The large greenish-red, purplish to reddish-brown larvae of 

 Heinrichia macrocarpana (Wlsm.) bore through the cones of 

 Monterey cypress and also feed on the cambium of twigs. 

 H. fuscodorsana (Kearf.) does similar work in Sitka spruce cones. 



Cones of incense cedar in Oregon are sometimes injured by the 

 slugs of a sawfly Augomonoctenus libocedri Rohw., which does 

 work similar to that of cone-feeding caterpillars. The adults are 

 14 to % inch long, shining blue-black, with the first five segments 

 of the abdomen brick red. 



CONE MAGGOTS 



The insects encountered in seed collecting probably more often 

 than any other group are small, white or pink, legless maggots, 

 which emerge in vast numbers from cones spread out to dry. These 

 are the larvae of tiny gnats, midges, or flies. A few cause consider- 

 able injury to cones and seeds, whereas others do no appreciable 

 damage. 



Cone and seed midges (Itonididae) are found in cones as small 

 pink maggots, the larvae of small gall gnats or midges. The adults 

 are small and very similar in appearance to mosquitoes. They lay 

 their eggs on the young, green cones, and the maggots work within 

 and cause little masses of resin to form among the cone scales or 

 cause hard resinous galls to form on the scales or in the seeds. The 

 damage from these insects is usually insignificant. Of the many 

 western species, only one, Janetiella siskiyou Felt, from the seeds 

 of Port Orf ord cedar, has been named. 



The white fir cone maggot (Lonchaea viridana Meig.) is the 

 common white maggot found so abundantly in white fir and other 

 true fir cones (fig. 8). These maggots mine through scales and 

 seeds, often causing great damage. The larvae leave the cones as 

 soon as they fall and form small puparia in the ground. Here they 

 overwinter, and in the spring some of them emerge as small, black, 

 shining flies. Most of the brood go through a 2-year life cycle, 

 emerging the second spring after beginning pupation. 



CONE BORERS 



The hard, dry cones of certain pines are frequently attacked by 

 the larvae of flatheaded and roundheaded borers, which riddle the 

 interior and destroy the seeds. 



The roundheaded cone borer (Paratimia conicola Fisher) bores 

 tunnels through the hard pitch and scales of knobcone pine cones. 

 It works also in the dry limbs of this pine and has been recorded 

 from the cones of shore pine in California. The adults are rusty 

 reddish-brown, and are V 2 inch long. 



The flatheaded cone borer (Chrysophana placida conicola Van 

 D.) has been found boring through the hard, dry cones of knob- 

 cone, Coulter, and ponderosa pines. The species C. placida Lee. 

 bores in the dead limbs, branches, trunks, and stumps of practic- 



