54 



MISC. PUBLICATION 273, U. S. DEPT. OF AGRICULTURE 



Apical, budlike swellings are formed on ponderosa pines in Colo- 

 rado by Contarinia coloradensis Felt and Dicrodiplosis gillettei Felt. 

 Several of the juniper galls are caused by species of gall midges. 

 WaJshom.yia juniperina Felt causes a slightly enlarged fruit of 

 Juniperiis californica, also a purplish, apical bud gall with three or 

 four diverging lobes. OJigotrophus hetheli Felt forms reddish, api- 

 cal, conical galls on Juniperus utahensis. AUo^nyia juniperi Felt 

 produces a prickly, burrlike bud gall with numerous short, nearly 

 straight, leaves and none reflexed. RJiopalomyia sabinae Felt attacks 



juniper in Colorado 

 and Utah and pro- 

 duces thick-walled, 

 purplish, apical bud 

 galls which split 

 open in four sections 

 Avhen t h e 



midges 



emero-e. 



Pine Pitch Midges 



Some of the pitch 

 or o-all mido-es attack 

 the tender twigs or 

 terminals of young 

 trees and, by form- 

 ing pitch pockets un- 

 der the bark, either 

 cause their death or 

 the deformation of 

 the wood. Their 

 work can be recog- 

 nized by the small 

 pink or red larvae 

 found imbedded in 

 pitchy pockets or 

 galls under the bark. 

 The adults are frail, 

 two- winged flies or 

 midges resembling: 

 mosquitoes. Many 

 of the western forms 

 have not been named 

 as yet. 

 The birdseye pine midge {Retinodiplosis sp. near inopis O. S.) is a 

 common species in southern Oregon, where for many years it has 

 killed the lateral tips of many young ponderosa pines (fig. 25). In 

 some years this damage has been so severe as to deform and in some 

 cases actually kill the trees. The damage is first noticeable very 

 early in the summer, when the new lateral shoots fade, droop, and 

 gradually turn yellow and die. In some cases nearly every new shoot 

 is affected. On examination of the dying tips the bark will be found 

 to be pitted with small resinous pockets, in each of which are small 



Figure 24. — Monterey pine needles galled by the Monterey 

 pine midge {Thecodiplosis pini-radiatae) . Insert, adult 

 midge, X 5. 



