ECONOMIC ZOOLOGY ENTOMOLOGY. 559 



bark immediately upon felling or between March 1 and June 1 aud the placing 

 of the logs in water after the larv;e have hatched and before they have entered 

 the wood are recommended as preventives. 



The red-headed clytus, Neoclytiis enjthrocephalus, does considerable damage 

 to the wood of dead and dying ash, as well as to a number of other trees. Its 

 host plants include the hornbeam, hickory, maple, sweet gum, chestnut, cypress, 

 hackberry, black walnut, dogwood, black oak, persimmon, peach, locust, sassa- 

 fras, holly, mesquite, Texas redbud, pine, Kentucky coffee tree, lilac, honey- 

 suckle, and grapevine. " The same preventive measures as those given for the 

 banded ash borer apply to this species except, it will be noted, that the egg-laying 

 period of this species is much longer than that of the banded ash borer, so that 

 there is scarcely any season of the year when trees may be cut and left with 

 bark on without danger of being damaged by this borer." 



The work of the oak pruner, EJaphidion viUosui/i, and the hickory twig- 

 girdler, Oncideres cingulata, which is conflued to the twigs and branches, is 

 often quite injurious. When these species occur in injurious numbers, the 

 fallen twigs and recently killed twigs of the trees should be gathered and 

 burned in the fall in order to destroy the larvfe -and pupse in them. For the 

 hickory twig girdler this should be repeated before vegetation starts in the 

 spring and again during June or July. 



The twig girdler (Oncideres cingulata and texana), O. E. Sanboen (Okla- 

 homa Sta. Bui. 91, pp. 13, figs. 7). — The twig girdler, which is known to occur 

 throughout the United States east and south of and including Kansas, sub- 

 sists during its larval period on the wood of branches which have been 

 girdled from the tree by the adult female. The adults begin to emerge about 

 the first of August from branches girdled the previous fall. AVithin one or two 

 iweeks after emergence the sexes pair, and the females begin to girdle and 

 generally, after completing the girdle, commence to oviposit in that part 

 girdled from the tree. In rare instances, however, they oviposit at intervals 

 in the branch while the process of girdling is under way. The branch is 

 girdled entirely around or until it has become so weakened that it bends 

 downward. " One female can easily girdle all of the branches from 2 5-year-old 

 trees or 5 3-year-old trees, or 15 or 20 2-year-old trees. The direct damage, 

 therefore, caused by the girdling of select stock can easily be computed at 

 about $10 per female beetle without taking into consideration the damage 

 caused by the pernicious food habits of both sexes." 



In Oklahoma oviposition commences about the first of September and con- 

 tinues until the time of heavy frosts late in the fall. " The number of eggs 

 deposited by a single female varies from about 10 to 150. The greatest number 

 I have found in a single girdled branch is 30. . . . The larvee do not all hatch 

 until late in winter. The egg generally hatches within about one week after it 

 is deposited. The larva emerges from it at the end nearest the puncture, be- 

 tween which points there is a vacant space in which it first feeds by eating 

 the soft tissue bordering the hard wood. As development proceeds it eats 

 the hard wood cells in proximity to the water tubes leading from the leaf scars 

 near the base of the bud or twig." Technical descriptions of the different stages 

 accompany the account. 



The author's observations prove conclusively that there is but one generation 

 per year, the season of adult activity being from August until frost. Experi- 

 ments conducted show that decaying wood is not suitable for the development 

 of the larvffi, as previously supposed. They prove that the best conditions for 

 the hatching of the eggs and the development of the larvje is in twigs which 

 do not fall to the ground but hang on the branches or trunk of the tree, thus 

 protected from the soil moisture and natural enemies of the developing beetles. 



