I 4- - I January », r.>12 U.S. DEPARTMENT OF AGRICULTURE, BUREAU OF ENTOMOLOGY CIRCULAR No. 111. L. O. HOWARD. Enlomologul and Chwf o( Bui«u THE DYING IIK'KOKV TREES CAl SE AMI REMEDY. BY A. D. HOPKINS, Fn Charge of For I In instigations. ■ i iu •A»HIIMJTO»< : OOVCRXHEXT PRINTISQ o«lCE : 1t12 BUREAU OF ENTOMOLOGY. L. O. Howabd, Entomologist and Chief of Bureau. C. L. Marlatt, Entomologist and Acting Chief in Absence of Chief. It. S. Clifton, Executive Assistant. W. F. Tastit, Chief fieri:. F. H. Chittenden, fa charge of truck crop and stored product insect investiga- tions. A. D. Hopkins, in charge of forest insect investigations. W. I>. Hunter, in charge of southern field crop insect investigations. V. M. Webster, in charge of cereal and forage insect investigations. A. L. Quaintanc'e, in charge of deciduous fruit insect investigations. E. F. Phillips, in charge of bee culture. I). M. Rogers, in charge of preventing spread of moths, field work. Rolla P. Currie. fa charge of editorial work. Mabel Colcobd, fa charge of library. Forest Insect Investigations. A. D. Hopkins, in charge. H. E. Bcrke, entomological assistant, in chargi of Forest insect Field Station'}, Yreka, Cal. W. D. Edmonston. agent and expert, in charge of Forest insect Field Station (I. Klamath Falls. Oreg. Josef Bbtjnnes, agent and expert, in charge of Forest Insect Field station J. Columbia Falls, Mont. E. B. Mason, entomological assistant, in charge of Forest Insect Field Station 7, Spartanburg, 8. C. T. E. Snydeb, agent and expert, engaged in investigations of insect damage to telegraph and telephone poles. J. L. Webb, entomological assistant, specialist on cerambycid beetles and larva'. S. A. Rohweb, agent and expert, specialist on saw flies iTcnlhrcdinoidea >. Mary E. Fatjnce, Mary C. Johnson. Maude Taylor. Elizabeth Ritchie, pre- parators. ii Circular No. 144. United States Department of Agriculture, BUREAU OK ENTOMOLOGY. L. O. HOWAKD. Entomologist «nd Chief of Bi THE 1>Y1\<; HICKORY TREES— CA1 8E VM> REM EDI Bj \ D Hopkins, In Charge 0/ Forttt limert Inn iligatint Within the past ten years a large percentage of the has died in various sections throughout the northern from Wisconsin to Ver- . mont and soul hv< ard through tlif Atlantic States to centra I ' reorgia and to b greater or less extent within the entire range of natural growth of t be \ a riou - species. 1 \i - While there are several and sometimes complicated causes of the death of the trees, investigations have revealed the fact that the hickory barkbeetle ' is by far the mosl destructive insect enemy, and is, there- fore, in the majority of cases, the primary cause of the dying of the tree-. HOW To RECOGNIZE THE WORK or mi', it i< K< 'i:v 1! IRKBEETLE. hickor t iir of y 1 rees States Work "i" the hickory i>.irkt n (SeoJ a ■1. Prlmnri rr»l mines. 1 Author's Illustration 1 The first evidence of the presence anil work of this beetle is the premature dying or falling of a few of the leaves in .Tidy and August, caused by the feeding of the adult or parent ,1,1s quaii - Order Coleoptera, famil] 2 THE DYING BICKOBY TREES — CAUSE AND REMEDY. beetle:- at the base of the leaf stein (fig. 4). but this work alone does not kill the tree-. The next evidence of its destructive work is the dying of part of a tree or of all of one or more trees. Tf the trees are dying from the attack of the beetle, an examination of the inner bark and surface of PIG. '2. — Complete brood galleries of the hickory bnrkbeetle on surface of wood. (Author's Illustration.) the wood on the main trunks will reveal curious centipede-like bur- rows (figs. 1, 2) in the bark and grooved on the surface of the wood. These are the galleries and burrows of the parent beetles and of their broods of young grubs or larvae. The girdling effect of these gal- leries is the real cause of the death of the tree-. nil. DYING III. K0R1 li;i i - CAU81 1ND REM] D1 . 1 1 \ in PS 01 nn. i;i i ii r. The broods of the beetle pass the winter in the bark of the trees that die during the preceding Bummer and fall. During the warm days of March and April these overwintered broods complete their development to the adult winged form and during Maj and June emerge through small round holes in the bark (fig. 3) and ll\ to the li\ ing trees. They then attack the i\\ igs . fig. I | to f I on the ba* the leaves and tender bark and also on the bark of the trunks and large branches of some of the living health) trees and bore through the bark to excavate their short, vertical i galleries i fig. 1. a). Thi ire de- posited along the sides of these galleries and the larva' hatching from them exca- vate the radiating food burrows (fig. 1. i>; fig. 2), which serve to girdle the tree or branch. THI i ; i . m i Di . The following rec mendations for the successful control of this beetle are based <>n investigations, experiments, and demonstrations conducted during the past ten year-. BECOM MENDATIONS. i 1 ) The best time to conduct the con- trol work is between October 1 and May I, but it must be completed before the 1st to middle of May in order to destroy the broods of the beetle before they begin to emerge. (•2) Locate and mark the hickory trees within an area of several square miles that died during the summer and fall and those of which pari or all of the tops or large branches died. (■•>> Fell the marked .lead trees ami cut out all A t -.iA or infested portions of the remaining marked tree, which Mill have sufficient life to make a new growth. Dispose of all infested trunk, and branches in such a manner as to kill the overwintering broods of the beetles in the lurk (a) by utilizing the wood for commercial products and burning the refuse; or (6) by utilizing the wood of the trunk, and I. ranch,- for ;ti I. .-irk of i.i.-kor.v tr.'- from which broods • <( th.' bickorj barkbeeUe bare tbor'a III Hon. i 4 THE DYING HICKORY TREES CAUSE AND REMEDY. or (c) by placing the logs in water and burning the branches and tops; or (d) by removing the infested bark from the trunks or logs and burning it with the branches or as fuel. (5) So far as combating the beetle is concerned it is unnecessary and a waste of time to dispose of trees or branches which have been dead 12 months or more, because the broods of the destructive beetle are not to be found in such trees. Fig. 4. — Injury by the hickory barkbeetlo to the twigs, buds, and base of leaves. i Original, i ((>) Spraying the tops or brandies or the application of any sub- stance as a preventive is not to be recommended. Nothing will save a 1 ice after the main trunk is attacked by large numbers of this beetle or after the bark and foliage begin to die. (7) The injuries to the twigs (fig. 4) by this beetle do not require treatment. (8) The bark and wood of dying and (had trees are almost inva- riably infested with manv kinds of bark and wood boring insects Mil DYING illi i\" u\ l'l t'Al'SI \M' KIM l.li\ . whh li can do no harm to tinny tn I here fore ;i II efforts should be concentrated on the disposal of the broods of the hickory barkbeetle > i-i I i 1 1 i_r to the above recommendations. To insure the protection of the remaining Living trees ii i- very important thai at leas! a large majority of the dead infested and partial]^ dead infested trees found within an entire ana of several Bquare miles be disposed of \\ ithin a single season in order to kill the broods of thi- beetle. Therefore there should be concerted action by all <>\\ ners of hickory tree-. On account of the value of the hickory for shade and outs and for many commercial wood products it is important that the people of a community, county, or State who are in any manner interested in 1 1 1 - - protection of hickory tnc- should give encouragement and support to any concerted or cooperative effort on the pari of the owner- toward the propei' control of the hickory barkbeetle. Approved : .1 \ Ml> Wii SON, try of . I [ir'" ult\ W k8HINGT0N, I '. ( '.. Nov* '. 1911. rpma PUBLICATION may be po- ■*• cured from the Superintendent ol Documents, Government Printing Office Washington, I>. O, at 5 cents per copy iETfci . UNIVERSITY OF FLORIDA 3 1262 09216 5975