SHORTLEAF PINE: IMPORTANCE AND MANAGEMENT. 25 



INSECTS. 



The southern pine beetle 1 (Dendroctonus frontalis Zimm.) has 

 been the subject of exhaustive study by Dr. A. D. Hopkins, in West 

 Virginia between 1891 and 1901 and in the Southern States from 

 1902 to the present time. According to these investigations this insect 

 has caused the death of millions of shortleaf and loblolly trees and 

 some longleaf. The loss during the past 20 years due to this in- 

 sect has been estimated at between 10 and 20 million dollars. From 

 1890 to 1893 a serious invasion occurred in Virginia and West Vir- 

 ginia. In the season of 1910 the trouble occurred in many places 

 in the Southern States, leading to a special study and demonstration 

 of methods of control by the Bureau of Entomology and the publica- 

 tion of Farmers' Bulletin 476, from which the recommendations for 

 controlling the insect pest are quoted below because of their value and 

 importance to owners of shortleaf stands. It is important, however, 

 that all of Farmers' Bulletin 476 be consulted in case of extensive 

 or serious infestation. 



Evidences of infestation. — (1) If in clumps or patches of pine, where there 

 is no plain evidence of serious injury by fire, the foliage fades to pale green 

 and changes to yellowish and pale brown, it indicates that the trees are dying 

 from the attack of the southern pine beetle, and that the bark of such trees is 

 infested with the developing broods of minute white grubs and transforming 

 beetles; therefore such infested trees are a menace to the living trees. 



(2) If the trees have reddish brown and partially fallen foliage, or if all 

 of the foliage has fallen, it indicates that the broods of beetles have emerged 

 and that such trees are no longer a menace to the living ones. 



(3) If the trees die during the period between the 1st of March and the 1st 

 of October they will be abandoned by the broods of beetles within a few weeks 

 after the foliage begins to fade. 



(4) If the trees begin to die during the period between the 1st of October and 

 the 1st of December the broods of beetles will remain in the bark until the fol- 

 lowing March or April. 



Essential details in methods of control. — There are certain essential details 

 in the recommended methods of combating the southern pine beetle which must 

 be observed in order to avoid not only serious mistakes but possibly ultimate 

 failure: 



(a) The principal clumps or patches of dying trees which are actually in- 

 fested by the broods of the destructive beetle, as indicated by the fading and 

 'ii/ing foliage, or otherwise, should be located and marked during the months 

 of November, December, January, and February. In order to do this work, 

 proper experience or special instruction is required. Therefore some one who 

 lias bad Instructions should have charge of the work in each important area in 

 which control work Is to be undertaken. 



i " K<[.oit on Investigations to Determine the Cause of Unhealthy Conditions of the 

 Spruce and Pine from 1880-1893," Bulletin 56, West Virginia Agricultural Experiment 

 Station, pp. U8i-::7H, 1809, by a. D. Hopkins, Entomologist. 



"'ill': Southern Pine Beetle," Bulletin 88, Part f, I'.ureau of Entomology, U. S. Depart- 

 ment of Agriculture, pp. 56 ~~, 1909, by A. D. Hopkins. 



"Tii' Dying I'lne in the Southern SI a! en : Cause, Extent, and Heinedy," Farmers' Bul- 

 letin 47';. i S. Department of Agriculture, in pages, 4 figures, 1011, by A. D. Hopkins. 



8497° Bull. 80S— 15 4 



