ti. ;5.>^ * B R A R Y I PENT,-SERIAL PE ORü Technical Bulletin No. 1169 United States Department of Agriculture Cone and Seed Insects of Western Forest Trees by F. P. Keen California Forest and Range Experiment Station Forest Service Technical Bulletin No. 1169 U. S. Department of Agriculture July 1958 For sale by the Superintendent of Documents, U. S. Government Printing Office Washington 25, D. C. - Price 55 cents CONTENTS Page Introduction 1 Western forest trees and their cone and seed insects 2 Abies fir 3 Abies amabilis Pacific silver fir 4 Abies bracteata bristlecone fir 4 Abies concolor white fir 4 Abies grandis grand fir 6 Abies lasiocarpa subalpine fir 7 Abies magnifica California red fir 7 Abies magnifica var. shastensis Shasta red fir 8 Abies procera noble fir 9 Acer cirdnatum vine maple 9 Acer macrophyllwm bigleaf maple 9 Castanopsis chrysophylla golden chinkapin 9 Chamaecyparis lawsoniana Port-Orford-cedar 10 Chamxiecyparis nootkatensis Alaska-cedar 10 Cupressus cypress 10 Cupressus goveniana Gowen cypress 10 Cupressics macrocarpa Monterey cypress 11 Fraxinus latifolia Oregon ash 11 Juniperus califomicà California juniper 11 Juniperus occidentalis western juniper 12 Libocedru^ decurrens incense-cedar 12 Lithocarpus densiflorus tanoak 12 Picea spruce 13 Picea breweriana Brewer spruce 13 Picea engelmunnii Engelmann spruce.,. 13 Picea glauca white spruce 14 Picea pungens blue spruce 15 Picea sitchensis Sitka spruce 15 Pinus pine 16 Pinv^ attenuata knobcone pine 16 Pinu^ contorta var. contorta shore pine 17 Pinus contorta var. latifolia lodgepole pine 18 Pinus coulteri Coulter pine 18 Pinu^ edulis pinyon 19 Pinu^ flexilis limber pine 19 Pinus jeffreyi Jeffrey pine 19 Pinu^ lambertiana sugar pine 20 Pinus leiophylla var. chihuahuana Chihuahua pine 21 Pinus monophylla singleleaf pinyon 21 Pinus monticola western white pine 22 Pinus ponderosa ponderosa pine 22 Pinu^ ponderosa var. ponderosa Pacific Coast form 23 Pinus ponderosa var. scopulorum Rocky Mountain form 25 Pinus radiata Monterey pine 25 Pinus sabiniana Digger pine 26 Pinus torreyana Torrey pine 26 Pseudotsuga menziesii Douglas-fir 26 Quercus agrifolia California live oak 29 Quercus kelloggii California black oak 29 Thuja plicata western redcedar 30 Tsuga heterophylla western hemlock 30 Tsuga mertensiana mountain hemlock 30 iii iv CONTENTS Page Biology and habits of cone and seed insects and their insect enemies 31 Order Coleóptera beetles 31 Family Anobiidae 31 Genus Ernobius 31 Family Anthicidae 35 Family Bostrichidae 36 Family Buprestidae 36 Family Cerambycidae 38 Family Chrysomelidae 40 Family Cleridae 40 Family Coccinellidae 41 Family Cryptophagidae 42 Family Cnrculionidae 42 Family Lathridiidae 45 Family Ptinidae 46 Family Scolytidae 46 Conophthorus spp. cone beetles 46 Order Diptera flies , 59 Family Chamaemyiidae 59 Family Chloropidae 59 Family Chyromyidae 59 Family Itonididae 60 Gall midges in fir cones 67 Gall midges in incense-cedar cones 67 Gall midges in pinyon cones .' 68 Gall midges in Douglas-fir cones 68 Gall midges in western redcedar cones 69 Family Larvaevoridae (Tachinidae) 69 Family Lauxaniidae 71 Family Lonchaeidae 71 Family Lycoriidae 76 Family Muscidae 77 Family Pallopteridae 80 Family Piophilidae 80 Family Sphaeroceridae 80 Order Hemiptera bugs 80 Family Anthocoridae 80 Family Pentatomidae 80 Order Hymenoptera wasps 81 Superfamily Megalodontoidea 81 Family Xyelidae 81 Superfamily Tenthredinoidea 81 Family Diprionidae 81 Superfamily Ichneumonoidea 82 Family Braconidae 82 Family Ichneumonidae 86 Superfamily Chalcidoidea 93 Family Encyrtidae 93 Family Eulophidae 94 Family Eupelmidae 96 Family Eurytomidae 97 Family Pteromalidae 98 Family Torymidae 102 Genus Megastigmus seed chalcids 102 Family Trichogrammatidae 112 Superfamily Cynipoidea 112 Family Cynipidae gall wasps 112 Family Figitidae 113 Superfamily Proctotrupoidea 113 Family Gasteruptiidae 113 Family Platygasteridae 114 Superfamily Scolioidea 115 Family Formicidae ants 115 Superfamily Sphecoidea 116 Family Sphecidae 116 CONTENTS V Page Superfamily Apoidea 116 Family Megachilidae 116 Order Lepidoptera moths 116 Family Blastobasidae 116 Family Cosmopterygidae 119 Family Gelechiidae 119 Family Geometridae 120 Family Hyponomeutidae 120 Family Olethreutidae 121 Family Phaloniidae 147 Family Phycitidae 148 Order Neuroptera nerve wings 155 Family Raphidiidae 155 Control of cone and seed insects 155 Natural control 155 Applied control ^ 156 Treatment of infested seeds 157 Suggested needs for further study 157 Literature cited , 159 Insect index 165 ACKNOWLEDGMENT The research on cone and seed insects reported in this publica- tion was done in the former Bureau of Entomology and Plant Quarantine. Research on forest insects is now being done in the Forest Service. John M. Miller took leadership in promoting the study of forest cone and seed insects at a time when these pests were of little economic importance. John E. Patterson should be credited with having taken most of the pictures used as illustra- tions. The author, who assisted with this work for 3 years, wishes to acknowledge the major contributions made by these associates, and is gratified that it is now possible to preserve through publica- tion their work on a forestry subject which inevitably will be of increasing importance as time goes on. CONE AND SEED INSECTS OF WESTERN FOREST TREES By F. P. KEEN, Entomologist, California Forest and Range Experiment Station,^ Forest Service, U, S. Department of Agriculture INTRODUCTION Insects that destroy the seeds of forest trees have an important bearing on reforestation. If a high percentage of a seed crop is destroyed in any year, seed collecting may be unprofitable, and nursery establishment and planting will be greatly hampered. Also the loss of seed may seriously threaten the natural reestab- lishment of commercially valuable tree species on burned or cut- over lands, where timing of seeding may be highly critical. The importance of developing knowledge of cone and seed infesting insects was first recognized by John M. Miller in May 1912 when he proposed to Dr. A. D. Hopkins, then Chief of the Division of Forest Insect Investigations, Bureau of Entomology, United States Department of Agriculture, that a study should be made of cone and seed insects. Miller pointed out the need to assist the Forest Service in seed-collecting work, so collectors could avoid badly infested, unprofitable areas. This study was approved by Dr. Hopkins in June 1912, and in the rest of 1912 Miller collected a good many seed and cone insects. His first report, dated January 1, 1913, gave the object of the work as furthering information along two general lines: (1) The actual amount of damage occurring in the forest or to stored forest tree seeds and (2) the life histories atid habits of the forest-seed insects. At first the work was centered at Placerville, Calif. In August 1913 Miller moved his headquarters to Ashland, Oreg., where cone and seed insect studies were the principal work of this sub- laboratory. P. D. Sergent, an agent employed by the Bureau, collected much of the cones and seeds. In August 1914, the force at the Ashland station was augmented by J. E. Patterson, agent, and the writer on his first appointment with the Bureau as entomo- logical ranger. The work was continued through 1915 and 1916 until interrupted by World War I, in July 1917. The period of study thus covered 5 years, and material was obtained from Cali- fornia, Oregon, Washington, Montana, and Colorado. Since then cone and seed insects have been collected only occasionally, in connection with other lines of work. 1 Maintained at Berkeley, Calif., in cooperation with the University of California. 2 TECHNICAL BULLETIN NO. 1169, U. S. DEPT. OF AGRICULTURE The work on cone and seed insects at Ashland was so far ahead of its economic usefulness, that for nearly 40 years,very little of the copious material collected at that time was assembled or published. Now forest-seed problems and reforestation are of increasing importance. Knowledge of cone- and seed-destroying insects is in great demand in order that steps may be taken for their control. Moreover, control is within the limits of practi- cability since the development of DDT and other new chemicals which can be released by helicopter or airplane. Therefore, it seems especially appropriate that our present knowledge on cone- and seed-infesting insects be put in such form as to be useful to practicing forest entomologists. In this report cone and seed insect injury is first discussed by host trees, arranged in alphabetical order. A key to recognition of damage and the associated insects accompanies the host com- pilation. Then the insects themselves are discussed as to their appearance, hosts, distribution, seasonal history, and parasites. The arrangement here is alphabetical by order, family, genus, and species. The following general reference books and bulletins briefly discuss a number of the more important cone- and seed-infesting species. DoANE, R. W., VAN DYKE, E. C, CHAMBERLIN, W. J., and BURKE, H.E. 1936. FOREST INSECTS. New York and London. 463 pp., illus. EssiG, E. O. 1926. INSECTS OF WESTERN NORTH AMERICA. New York. 1035 pp., illus. KEEN, F. P. 1928. INSECT ENEMIES OF CALIFORNIA PINES AND THEIR CONTROL. California Dept. Nati. Resources, Div. Forestry Bui. 7, 113 pp., illus. KEEN, F. P. 1938. INSECT ENEMIES OF WESTERN FORESTS. U. S. Dept. Agr. Misc. Pub. 273, 280 pp., illus. (Rev. 1952). MILLER, JOHN M. 1914. INSECT DAMAGE TO THE CONES AND SEEDS OF PACIFIC COAST CONIFERS. U. S. Dept. Agr. Bui. 95, 7 pp., illus. Other literature citations are indicated in the text, by italic num- bers in parentheses, and listed under Literature Cited, p. 159. WESTERN FOREST TREES AND THEIR CONE AND SEED INSECTS Western forest trees from which cone and seed insects have been collected or reared are here listed in alphabetical order by genera and species. Under each tree is given a brief discussion of seed damage frequently encountered and a list of insects and parasites reared from each host, grouped by general habits. A key to recognition of the work of destructive species is included.