SSHTK'i^rrWi'ifliP^Blf :ial:!i:;,.:aiiy!!''-!!|tM.: ;,.-::';>iil; i^jlti;!; ■^•iiiiiiJiiiiLilik^ii-ill ;iil:i.-.tf.-.fli;H;;!:.-., IliiitiU^Wml^Ffliia mmM'VK'M mmtM VOLUME II Nos. 1 and 2 THE MONTHLY BULLETIN INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA By E. O. ESSIG OF STATE COMMISSION OF HORTICULTURE SACRAMENTO, CALIFORNIA JANUARY AND FEBRUARY, 1913 STATE COMMISSION OF HORTICULTURE January and February, 1913 THE MONTHLY BULLETIN VOLUME II Nos. 1 and 2 DEVOTKI) TO THK DICSCRIPTIONS, LIFE HABITS AND METHODS OF CONTROL OF INSECTS FUNGOID DISEASES AND >0X10US WEEDS AND ANIMALS, ESPECIALLY IN THEIR RELATION*; TO AGRICULTURE AND HORTICULTURE. EDITED BY 1111 IMIRK FORCE OF THE COMMISSION UNDER THE FOLLOWING DIRECTORS: A. J. ( OOK E. 0. ESSIG - G. E. MERRILL - HARRY S. SMITH - FREDERICK MASKEW H. S. F\WCETT CENSOR State Commissioner of Horticulture, Sacramento EDITOR Secretary, Sacramento ASSOCIATE EDITORS Chief Deputy Commissioner, Sacramento Superintendent State Insectary, Satririento Chief Deputy Quaratine Officer, San Frfvicisco Plant Pathologist, ^i^hittie'^ Sent free to all citizens of the State of California. Offered in exchange for bulletins of the Federal Government and experiment stations, entomological and mycological journals, agricultural and horticultural papers, botanical and other publications of a similar natjre. Kntered as second class matter December 28, 1911, at the post afllce at .Sapranieato, California. under the act of July 10. 1804. Friend Wm. Richardson, Superintendent of State Printing sacramento, california lpl3 LIBRARY pfEW YOfUC BOTANICAL QARBEN INJURIOUS AND BENEFICIAL Insects of California BY E. O. ESSIG Secretary State Commission of Horticulture :) 2%% INTRODUCTION AND ACKNOWLEDGMENT. There have always been repeated requests at this office for publica- tions on California insects, suitable for use by the orchardist and horti- cultural inspector. To meet these demands Mr. 0. E. Bremner, then secretary of the State Commission of Horticulture, issued a bulletin on "Destructive Insects and Their Control" in the year 1910. That the work was popular is shown by the fact that the large supply printed has l)een entirely exhausted for nearly a year and with urgent requests con- tinuing to arrive at the office for a similar treatise. The present bulletin has been printed to meet these demands. It has been the aim to make this issue as clear, concise and practical as possible. Only insects of the most economic importance known to occur in California are considered, so this is in no wise a work on general entomology, and such limitations will better enable an orchardist or horticultural official to get a more thorough grasp of the field of insect life as it actually exists in this State. Much of the information contained herein has been compiled from entomological publications of the State University, the many state ex- periment stations, Bureau of Entomology of the United States Depart- ment of Agriculture, and of private authors. The cuts alreadj^ in the office have been used for illustrative purposes as far as available. Most of these are reproductions from publications of the United States Department of Agriculture. The State University has also loaned us a generous supply. The author's illustrations for- merly used in the Pomona College Journal of Entomology have also been procured, while many new cuts appear herein for the first time. E. 0. ESSIG. Sacramento, California. January 1, 1913. CONTENTS. Page. HOST INDEX "^ii GENERAL CLASSIFICATION 1 ARACHNIDA 3 INSECTA OR HEXAPODA H ORTHOPTERA 1- acridiid.^ ^'^ locustid^ -^ Gryllid^ -"^ PLATYPTERA 27 Termitid^e -' THTSANOPTERA 29 HEMIPTERA 38 HOMOPTERA 38 CiCADID.E 39 Membracid^ 39 Jassid.e ■* PsyLLin.E ^'^ Apiiidiu.e ■^^ COCCID^ '^^ Aleyrodid.e 1^"-' HETEROPTERA 145 PARASITA OR ANOPLURA 150 NEUROPTERA 150 LEPIDOPTERA 1-54 Sphingid^ l'^4 NOCTUID^ ' 159 COLEOPTERA 199 199 Elaterid.e -^ I Syrphid.e "^ 252 Cocci NELLID.E DIPTERA 241 Syrph] Drosophilid.e Tachinid.e 258 HYMENOPTERA 261 True Parasites 262 POTATO EELWORM 282 INSECT COLLECTIONS 285 STATE INSECTARY 295 SPRAYS AND POISONS 297 FUMIGATION 318 HORTICULTURAL LAWS AND QUARANTINE ORDERS RELATING TO INSECTS 337 INDEX 1 353 HOST INDEX OF INJURIOUS INSECTS DESCRIBED OR CITED. Acacia (Acacia sps.)- Page. Cottony cushion scale, Icerya purchasi 89 Greedy scale, Aspidiotus camelliw 127 Ivy scale, Aspidiottis hederce 128 Red scale, Chnjsoniphalus aurantii 133 >Egopoclium podograria. Parsnip louse, Hyadaphis pastinacw oo Agave. Ivy scale, Aspidiotus hederce J-^o Red scale, Ghrysomphalus aurantii 134 Ageratum. (ii-eenhouse orthezia, Orthezia insignis o6 Greenhouse white fly, Aleyrodes vaporarioru ni 145 Agrostis. Hessian fly, Mayetiola destructor --io Alder (Alnus sp.). Cottony maple scale, Pulvinaria vitis 111 Alfalfa (Medicago sativa). Alfalfa crane fly, Tipula simplex 243 Alfalfa looper, Autogropha gamma caUfornica 162 Apple leaf-hopper, Empoasca mali 41 Clover mite, Bryohia pratertsis 7 Grain thrips, Euthrips tritici 33 Grape leaf-hopper, Typhlocyba comes ^ 42 Grasshoppers 16, 17, 18, 24 Twelve-spotted cucumber beetle, Diahrotica soror 229 Western army worm, Chorizagrotis agrestis 163 Allamanda (Allamanda neriifolia) . Citrus white fly, Aleyrodes citri 350 Almond {Primus amygdalus) . Almond mite, Bryohia pratcnsis 7, 302 Black scale, Saissetia olew 119 Cottony cushion scale, Icerya purchasi 91 Greedy scale, Aspidiotus camelliw 127 Green peach aphid, Myzus persicw 79 Pear thrips, Euthrips pyri 36 San Jose scale, Aspidiotus pernidosus 130 Aloe umbellata. Ivy scale, Aspidiotus hederw 1-8 Amsinckia spectabilis. Green peach aphid, Myzus persicw 79 Andromeda sp. Florida wax scale, Geroplastes floridensis 113 Angelica sylvestris. Parsnip louse, Hyadaphis pastinacw 86 Anise {Carum kelloggii) . California orange dog, Papilio zolicaon 199 Anthurium sp. Florida wax scale, Ceroplastes floridensis 113 Antidesma sp. Black scale. Saissetia olew 119 viii HOST INDEX. Apple (I'yrus malus). Page. liti^t army worm, Laphygma exigua 163 BliU'k sralo. SaiKsctia olcw 119 California peach borer, Sanninoidca opalescens 195 California tussock moth. Ilcmerocanipa vetusta 179 Cankcrworm, fall. Aluopliila pometaria 187 Cankorworm, spring, I'aJcacrita vcrriata ■ 185 Canlalonpc Hy, Euxcsta notata 249 Citrns rod spider. Tctraiu/chus mytilaspidis 9 Clover mite, liryubiu protciisis 7 Codling moth, Vydia pomonella 177 Cottony cushion scale, Icerya purchasi 89 Cottony niaiile scale, Pulvinaria vitis 111 Euroi)eaM fruit scale, Leeanium corni 120 Fals(^ cliiut'ii hug, Ny-sius aiir/iistatns 150 Flat-headed apple-tree borer, Chryftohothris feniorata 236 Florida wax scale, Ccroplastea floridensis 113 Frosted scale, Eulecanium pruinosum 116 Greedy scale, AspidiotKs camelliw 127 Green ajjple aphis. Aphis ponii 70 Leaf-hoi)i)er. Empoa.sca mali 41 Oyster shell scale, Lepidosaphes uhni 139 Pear-leaf blister-mite, Eriophyes pyri 6 Pear scale, Epidiaspis piricola 126 Pear thrips. Eiithrips pyri 36 Red-huniijed caterpillar, Schiztira concinna 188 Red scale, Clirysomphalus aurantii 133 Rosy or purple apple aphis, Aphis sorhi 71 San Jose scale, A.ipdiotus perniciosus 130 Scurfy scale, Chionaspis furfiira 123 Striped cucumber beetle, Diahrotica vittata 230 Tarnished plant bug, Lygus pratensis 148 Tent caterpillar, eastern, Malacosoma americana 181 Tent caterpillar, western, Mahicosoma disstria 182 Walnut mealy bug, I'seudococciis hakeri 99 Apple, Thorn, {Datura sp. ). Apple leaf-hopper, Empoasca mali 41 White-lined sphinx. Celerio lineatn 1.56 AVoolly apple a|)his. Eriosoma hnrigrra 50 Apricot {I'niiius arinciiiaca) . Black scale, Sain.srtia olew 119 Citrus thrips, Eiithrips citri 34 Clover or almond mite, Bryobia pratensis 7 Common termite, Termes hicifugus 28 Cottony cushion scale, Icerya purchasi 89 European fruit scale, Leeanium corni 120 Fall cankerworm, Ahophila pometaria 187 Frosted scale, Eulecanium pruinosum 116 ^lealy plum louse, Ilyaloptcrus arundinis 86 Orange tortrix, Tortri.r citrana 176 Peach borer, Sanninoidea opalescens 195 Pear thrips, Euthrips pyri 36 Spring cankerworm, Paleacrita vcrnata 185 While peach scale, Aulacaspis pentagona 124 Aralia japonica. • 'oiloiiy itiaple scale. I'uhinaHa vitis 111 Archangelica atropurpurea. I'arsiiii, louse, Hyadaphis pastinaciE 86 Argyreia speciosa. While ]Mach scale, Aulacaspis pentagona 12.5 Arrow-wood ( \'ihurnuw deiitatum). • Ollony maple scale, I'ulrinaria vitis 111 Arrow -wood, see Laurestinus HOST INDEX. IX Ash {Fraxinus svs.). ^^-^^^(^ Black scale, Saissetia olcw 11^ Citrus white fly, Aleyrodes citri 350 Frosted scale, Eulecanium pruinosum H" Ash, Mountain {Sorbus sps.). Peai'-leaf blister-mite, Eriophyes pi/ri _ 6 Pear slug, Caliroa cerasi ^ -°-'- Rosy or purple apple aphis, Aphis sorbi ^^1 Scurfy scale, Ghionaspis furfura 12^ Ash, Prickly {Xanthoxylum clava-hercuUs) . Citrus white fly, Aleyrodes citri 350 Asparagus (Asparagus sps.)- Asparagus miner, Agromyza simplex 251 Common asparagus beetle, Grioceris asparagi 2-7 Hemispherical scale, tiaissetia hemisphrerica 117 Ivy scale. Aspidiotus liederw 128 Aspen (Fopuhis tremuloides) . Popular-stem gall louse. Pemphigus popuUcaulis o4 Aspidistra lurida. ^„^ Florida red scale, Chrysomphalus aonidum -I'jJ- Aster (Asier sps.). Black scale, Saissetia olew H^ Greenhouse white fly, Aleyrodes vaporariorum 145 Australian Blackwood {Acacia melanoxylon) . Cottony cushion scale, Icerya purchasi 89 Red scale. GhrysoiiiphaJus aurantii 133 Aucuba sp. . ^„_ Red scale. Vhrysomphalus aurantii J-*J"^ Azalea {Rhododendron sp.). (ireenhouse thrips, Heliothrips hwmorrhoidalis 32 Bamboo {Arundinaria sp.). Bamboo louse. Myzocallis arundicolens 83 Cottony bamboo scale, Antonina crawi 108 Banana Shrub {Magnolia fuscata) . Citrus white fly, Aleyrodes citri 350 Banana {Musa sapientinm) . Displacus ceroputo, Geropnto yuccce 96 Florida red scale, Ghrysomphalus aonidum 132 Lesser fruit flies, Drosophila sps 2.54, 25o Banksia integrifolia. Purple scale, Lcpidosaphes heckii 13( Barley {Hordeum sp.). Alfalfa looper. Autographa gamma californica 162 Angonmois grain moth, Sitotroga cerealella 173 Corn leaf-aphis, Aphis maidis *54 Grasshoppers I'' Basswood, see Linden. Bay {Laurus sps.). Citrus white fly, Aleyrodes citri 144. 350 Florida wax scale, Gcroplastes floridensis 113 Bay, California, see California Laurel. Bean {I'hnseohis sps.). Apple leaf-hopper, Empoasca mali 11 Bean thrips, Heliothrips fasciatus 30 Bean weevil, Acanthoscelides ohtectus 237 Greenhouse white fly, Aleyrodes vaporariorum 145 Harlequin cabbage bug, Murgantia histrionica 146 Lima bean pod-borer, Etiella zinckenella 1"4 Six-spotted mite, Tetranychus bimaculattis 8 Twelve-spotted cucumber beetle, Diabrotica soror 229 Bear's Breech {Acanthus sp.). White peach scale, Aulacaspis pentagona 1-5 X HOST INDEX. „ . ,. Page. Beech ( / I> !/!/>» a crif/iia lO'^ Harlequin cahhafr.- bus, Muryuutia histrioiiica 1^(> Hop flea beetle. I'si/Uiodes ininctulata -^1 MiiHiK- falsi' (bincb buji. Xi/siiis turor 229 Wfsicni .iniiy woi'mi. (liorhduruti)^ uijrcsiis 163 Begonia sp. Ciirus mealy Imu. I'scudococcus cttn ^^^ I-Morida red scale i'liiiisoinphnUis aonidum 132 (Ji iilhMisc lliriiis. Hcliothriiis hanwrrhoidaUs 32 Bermuda Grass {Ciiintdun ductiilon) . ('.)tiiiny I'ushion scale, Icenja piirchasi 91 Bidens sp. Ui-an llirii)s. llfliothriiht fasciatus 30 Ki'd scab', ('hii/soiiiplu/his aiirantii 134 Bignonia sp. <"iinis mraly buu. I'sciidococcus citri 102 lli-mispberical scale, Saissetia hrwisphwrica IIT Billbergia zebrina. I'irM'.ipplf sc;ilc. Diaspis hromeliw 1-3 Birch ( Hi tula sps. I. .Vplilc l('af-b()i)i)er. Einpoasca mail 11 Frosted scale. Eutccaniinn pruinosum 116 < )ysri'r sbcll scale. Lepidosaphes ulmi 139 Bird of Paradise t Stnlitzia sps.). Citrus mealy luiu'. Pscndocdvciis citri 102 Greedy scale Aspidiotiis camellia' 127 Blackberry [I'tilius sp.). Appli' lcat'-lioi)))er. Em poasca mall 41 Cottony maple scale. I'lilvinaria vitis 111 Oyster shell scale. Lcpidosaplics ulmi 139 Itaspbi-rry born-tail. JIartigia crcssoni 280 Kose scale, A nlacaspis rosa- 125 Snowy tri'e-cricket, (Ecanthiis nivciis 26 Strawberry crown moth, Sesia riitilans 191 Bottle-brush ( Callixtcmon lanceolatiis) . ('itriH mealy buy. I'sciidococciis citri 102 Bouvardia sp. ('inns iMeal.\ liuii, I'.scadococcus citri 102 Box-elder t Xif/inidn aceroides) . .\pple leaf-bopper. Empoasca maU 41 Cotiuiiy maple scale. J'lilriiiaria vitis 111 Ked scale. Cliri/soiiipliahis aurantii 134 Soft brown scale, (.'occus hesperidum 114 Boxwood {Hums sp.). Iv.\ scale. Aspidiotiis hederw 128 Bread Fruit i Artix-arpiis sp. ). Kill ^laje. ('hnjxduiphaJus aurantii 1.34 Broad Bean { \i(ia faha). I'.road-bean weevil. Laria nifimaiia 239 Broom iCpstiHiis sp. I. < »yster shell scale, Lepidosaphes ulmi 139 Brussels Sprouts, see Cabbage. Bryophyllum calycinum. White peach scale. Aulacaspis pentagona 125 Buckeye {.IJsculiis sps.). Cottony maple scale, Pulvinaria vitis 111 HOST INDEX. XI Buckthorn {Rhamiis s\).) . P^^^- Apple leaf-hopper, Einpousca iiiali ^ Black scale, Saissetia olew |^J^ Ivy scale, Aspidiotus hederce " Oyster shell scale, Lepidosaphes vlmi ^^"f Pear slug, Caliroa cerasi Buckwheat {Fagopiirum esculentum) . Apple leaf-hopper, Empoasca mali ^^ Clover mite, Brijohia prateiisis * Bur Marigold, see Bidens. Burning Bush, see Euonynius. Butcher's Broom (Ruscus aculeatus). Ivy scale, Aspidiotus hederce -^"^ Buttercup (Ranunculus calif ornicus) . ^ Woolly buttercup louse. Pemphigus californicus ^^ Butternut (Juc/huis ciucrea). Oyster shell scale, Lepidosaphes ulmi ^•^'^ Button-bush (Cephalanthus sp.). Pear slug, Caliroa cerasi -^ Cabbage {Brassica olcracea). Alfalfa looper, Autographa gamma californica io- Cabbage louse, Aphis brassicw --^ ,_^^X Cabbage maggot. Phorbia brassicw -'^", ^o( Cabbage worm, Pontia rapw V^ False chiuch bug, Nijsius angustafiis 15|| Green peach aphid, Myzus persicw '^ Harlequin cabbage bug, Murgantia hisfrionica 14b Hop flea beetle, Psylliodes punctulata^- ^^1 Twelve-spotted cucumber beetle, Diabrotica soror --o Western army worm, Chorizagrotis agresfis 16^ Cajanus sp. -.-.q Black scale, Haissetia olew ^^^ Cajaput Tree (Melaleuca sp.). Black scale, Saissetia olew H'^ Calla (Zantedcschia a^thiopica). Six-spotted mite. Tetranijchus bimaculatus o Callacarpa lanata. ^^-■ White peach scale, Aulacaspis pentagona J^— J Calotropis procera. -,,,^ White peach scale, Aulacaspis pentagona -L— ^ Camellia sps. oo Black citrus louse, Toj;optcru aurantiw ** Black scale, Saissetia olew 11^ Florida red scale. Chrysomphalus aonidum l-J^ Fuller's rose beetle, Aramigus fulleri 240 Greedy scale. Aspidiotus camelliw ^^^ Hemispherical scale. Saissetia hemispharica 11^ Ivy scale, Aspidiotus hederw 1^^ .lapanese wax scale, Ceroplastes ceriferus 111 Soft brown scale. Coccus hesperidum 114 Camphor (Camphoru officinalis). Florida red scale, Chrijsomphalus aonidum 1^- Greedy scale. Aspidiotus camelliw 12< Red scale. Chrysomphalus aurantii 1^3 Canna sp. ,-,<() Fuller's rose beetle, Aramigus fulleri -*^ Pineapple scale, Diaspis bromeliw 1—"* Cantaloupe (Cuenmis sp. ). Cantaloupe fly. Euxesta notata -'^ Striped cucumber beetle, Diabrotica vittata 230 Caraway (Carum carui) . Celery caterpillar. Papilio polyxenes 1^^ Carob Tree (Ceratonia sp.) Ivy scale. Aspidiotus hederw 1-^ Xii HOST INDEX. Carnation iDidiitlnis iiniiophiilhis) . Page. (Jn'cii iK'iH'li npliid. Myzus pcrsicw 79 Onion tlirii)s. 'I'luiiis tahaci 38 Carpodetus serrata. Iv.v sfiilc. A.ipidiotiis hcderw I'^o Carrot (l)aciis carota). CMory caterpillnr. I'opilio iioJii-iciics 198 Parsiiii) lovis(\ 1/ i/dddphis jxisliiiacw 86 Castor Bean {liicinus sp.). ("ottoiiy ciisliion scale, Jcerya purchasi 89 Cat-tail (Ti/phd aiujustifolia) . rutnto tuber moth. Phthoiinuni oprrciilella 167 Cauliflower, see Calihajie. Ceanothus sps. Citrus nical.v bu,^-, I'scudococcus citri 102 Diplacus ceroputo, Ceroputo yiiccw 96 (ireed.v scale. Aspidiotns camelUw 127 Oyster shell scale. Lepidosaphes ulnii 139 Celery {Apimn (/mrcolcns). Apple leaf-hopper, Bmpoasca mali 41 Celery caterpillar, Papilio polyxenvs 198 Parsnip louse, Hydaplm pasUnacw 86 Western army worm, Chorizagrotis agrestis 163 Cerasus sps. California peach borer, Saniiinoidea opalescens 195 ("ilnis white Hy. Alryrodes citri 350 Cercidiphyllum Japonicum. I'urple scale, Lcpidasaphcs heckii 137 Chaerophylium temulum. Parsiii]) louse, II iii)])er, l-hupoasca mali 41 P>lack cherry louse, Myzus cerasi 77 California tussock moth, Hemerocampa vetiista 179 Cherry scale, Eiilccanium cerasorum : 115 Cherry slug, Caliroa cerasi 281 Clover mite, Bryohia pratensis 7 Eastern tent calerpillar, Malacosoma americana 181 European fruit scale. Lecaniiim corni 120 Fall cankerworm. Alsophila pometaria 187 Frosted scale, Enlecanium pruinosum 116 (Jreedy scale, Aspidiotns catnclJiw 127 Oreenhouse thrips, Nclioflirips h(cmorrhoidalis 32 (Jreen i)each aphid, Myziis persicw 79 Harlequin cabbaj;e bu.?, Miirgaiifia histrionica 146 Ivy scale, Aspidiotns hcderw 128 Oyster shell scale. Lepiodosaphes ulmi 139 Peach borer. Sanninoidea opalescens 195 Pear thrips. hhithrips pyri ^ 36 lied-luunped caterijillar, Hchiziira concinna 188 San Jose scale, Aspidiotus perniciosus 130 Scurfy scale, dhionaspis fnrfiira 123 Walnut scale, Aspidiotns juglans-regiw 129 White ]ie;K'h scale, Aulacaspis pcntagona 124 Cherry, Choke (J'ruiius rirginiana). Apple leaf-hopi)er, Kinpousca mali 41 Scurfy seale. Chionnspis fnrfnrn 123 Cherry Laurel ( I'niniis lanroccrusns) . Citrus white |ly. Aleyrndcs citri 350 Chestnut, Spanish {<'astun(a satira). European fruit scale. Lecaninm corni 120 Chinaberry. see ITmbrella Tree. Christmas Berry, .see Mountain Holly, HOST INDEX. Xin Chrysanthemum sps. ^^^q<) Greenhouse orthezia, Orthesia insignis • '^- Greeuhouse white fly, Aleyrodes vaporariorum 145 Green peach aphid, Myzus persicce '^9 Harlequin cabbage bug, Murguntia histrionica 140 Hemispherical scale, Sai^setia hemisphwrica 117 Six-spotted mite, Tctrangchus bimaciilatus _ 8 Twelve-spotted cucumber beetle, Diabrotica soror 229 Cissus sp. . ^,-,_ (ireedy scale, Aspidiotiis camelhw -L-' Citron {Citrus medica) . -tno Citrus mealy bug, Pseudococcus citri 10- Citrus white fly, Aleyrodes citri 350 Citrus sps. See Orange and Lemon. Barnacle scale, Ceroplastes cirrlpcdiformis 112 Black citrus louse, Toxoptera auruntar 88 Black scale, Saissctia olew H^ Citrus mealy bug, Pseudoeoccus citri 102 Citrus red spider, Tetranychys mytilaspidis 9. 302 Common termite, Tcrmes lucifugus 28 Cottony cushion scale, Icerya purchasi 89 Florida red scale, Chrysomphalus aonidum 132 Florida wax scale, Ceroplastes floridensis 113 Fuller's rose beetle, Aramigus fulleri 240 Glover's .scale, Lcpidosaphes gloverii 138 Greenhouse orthezia, Orthezia insignis 93 Greenhouse thrips, Heliothrips hwmorrhoidaUs 32 Green peach aphid, Myzus persicw '''8 Harlequin cabbage bug, Murgantia histrionica 146 Hemispherical scale, Saissetia hemisphwrica 117 Ivy scale, Aspidiotiis hederw 1-8 Long tailed mealy bug, Pseudococcus longispinus 106 Melon aphis. Aphis gossypii ^^ Minute false chinch bug, Nysius angustatus uiinutus 150 Orange chionaspis, Chionaspis, citri 121 Purple scale, Lepidosaphcs heckii 137 Red scale, Chrysomphalus aurantii 133 Silver mite, Eriophyes oleivorus 4 Soft brown scale. Coccus hesperidum 114 Twelve-spotted cucumber beetle, Diahrotica soror 229 Woolly citrus aphid, Aphis cookii 61 Yellow scale, Chrysomphalus citrinus 135 Clematis sp. Six-spotted mite, Tetranychus himaeulatus ^ Soft brown scale, Coccus hesperidum 114 Clover {TrifoUum sps.). ^ Alfalfa crane fly, Tipula simplex 24o Alfalfa looper, Autographa gamma californica 162 Apple leaf-hopper, Empoasca mali 41 Bean thrips, Heliothrips faseiatus 30 Clover mite, Bryohia pratensis ' Grape leaf-hopper, Typhlocyha comes- 42 Grasshoppers '\ ^ Hop flea beetle, Psylliodes punctulata -pi Ivy scale, Aspidiotus hederw 1-8 Western army worm, Chorizagrotis agrestis 103 Cocoanut {Cocos nucifera) . Florida red scale, Chrysomphalus aonidum 132 Kentia mealy bug, Pseudococcus pseudonipw 107 Red scale, Chrysomphalus aurantii 134 Coffee (Cofea arabica). Black citrus louse, Toxoptera aurantiw 88 Citrus mealy bug, Pseudococcus citri 10- Citrus white fly, Aleyrodes citri 144, 350 o Xiv HOST INDEX. -> , Page. Coleus sp. . ^f.(y Grecnhouso orthezia, Orthezia insignis 92 Grwnliouso white fly, Aleyrodes vaporaiiorum 145 Lonji-taikHl inoaly bug. Psciidococcus loiigispinus 106 Corn (/<•« iiKiiis). Augouniois jirain moth, Sitotrof/d ccrcalella I'o Apple Icaf-hoppor, Empoasca mali 41 Beet army worm, Laphygma cxigita 163 Chinch bui;. Blisniis Inicopterus 149 Corn-ear worm, Ucliothis obsohta 165 Corn loaf-aphis. Aphis maidis 64 Grasshoppers 1^ Twelve-spotted cucumber beetle, Diabrotica soror ^^» Wcsli'rn army worm. Vhorizagrotis agrestis 163 Cotoneaster sp. I't-ar-lcaf blister mite, Eriophyes pyrt o Cotton ((jossypiiim sp. ). Beau thrips, HcUothrips fasciattis 30 Cantaloupe fly, Eu.vesta notata 249 Citrus mealy bug, Pseudococcus citri 102 Cotton-boll worm, Hcliothis obsoleta 165 Melon aphis. Aphis gossypii 62 White peach scale, Aulacaspis pentagona 125 Cottonwood {Populus sps. ). Ai)ple leaf-hopper, Empoasca mali 41 Bead-like cottonwood gall-louse. Pemphigus populimonilis 58 Common cottonwood louse, Thomasia populicola 84 (ireedy scale, Aspidiotus camclliw 127 Oyster shell scale, Lepidosnphes iilmi 139 Poplar-stem gall-louse, Pemphigus populicaulis 54 Walnut scale, Auspidiotiis juglans-regiw 129 Cowpea i\igii Fern, Maidenhair (.Adidiitum sp. ) . Ivy scale, .[■•ipidiotus hederw 1-8 Fern, Staghorn { I'latiiecrinm sp.). Lon.tj-tailcd mealy hug, Pseudococcus longispinus l'"> Fern, Wood {.\si)idium sp. ). (iieenhouse thrips, HcHothrips hwinorrhoidalis 32 Feverfew, see Chrysanthemum. Fig ( Ficus sps). Blast 01 iliaga. lildxIopluKja grossorum 268 Citrus white Hy, Aleijrodes citri 350 Cottony cushion scale. Icerya piirchasi 89 Florida wax scale, Ceroplastes floridensis 113 Greenhouse thrips, HcHothrips hamorrhoidalis 32 Lesser fruit fly, Drosophila ampclophila 254 Long-tailed mealy bus. Pseudococcus longispinus 106 Pear thrips, Euthrips pyri 36 Purple scale, Lepidosaphes heckii 137 Red scale, Chrysomphalus aurantii 133 Soft brown scale. Coccus hesperidum 114 Filaree (Erodium sp.). (Ii'ape leaf-hopi)er, Typhlocyha comes 42 Flacourtia sepiaria. Long-tailed mealy bug, Pseudococcus longispinus 106 Four-o'clock (Mirabilis calif ornica) . 15ean thrips, HcHothrips fasciatus 30 Fuchsia sp. (.'itrus mealy bug, Pseudococcus citri 102 Greedy scale, Aspidiotus camcUiw 127 Greenhouse thrips, HcHothrips hwmorrhoidalis 32 Greenhouse white fly, Aleyrodcs vaporariorum 145 Red scale, Chrysomphalus aurantii 184 Six-s[)0tted mite, Tetranychus himaculatus 8 Gardenia sps. Citrus white fly, Aleyrodcs citri . : 350 Greenhouse orthezia, Orthezia insignis 93 .lapanese wax scale, Ceroplastes ceriferus 111 Genista sp. Ivy scale, Aspidiotus hederw 127 Geranium {Pelargonium sp. ). <'()ti()ny cushion scale, Icerya purchasi 89 Greenhouse white fly, Aleyrodcs vaporariorum 145 Six-si)0tted mite, Tetranychus himaculatus 8 White peach sale, Aulaeaspis pcntagona 124 Godetia sp. Six-spotted mite, Tetranychus himaculatus ' 8 Golden Rod {fiolidago sp. ). Orange tortrix, Tortrix citrana 176 Red scale. Chrysomphalus aurantii 1.34 Gooseberry ( Rihcs gross ularia) . .\l)pl(" leaf-hopper, Empoasca mali 41 European fruit scale, Lecanium corni 120 Imi)orted currant borer, Scsia tipuliformis 193 Scurfy scale, Chionaspis furfura 123 Goosefoot {Chenopodium sp.). I'.ean thrips, HcUothrips fasciatus 30 Gourd {('ncurhita pcpo var. ovifera) . Squash hug. Anasa tristis 147 HOST INDEX. XVI 1 Gourd, Powder Horn ( Laneiiaria vulgaris) . Page. Moluii aphis. Apliis (jussypii 62 Grape ( Viiis sp. ) . Apple leaf-hopper, Empoasca mali 41 Achemon sphinx, Pholiis achemon 158 Black scale, Saissctia olew 119 California grape root-worm, Adoxus obscunis 226 Citrus thrips, Eiithrips citri 34 Common cut worm. Eiixoa atomarin 161 Cottony cushion scale, Icerya purchasi 89 Cottony maple scale, Pulvinaria vitis HI European fruit scale, Lecanitim coriii 120 False chinch bug, Nysiiis angitstatus 149 I"'rosted scale. Eiilecaniuni pruinosum 116 Grapevine flea beetle, Haltica cariudtu 230 Grapevine hoplia, Iloplia callipyge 1 233 Greedy scale. Aspidiotiis camelliw 127 Greenhouse white fly, Aleyrodes vaporarionim 145 Greenhouse thrips. Hcliothrips hwmorrhoidalis 32 Leaf-hopper, Typhlocyha comes 42 Pear thrips, Euthrips pyri 36 Phylloxera, Phyllojcra vastatrix 48 Red scale. Chrysoiitplniliis aurantii 133 Rose snout beetle, llliynchites bicolor 241 White-lined sphinx, Celerio lineata 156 White peach scale. Aiilacaspis pentagoiia _ 125 Grapefruit, see Pomelo. Grass {G ra min ece ) . Apple leaf-hopper, Empoasca mali 41 Beet army worm, Luphygina exigtia 163 Chinch bug. Blissus Icucopterus 149 Clover mite, Bryohia pratensis 7 False chinch bug, Xysiiis angiistatus 149 Grape leaf-hopper. Typhlocyha comes _ 42 Grasshoppers 16, 24 Ivy scale, Aspidiotiis hcdcrw 128 Mealy plum louse. Ilyalopterus anindinis 86 Onion thrips, Thrips tahaci 38 Tarnished plant bug, Lygus pratensis 148 Western army worm, (Jhorizagrotis agrcsHs 163 Greasewood (Adenostomn fasciculatiim). Grapevine hoplia, Hoplia callipyge 233 Grevillea sp. Black scale, Saissetia olew — . 119 Grewia sp. Black scale, Saissctia olew ny Groundsel (Senecio vulgaris). Green peach aphid. Myziis persicie 79 Groundsel Tree (Baccharis sps.). Black scale, Saissetia olew 119 Greedy scale, Aspidiotiis camelliw 127 Guadeloupe Palm {Erythea edulis). Citrus mealy bug, Psciidococcus citri 102 Guaguma ulmifolia. White peach scale, Aulacaspis pentagona 127 Guava {Psidium sp. ). Black scale, Saissetia olew 119 Florida red scale, Vhrysomphalus aonidmn — . 132 Florida wax scale, Ceroplastes floridetisis 113 Guava mealy bug, Pseudococcus nipw 106 Hemispherical scale. Saissetia hemisphwrica 117 Long-tailed mealy bug, Pseudococcus longispiniis 106 -HM Xviii HOST INDEX. Gumbo (JJibiscus sps.)- '^'^*l^' Japancso wax scale, Ceroplastes ccrifcni-s 111 riiu'niiplc scale, Diaspis hromcUw 1^^ Wliilc peach sale, Aiilacaspis pentagona l25 Habrothamnus sp. „ lllack st-aic, SSaifisctia olcw 11^ Citrus mealy bug, Pseiidococcus citri . ^ 1'^- Hawksbeard {Crepis sp.)- „„ r.taii llirips. Heliothrips fasciatiis ^^ Hawthorn (Rham mis sp.) see Bucktliorn. Cotldii.v maple scale, Pulvinuria riti.s 111 Frosted scale, Eidecanium pruinosnm 11" Green apple aphis. Aphis pomi '" Ivy scale, Aspidiotus hederw l'^^ Oyster shell scale, Lejndosaphes ulmi l39 Ked-luimped caterpillar, Schizura concinna 188 Rosy or purple apple aphis. Aphis sorhi 171 San Jose scale, Aspidiotus perniciosus 130 Scurfy scale, Chionaspis furfvra 1-3 Hazel (Caryl us sp.). Ai)i)le l(>af-hopper, Empoasca luali 41 Heath ( Erica sp. ). Greedy scale, Aspidiotus camellice l^l" Ivy scale. Aspidiotus hedercE 128 Heliotrope {HeUotropium sps.). Beau thrips, Heliothrips fasciatus 30 Six-spotted mite, Tetranychus himaculatiis 8 White peach scale, Aiilacaspis pentagona 125 Hemp (Cannabis sp. ). .\l)ple leaf-hopper. Empoasca mali 41 Heracleum sphondylium. rarsiiip louse, Hyadaphis pa.itinaci) flea beetle. Psi/lUodes punctulata 231 Hop louse, I'horodon humuli 85 Six-spotted mite, !'( trani/elius bimaculafus S, 302 Hop-tree (J'tclea buldirinii var. erenuUitu) . Oyster shell scale, Lepidosaphes ulmi 139 Horse Bean, see Broad Bean. Horse-chestnut (.Eseulus hippocasfdnuiii ). Apple leaf-hopper, Empoasca mali 41 Oyster shell scale. Lepidosaphes ulmi 139 Horse Radish (Covhlearia annoracia) . Ci\\)\MiH' worm, Pontia rapw 196 IIarle(|uin cabbage bug, Margantia histrionica 146 Wi'stdii army worm, Chorizagrotis agrestis 163 Hound's Tongue (('ynoglossum sp. ) . (Jreeu peach aphid, Myzus persicce 79 Iris sp. White flies, Aleyrodes sps 275 Ivy, Boston (Ampelopsis tricuspidata). Cjiriis white fly, Aleyrodes citri 3.50 HOST INDEX. XIX !vy, English (Hedera helix). ^^^m Citrus mealy bug, Pseudococcus citn ^^- Citrus white fly. Alei/rodes citri l"**- ^^^ Greedy scale. Aspidiotiis camellim 1-' Green peach aphid, Myzus persicce j^^ Ivy scale, Aspidiotiis hederce 1-° Pineapple scale, Diaspis iromeliw 1'-^ Soft brown scale, Coccus hesperidum H* Ivy, German (Senecio sp.), see Groundsel. Green peach aphid, Mijsus persicce '^ Japan Plum {Biotrites japonica). Florida wax scale, Veroplastes floridensis -L-^o Japonica sp. -■ .r, Chaff scale, Parlatoria pergandii -l-*- Jasmine {Jasminnm sps. ). „p^ Citrus white fly, Aleyrodes citri '^-^^ Soft brown scale, Coccus hesperidum 1^4 White peach scale, Aidacapis pentagona 1-5 Jessamine, see Gardenia. Jimpson Weed, see Thorn-apple. Jujube (Zizyphus sp.). ^ _ White peach scale, Aulacaspis pentagona J-o June-berry, see Service-berry. Juniper, Irish {Jinnperus sp.). ^ Black scale, ,S(iissetia olea- i^-J Kennedya sp. ^.^_, Red scale, Chriisomphahis aiirantii ^•^'^ Kentia sp. .,, _ Kentia mealy bng, Pseudococcus pseudompw ^^' Palm scale, Eueahjinnutus perforatus 11^ Knotweed (^I'olygonum urricuJare). Beet louse. Pemphigus betw ^'^ Kumquat {Citrus japonica). „ Citrus white fly, Aleyrodes citri '^-^^ Lambsquarters {Chenopodium albmn). Beet army worm, Laphygma exigua 163 Harlequin cabbage bug, Murgantia histrionica 146 Hop flea beetle, PsyUiodes punctulata ^'*-'- Lantana sp. „P Diplacus ceroputo, Ceroputo yuccw ^^ Greenhouse orthezia, Orthezia insignis •'- Greenhouse white fly, Aleyrodes vaporariorum I'lS Latania bonbon ica. -,o Ivy scale, Aspidiotus hederce _ |-^ Red scale, Chrysomphalus ouraiitii ^'^^ Laurel {Laurus sps.). „ Black scale, Saissctia olew ||^ Frosted scale, Eulecanium pruinosum ^^^ Greenhouse thrips, Heliothrips hcemorrhoidalis 32 Soft brown scale. Coccus hesperidum 114 White peach scale, Aulacaspis pentagona 125 Laurel, California (UmheUularia calif ornica). Ivy scale, Aspidiotus hederce 1-"^ Soft brown scale. Coccus hesperidum 114 Laurel, Cherry {Prunus laurocerasus) . Citrus white fly, Aleyrodes citri •=»^^ Laurestinus {Viburnum tinus). Citrus white fly, Aleyrodes citri "^^Y Cottony maple scale, Pulvinaria vitis HI Lavatera sp. ^r>7 Greedy scale, Aspidiotus camelliw l-^' Lemon {Citrus rnedica var. limon), see Citrus. Chaff scale, Parlatoria pergandii 142 Citrus mealy bug, Pseudococcus citri 1^^ Citrus white fly, Aleyrodes citri 350 Silver mite, Eriophyes oleivorus ' 4 Walnut mealy bug, Pseudococcus hakeri "^ XX HOST INDEX. Lettuce {Lactuca sps.). Page. Bonn thrips, Ileliothrips fasciatns ■ 30 False chinch bug, Nysius a iipii. status 140 ( Ji-(M'iih(iiiso wliite fly, Alci/rodcs viiporu riorum 145 IIiirl('(juiu cabbage bug, Murgantia histrionica 146 Twelve-spotted cucumber beetle, Diabrotica soror 229 Lignum vitae. Ilariiaclc scale, Geroplastes cirripediformis 112 i'Morida wax scale, Cerophistr.s floridensis 113 K(m1 scale, (Jlirj/somphalua auraiitii 134 Lilac {St/riiiga sps.). Apple leaf-hopper, Empoasca mali 41 Citrus white fly, Alei/rodes citri 144, 350 Cottony maple scale, Pulvinaria vitis 111 (Jrain thrips, Euthrips tritici - 33 Oyster shell scale, Lepidosaphes uhui 139 Lime (Citrus iimetta). Diplacus ceroputo, Ceroputo yuccw 96 Linden {Tilia sp. ). Apple leaf-hopi)er, Empoasca mali 41 Cottony maple scale, PuUiiiaria vitis 111 Oyster shell scale, Lepidosaphes ulmi 139 Locust (Robinia pseudacacia) . Cottony cushion scale, Icerya purchasi 89 Cottony maple scale, Pulvinaria vitis 111 Ilarlequiu cabbage bug, Murgantia histrionica 146 ^\'alllut scale. Aspidiotus jmjlans-regice 129 Locust, Honey (Oleditschia triacauthos). Itlack scale, Haissetia olece 119 Loganberry (Ruhus vitifolius) . Frosted scale, Eulecanium pruinosum 116 Hasjiberry horn-tail, Hartigia cressoni 280 Lonicera sp. (ircciihouse orthezia, Orthezia insignis 93 Lucerne, see Alfalfa. Lupine iLupiinis sps.). California tussock moth, Hemcrocauipa vetusta 179 Lupine aphid, Macrosiphum albifrons 72 Madder (Rubia peregrina) . I\y scale. Aspidiotus hederw 128 Magnolia sps. I'.lack scale, Saissetia olew 119 Citrus white fly, Alei/rodes citri 350 Cottony cushion scale, Icerya purchasi-- 89 Glover's scale, Lepidosaphes gloverii 138 Ivy scale, Aspidiotus hederw 128 Mallow {Malva sps.). Alfalfa looper, Autographa gamma californica 162 Beet army worm, Laphygma exigua 163 Green peach aphid, Myzus persicw 179 Mango i Mnngifera sp.). Florida wax scale, Geroplastes floridensis 113 Greenhouse thrips. HcUothrips hwmorrhoidalis 32 Japanese wax scale, Geroplastes ceriferus 111 Long-tailed mealy bug, Pseudococcus longispinus 106 Manzanita (Arctostaphylos sp.). <{rain thrips. Euthrips tritici .33 Maple. {Acer sp. I. A])ple leaf-hopper Empoasca mali 41 Black scale, Saissetia olew 119 Cottony maple scale, Pulvinaria vitis 111 Ivy scale, Aspidiotus hederw 128 Oyster shell scale, Lepidosaphes ulmi-^ 139 HOST INDEX. XXI Melons {Ciicurbita, Cucumeris, etc.)- Page. Black scale, Saissetia olew ■ 119 Cantaloupe fly, Euxesta notata 249 Greenhouse white fly, Alei/rodes vaporariorum 145 Melon aphis, Aphis gossypii 62 Twelve-spotted cucumber beetle, Diabrotica soror 229 White-lined sphinx, Celerio lineata 156 Mesembryanthemum sp. I>il)lacus ceroputo, Ceroputo yuccee 96 Mignonette (Reseda sp.). Cabbage worm, Pontia rapw 197 Six-spotted mite, Tetranychus iimaculatns 8 Mistletoe {Phoradendron flavescens) . Greedy scale, Aspidiotus camellia' 127 Ivy scale. Aspidiotus hederw 128 Monkey Flower (Diplacus glutinosiis) . I>iplacus ceroputo, Ceroputo yuccw 96 Moonflower {Ipomaa boiia-nox). Lonu-tailed mealy bug, Pseudococcus longispinus 106 Six-spotted mite, Tetranychus iimaeulatus 8 Morning-glory {Ipomoca purpurea) . Soft brown scale. Coccus hesperidum 114 Mulberry [Morus sp. ). Cottony maple scale, Pulvinaria vitis HI Ivy scale, Aspidiotus hederw 128 Soft brown scale. Coccus hesperidum 114 White peach scale, Aulacaspis pentagona 124 Mullein {Vcrhascum rirgatum) . Benn thrips, Heliothnps fasciatus 30 Mustard (Brassica sps.) . Cabbage louse. Aphis brassicw 60 Cabbage worm, Pontia rapw 196 False chinch bug, Nysius angustatus 150 Grape leaf-hopper. Typhlocyba comes 42 Harlequin cabbage bug, Murgantia histrionica 146 Hop flea beetle, Psylliodes punctulata 231 Twelve-spotted cucumber beetle, Diabrotica soror 229 Western army worm, Chorizagrotis agrestis 163 Myoporum sp. Black scale. Saissetia olew ; 119 Myrica cerifera. Japanese wax scale, Ceroplastes ceriferus HI Myrsine retusa. Ivy scale, Aspidiotus hederw 128 Myrtle (Myrtus sps. ) Barnacle .scale, Ceroplastes cirripediformis 112 Citrus white fly, Aleyrodes citri : 144, 850 Florida wax scale, Ceroplastes floridciisis 113 Greedy scale, Aspidiotus camelliw 127 Soft bi'own scale. Coccus hesperidum 114 Nasturtium (Tropwolum major). Bean thrips. Heliothrips fasciatus 30 Cabbage worm, Pontia rapw 197 Nectarine {Prunus persica) . Black peach aphis. Aphis persicw-niger 67 Common termite, Termes lucifugus 28 Nephrodium sp. Long-tailed mealy bug, Pseudococcus longispinus 106 Nettle (Urtica urens) . Cottony cushion scale, Icerya purchasi 89 Green peach aphid, Myzus persicw 79 Hop flea beetle, Psylliodes punctulata 231 Xxil HOST INDEX. Nettle, Horse {Solanum carolinense) . Page. ( "niitnloiipe Hy. Euxesta notafa 249 Nightshade {Solanum sp.). IMack scale, Saissetia olew 119 ('itnig mealy bujj, Pseudococciis citri 102 t'itrus thrips, Enthrips citri 34 Cottouy cushion scale, Icerija purchasi 91 Greedy scale, Aspidiotiis cameHiw 127 Ivy scale, Aspidiotiis hederw 129 Potato tuber moth, Phthorimwa operculella 167 Red scale. Vhriisomphaliis auraiitii 133 Solnnum root louse, Trifidaplus radiricola 5'S Nipa fruticans. (iuava mealy bug, Pscudococcus nipw — 100 Norfolk Island Pine {Aiiracaria excelsa) . (Joldcii mealy bug, Pscudococcus aurilauatus 98 (Jreenhouse thrips, Heliothrips hwmorrhoidalis 32 Oak ( Q ucrcus sps. ) . Cottony maple scale, Pulvinaria vitis 111 Fuller's rose beetle, Aramigus fulleri 240 Orange tortrix, Tortrix citrana 176 Oyster shell scale, Lcpidosaphes ulmi 139 Purple scale, Lcpidosaphes beckii 137 Red scale, Vhrysomphalus aurantii 133 Rose snout beetle, Rhynchites bicolor 241 Oak, Live (Qucrcus agrifolia) . California tussock moth. Hcmcrocampa vetusta 179 Oak, Water {Qucrcus aqiiatica). Citrus white fly, Aleyrodes citri i 350 Oak. White (Qucrcus alha) . ("ottony cushion scale, Iccrya iiunhusi 91 Oats {Avctui satira). Apple leaf-hopper, Empoasca mall 41 (Grasshoppers 16 Okra, .see Gumbo. Oleander {?(crium oleander). Black scale. Saissctia ole(e 119 Citrus mealy bug, Pscudococcus citri 102 Florida red scale, Chrysomphalus aonidum 132 Florida wax scale, (Jcroplastcs fioridciisis 113 Hemispherical scale, Saissctia heinispluerica 117 Ivy scale, Aspidiotus hedera' 128 Long-tailed mealy bug, Pscudococcus longispinus lOG Oleander aphid. Aphis nerii 6G Soft brown scale. Coccus hesperiduin 114 Olive (Oica sps.). Plack citrus louse, To.ropfcra aurantiw 88 P>hick scale. Saisscfia olcw 119 (lirynoiiiphalus rossi 13(> Citrus thrips, Euthrips citri 34 Greedy scale, Aspidiotus camelliw 127 Ivy scale. Aspidiotus hcdcra' 128 Pineapple scale. Diaspis hromelim 123 Purple scale, Lcpidosaphes lieckii 137 Red scale, ('hrysoHiphalus aurantii 133 Olive, Mock ( Prunus caroliniana). Citrus white fly. Aleyrodes citri 350 Olive, Wild, see Devilwood. Onion (Allium ecpa). lleet army woi'm, Luphygina r.tigua 103 Cantaloupe fly, Euxesta notata 249 Onion thrips. Thrips tahaci 37. 38 Western arm.\- worm, Chorizagrotis agrestis l(i8 Opuntia littoralis. Ivy scale, Aspidiotus hederw 128 HOST INDEX. XXlll Orange (Citrus uinaiitiiiin ) . sc ■ ("irnis. '^'*'°i^ Black scale, Saissetia ole(F 119 Cantaloupe fly, Euxesta notata --^9 Chaff scale. Parlatoria pergandii _^ 1^^ Citrus mealy bus. Pseud (xocciis citri 1*^'"— -'^ Cottony cushion scale. Iccrija piirvliusi ^^ Cottony maple scale, Piilvinaria vitis 111 Frosted scale, Eiilccauium pniinosiun 11^ Grain thrips, Euthrips tritici J^^ Ivy scale. Aspidiotiis hrdrni' 1;^^ Japanese wax scale. Ccroplastes ccrifenis 111 Katydid. Microcri(tn(iii Jaiirifoliiini -- Orange chionaspis, Vhioiianpis citri 1^1 Orange tortrix, Tortrix citrana 1^^ Woolly citrus aphid. Aphis cookii ■ "1 Orange, Mexican {Choisi/a ternata). Citrus white fly, Alcyrodes citri 350 Orange, Osage (Toxylon pomiforum) . Cantaloupe fly. Euxesta notata ^3^ Citrus white fly, Aleyrodes citri 350 San Jose scale, Aspidiotiis perniciosiis 130 Orchids (Cattlcya sp.). Greenhouse thrips, Hcliothrips hwniorrhoidalis *>^ Hemispherical scale, Saissetia hemisphoerica H''' Pa\m. cy.f. Fuller's rose beetle, Aramigus fulleri ^^^ Glover's scale. Lcpidosaphes gloverii 139 Greenhouse thrips, Hcliothrips hwmorrhoidalis 32 Guava mealy bug, Pseudococcus nipw 106 Hemispherical scale, Saissetia hemisphcerica H*^ Kentia mealy bug, Pscudococctis pseudonipce '■ 1"'^ Marlatt scale, Phwnicococciis marlatti 94 Orange chionaspis, Chionaspis citri 121 Palm scale, Eucuhjmnatus perforatus 113 Palm. Curly {Howea hclnioreana) . Palm scale, Eucahjmnatus perforatus 113 Palm. Date (Phwnix dactylifera) . Date palm scale, Parlatoria blanchardii 140 Ivy scale, Aspidiotiis hederce l'^^ Marlatt scale, Phosnicococciis marlatti 94 Red scale. Chrysomphalus auraiitii 133 Palm, Fan, see Latania horbonica. Palm, Fish-tail {Garyota cumingii). Palm scale, Eiicalymnatus perforatus 11!his yussi/pii (32 Smilax sp. Citrus while fiy. Alei/rodes citri 350 (Jreenhouse thrijis. Ileliolhrips hwmorrhoidalis 32 Six-spotted mite, 'retriin yehus hiindciildfiis 8 Snowball ( \'iliiiniiiin s|).). A]jplc Iear-hoi)])cr. Hiiipoiisca iiiali 41 Sorghum sj). ('oni-lcaf aphis. Apiiis iniiidis (34 Sow-thistle { Sdiielnis sps. ). (frci'ii peach n])his, Myzus persicw 79 Spearmint {M cut lid sp. ). Cottony cushion scale, Iccrya purchasi 87 Spinach iHjiinacid olerdccd) . Twelve-spotted cucuniber beetle, Diahrotica soror 229 Spindle Tree, see Buonymus. Cahhaij:*' worm, Pontia rapw ^^' HOST INDEX. XXIX Squash {('itcurbitu sp. ) . ' Itrosophila husckii ^^^ Ilarlequiu cabbage bug. MuryunUa histrionka 1'*':^ Six-spotted mite, Tvtninijclius blmnciikitiis * Squash bug, Aiiasa trisiis 1^' Striped cucumber beetle, Uiahroikii rlttuta -'^J^ Twelve-spotted cucumber beetle, Diabrotica soror ^'— J Stangeria schizodon. _ ^^ Long-tailed mealy bug. Pseiidococcus longtsptiiiis J-UO Strawberry (Fixnidiia sp. ) . False chinch bug, Nysiiis aiKjustatiis 1^-' Fuller's rose beetle, Aramigus fiiUcri -40 Grain thrips. Eiifhrips tritici ^^ Greenhouse orthezia. Orthezia insiyiiis ^-J Strawberry crown borer, Sesia riitikin>s 191 Strobilanthes sp. „._, Greenhouse orthezia, Orthezia iiisigiiis -J'^ Sunflower {HcUtnifhiis aniinus). ^ Beau thrips. HduAhnps fasciatus /J_^ Beet army worm, LapJn/fiina exigiia l'^'^ Harlequin cabbage bug, Miirgantia histrionica 146 Sumach (Rhus sp. ). Apple leaf-hopper. Empoasca mali 41 Black scale. t' worm-like with numerous legs. A very peculiar animal which is sel- dom met with. Exam|)l(': Peri pat us. 4. Diplopoda. — I^and f o r m s ; body long, cylindrical, many seg- mented; two pairs of short legs to each segment; antennie short. Ex- ample: thousand-legged worms (Spi- roholus). (Fig. 3.) 5. Chilopoda. — Land forms; l)ody long, fiat, many segmented ; one pair of rather long legs to each seg- ment ; antenna? long. Example : cen- tipedes {Scolopendra) . (Fig. 4.) 6. Insecta or Hexapod a. — Aquatic and terrestrial, but prima- rily the latter. Body of the adults divided into three distinct regions : head, thorax and abdomen. Adult forms with six legs and many are winged. Transformations or meta- morphoses occur in all except the two lowest orders, Tlnjsamira and Collemhola. Example : insects. Fig. 1. — A scorpion, Buthus sp. (After Folsom. ) -PI THE MONTHLY BULLETIN. Fig. 2. — A mite, Rhyncolophus arenicola Hall. (.After Hall.) Fig. 4. — A centipede, Scolopendra heros. (After Folsom. ) Fig. ?,. — A diplopod, Spirobolus ■warr/inatns. (After Folsom.) THE MONTHLY BULLETIN. ARACHNIDA (Class). SPIDERS AND MITES. ^''r^'^'v^-^ Because of their economic importance we have thought it best to in- clude here the common injurious mites of California, even though they are not insects. As pointed out in the general classification, mites usually have eight legs and have the head and thorax united. Some species, however, especially the blister mites, have only four legs, while the young red spiders have six legs before the first molt. All forms feed by piercing the plant tissues and extracting the juice. They multiply very rap- idly and thus are capable of much damage. The winters are usually passed in the adult stage, under buds and bark scales. As soon as the first leaves appear the mites begin work. The eggs are laid singly on the outside or inside of the plant tissues, or in clusters upon the bark ; in the latter case they may be deposited around the buds, some time before they begin to open. The young de- velop very rapidly and are soon capable of bringing forth new broods. Tlie breeding continues throughout the summer — t h e greatest number of mites being evident during the hottest and dryest weather. Cold, damp weather seems to retard all activities. Fig. 5. — Mite eggs deposited around a bud. Greatly enlarged. (Original.) Control. — The control of mites has been no little task and con- siderable work has been done with exceedingly satisfactory results. Mites are generally controlled either by the application of dry flowers of sulphur alone, finely powdered dehj^drated lime and flowers of sul- phur in equal proportions, by hand or with a blower, or a two per cent solution of commercial lime-sulphur wdth spraying machines. A late development in the control of mites on truck crops has resulted in the discovery by the United States Department of Agriculture of a flour paste, made by mixing four pounds of flour in one hundred gallons of water and adding one gallon of lime-sulphur solution. This is applied as a spray. 4 THE MOX'niI.V RT'M.KTIX. Strong solutions of commercial lime-sulphur (1 to 11) ;is used for Bcale insects will greatly aid in i-idding deciduous trees of the over- wintering mites. Thorough application is essential to obtain good residts. A tine mist under high pressure is especially desirable in applying the spray. THE SILVER MITE OF THE LEMON. Eriojili ti< s (th'ironis Ashm. { I'In/topfKs olcironis Ashm.) (Fig. 6.) General appearance. — The adult mites are so small as to be invisible except with the aid of a lens. They are light yellow in color, long and jiointed anteriorly with two pairs of legs near the head. The eggs are exceedingly small, circular and faintly yellow in color. The presence of the mite is easily told by the charac- teristic silvery chafing of the skin of the lemon, due to the destruction of the oil cells. In Florida the oranges are also chafed, causing a russeting. Life History. — The eggs are depos- ited singly or in small clusters on the leaves or fruit. They hatch in less than a week in hot weather but require twice as long in cold w-eather. After several molts the mites liecome full grown in from two to three weeks. The young and adults feed ui)on the oil in the succulent parts of citrus plants. Fig. 6.— The silver mite (BWo2j7ii/es which is ()])taiii('d l)y piercing the oil ,we/i-ojHs Ashm.) ;« and?;, dorsal and f,^\\^ ^y\x\\ their bcaks. The adults are lateral views of adult ; c, egg. (After • i r? • t i , • i Hubbard.) Capable 01 ra[)id locomotion and move freely. They breed from spring until iatc fall, giving rise to many overlapping broods a .^'ear. Distribution. — Though this mite was introduced into San Diego County in 1889. it has spread very little, and is still confined to the ex- treme southern part of the State. Food plants. — AVorks upon ])ark, foliage and fruits of citrus trees. Tn California its attacks are usually confined to the lemon. Control. — Same as for the citrus red spider {Tcfrdiiijcli lis niytUus- pklis). THE MONTHLY BULLETIN. Fig. 7. — Work of the pear-leaf blister-mite {Eriophyes pijri Pgst. ) on pear leaves. (Cal. Hort. Com.) 6 THE MONTHLY BULLETIN. PEAR-LEAF BLISTER-MITE. Eriophyes pt/ri Pgst. (Figs. 7, S.) General Appearance. — The work of this mite makes its presence easily distinguishable from all others. Pear leaves are so affected as to produce reddish or dark brown spots which become darker with age and may spread so as to entirely cover and destroy the foliage. On the apple the galls remain the color of the leaves. The younger shoots suffer most. The mites are very minute and can be seen only with the aid of a microscope. The body is elongated with roughened surface, transparent and having but two pairs of legs near the head. Life History. — The mites pass the winter on the trees under the bud scales and begin to work upon the leaves as soon as they appear in the spring. The eggs are deposited in holes bored into the under- sides of the leaves. The work of the young after hatching causes the galls or swellings. The destruc- tiveness continues throughout the summer and until the leaves begin to fall in winter. There are several generations each year. Distribution. — Especially abundant in the San Jna(|uiii and Sacramento valleys. Food Plants. — The pear and apple are seriously i^a^fbiisto-mue.^r^r affected, the mites attacking the foliage as well as ophyes pyn 'pgst. the stems of the leaves and fruit. On the foliage of the pear the galls are made along the sides of the midribs of the leaves ; on the apple at the base and along the margins of the leaves. Other plants found as hosts are white beam tree, European mountain ash, wild service berry, common cotoneaster. Control. — Same as for the common red or six-spotted spider or mite. {Tetranychuf! himonilafus Ilarv.) THE CLOVER OR ALMOND MITE. Bryobia pratensis Garman. (Fig. 9.) General appearance. — The young mites are red, becoming bro^vn when fully developed. Though very much smaller than a pinhead this species is much larger than any of the connnon destructive mites in this State. The eggs are very minute, so small as to be scarcely visible to the naked eye; globular and red. Life History.— The eggs deposited in the fall hatch with the first warm spring weather and the mites at once begin to work. Their de- THE MONTHLY BULLETIN. ' velopnient is very rapid and reproduction exceedingly great, so by sum- mer there are often sufficient numbers to do great damage. Breeding and worlc continue until fall, when the eggs are laid and operations sus- pended until these hatch in the spring. Distribution. — Abundant in all parts of the State. Food Plants. — This mite is an omnivorous feeder and may be found upon a great variety of plants. Peas, clover and alfalfa are severely ViG. 9. — The clover or almond mite, Bryuhia pratensis Gar. (After Riley and Marlatt.) attacked, while they also feed upon grass, grains and buckwheat. Peach, apple, plum, apricot, prune, cherry, almond and quince trees are also among the food plants. Control.— For this pest Mr. W. H. Volck especially recommends the following formula : water, 100 gallons ; flour paste, 4 gallons ; lime-sul- phur solution, 5 quarts ; iron sulphate, 2 pounds. The flour paste and lime sulphur are thoroughly mixed in the spray tank after which the iron sulphate is added and all thoroughly agitated. Natural Enemies — The larvae of the minute black ladybird beetles [Stethorus vagans Blackb. and Stethorus picipes Casey) and the green lacewing {Chrysopa calif ornica Coq.) prey upon the clover mite hut they do not appear to be important factors in keeping it down. 8 THE MONTHLY BULLETIN. THE COMMON RED OR SIX-SPOTTED SPIDER OR MITE. *Tctn/in/cJni.s hiiiKtciihii iix Ilarv. ( 'I'cf )•(!)) i/cli lis scj'iiKicuUitiis Kilcy.) (Pig. 10.) General Appearance. — This species dike the other mites) is exceed- ingly small and individuals are seldom noticed exceptiny' when they collect in ^reat numbers. The color is red with a yellowish tinge and usually with two darker spots on each side of the body. The young greath^ resemble the adults but have six rather than eight legs. Life History. — The mites usually begin to appear after the first warm weather in the spring, the winter having been spent in the ground. They spin threads so as to conceal themselves, their eggs and young, on the undersides of the leaves and feed directly upon the tissues of the plant by sucking which gradually stunts and kills the latter. The common red mite is a serious greenhouse pest, where, under favorable conditions, it is able to woi'k throughout the entire year. Distribution. — Though of foreign origin this mite has become thoroughly distributed over the entire State and is met alike in field and greenhouse. Food Plants. — This mite is an omniv- orous feeder, apparently without any favorite food. The plants which it is known to attack are sugar beets, beans, sage, tomato, eggplant, pepper, cucum- ber, squash, cowpea, hops, berries, violet. rose, clematis, mignonette, pink, fuchsia, pelargonium, godetia, passiflora, fever- few, thunbergia, verbena, heliotrope, moon-fiower, calla. smilax and easier lil^'. Via. 10. The common i-ed .spider ' ^ ( Tet7-(tvijrhus bimaculatus Harv. ). Control. — Sull)hur and dehydrated «. tidult; t, tarsus; c, beak and pal- liiiiQ i^iivrwl ;,, ^ ^1 A- " J P"^> ''• tip f*f palpus. (L^. S. Dept. lime mixed m equal proportions and Agrci.) thoroughly sprinkled over the plants are recommended. Sprays such as emulsions, resin wash and soap solu- tions are efficient remedies, but these are usually too destructive to the tender leaves of the food plants to be practicalile. The flour paste spray is especially recommendt'tl iu such cases. Natural Enemies.— The minute black ladybirtl beetles {Stet horns vagans and Stethorus picipes) and the larva^ of the syrphid flies ])rey upon this mite. *We are informed by Dr. H. E. Ewing tliat the correct name of this species is Tetranychus telarius lAnn. THE MONTHLY BULLETIN. 9 THE CITRUS RED SPIDER. Tctran.i/chus inytllaspidis Riley. (Fig. 11.) General Appearance. — The adult insects are cardinal red and scarcelj^ larger than a pin point. They often occnr so abundantly as to give the fruit and foliage a red color. The eggs are globular and red, as are also the younger stages. Life History. — The eggs are suspended upon minute stalks with guy webs as supports. They hatch in from nine to twelve days, being laid from ]\Iay on throughout the warm summer months. The first born are six-legged l)ut after the first molt acquire another pair, making the usual number. In two weeks they are full grown and begin egg Fig. 11. — The citru.s red spider, Tetrnni/chus nii/tilaspidis Riley. Much enlarged. (After Volck. Courtesy Cal. Exp. Sta.) laying. They live from thirty to thirty-five days, thus making the life cycle cover a period of about six weeks. By far the greater numbers occur during the warm summer months when most of the damage is done, but great damage often occurs until late in winter. On deciduous fruit trees the eggs are deposited at the bases of the last year's shoots and do not hatch until the following spring. Distribution. — Occurs throughout most of the State, but is particu- larly destructive in the southern citrus-growing sections. Food Plants. — Primarily a citrus pest, working uniformly upon the foliage and fruit. Other food plants are as follows : apple, prune, peach. Control. — The first methods of control consisted in the application of dry flowers of sulphur thrown upon the tree by hand. Later power blowers were employed and these are still used, but to the sulphur is 10 THE MONTHLY BULLETIN. added an equal amount of dehydrated lime. The applications are preferably made early in the morning when the foliage is damp and the dust readily adheres to it ; however in large groves it is often impossi- ble to delay for such favorable conditions. In cold weather the dry sprays do little or no good, due to the slow liberation of the fumes. During the past few years liquid sprays of the commercial lime- sulphur have met Avith great favor and promise to completely do aw^ay with the dust sprays. The commercial product is reduced to from 2 to 2^ per cent and applied as a fine mist under a pressure of from 150 to 200 pounds. Care must be taken not to use the spray stronger than is absolutely necessary, for in some cases severe burnings occur to young lemons. Applications of both the dry and liquid sprays should be made as soon as the spiders appear in any considerable number. Natural Enemies. — Natural enemies pla^^ an important part in the control of the citrus red spider and are often responsible for keeping its numbers so small as to do little damage. Conventzia hageni Banks, the green lacewing (Chrysopa calif ornica Coq.) and the brown lace- Mdngs (Symplierohius angnsfus Bks. and Hemerohiiis pacifimis Bks.) are important enemies belonging to the order Neuroptera. The jninute black ladybird beetles {Stethorus vagans and S. picipes), a staphylinid beetle (Oligota oviformis Casey), the thrips {Scolothrips sexmaculatus Perg.), the larvee of a fly (Arthroconodax occidentalis Felt) and the carnivorous bug {Thriphleps insidiosus Say) prey upon the red spiders. THE MONTHLY BULLETIN. 11 INSECTA OR HEXAPODA (Class). INSECTS. ^'ORDERS. The following study is based upon the order as a unit of classification. This is done to avoid confusion and to aid in the more systematic study of these important animals. The following is a list of orders and suborders, beginning with the lowest : 1. Thysanura. — Silver-fish or silver moth, spring tails, bristle tails. 2. Collembola. — Achorutes, Sniinthurus. 3. Orthoptera. — Earwigs, cockroaches, praying mantids, -walking sticks, grasshoppers, katydids, crickets. 4. Platyptera. — 1. Suborder Corrodentia — AVhite ants or termites, psocids or bark lice and embiids. 2. Suborder Mallophaga — Biting bird lice. 5. Plecoptera.— Stone flies. 6. Ephemerida. — May flies. 7. Odonata. — Dragon flies. 8. Thysanoptera. — Thrips. 9. Hemiptera. — Bugs. 1. Suborder Homoptera — Cicadas, plant lice, scale insects, white flies. 2. Suborder Heteroptera — True bugs. 3. Suborder Parasita — Head and body lice. 10. Neuroptera. — Lacewings, including brown and green lace- wings so well known as beneficial insects. 11. Mecoptera. — Scorpion flies (Bittacus sp.). 12. Trichoptera. — Caddis flies. 13. Lepidoptera. — Moths and butterflies. 14. Coleoptera. — Beetles and weevils. 15. Diptera. — Two-winged flies. 16. Siphonaptera. — Fleas. 17. Hymenoptera. — Horntails, sawflies, wasps, bees, and many small and large parasites. "This classification is based upon that of Dr. J. W. Folsom. 12 ' THE MONTHLY BULLETIN'. Because of their ^on-^sef^ln(^s.s in snob a work as this, the following orders will not he considered : TInjsaiiufa Collemhola Plecoptcra Epliemerida Odonata Mecopfera Trichoptera Siphonaptera ORTHOPTERA (Order). STRAIGHT-WINGED INSECTS. EARWIGS, COCKROACHES, PRAYING MANTIDS. WALKING STICKS, GRASS- HOPPERS, KATYDIDS AND CRICKETS. All of the members of this order, with the exception of the praying mantids {Mantid(e) and certain exceptions among the earwigs (ForficH- lid(c), are destructive to vegetation and most of them are serious pests to cultivated crops. Though most of them possess four wings, a few genera and species have none at all. The fore wings are called tegmina and differ from those of most insects in that they are leathery being a means of protection for the delicate thin hind wings which are used for flying. All the members have strong and well developed month- parts for biting and chewing. The metamorphosis or change from the young to the adult is gradual and scarcely noticeable. The first born always resemble the adult, with the exception that they have no \vings and undeveloped sexual organs. To follow out the systematic arrangement of this order, the families are usually arranged as follows : L ^Forficulidce; 2. Blaftidm; 8. M ant idee; 4. Fliasin>d(r : 5. Acridildce; 6. Locustidxc; 7. Gryllidce. While practically all of these are of great interest and often of economic value, only the last three are deemed of sufficient importance to be included in a work of this character. These will be considered in the order as given above. *The ForficitUdw are placed in a .^I'parate order Euplexoptcra by many entomologists. THE MONTHLY BULLETIN. 13 ACRIDIIDyE (Family). SHORT-HORNED GRASSHOPPERS OR TRUE LOCUSTS. The insects of this family include the most destructive members of the entire order and are common practically everywhere. They are separated from the other families by their short antenna^ which are never as long as the body; by the three-jointed tarsi; and by the short plated ovipositor. The hind legs are large and long to enable them to travel rapidly by jumping. With the exception of a few species all have well-developed wings and are al)le to make long and continuous migra- tory tiights. ¥ ^.\ Fig. 12. — The Rocky Mountain Locust (Melanophis sprc- tiis) laying eggs. (After Riley.) The members of this family are very prolific and increase in such numbers as to cause great ruin to vegetation. Many species migrate long distances, leaving a trail of devastation in their wake. The eggs are usually laid at the bottom of a hole drilled into the soil by the abdomen of the female (Fig. 12). As the winter is passed in this stage, the eggs are thoroughly protected from cold and moisture by a fluid cement secreted by the female for this purpose. In the spring the young hoppers emerge from the holes and begin to feed upon the first green vegetation and develop very rapidly. In the early fall they begin to mate, the females depositing their eggs before winter. Control. — The control of grasshoppers is often a perplexing problem, due to their great numbers and migratory habits. Their appearance is often so sudden as to take the farmer wholly unawares and the damage done before he can defend his crops. Extensive experiments on control work have been conducted by trained men all over the world, the results of which have made the hopper invasions less dreaded. The reclamation of arid lands and the extension of agriculture to the foothills and deserts 14 THE MONTHLY BULLETIN. have eliminated many of the old and favorite breeding places, and greatly reduced the size and numbers of migrations. In this State the most destructive species are controlled as follows : Poisoned Bran. — In California the poisoned bran bait has proven exceedingly effective. This is recommended by J. S. Hunter (Bull. 170 Cal. Agrcl. Exp. Sta.), as follows: Bran 40 pounds. Molasses (cheapest) 2 gallons. Arsenic 5 pounds. The bran should be wet so that water can be just squeezed out of a lump held in the hand. After this, stir in the molasses and then the arsenic. Let stand over night and stir well before placing in the field, so as to allow the poison to penetrate every particle. The poison should be scattered in small piles, about the size of an egg, in front of the path of the hoppers throughout the infested area. In orchards bait should be placed at the trunk of each tree. This bait should be either occa- sionally moistened or renewed. Griddle Mixture. — This is one of the poisons used in the East and Middle West with such eft'ectiveness and is prepared as follows : Paris green 1 pound. Common salt 2 pounds. Fresh horse dung 60 pounds. The paris green is first mixed with Avater to form a paste and then thoroughly stirred into the horse dung with the salt. The mixture is then scattered in some such manner as is the poisoned bran. Protecting Orchard Trees. — The general practice has long been to whitewasli the trunks of trees to prevent the grasshoppers from crawl- ing up into the trees. If occasionally renewed this wash does great good in this way and is worthy of recommendation. A broad tanglefoot band near the base of the trunks will catch manv of the hoppers but if not applied very thickly the larger and stronger ones will pull out. Poison baits placed at the bases of the trees will keep mo.st of the hoppers from attempting to ascend to the foliage. Cultivation. — As previously stated the grasshoppers lay their eggs in the fall in small holes in the soil an inch or two deep. The eggs hatch in the spring and the young easily escape. Late fall or winter plowing from four to six inches deep will so cover the egg sacs as to make the escape of the newly hatched hoppers impossible. The greatest menaces are the places held by speculators, M^ho are indifferent to the ravages of these pests. Such localities afford excellent breeding places and in every community where the hoppers are bad, steps should be taken to see that such places are plowed at least during the winter months. A thorough harrowing or disking after a rain serves to fill up the burrows and to crush many of the egg masses. THE MONTHLY BULLETIN. 15 Burning. — Another means of reducing the pests is to burn the grass or stubble of the breeding places or infested field when hoppers are the most plentiful or when the females are collecting on the breeding grounds to begin egg laying. The best time for firing is during the night when the hoppers are less active and are unable to escape the approaching flames by flight. Of course only waste stubble, or pasture lands, can be so treated, but these are usually the breeding places. Great care should always be exercised to see that sufficient help is ready to keep such a fire under complete control. Hopper-dozer. — The use of the hopper-dozer has become an impor- tant factor in the control of grasshoppers, especially in grain and hay fields, in pastures and even in cultivated crops. The hopper-dozer is constructed as shown in Fig. 13. The back and sides are made of thin sheet iron or cloth and the pan at the bottom constructed to hold about two inches of kerosene. These dozers may be made any length but a two-horse size is the most practicable. They are simply drawn across the fields and capture the hoppers as the latter endeavor to escape their Fig. 13. — Plan of a very good hopper-dozer. (After Urbahns. 1 approach. Though the hoppers may escape from the kerosene bath they are doomed. The best time of operation is on warm days if possible, early in the season before the hoppers have acquired wings. A brief description of some of the most common and destructive Cali- fornia species follows. THE YELLOW-WINGED OR PELLUCID GRASSHOPPER. Camuiila pcllucida Scudd. (Fig. 14.) General Appearance. — The adults are slightly over one inch in length and are quite variable in color, varying from light yellow to dark ashy brown, with well defined black markings and two amber lines down the angles of the tegmina, noticeable when resting. These lines merge about one third the distance from the base. The head and thorax are darker than the abdomen. The basal halves of the antenna? are light while the apical halves are dark. The first two pairs of legs and hind femora are concolorous with the body — the hind femora with darker markings, while the hind tibiae are light yellow. The young are very dark in color, often almost black. If) THE MONTHLY BULLETIN. Life History, — This is one of the most famous migratory species, often Hying in great swarms, and was formerly a serious pest in the states west of the Mississippi River and often those just east. The eggs are laid in small sacs in sandy or gravelly soils. They are deposited during August and hatch in May and June. The growth of the young hoppers is very rapid so that within a month they have acquired wings and are ready to migrate. The breeding places are often located in the higher altitudes, and the adults migrate to the lowlands, many remaining along the path to deposit their eggs for tlie following- year. In the fall the species returns to old or selects new breeding grounds to deposit the over-wintering eggs. Distribution. — Throughout the State, especially prevalent in the Sierra foothills from whence they migrate into the Sacramento and San Joaquin valleys. Considerable numbers were collected around Lake Tahoe during the months of July and August of last year. Fig. 14. — The yelow-winged or pellucid gnisshopper, Camnula pellucida Scudd. (Original.) Food Plants. — This species is especially destructive to the grasses, including oats, wheat, barley, etc. Alfalfa is seldom injured, not being a favorite food. At present no serious outbreak of this pest has been definitely recorded in California, though in the earlier days it must have done considerable damage to the wheat crops in the interior valleys. THE VALLEY GRASSHOPPER. (h'dti'Icoiittt IIS iiiif/iiKf Scudd. (Fig. 15.) General Appearance. — One of the smaller species, the adults being about one fourth of an inch long. The general color is rich amber with reddish hue around the eyes. The dorsum and carimp of the thorax are dark. The tegmina are mottled with l)lack and dusky spots. The antennae and first two pairs of legs are concolorous with the body, while the femora of the hind legs are richly marked with black and the tibia? are pale blue. The young are nearly of the same general color, with the dark markings less pronounced. THE MONTHLY BULLETIN. 17 Life History.— The holes in which the eggs are laid are usually drilled in hard or compact soil. The eggs are laid regularly and horizon- tally and cemented together, as well as being surrounded with a liquid cement which renders the mass waterproof. The young hatch the fol- lowing spring, as soon as it becomes warm and they begin to reach maturity early in June. Pairing begins soon after and eggs are deposited from August to October. There are two forms of the adults, Fig. 15. — The valley srasshopper, Q^daleonotus enigma ScucM. (Original.) characterized by long and short wings. The species is very prolific and does much damage. It is only occasionally migratory. Distribution.— Throughout the lower San Joaquin Valley especially in the Turloek region. Food Plants.— All forms of vegetation, including the foliage of orchards and vineyards, uncultivated field crops, such as alfalfa, clover, grain, etc., and cultivated crops, such as vegetables, corn, potatoes, etc., are attacked. THE DIFFERENTIAL GRASSHOPPER. Melanoplus differ entialis Thomas. (Fig. 16.) General Appearance.— This is one of the larger hoppers, averaging one and five eighths inche.s from front to the tip of the tegmina or wing covers. A very beautifully colored insect when fully matured. The head, thorax, abdomen and first two pairs of legs are amber or rich brown, the sutures being dark. The wing covers are brownish gray— the true wings being transparent. The hind femora are yellow with black cross lines, while the tibial and tarsi are bright red, the former with black spots near the outer base. The spines and claws are black. The antennffi are reddish with dusky tips. The nymphs are green. Life History.— Egg-laying begins about the middle of the summer. The holes for the eggs are drilled into the soil in bare and vacant places, especially in alfalfa fields. From sixty to eighty eggs are laid by each female. They are protected from winter rains and freezes by an excretion of the female which makes the capsule containing them waterproof. They begin to hatch in the warmer spring months, appear- 2— H 18 THE MONTHLY BULLETIN. ing early in June Miid keep up their destructive work until Aujiust. The young green hoppers, as they mature, acquire wings and asraine a yellowish tint, thus causing the l^elief that there are two distiiict sj^ecies. The largest brood appears early in the sunnnci-, and the greatest amount of damage is done h^• the first of August. Fig. 16. — The differential grasshopper, Melanonlus diffevevtktUs Thomas. ( Original. ) Distribution. — Especially abundant in the San Joaquin Valley, though the species has a somewhat wider range throughout the State. Outbreaks have been recorded at Newman and Los Banos in past years. This year it was especially abundant in ^ladera County. Food Plants. — Practically all kinds of green vegetation, including most of the forage and truck crops. Especially destructive to alfalfa. Orchard trees and vineyards are also attacked, some trees and vines being completely defoliated and many killed. THE CONSPICUOUS DEVASTATING GRASSHOPPER. M cldiKi/ihis dci'd.sfiiidr cuiisiiicims Scudd. (Fig. 17.) General Appearance. — This is one of the smaller hoppers, averag- ing about one inch in length. The general color is amber or brownish with dark markings on the sides of the prothorax, on the tegmina and hind femora on which there are three distinct spots and a dark tip. The hind tibige are distinctly blue at their bases, gradually becoming amber tow'ards the tips. The hind or true wings are transparent. The antenna" are light amber. The young are lighter in color and usually without markings. Life History. — A partially migratory species which at times works from the foothills to the cultivated lands below. The eggs are deposited in the ground in the foothills, which are the special breeding grounds. Late in June the hoppers often become very destructive and though they feed mostly upon the ranges, fruit trees and small crops in those resfions are often comnletelv destroved. In the late summer and fall THE MONTHLY BULLETIN. 19 the adults collect in the breeding places and deposit their eggs for the next year's l)roods. Distribution.— In the foothill regions of the San Joaquin Valley, especially below Mariposa. Food Plants.— The food plants of this pest are about the same as for most grasshoppers and include grasses, foliage of deciduous trees, cultivated and wild, nearly all cultivated crops and succulent vege- tation. Grain and hay crops usually suffer mo>:t from their attacks. Fig. 17. The devastating gras.shopper, Melanopliis devastator conspicnvs Scudd. (Original.) Control Measures. — Control is necessary only when this species develops the migratory habit. Its attacks are -so sudden as to make control measures very necessary and prompt. In the fields the hopper- dozers may be used. Burning over the breeding grounds is recom- mended, as the most effective remedy, but great care must be exercised to avoid range and timber fires. Such treatment affects only the next vear's broods. Poisoning may be used effectually in cultivated areas. THE PALE-WINGED GRASSHOPPER. MclanopUiH iniif(jnnis Scudd. (Fig. 18.) General Appearance. — This species is characterized by the light uniformly colored bodies, which vary from dark straw to amber. The wing covers are grayish. The tips of the hind femora have two long, lateral, dark spots, and there are indications of the three dark blotches usually present. The tibia^ of the hind legs are very pale blue. The length of the adult is slightly over one and one fourth inches. The young are slightl}^ lighter in color. 20 THE MONTHLY BULLETIN. Life History. — This is a truly migratory species, being very restless and hardly remaining long enongh in one place to become harmful. The first migration occurs in the Turloek and Newman districts* during the early part of June. The swarms continue to move about through September. The young reach maturity slowly and pairing begins in August. The eggs are deposited in October and November and hatch as soon as the ground becomes warm the following spring. Fig. 18. — The pale-winged grasshopper, Melanopliis uniformis Scudd. (Original.) Distribution. — Especially abundant in the central San Joaquin Val- ley, in the region southeast of Turloek, but the range compris&s much of the central part of the State. Food Plants. — Practically the same as for Melanoplus cliff ere ntialis, though not so destructive to tfee crops. LOCUSTID^ (Family). THE LONG-HORNED GRASSHOPPERS. KATYDIDS. The members of this family are characterized by having long filiform antennffi, four jointed tarsi and a six-pieced, fiat, sickle- shaped ovipositor. The usual color is pale or bright green though many members are quite dark. All are great singers. The wings Avhen present are large but thin and delicate. Practically all of the species are vegetable feeders and while more or less destructive are not so much so as the short-horned grasshoppers {AcrklUdcc) . The control of the members of this family is practically the same as for the short-horned grasshoppers. *Bull. No. 170, p. 5, Cal. Agrcl. Exp. Sta. 1905. THE MONTHLY BULLETIN. 21 THE CALIFORNIA ANGULAR-WINGED KATYDID. Microcentriim laurifoli/um Linn. (Fig. 19.) General Appearance. — Large green long-horned grasshopper or katydid, from one and a half to two and a half inches long. Easily distinguished from the ordinary grasshoppers by the long, thin an- FiG. 19. — The California angular-winged katydid, Microcentriim laurifoliuvi Linn. (Original.) tenna^ and slender hind legs. The eggs are oval and flat, white in color, laid so as to overlap like shingles. They may be laid in a single row around the edge of the leaves or on the young stems (Fig. 21) or in Fig. 20. — Orange showing work of katydid. double rows on the latter. The young katydids are bright green and appear to be all legs and antenna. The adult females have a character- istic sickle-shaped ovipositor. 22 TKE xMONTIlLV BULLETIN. Life History. — Tho eggs are deposited in the fall and constitute the winter stage. In the spring the young katydids escape from the exposed ends and immediately begin work upon the foliage, continuing their destructiveness throughout the spring, summer and fall. The broods <\ro uneven so ^dl stayes mav Ik^ found throngliout the summer. Fig. 21. — Katydid <:ggs, showing exit lioles of tlie egg-parasite, Eupehivus inirahilis. ■ (Original.) Distribution.— Throughout the entire State, but especially common in the.citrus-growing'sections. More damage is done in the Sacramento Valley than anywhere else. Food Plants. — Particularl.y destructiv(^ to orange trees. Usually the foliage is the only part affected, but occasionally they gnaw into the young fruit, producing deep and ugly scars, which render it unfit for market. (Fig. 20.) Control and Natural Enemy. — The egg parasite (EupebuKs iiiirah- ilis) is practically responsible for the control of this pest and may be relied upon to keep it down to where great or excessive damages can not resnlt. It is wise to collect the eggs during the winter and place them into boxes covered with screen. As the small parasites gnaw their way out of the egg through small holes at the top they may escape to continue their good work, while any young katydids that may hatch out cannot escape because of their long legs and antenniv. It is very difficult to secure colonies of the eggs without finding many showing the holes made by the parasites. THE MONTHLY BULLETIN. 23 THE LONG-LEGGED GRASSHOPPER. *Cliiiot)h'iir show- ing punctures ; h. twig split open to show eggs : c, egg; (1. cap of egg. Enlarged. (After Kiley. ) ITpper right, female of (JJcinitlnix iiircus DeGeer. l.,ower right, male of (Kctnitliiis f t^- B ■ ', l^'> "' 1 1 P r ' -. V^^ Ik i i r ^ r Fig. 26. — Termes lucifugus Ro.ssi, working on roots of nectarine tree. (Original.) THE MONTHLY BULLETIN. 29 THYSANOPTERA (Order). THRIPS. The numerous species of the minute f ringed-winged jnsects, known as thrips, are placed in a single order as given above. These insects, though exceedingly small, may be readily observed by simply shaking almost any flower, especially the sunflowers and their allies, into the hand and observing the small yellowish or brownish slender individuals crawling out in the palm of the hand. They hop and fly very readily. The eggs are laid upon the outside, or within the tissues of the plant. In the latter case the female inserts the egg with her sharp ovipositor. The insects have direct or incomplete transformations, the larva greatly resembling the adults. The pupa of some species have a quiescent stage, thus differing from most insects having incomplete metamorphosis, in which this stage is very active, differing from the adults only by the small wing pads. Those species having a quiescent pupal stage are characterized by the larvae going into the ground for pupation and remaining there during the winter, the adult insects emerging in the early spring. The mouth-parts are modified so that the insects chafe rather than bite, and due to their constant work and tremendous num- bers are able to accomplish very disastrous results. They work prin- cipally upon the young buds and flowers, though they often do consid- erable damage to fruits and foliage. In this State thrips are among the mo.st serious pests, especially in the Sacramento and San Joaquin valleys, where thousands of dollars are spent each year in protecting the orchards. The control measures vary somewhat and are given under each indi- vidual species. Several species have been known to be attacked by internal hymenopterous parasites, but the exact amount of this para- sitism for the various species is not well known. THE BEAN THRIPS. Heliothrips fasciattis Pergande. (Fig. 27.) General Appearance. — The adult insect is black with head and thorax dark brown ; antennaB are whitish with tips dark ; legs are black and yellow ; front wings are blackish with white base ; posterior wings uniformly yellow with dark fringes. The young stages are lighter in appearance than the adult. Life History. — According to Mr. H. M. Russell the insects hiber- nate in the adult stage only, under leaves, rubbish, etc. They begin to emerge about January and immediately begin egg-laying. The eggs are inserted in the leaves or tender stems. The young begin feeding soon after hatching. When ready to pupate the larvae seek shelter under rubbish or in the ground, where the nymphal stage is completed and the adults emerge. There is an overlapping of broods so that 30 THE MONTHLY BULLETIN. during the summer months all stages may be found. A complete life cycle from egg to adult occupies about two mouths. The adults begin to hibernate during the months of October, November and Decemlier. Distribution. — The bean thrips are distril)uted throughout the entire State. It was first collected by Geo. W. Harney, present horti- cultural commissioner of Yuba County, in 1894. Pig. 27. — The bean tlirips, Heliothrips fasciotus Perg. Greatly enlargvil. ( After Russell. ) Food Plants. — Due to its large numbers this insect has proved n serioiLs pest to oranges, alfalfa, pear trees and various garden crops, the work being the same as that of other members of the family. !ii addition to these, the following plants are also attacked by this i)e^t: beans', burr-clover, beets, radishes, pea, lettuce, wild lettuce, sow-thistk'. w^ld heliotrope. Euryptera Incida, Gnaphalium caJifornicut». Mirabllls califoDnca, Ex nanus brevipcs, Chcnopodiioii inurale, wild sunflower. wild turnip, wild pea, nasturium. NicofiaHa glauca, Bidens pilosa, Ver- bascum virgafuni, Polygo)n(i)i (iriculare, Ci'cpis sp. Tacsoiiia nioUis.siina, tulip, jjcar, cotton. Control. — Control measures for this pest are the same as recom- mended for pear, citrus or grain thrips, depending u]>on th<' plants which are infested. A flour paste consisting of from six to eight })()unds of eheap flour to one hundred gallons of water and applied thoroughly has given excellent results in controlling this pest upon truck crops, such as beMiis, peas, beets, etc., which have tender foliage. THE MONTHLY BULLETIN. 31 THE GREENHOUSE THRIPS. HcUoflniii.s InniKJirhoiddlix Bouche. (Fig. 28.) General Appearance. — The adult insect is characterized by having the antennje eight-segmented and twice as long as the head, while the surface of the body is distinctly reticulated. The abdomen is yellowish brown, with head and thorax dark brown and antenna?, legs and wings colorless. Fig. 2 8. — The greenhouse tlirips { Ileliothrius hirmorrhoidalis Bouche) ; adult female and antenna. (After Russell.) Life History. — The very minute, bean-shaped, colorless eggs are inserted in the leaf tissues cf the food plants, usually on the underside. They hatch in about ten days. Each female lays from ten to twenty eggs. The first hatched larva? are colorless, with seven-segmented an- tennae As they age they become darker in color and the antenna' i)ecome eight-articulated. The larval and pupal stages occupy from four to six weeks. All stages feed throughout their life cycles. There are continuous and overlapping generations, estimated by H. M. Russell to be twelve a year. Distribution. — In greenhouses throughout the State. Also abund- ant in the open, especially in the central and southern parts of the State. 32 THE MONTHLY BULLETIN. Food Plants. — Citrus, azalea, Aspidhmi, crotons, dahlias, phlox, verbena, pink, ferns, vines, cherry, lanrel, laurestinus, palms, Ficus sps. Fellcea hastata, Liliacece, fuchsia, mango, begonia, cattleya, grape, Norfolk Island pine, smilax. On citrus the fruit as well as the foliage is scarred. Control. — Sprays recommended for pear thrips {Eiithrips pyri) are also applicable for this pest, ])ut in spraying tender greenhouse plants these should be weakened to two thirds normal strength. In spraying for the greenhouse thrips on citrus trees, use the formulae recommended for citrus thrips {Eutlirips citri). Fumigating may be employed if the greenhouses can be made reason- ably tight, using one third to one half of an ounce of potassium cyanide to every one hundred cubic feet of space, proceeding as directed for orchard fumigation work. Natural Enemies. — Mites prey upon this species to a considerable extent, but render little reliable aid. THE GRAIN OR STRAWBERRY THRIPS. Euthrips tritici Fitch. (Fig. 29.) General Appearance. — Very minute, being from 0.029 to 0.031 of an inch in length. The color is yellow, with orange-tinted thorax. Life History. — The eggs are very minute, globular in shape and red in color. They are inserted within the tissues of the host and hatch within a few days. The nymphs or young greatly resemble the Fig. 29. — The grain or strawberry thrips, Euthrips tritici Fitcli. (After Folsom.) adults, and begin to feed at once. The principal damage is done to the blossoms of the host. Strawberries especially suffer from their attacks. According to Professor Quaintanee, the pistil is the portion of the blossom destroyed. The winter is probably passed in the soil, as in the case of the pear thrips {Euthrips pyri) . THE MONTHLY BULLETIN. 33 Distribution. — Throughout the entire State. Food Plants. — Strawberry, orange, rose, lilac, alfalfa, grass, Cali- fornia sage {Artemisia calif ornica) and manzanita. Control. — This insect is seldom destructive enough to warrant control, but sometimes this is necessary. The sprat's used for pear thrips (excepting whitewash) are equally effective in controlling this pest. THE CITRUS THRIPS. Euthrvps citri Moulton. (Fig. 30.) General Appearance. — The adult thrips are orange-yellow in color, with the thorax and the second antennal segment orange-brown. They are very minute ; so small as to be scarcely observed by the average orchardist, being less than one thirtieth of an inch in length and one one-hundredth of an inch in width. The presence of this insect is Fig. 30. — Citrus tlarips (Enthrips citri Moult.). Pliotomicrograph of adult female. (Plioto by Arizona Agricultural Experiment Station.) 3— H 34 THE MONTHLY BULLETIN. usually ascertained by the work, which consists m scarring the fruit in such a way as to form nearly regular circles around the stem and blos- som ends, although these scars may extend almost over the entire surface. They also cause a characteristic crinkling and thickening of the young citrus foliage, just as the buds are unfolding. Life History. — The winter is spent in the adult form, which hiber- nates in various protected places. The thrips become especially abun- dant about the time the citrus trees are in bloom and begin their work as soon as the petals fall and continue throughout the summer. The eggs are laid from May to August, hatching in six or ten days. The larvae greatly resemble the adults but are at first somewhat lighter in color. In from six to eight days they change into the pupal stage, and in another three to five days become adult insects. The entire life cycle, from the laying of the egg to the beginning of the egg-laying of the adults of the second generation, is about twenty days. There are from eight to ten generations a year in the San Joaquin Valley, as estimated by Jones and Horton. Fig. .31 — Oranges showing the work of the citrus thrips. (LT. S. Dept. Agrcl.) Distribution. — Up to the present lime the distribution of the citrus thrips is limited to the citrus sections in the San Joaquin Valley, along the western border of the Sierra foothills. This includes the Porter- ville and Bakersfield citrus belts. Food Plants. — Citrus, Funica (jranatum (pomegranate), Yitis vin- ifera (European grape varieties), Schimis molle (California pepper tree), "umbrella tree," Pyrus communis (pear), Pnonis armeniaca (apricot), Prunus persica (peach). Primus domestica (European plum varieties), Salix sp. (willow), Rumex sp. (dock), Porfulaca oleracea (purslane), Olea europma (olive), Euhus idanis (European raspberry), Rosa sp. (ro.se), Solmiimi sp. The work upon oranges sometimes results in great losses. Fig. 31 shows characteristic chafing. THE MONTHLY BULLETIN. 35 Control.— So far the best results in controlling the citrus thrips have come from spraying; experiments being conducted in California and Arizona with very good results. Two sprays were used in the work, lime-sulphur diluted at the rate of one part to eighty parts of water, and tobacco extract (40 per cent nicotine) diluted one part to eighteen hundred parts of water. The lime-sulphur causes slight burnings, but otherwise is as effectual and much less expensive than the tobacco extract. Four applications are recommended : the first just after most of the petals have fallen; the second in ten to fifteen days after the first; the third from three to four weeks after the second and the fourth during the months of August or September, wheu the thrips are numerous on the foliage. In spraying for this insect it is advisable to use angle nozzles and from 175 to 200 pounds pressure, care being taken that every portion of the tree is thoroughly drenched. THE PEAR THRIPS. Eiithiips pijri Daniel. (Fig. 32.) General Appearance. — The eggs are very minute, white and bean shaped. They are embedded in the tender tissues of the host. The first born larvae are white, with distinct red eyes, and move slowly. They are often very thick on the trees and are known as "white thrips." Pupation takes place in the ground, the pupai being white and .seldom met with except by careful investigation. The adult insect is dark in Fig. 32. — The pear thrips ( Euthrips pyri Dan.). (After Moulton. ) Adult female and nymph. color, varying from an amber to a dark brown or almost black. The presence of this species is usually told by ravages on the tender tissues. of the expanding flowers and leaf buds and later by the attacks on the young fruit. In badly infected orchards the buds often fail to openi and the whole orchard may present a brown fire-swept appearance. 36 THE MONTHLY BULLETIN. ' The fruit may be scabbed and curled or otherwise deformed by the constant chafing. Life History.— As stated above, the eggs are inserted in the stem, leaf or small fruits of the host. They hatch in from four to five days, the larvffi or "white thrips" beginning to feed at once and to do damage. When full grown, which takes from two to three weeks, they drop to the ground and after penetrating several inches enclose themselves in a small cell, where they remain throughout the transforming or pupal period. This period usually begins about September and continues throughout the months of October, November and December, when adult insects are formed. These remain in the ground until February before emerging. The transformation from the larval to the adult stage occupies several months, the slow growth being probably due to the cold winter season. Distribution.— The pear thrips is distributed throughout the Sacra- mento and San Joaquin valleys, and particularly in the following counties: Santa Clara, Alameda, Contra Costa, San Joaquin, Solano, Sacramento. Yolo, Napa and Sonoma. It has also been reported from the Sierra foothills in Placer County. Food Plants. — This insect is particularly a deciduous tree pest and works great damage upon the leaf and flower buds as well as the young fruit. The initial damage is done just before or after blossom- ing time. The pear suffers probably more than any other tree due to ravages of this insect, although prunes and plums are also severely attacked. Peaches, apricots and almonds also receive serious damage some seasons. The following are other hosts of this pest :• apple, cherry, fig, grape and English walnut. Control. — ^Government Formula. — "The formula which has given the best results is made up of the 3 per cent distillate oil emulsion, to which is added from 1 per cent to If per cent of tobacco extract No. 1 (black leaf containing 2.75 per cent nicotine) or tobacco extract No. 2 (sulphate of nicotine or black leaf 40), which is 40 per cent nicotine, at the rate of one part to from 1,500 to 2,000 parts of the spray mixture. The distillate oil emulsion may be obtained from several dealers in chemical and spraying supplies, or may be made at home. By the use of the homemade emulsion, a considerable proportion of the cost of spraying is saved and, what is more important, the quality of the emul- sion is above reproach, when good materials are properly used in its manufacture. ' ' Whitewash. — Mr. Earl Morris, horticultural commissioner of Santa Clara County, has had remarkable results in controlling pear thrips on pear trees by the use of a whitewash spray. His work covers a period of two years. The trees were sprayed with thick whitewash when the buds were just beginning to open. Some of his results as published in Bull. No. 238, Cal. Agrcl. Exp. Sta-. are as follows: "We used eighty (80) pounds of quicklime for one hundred (100) *From G. E. Merrill, M. B. Cal. Hort. Com., Vol. I, No. 2, p. 54. THE MONTHLY BULLETIN. 37 gallons of spraying material. The whitewash was strained through a one fourteenth "(1-14) inch mesh wire screen and the same sized screen used on the suction hose of the pump. The ordinary Bordeaux nozzles worked well, but it was necessary to enlarge slightly the opening in the disks of vermorel type nozzles. We found it very important to have the lime properly slaked. Good lime properly slaked is of creamy consistency, with a negligible amount of grit. It forms a smooth, uniform, creamy coating on the tree. An attempt to use improperly slaked lime will usually result in complete failure. No amount of written instruction will teach one to slake lime. The knowledge must come from actual work with some one who has had the experience. In orchard practice we found it convenient to have our slaking vat, which was 1 by 4 by 6 feet, elevated al)Out three feet, with one end slightly lower than the other. In the lower end we arranged a sliding door through which the whitewash flowed by gravity into a containing vat. The lower vat was shorter, narrower and deeper than the slaking vat to facilitate the removal of the material to the spray tank. Be- tween the two vats we arranged a piece of window screen, of one four- teenth inch mesh, sui)ported by chicken fencing, through which the whitewash passed in flowing from the slaking vat. The cost of material ranges from one (1) to one and one half (1^) cents per gallon, depending upon the cost of lime and labor. One appli- cation proved sufficient to protect the blossoms and permit setting of fruit. We did not find it necessary to spray a second time for larvffi, although in the first experiment enough larvae appeared to lead us to believe that in some cases a second spraying would he necessary with some good contact spray." THE ONION THRIPS. Thrips tahaci Lindeman. General Appearance. — The adult female is pale yellow in color with an elongated dusky spot on the dorsal surface of the middle thoracic segment. The length of the body varies from 1 to 1.2 mm. The eyes are brown, while the antenna^ and legs are dusky. The wings are faintly yellowish, their fringes being dusky. The antennti' are seven jointed. The male larvK are somewhat smaller than the female and of a darker color and often with a greenish tint. The eyes are red. Life History. — The life history of this pest has not been thoroughly worked out, but no doulit greatly resembles those previously described. Distribution. — This species is generally distributed throughout the entire State. Food Plants. — The onion thrips is especially destructive to onions grown for seed. It damages the seed buds before the seeds have hard- ened and in many instances causes a complete failure of the seed crop. 38 THE MONTHLY BULLETIN. It is also destructive to roses, carnations and other flowers (wild and cultivated), grasses, fruit blossoms and truck crops. Control. — Nicotine extracts or the Government formula as recom- mended for pear thrips are efficient control methods for this species. The thrips are most active on tlie outside of the buds early in the morning, so that is the best time for applying a spray. The flour paste as recommended for the bean thrips is also applicable to this species. HEMIPTERA (Order). HALF-WINGED INSECTS. CICADAS, LEAF-HOPPERS, TREE-HOPPERS, PLANT LICE, SCALE INSECTS AND TRUE BUGS. This is one of the largest orders of insects as well as one of the most destructive known. There are nearly twenty thousand species. The term Hemiptera comes from the fact that the fore wings of one of the suborders are thickened at the base, the tips being membranous and overlapping, thus appearing like half wings. Not all of the mem- bers possess these thickened wings, in fact a great many of them have no wings at all. This is specially true of some plant lice and of the female scale insects. The mouth-parts are formed for piercing and sucking and not for chewing. The metamorphoses are incomplete ; that is, the young and nymphs differ from the adults only by the lack of wings in those species having well developed wings, while the young in those individuals not having wings appear almost identical with the adults. The order Hemiptera is usually divided into the three following sub- orders : Homoptera, Heteroptera and Parasita or Anoplura, each of which will be considered separately. HOMOPTERA (Suborder). This suborder includes insects of the order Hemiptera, all of which, without exception, are very destructive to plant life. Wherever wings are present they are usually membranous and held roof-like over the body when at rest. The front of the head is lient under so as to touch the bases of the fore legs. The families of this suborder are : CicadidcB (Cicadas). Fulgoridce (Lantern flies). Memhracidce (Tree-hoppers). Cercopidce (Spittle insects). JassidcB (Leaf -hoppers). PsyllidcE (Jumping plant lice). Apliididce (Plant lice). Coccidce (Scale insects). Aleyrodidce (Mealy wings or white flies). The Fulgoridce and Cercopidm will not be considered here. THE MONTHLY BULLETIN. 39 CICADID^ (Family). CICADAS. The cicadas are well-known insects, being commonly called harvest flies or locusts in the eastern states. The proboscis rises plainly from the head ; there are ocelli present ; the males have musical organs ; feet with three segments and the antennaB are very small and bristle-like. The eggs are laid by the female in small twigs, punctures being made Fig. 33. — The periodical cicada. {Tibicen septendecini Linn.), a, pupa ready to transform; b, old pupal skin; c, adult; d, egg-punctures; e, eggs. (After Riley.) by the ovipositor for their insertion. The damage is caused by these egg-punctures. The young larvae hatch within a few weeks and con- tinue throughout their existence under the ground, where they remain for two or more years, depending upon the species : the so-called 17-year locusts requiring about seventeen years in which to transform from the larva to the adult. The pupa stage is passed in a small cell, also in the earth. When ready to change into the adult the pupa or nymph leaves the ground and crawls up some tree or shrub. The back splits and the adult issues. These insects appear in such great numbers during certain years as to become terrible pests, their depredations being known as plagues. There are many species in California, though none of them are as destructive as the 17-year locusts or the periodical cicada of the eastern states. MEMBRACID^ (Family). TREE-HOPPERS. The membracids are rather small insects and generally characterized by the prolongation of the prothorax which covers nearly the entire 40 THE MONTHLY BULLETIN. abdomen. The antennae are minute and bristle-like; the beak plainly inserted in the head and feet with three segments. The most common species of this family in California is the Buffalo tree-hopper. THE BUFFALO TREE-HOPPER. Gcresa hidiaJiis Vi\\>. CFig. 34.) General Appearance. — A small oreen hoi)per, scarcely one fourth of an inch long. The body is distinctly thin and tall, with pro thorax widest in front and two horns above the head. Life History. — The females deposit their two or three hundred eggs in large holes made through the bark of the limbs with their saw-like ovipositors. They usually select the two or three years' growth, which they often completely kill. The wingless n^ymphs emerge in the spring, having hiber- nated over the winter in the eggs, and begin feeding , uiioii the leaves. Pig. .34. — The Distribution. — Throughout the entire State. buffalo tree-hop- Tis'Fab^^"' ^"^"' -^^^^ Plants.— The principal injuries are due to the puncturing for egg laying in the smaller limbs of various trees ; this process being very destructive to nursery trees. Deciduous fruits as well as many other trees and .shrubs are attacked in this way. The insects feed upon all kinds of succulent vegetation, including vegetables and weeds. Control. — Control measures are very difficult and impracticable, due to the wide distribution and great variety of food plants, but in cases where great damage is done in making the egg punctures in the twigs, the pest may be reduced for the following year by an application of kerosene or distillate emulsion as soon as the young appear. The cutting out of punctured branches during the winter and practicing clean culture also aid in checking their ravages. JASSIDv^ (Family). LEAF-HOPPERS. The leaf-hoppers are also small insects and are specially active, being able to jump very freely and great distances. They greatly resemble the tree-hoppers but the prothorax does not extend back over the abdomen. The hind tibige have two very characteristic rows of spines below. The members of this family are exceedingly numerous and may be found upon most any kind of vegetation. There are two common and destructive species in California: the npple leaf-hopper and the grape leaf-hopper. THE MONTHLY BULLETIN. 41 THE APPLE LEAF-HOPPER. Empoasca mail LeB. (Fig. 35.) General Appearance.— The presence of the insect is made known by the curling and twisting of the infested leaves, especially on nursery stock : it being primarily a nursery pest. The adult insect is pale j^ellowish-green in color, with white marking and is about one eighth of an inch long. The young appear nuieh like the adults except that they lack wings. Life History. — The winter is passed both in the adult and egg stage. The winter eggs are white, very delicate and curved in the middle. They are inserted under the bark of young apple trees ( preferably" under bark of two or three years' growth). These eggs hatch in the early spring so that the young nymphs and hiberating adults attack the first green foliage. During th^" summer, eggs are deposited in large numbers on the food plants in the leaf petioles or in the larger veins. Favorite places are the leaf petioles of apple trees and alfalfa. The position of the egg under the bark or epider- mis is made known by a slight swelling of the surface. Distribution. — Throughout the State; sel- dom becoming a serious pest in any locality, though occasionally it may do great damage. Food Plants. — As previously stated, the apple leaf-hopper is primarily a nursery pest affecting especially young apple trees, thus dwarfing them. The work is particularly on the leaves. Besides the apple it feeds upon currant, gooseberry, blackberry, pear, cherry, plum, thorn-apple, black walnut, grapes, Cot- tonwood, elm, birch, maple, box-elder, hazel, choke-cherry, sumach, oak, syringa, snowball, canaigre, basswood, buck- thorn, rose, buckeye, corn, beans, potatoes, sugar beet, clover, grasses, buckwheat, dahlia, rhubarb, hemp, alfalfa, oats, celery and hollyhock. Without doubt other plants are also attacked. Control. — The difficulty of control lies in the impossibility of killing the eggs without injuring the young trees. Successive sprayings with the oil emulsions, whale oil soap solution of 1 pound to 8 gallons of water, or tobacco decoctions, as often as the young become apparent, will prevent serious attacks and hold the pest in subjection. Affected nursery stock should be thoroughly dipped in such solutions before shipping. To prevent attacks nurseries should not be located near \ \ / \\ ^ 7 ''^C^^^l^^l IV /w^ ^^^^^^H ^^B ^ ^^V ■ ^"^ H 4- ['"■■" ' Fig. 35. — The apple leaf- hopper, Empoasca inali LeB. (After Forbe.s. ) 42 THE MONTHLY BULLETIN. orchards or fields in wliieli tlie liopper breeds. All food plants should be kept out of the nursery. Sticky shields and hopperdozers may be used with good effect. Natural Enemies. — The most effective natural enemy is the small dark bug (TripJdeps insidiosus Say), which preys upon the nymphs by puncturing their bodies and extracting the contents. The larvffi of the green lacewings also prey upon the young hoppers. THE GRAPE LEAF-HOPPER. Typlilocyha comes Say. (Fig. 36.) General Appearance.— The adult insects are very small scarcely more tlian one eighth of an inch long. During the summer they appear light yellow with the wing covers or elytra mottled with red. As the season advances the color becomes darker until winter it is dark red — this change is due to the increasing brightness of the red markings, which are very faint dur- ing the summer months. The young appear very much like the adults, excepting that their wings are not fully developed and there are less of the red markings. Life History. — The eggs are bean-shaped and so small as to be almost microscopic. They are inserted .just beneath the epidermis on the underside of the grape leaves and hatch in from fifteen to twenty days. The young nymphs begin at once to feed upon the first appearing foliage by extracting the juices from the leaves with the sharp beaks. There are two broods a year — winter and summer. The adults of the former hibernate and begin feeding upon the first foliage in the spring. During May they begin egg-laying, which gives rise to the summer brood. This brood grows very rapidly and lays eggs within a few weeks, dying off in the fall. Their eggs give rise to the coming winter brood. Thus the destruction may begin in May and end only when all of the leaves have fallen. Fig. hopper (After 3 6. — The f Much Johnson.) :i'ape leaf- enlarged. all of the in the San vnie-growmg sections of the Joaquin and Sacramento Distribution. — Throughout State. Especially abundant valleys. Food Plants. — The principal and practically the only food during the summer months is the foliage of the grape, but during the winter many other plants are attacked, such as grasses, clover, alfalfa, mustard, ragweed and filaree. THE MONTHLY BULLETIN. 43 Control.— A spray containing .02 of one per. cent nicotine has proven to be the most effective contact insecticide for this pest. This must be applied when the nymphs begin to appear about the first of June, and great care fallen to drench the under sides of the leaves. High pressure is necessary for good work. Screen cages have been used very successfully in many localities in the State. Plowing and cultivating close to the vines and practicing clean culture aid in reducing the numbers. Natural Enemies. — So far no internal parasites of this pest are known. The larva of the California green lacewing {Chrysopa cali- fornica Coq.). devour the young nymphs. Ladybird beetles also prey upon the young, but are of little consequence in the matter of control. PSYLLID^ (Family). JUMPING PLANT LICE. The adults of the members of this family greatly resemble minute cicadas and are exceedingly like the large Avinged plant lice. They differ from the former in having the proboscis rising from the middle of the sternum and being much smaller, and from the latter in having the hind femora greatly developed, enabling them to .jump freely. The pupffi are also characterized by the large and conspicuous wing pads. These insects, like plant lice, feed upon the tender foliage and bark of various plants. The most important member of this family in California is the pear psylla. THE PEAR PSYLLA, Psylla pjjricola Foerst. (Fig. 37.) General Appearance.— Adults are small, orange yellow, jumping insects, not unlike miniature cicadas. More common than the adults are the nymphs, which are queer looking creatures with wide flat bodies and large heads. The general color is orange with dark striped Fig. 37. — The pear psylla (Psylla vyricola Foerst). Young, nymph and adult. (U. S. Dept. Agrcl.) 44 THE MONTHLY BULLETIN. thorax and blaekish-ln-own alidomeii. In the mature winged form the abdomen is greenish. Life History. — The insects appear with the first healthy growing- shoots, which they attack vigorously. They increase rapidly and often do great damage. All stages are to be found throughout the summer months. Distribution. — Tliroughout the State, especially in the Sacramento Valley. Food Plant. — The pear. Control. — Same as for plant lice {Aplddidce), consisting of soap and emulsion spra.ys. Natural Enemies. — The two-spotted ladybird beetle (Adalia hipunc- tata Linn.) and the green lacewing {Clirysopa calif ornica Coq.) feed upon the eggs and larvas of the pear psylla. APHIDIDv^ (Family). PLANT LICE. The members of this family comprise one of the most important groups of destructive insects known. Every one is familiar with the soft-bodied winged and wingless lice which gather so a])undantly upon all sorts of plants. The proboscis appears to rise in the middle of the sternum, the legs being rather long and slender; the wings when pres- ent are membranous and with few veins. Many of the females of this family have the power of producing living young without sexual inter- course, though true sexual forms usually appear sometime during the life cycle. Winged or migratory forms also appear. Some species live almost entirely underground while others are aerial in habits. As this family plays such an important part in the role of insect pests, we are including a large number of the most common species. The life history of the green apple aphis {Aphis pomi De Geer) is given as an example on page 67. METHODS OF CONTROL. Plant lice are more subject to the attaclvs of other insects than per- haps any other one group of insects, but several species are by no means held in subjection by these natural enemies. In considering methods of control, then, we should take into account the natural as well as the artificial. Natural Enemies. Three families of insects are recognized as effectual predaceous enemies of plant lice. They are, Syrphidce, Coccinellidce and CJiry- sopidce. SyrpJtidce. The larva of th(^ syrphid flies are legless, worm-like animals, which are usually found among the plant lice upon which they THE MONTHLY BULLETIN. 45 feed. These larvte vary from lirown, yellow, or orange to dark green in color, according to the species. They are true maggots, with one end bhnit and the other pointed. In feeding, they clasp their support by the blunt end, lift the plant louse bodily into the air with the pointed end and suck out the juices. The most common adult insects have yellow bodies with dark transverse stripes across the abdomen. The small syrphid {Allograpfa obliqua Say), the very large syrphid {Lasiophthicus pyrastri L.) and Sijrphus amencanus Wied. are com- mon in California. Coccinellidce. The work of the ladybird beetles on plant lice is known to all. The red ladybird beetles {Cydoneda sanguinca Linn., and Cocci- nclla calif ornka Mann.), the black-spotted ladybird beetle {Hippo- damia convergens Guer.). Hippodamia amhigua Lee, Megilla maculata DeG., the eyed ladybird {Olla oculata Fab.), OUa ahdominalis Say and the two-spotted ladybird {Adalia Upunctata Linn.) are the most com- mon California species. Chrysopidcv. One of the most common insect predators, preying on all sorts of soft-bodied insects, is the common green lacewing, called aphis lion because of its destructiveness to all plant lice. The eggs, larvffi, pupte and adults are to be found everywhere in the fields, woods and orchards; wherever there are infestations of plant lice. In the orchards of California they are very abundant and play an important part in the control of many bad pests, but more important in keeping down the aphids. When there is no prey in the orchards they go to the fields and brush to seek other game and return as soon as the lice begin to appear. Internal Parasites. Internal parasites are those which develop within the body of the host. The adult female, by means of a sharp ovipositor, deposits her eggs within the bodies of the lice. These eggs hatch, and the resulting young develop into legless, maggot-like individuals which live on the body juices of the aphids, thereby completely destroying them. When fully developed, a small hole cut in the backs of the lice liberates the adults, which immediately attack other living lice. To these parasites, more than to all others, is due the credit of com- pletely controlling many aphids which would otherwise become very destructive. They do not usually get in their work until rather late in the season, after the aphids have done most of their damage, but though late, it is sure. Though the natural enemies are very efficient in a majority of cases, yet all of the real pests (pests because they are not. so held in check) must usually be controlled by artificial methods, of which spraying is recognized as the most efficient. Artificial Methods of Control. Sprays. Treatment for insects which are both aerial and subter- ranean in habits naturally calls for entirely different methods for each 46 THE MONTHLY BULLETIN. form. Of the species named above, two stand out as splendid examples of the subterranean form. They are woolly aphis and the black peach aphis, but both of these have aerial generations. The beet aphis {Pem- phigiis hetce Doane) and {Trifidaplns radicicola Essig) are not known to be other than strictly subterranean in their habits. In considering methods of control we shall take the woolly aphis {Eriosoma lanigera Hausm.) as an example. Methods for Controlling Underground Forms. Prevention. In setting out a young orchard one of the first things to consider is how to prevent the introduction of certain serious pests and diseases which may be carried on nursery stock. Both the peach aphis and the woolly aphis are easily distributed on young trees. The following precautions should be taken in setting out any new apple or peach orchard : 1. Set out clean stock. Do not buy trees which have the roots puddled unless the mud is washed off — it may hide the woolly aphis or black peach aphis and such infested trees would be severely handicapped and are not worth planting. 2. Woolly aphis does very little damage to the Northern Spy; espe- cially is this true regarding the attacks on the roots, therefore, if possi- ble, buy apple trees grafted on Northern Spy roots, if your section is troubled with the woolly aphis. 3. Set trees fairly deep, keep soil thoroughly cultivated so as to get roots down as far as possible. The woolly aphis seldom works lower than ten (10) inches below the surface. Sprays. Before making applications around the crown of the tree for the controlling of root forms, first remove earth around the roots to a depth of six or seven inches and a distance of two or three feet from the crown. Use two or three gallons of liquid per tree, spraying thoroughly on exposed roots. When the liquid is nearly all soaked into the soil cover up the basin. The sprays which have given the most satisfaction in these cases are as follows: Tobacco Leaves. A large number of tobacco leaves placed around the roots of the trees in the fall will do much to keep out underground lice. Tobacco Decoction. Tobacco stems, dust or waste, 2 pounds ; water, 3 gallons. Steep tobacco stems in water for at least one hour before applying. If whole leaf tobacco is used, 1 pound is sufficient for 3 gallons of water. Black Leaf. Black leaf in proportions of 1 to 70 of water is also effective on the root forms. Tanglefoot. If the dormant trees are sprayed with a strong solution of kerosene emulsion or lime-sulphur just before the buds open in the spring, it is well to put a tangle-foot band around the trunk of the tree to keep root forms from migrating to the top. In order to prevent injury to the tree the tangle-foot is smeared on heavy joaper, which is THE MONTHLY BULLETIN. 47 placed around the tree in the form of a band with a thin layer of cotton beneath to keep any from crawling under. Carbon Bisulfld. In light sandy or porous soils, carbon bisulfid is used very effectively. The treatment should be made early in the spring about April, as follows : Make 4 or 5 holes 8 inches deep from 18 inches to 2 feet from the tree. Into each pour from 3 to 4 liquid ounces of carbon bisulfid, and immediately cover the hole. See that the liquid does not come in contact with the roots. Kerosene Emulsion. Kerosene emulsion is often used successfully on the roots, but is rather a severe treatment and should be avoided except by those experienced in its application. Methods for Controlling Aerial Forms. Winter Sprays for Dormant Trees. In order to destroy the eggs deposited by the sexual females in the fall, strong sprays should be applied in the winter when the trees are dormant, so as to prevent infestations for the coming year. The following sprays are recom- mended for this purpose : Commercial lime sulphur, diluted 1 gallon to 6 gallons of water. Kerosene emulsion. Spring and Summer Sprays for Trees and Plants in Foliage. Sprays for foliage cannot be as strong and severe as those used on dormant trees, and care must be taken to prevent serious burn- ings. In view of this, experience has proved the following sprays to be practical: Kerosene emulsion. Resin wash. Soap and fish-oil wash. Carbolic acid emulsion. The above sprays should be used on hardy plants and particularly on orchard trees. While the following formula is specially recom- mended for tender plants, such as melon vines, vegetables, flowers, etc., it is equally good for fruit trees: Soap and Tobacco Wash. Soap, 1| pounds; tobacco decoction (as prepared on page 46), 1 quart; water, 5 gallons. Dissolve the soap in five gallons of hot or boiling water; add the tobacco decoction ; boil together five or ten minutes. If the mixture has boiled down, add enough water to make five gallons of spraying material. This spray is specially recommended as a remedy for the melon aphis {Aphis gossypii Glover). THE GRAPE PHYLLOXERA. *Fhi)Jloxcra vastatrir Plauchou. (Fig. 38.) General Appearance. — The presence of this pest is usually mani- fested by its work, which consists in the formation of rough wart-like galls upon the leaves and small knots upon the roots. The lice pro- *According- to priority rules tlie scientific name of tliis species sliould be Peritymbia vitifoliw (Fitcli). 48 THE MONTHLY BULLETIN. dueing the galls are very small and orange-colored. White eggs and the yonng are also to be found within the galls, which are seldom found in California. The root lice are about one twenty-fifth of an inch long and greenish-yellow in summer and a little darker in winter. Life History. — During the months of July and August some of the eggs laid by the females of the root forms hatch into individuals which acquire wings. These seek the foliage of the vines and lay large eggs which produce true females and small eggs which produce males. These mate and each female lays a single winter egg upon the bark of the two-year old wood. In the spring this egg hatches into a root form (or gall-making form) which gives rise to the root forms in other stages. These lay eggs which give rise to the many summer genera- tions of devastating root insects. In California the latter hibernate in the soil and may continue for at least four years without reverting to the sexual forms. Distribution.— While this pest has been supposed to be limited to the central portions of the State, its appearance in the north seems to indicate that it occurs to some degree in most grape-growing sections north of the Tehachapi. Fig.' 38. — The grape phyUoxera (Phylloxera vastairix Planch.). A, Infested grape root; B, galls on leaf ; C, the root louse. Food Plants. — This insect feeds upon practically all varieties of grape vines, but is most damaging to the European varieties. Many cultivated varieties and hybrids as well as wild species are slightly attacked, but not so as to greatly impair their growth. These latter are known as resistant vines and are important factors in the selection of roots for vines set out in Phvlloxera-infested districts. While the THE MONTHLY BULLETIN. 49 leaves are damaged to some degree, the main source of injury is due to the attacks upon the young and vigorous roots which are completely destroyed. The roots of the so-called "resistant stock" do not mate- rially suffer from such attacks. Control. — By far the most impoi'taut method of control is the use of resistant root stocks ui)on which are grafted the desired varieties. Of course care must be exercised in selecting stock for the various varieties and expert advice obtained before making extensive selec- tions or plantings. Dirct remedies for infestations are unsatisfactory. Flooding the vineyards if the water can be held for a month will almost exterminate the pest, if done in the winter, but such a method is impracticable in most of the grape-groAving sections of the State. Carbon bisulfid is an efficient remedy in loose sandy soil, but in such places the pest is usually less abundant. Natural Enemies. — In the eastern states nuiny predaceous insects feed upon the gall form, ])ut as this stage does not occur to any extent in California there are practically no results from these or other nat- ural cheeks. THE WOOLLY APPLE APHIS. Eriosoiiiu l