27/7 Pomona College Journal of Entomology Volumes III and I\' 19n-1912 2238I<> Pi:HI,ISHF.I) glARTERI.V IIV THE Department of Zoolojjy of" Pomona College Claremont, California, L'. S. A. ^' Contents of Volumes 111 and IV Volume III, Number 1 Essig, E. O. Till' Use of S.Mliuni Cyani.lc. 385-389. Essig, E. O. Tile Natural Enemies of the Citrus NUaly HuR III, 390-397. Davidson, W. M. Nolis on Some Apliidiil.e Taken in I'lacer County, 398-399. Essig, E, O. Apliiilichi- of Southern California V, 4t Index to California Plant Lice. 45/"-4<)8. Essig, E. O. Notes on Coccidie \'l, 469. Chamberlain, R. V. The Chih.poda of California 11, 470- 479. Crawford, D, L. Ameriean Psyllid.e IV, 4.S0 503. Hall, H. V. M. Studies in .\carina I, 504-510. "Sj Coolidge, K. R. Notes on Rhopalocera, 511-514. Volume III, Number 3 Messenger. C, B. .\ Conuni>sioner .Makes Good, 515-517. Essig, E. O. riic Natural Enemies of the Citrus .Mealy HuK IV, 518-522. Essig, E. O. .-\phidid;e of Southern California VI 1, 523-557. Smith, J. B. , X Noctind.e of California 111, 558-567. '^ Distant, W. L. A New Species of Cicadid.i-, 568. Stout. V. R. .\ .New Suliterranean I'reshwater .Xni- phipod, 569 571. StalTcrd. B. E, .\ .New Subterranean l-reshwater Iso- pod. 572-575. Cook. A, J. Three Alarming Insect Pests, 576-577. Grinnell, Fordyce \\\-t Co.ist News Notes, 578-579. Volume III, Number 4. Essig, E. O. .\phijid:e of Southern California VII I, 586-603. Essig, E. O. Natural Enemies of the Citrus Plant Lice, 604 616. Essig, E. O. Remedies for I'lant Lice on Citrus Trees, 617-619. Kuwana, S. I. The White Flies of Japan, 620-627. Crawford, D, L, .\nierican Psyllid;e \', 628-632. Banks, Nathan The Pseudoscorpions of California, 633-640. Hall. H. y. M. Studies in .Xcarina 11, 641-648. Volume IV, Number 1 Chamberlain, R. V. The Chilopoda of California III, 651- 672. Schrader, Wilhelm Inhreedinj; ol JuMonia coenia under "L-' llinh Temperature through Twenty- two Successive Generations, 673-677. Bernhauer, Max Zur Staphylinidenfaima von Nordamer- ika 5. BeitraR. 678-683. Crawford. D. L. .\ Note on Certain Psyllid.e, 684. Grinnell. Fordyce West Coast News Notes. 685-686. PoMOXA CoiJ^EGE Journal of Entomology Volume IV, Number 2 Crawford, D. L. . „ ,.. ^07 The retrolcuni l'"ly m Calilornia, &«/- 697. Essig, E. O. . . Xphidida; of Southern Cahfornia VI 11, I IX) 698-745. Dyar, H. G. , », • 74^ Some Lepidoptera from Mexico, /4t)- 748. Studies in .\carina III. 749-751. Felt, E. P. ,.^ _.- Diarthronomyia californica, /3Z. Volume IV, Number 3 Felt, E. P. , „, ^ The Gall Midge Fauna of Western Xorth America, 753-757. Essig, E. O. ^ ,.^ . „ Vphididac of Southern California X. 758-797. ^The°"LonguIus" Scale, 798-800. Schrader, Wilhelm Cool ^ir Experiim-nts with Junonia coenia. 801-806. Hilton, W. A. , J c Sensory Setre of Tarantula and Some of its Relatives, 810-817. Longstaff, C. B. . ,, t 1 P.uttertiv Hunting in Many Lands (Book Review), 818. Grinnell, Fordyce West Coast News Notes, 819-820. Volume IV, Number 4 Weiiiland, H. A. r , t- ■. The Cosmopolitan Habits of the Fruit Fly, 821-825. ^Host index to California Plant Lice, II, 826-828. Alexander, C. P. , . , , , The American Species of Adelphomyia Bergroth, 829-831. Hilton, W. A. , , ^ 1 A Preliminary Study of the Central Nervous System of Spiders, 832-836. Cole, F. R. ^ ^ „ , Notes on the Diptera of Laguna Beach. 837-840. Bacon, Gertrude Some Collembola of Laguna Beach. S41-845. Shorter Articles and Important Litera- ture of the Past Year, 846-865. Bryant. H. C. Some Insects and Other .Arthropods „ t- j 7>y?'^,^^ ''- ''--'''" "'''"°'" "" W"?t!:aff^ews Notes, 866 lark, 5U/-Blatan(iides. 759. rudbeckiae. 400. Ari'iiophilus bipunticeps, 658. Arrup pylorus, 654. Artochia californica, 679 Asphondyliariae, 755. Atissa pygmaea, 838. Atwood, G. VV., 847. Cacon, Gertrude, 841. Banks, .v., 413, 633. Bernhauer, M., 678. Blothrus californicus. 640. magnus, 640. Bolitobius arizonensis, 681. californicus, 680. elefas, 681. nepigonensis, 681. Brazillian membracid, 864. Brewster, VV., 848. Bryant, H. C. 807. Callipterus <|uercus, 399. Carbolic acid emulsion, 405. Carsidara concolor, 484. gigantea, 486. mcxicana, 487. rostrata, 486. Carsidarinac, 481. Campodeidae, 860. Chaitophorus nigrae, 398. populifoliae, 399. salicicola, 532. Chamberlin, R. V., 470, 651. Chclanops acuminatus, 638. dorsalis, 638. oblongus, 638. pallipes, 638. Chelifcr cancroides. 637. fuscipes, 637. scubrisulis, 637. Chilopoda. 470, 651. Pomona College Journal op Entomology Chordotonal organs, 853, 856. Chrysopa californica, 604. Chrysoplatycerus spleiulens, 521. Cicadidae, 568. Citrus mealy bug, 39(), 518. Coccidae, 404, 468. Cocciiiella abdominalis, 608. callifornica, 607. Cole, T. R., 837. Coolidge, K. R., 511. Cook, A. J., 576, 581. Crawford, D. L., 422, 480, 628, 687. Cryptops hyalinus, 476. Cynorta bimaculata, 415. Currant fly, 850. Damacus cephalotus, 504. Daniels, N. W., 849. Dasyneuriariae, 754. Davidson, 398. Dendrolasma mirabilis, 418. Diarthrononiyia californica, 752. Disease and insects, 849- Distant, W. L., 568. Dolichopus bakeri, 839. Doxocopa codes, 510. Dyar, H., 746. Dytiscus, 856. Ecology of Dragon-fly nymphs, 859. Eichochaitophorus populifolii, 722. Ephelinus arizonensis, 680. Epicarsa corniculata, 488. Epidosariae, 754. Epitrioza medicaginis, 452. oaxacensis, 453. Eriococcus adenostomac, 408. Euchloe sara, 513. Eulecanium pruinosum, 404. Eumaeus atala, 512. Eurybunus brunneus, 419. spinosus, 419. Essig, E. O., 386, 390, 4U0, 404, 457, 468, 518, 523, 586, 604, 617, 698, 826. Essigella californicus, 780. Eyes of Dytiscus, 852. Felt, E. P., 752, 753. Fossil Coleoptera, 861. Fullawaya saliciradicus, 735, Til . l^'ungus gnats, 860. Galls, 852. Gall midge fauna, 753. Garypus californicus, 635. Geophilus nasintus, 658. regnans, 657. rubens, 656. Gingla phonicoruma, 74iS. Gipsy moth, 847. Globipes spinulatus, 420. Gnatliomercum melanonotum, 661. Gosiphilus bakeri, 672. laticeps, 672. minor, 672. Grinnell, F., 454, 578, 685, 820, 866. Guernsey, M., 859. Hall, H. V. M.. 504, 749. Halteres, 853. Head glands, Orthoptera, 858. Hercostomus occidentalis, . Hermannia hieroglyphica, 647. Hilton, W. A., 810, 818, 832, 85.3. Hippodamia convergens, 607. Hoploderma capitata, 508. Hyadaphis pastimacae, 534. Hylecoetus dermestoides, 862. Hyperaspis lateralis, 519. Ideobisium magnum, 639. threveneti, 639. Ideoroncus obscurus, 639. Ideopterus nephrelepidis, 538. Infantile paralysis, 849. Isopod, 573. Isotoma bidenticulata, 842. besselsii, 843. llonidinariae, 756. Junonia coenia, 673, 801. Kell, D., 798. Kuwana, 621. Lachnus dentatus, 398. juniperi, 541. pini-radiatae, 398. Lacinia, 858. Lascophthicus pyrastri, 611. Leg muscles, 857. Lcpidoptera from Mexico, 746. Lepidosaphis gloverii, 406. Leptobunus californicus, 420. Leuronychus paciticus, 420. parvulus, 420. Lestrcmiinae, 753. Linotenia laevipes, 659. Liobunum bimaculatuni, 421. exilipcs, 421. Live Oak insects, 850. Lohniannia spinosa, 645. Longipeltina bakeri, 682. "Longulus" scale, 798. Loxostcge aulocratoralis, 747. Lycaena hilda, 512. Macrosiphum albifrons, 543. californicum, 399. frigidae, 546. laevigatae, 548. rosae, 399, 550. Pomona f'oi.i.KOK Jocrnai, ok Entomoi/mjy Meadow lark, dit-t. 807. Mc-cisti>coi>liaIiis nnomaliis. 653, liinatiis, 653. Mrlitaoa colon, 510. Mclanoxantlicriiim riifiis, 786. Mi-inbracidac, 864. MiiTcIla monclli. 717. Minianomma spectrum. 864. Moncllia californiciis, 767. Myriapoda, 860. Myzocallis alni. 764. Myziis persicae 598. N'cmastoma iiiodcsta. 417. Ncotrioza iiiiniaculata. 450. laticeps, 451. Nitopus californiciis, 420. N'otaspis bilamellatus, 505. niida, 640. pectnate, 749. Xotobus incrmis, 671. tcniopsis, 670. Obisiuni niacilentiim, 639. OliKotrophiariae, 755. Oribata alata californica, 643. luiniida, 643. latincisa gigantca. 508. Orthczia artcniisiae, 469. Ortholasnia pictipes, 417. nigosa, 417. Otocryptops gracilis, 473. niundus, 473. scxspinosus, 473. Papilio mylotcs, 513. Paraliodes cnciirvata, 646. Paratrioza cockcrclli, 448. maciilipcnnis, 450. ocellata, 447. 628. I'l-ctiniungiiis anicricanus, 668. licalhi, 668. heatlii catalinac, 669. niontiTcus, 668. Pclopsis niidiiiscula, 508. Pemphigus californiciis, 7(X1. fraxiiii-dipctalac, 553. )>opiiIica(ilis, 7(^. popiilimonilis, 398, 704. populitransvcrsiis, 398. PcpiHT tree caterpillar, 846. Perla, 858. IVrrin. C. A.. 848. Pctrolenm fly, 687. Phalangida. 412. Phlegmaccra occidentalis, 417. Plitliiracarus contractilis, 751. retralticus, 750. Plant lice, host index, 457. 826 Pleonectyptera cncrnavacalis, 746. Protciniis densipens, 678. Protolopliiis. singiilaris, 419. ttibcrciilatus, 419. Porotopacc Carolina, 858. Pseudoscorpioiis, 633. Pseudogarypiis bicornis, 637. Psilopa petrolci, 687. Physlla alni trimaciilata. 631. americana, 628. Psyllidac. 422, 480, 628. Psyllf)pa floridensis, 629. ilicis, 632. magna, 629. rubesiae, 630. Ptychoglenc haematodes, 746. Receptiilum seminis, 857. Rhopalocera. 511. Rhinopsylla aiitennata, 441. antcnnala proxima, 442. jalapensis, 490. Rhizobius lopanthae, 518. Rhizoglyphus longitarsus californicus, 751. Rhopalosiphum nymphacae, 793. Rhopalosiphum dianthi, 399. Sensory system of insects, 855. Sensory setae, 855. Schradcr, W.. 673, 801. Schizonenra cjiierci, 398. Sclerobiiniis brunnciis, 416. robustiis, 416. Scolopendra dihaani, 478. heros, 478. niorsitans, 479. polymorpha, 478. Scolopocryptops miersii, 475. Scotolenion californica, 416. Scymnns sordidiis, 520, 610. guttulatus, 395. Siphocoryne coiiii, 399. Smith, J. B., 558. Soniphiliis >eciindns, (>65. Spider book, 863. Spider's nervous system, M2. Spider webs, 862. , Stafford, B. E., 573. Staphylini denfauna, 679. Static organs, 855- St. Clair, R. E., 851. Sitalces californicus, 415. Stigma of bugs, 858. Sting of ants, 857. VIII Pomona College Journal of Entomology Stout, V. R., 570. Symdobiiis salicicorticis, 731. niacrostachyae, 727. Syrphus americanus, 612. Tabiphilus rex, 665. Taiajiina claremontus, 662. occidentalis, 661. Tampiya pylorus, 655. Tampiyidae, 654. Taracus pallipes, 416. spinosus, 416. Terias linda, 511. Tarantula, 810. Termites, 850. Theatops erythroccplialus californiensis, 472. Thecia suiiaethis, 513. Thoniasia crucis, 741. Thorax of insects, 857. Toxoptera aurantiae, 601. Trioza albifrons, 438. assimilis, 438. aurantiaca, 628. frontalis sulcata, 436. longi stylus, 434. mexicana, 439. inexicana minuta. 440. niinuta, 432. minuta similis, 433. montana, 631. nicaraguensis, 436. proximata, 435. quadripunctata, 433. salicis, 432. similis fovealis, 438. tripunctata, 430. varians, 628. Triozinae, 422. Triozoida californica, 492. johnsonii, 492. Tuberolachnus viminalis, 774. Vertebrates and their kin, 862. Watophilus errans, 663. laetus, 663. Weinland, H. A., 821. White ants, 850. White flies of Japan, 620. White scale of mulberry, 848. Yrias prophronis, 747. / i-^6'1 0 6^3 VOLUME THREE NUMBER ONE ilourual of iEutumulo^ii FEBRUARY 1911 vViX'*^ ' . :l '^//, I'. Contents; 1 ESSIC. E. O. 2 ESSIG. E, O. 3. DAVIDSON. W. M. 4. ESSIG. E. O. - 5. ESSIG. E O. 6. BANKS. NATHAN 7. CRAWFORD. D. L. 8. CRINNCLU FOROYCE The Uso of Sodium Cyanide - Natural Enemies of Citrus Mealy Bud III, Aphldldae of Placer County Aphldldae of Southern California V. Notes on Coccldae VI. The Phalantflda of California American Psyllldae III (Triozlnae) - Wast Coast Naws Notas PUBLISHED BY THE Sppartmrnt nf linlogii nf JJnmmta (EoUriTir A. J COOK. D. Sc.. Head Professor CLAREMONT, CALIFORNIA. U. S. A. POMONA COLLEGE JOURxNAL OF ENTOMOLOGY Subscription price, $1.00 to domestic and $1.25 to foreign postal countries. Reprints of any of the articles can be obtained at a nominal price. The pages of the Journal are open especially to West American entomol- ogists, but also general taxonomic papers from any source will be welcome. Especially is this Journal offered in exchange for all entomological and zoological journals, and proceedings, transactions, and reports of societies, mu- seums, laboratories, and expeditions. The separates are likewise offered in exchange for other entomological and zoological separates. During 1909 the existence of the Journal was credited to the support of the Ontano-Cucamonga Citrus Association. It is to be noted, however, with due appreciation, that one member of that Exchange, Mr. A. P. Harwood, was the donor of one-half of the amount from that source. During 1910, the Journal is pleased to acknowledge a wider support, now including the Ontario- Cucamonga Exchange, with Mr. A. P. Harwood. The Call Fruit Company, The A. C. G. Fruit Exchange, The Covina Fruit Exchange, The Semi- tropic Fruit Exchange, The Arlington Heights Fruit Exchange, The Santa Paula Fruit Exchange, and The Tulare Frnit Exchange. Address all communications to POMONA COLLEGE JOURNAL OF ENTOMOLOGY, C. F. B.\KER, Editor. Claremont, California, U. S. A. Best facilities T) ^-^ ^^^ 1 . ^^ for supplying IjCJUKo Catalotjues Free Correspondence Solicited AMRKICAN RNCLISII I'KHNCII GHRMAN ITALIAN SI'ANIMI LEMCKE & BLECHXER KstablMifd ovtr 60 icnrs 30-32 West 27th Street New ^'ork City Journal of Economic Biology Edited by Walter E. Coltinge, Af. Sc, F. L. S.. F. E. S. With the co-operation of Prof. A. H. Reginald Butter, D. Sc, Ph.D., Prof. Percy Groom, /I/. A., D. Sc, F. /..S. Prof. Geo. H. Carpenter, B. Sc , M. R.I. A., Robert Newstead, A/. -SV. .A.I..S., /•'. /;'. .V. and A. E. Shipley, M. A. , Hon. D. Sc. , F. R. S. 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Single Copies 2^ Cettis Address Entomological News, the Academy of Natural Sciences Logan Square, Philadelphia, Pa. Derallgemeinenund angewandfen Ent-omologie wie der Jnsekhen-Bioiogie gewidmeh |et)e5 \ stfctste *fe5 enL "teJrvuAuslandes Wer^volle ^ Original Abhandlungenaus dem Qesamlgebiele UmFassende jahrliche Samrnelreferale nach tinzelgebielen Die ganze Literafur erschopfende Berichte Dn vielscitiger Anzeigenleil. romona C^ollcue Journal of rLntomology Volume III II- HR I A R ^ 1 '» II Numhi-r 1 THE USE OF SODIUM CYANIDE BY E. O. ESSlC HORTICULTURAL COMMISSIONER OF VENTURA COUNTY At the middle of the past fumigation season, the fumigators of tlic soiitiuTn part of the state, without any advanced warning, were forced to finish up the season with sodium cyanide. To a great many this meant that thcv were to begin using a substance with which they were totally ignorant. It came as a last resort to those who had not already fumigated, and its use was forced upon them. Personally, I had had no experience with the sodium cyanide, and did not know what serious mistakes might result from its use. It also meant that a new equipment was necessary for measuring the acid and water and that new charts must be printed for fumigators of the county. At once there was a clamor among the smaller fumigators for information concerning the use of the new material. They had no charts and no way of making new ones. The graduates for measuring the acid and water could not be had. In the face of these conditions the fumigators of X'cntura County got together and began to find out for themselves the value of sodium cyanide and the best means of using it. Those who led in the work were: Mr. C. E. McFadden, from Fullerton, who had two large tumit^ation outfits working in this county. The Limoncira Company, and The County Fumigation outfit. Charts were printed, after the recommended dosage had been thoroughly tested. Graduates were made by etching ordinary glass pitchers and the work was delayed only temporarily. In all, more than 20 tons of the sodium cyanide was used with excellent results. Our experience was such as to give us perfect confidence in the use of this ma- terial for another year and by some it is preferred to the potassium cyanide. Relieving that others may be interested in what we found out, our com- bined resultant observations and experiences are brietly stated in this article. KIND OF CYAN' IDE USED The only available cyanide, at the time, was what is known as the 133 per cent sodium cyanide, manufactured by the Roesslcr & Hasslacher Chemical Co., for sale by the Braun Corporation. I first obtained 400 pounds for trial purposes, and observing no marked differences in it from what we were accustomed to, later ordered large amounts. 386 Pomona College Journal of Entomology PROPORTIONS We followed closely the directions laid down by R. S. Woglum and so used the chemicals in the following proportions: Sodium cyanide 1 dry weight. Sulphuric acid 1>4 liquid " Water - 2 Some have recommended using 1 of acid instead of Ij^j, which will make a little saving, but which we considered too small to again change our apparatus. SCHEDULES Sodium cyanide, containing much more available hydrocyanic acid gas, is more powerful as an insecticide than potassium cyanide. The amount is therefore cut down 25% less thart the potassium. For a purple scale dosage we cut Woglum's Schedule No. 1 just 25%, and for black scale cut the potassium cyanide purple scale dosage 25%. It simply means that with three- fourths of a pound of sodium cyanide, as much efficiency may be obtained as from a full pound of the potassium cyanide. Accordingly a large number of schedules as per accompanying cut were printed for use in fumigating black scale. (Figure 133.) HORTICULTURAL COMMISSIONER FUMIGATING SCHEDULE FOR BLACK SCALE SODIUM CYANIDE le IR 20 22 21 20 28 30 32 34 36 M .0 42 44 46 48 10 1 1 1 10 13 1 2 2 2 13 14 2 2 2 3 3 3 14 le 3 3 ' 3 3 3 4 16 18 2 3 3 3 4 4 18 20 22 24 20 28 30 32 34 38 38 40 42 « 40 48 00 02 54 58 68 00 20 2 3 3 4 < 4 S 6 6 20 22 4 4 4 4 e 6 8 23 u 4 4 B 0 e 7 7 24 26 4 B , 8 8 8 8 8 8 30 28 0 8 8 8 8 8 0 9 28 30 33 34 30 38 40 42 40 48 50 52 04 50 68 60 62 04 66 OS 30 I « a S s s 8 8 0 10 11 11 11 11 13 12 30 32 7 9 g g 10 10 11 11 11 11 12 12 13 32 3« 10 10 1, 11 11 11 11 12 12 13 13 13 34 30 10 10 11 11 11 11 12 13 13 13 13 14 14 30 38 » I!) ,, 12 12 13 13 13 14 14 14 15 38 43 48 .W 52 54 56 53 CD 02 M 66 08 « g 10 „ „ 11 12 13 13 14 14 14 15 It 15 40 •' ,1 1, u 12 13 13 14 14 14 15 15 n 18 42 «1 11 11 13 13 13 14 14 14 15 15 16 18 18 44 U 12 13 13 14 14 14 15 15 15 15 16 17 40 ♦• 13 14 14 14 15 15 16 16 17 17 48 10 53 « 56 58 00 62 04 60 08 « 13 14 14 15 15 It 16 17 17 If 50 « 11 14 18 15 IS 10 17 17 17 17 52 « „ 14 a 15 16 17 17 17 17 18 54 « 14 Ij 15 16 17 17 17 17 18 18 56 u 14 It 16 16 17 17 17 n 18 19 SS "Z ', 11.9 .v.: Z'ZZ"'~cl"T Sulphurk er«p«HI«n. »cT.°"rwZ ! Figure 133. Sodium Cyanide Schedule for Black Scale. Pomona Coi.lk.ck Journal of Entomology 387 These schedules are printed on fairly stiflF paper so that they may be tacked upon a board for the use of the generator of the outfit. Tlie figures are black and large enough to be plainly seen by the light of a torch or lantern on the darkest night. Half and quarter ounces arc oniittcfi. because of the difficulty in reading the small fractions at night and because few scales arc fine enough to register so small amounts accurately. All less than half oimces are placed in the lower figure, while half-ounces or over arc I)laced in the next higher figure. A more convenient way of fixing up this schedule is to have a cylinder made of zinc, with a narrow slot, the wi' and damp nights, which are excellent for the crops, but bad for fumigation. If the bulk of the work was not done during the months of September and October it was found difficult to do it afterwards. In using the sodium cyanide we found out that the matter of moisture and moderate cold 40° F. did not make any difference at all. In fact many tests were made when the trees were very damp and the thermometer was as low as 37° without a sign of burning. In these tests the regular black scale dosage, as shown, was used. This information zve consider to be ver\ valuable. because it zvill mean that more work can be done while the crew is in the field a)id in operation. Many nights we have been able to w(^rk but 2 or 3 hours, and under such conditions it was very difficult to keep a crew in the field at all. This may not have been the experience with all other parties, but was certainly so with all who used it in this vicinity. Killing Power. — In the matter of efficiency against black scale, I am satisfied that the work done will equal that done by the use of the potassium cyanide. Some five or six hundred acres were fumigated and all results are splendid. There was no guess-work, nothing but intelligent and up-to-date fumigation with marked tents and chemical charts. Costs. — Last fall potassium cyanide, 98 to 99 per cent pure, cost our growers 25i/2 cents a pound delivered. Sodium cyanide cost 29 cents a pound delivered. The cost per ounce of potassium was approximately 1.593c; that of sodium, 1.801c; or about $.016 for potassium and $.018 for the sodium. The following tal)!c will give some idea of the diiYercnce in costs : Cyanide Over Around rotassiuiii 30 50 Sutlium 3U 50 I'otassium 34 50 Sodium 34 50 IVitassiuiii 49 62 Sodium 49 62 Total co.st Price per oz. per tree .016 .176 .018 .144 .016 .221 .018 .198 .016 .368 .018 .306 Po.\ION.\ COLLEGK JOURN.M, OF EnTO.MOLOCY 389 Tree measurements ( )unces of cyanide per tree 11 8 13/. 11 23 17 It will lie seen that the cost is of enough importance to warrant the buying of the sodium cyanide, providing that it does as good work and will not burn the fruit or injure the foliage. With us it is just as good as the ])otassium without the injurious (|ualities and with the additional advantage that it does not burn damp and cold foliage and fruit as readily as does the potassium cyanide. I understand that the ".\merican" sodium cyanide is much cheaper than the imported brand under discussion. It corresponds more to the potassium cyanide in the amount of available hydrocyanic acid gas available, being what is known as 98-100 per cent. Mr. VVoglum made some tests regarding this chemical with the result that he pronounced it unfit for fumigation purposes. Since then Mr. C. H. McFadden, who has had a great deal of fumigation experience in the most practical way, gave this cyanide a trial. He told the writer that he got excellent results with it and I remember (juite distinctly that he expressed his desire to get this form of sodium cyanide last fall in place of the European brand. From our experience with the sodium. 1 can see no reason why the cheaper quality will not do the work. It is at least worth trying, and I think that every progressive fruit grower should look into the matter. The cyanide outlook is not at all encouraging. If a cheaper form can be obtained, so much cheaper as the form under dis- cussion, it should be given a thorough test. Certainly I shall make experi- ments with it as soon as any quantity of it may be had. The one objection to sodium cyanide, not mentioned above, is the formation of the sodium or alkali salt from the residue. The residue of the potassium cyanide amounts to several dollars worth of good fertilizer to a ton, which is no little item in a large orchard, while the salt from the sodium cyanide has a negative value and is a distinctly harmful product. It might be ad- visable to empty the residue in a waste tank and