THE SOFT SCALE ( HESPERIDUM ) INFESTING HOllY ON VANCOUVER ISLAND

( A Preliminary Report )

Tile :,,,ft ;.;cale ( Coccus hesperidum ( L. )) ha,; iJec\J111e \ery pre\-­ alent o n holly tre es in many part:; PI' the :,() uthe rn Yanc(lu\-e r I sland d istrict durin'g t h e past :-e,;r. It \\' <1" Ilrst noticed in the I'ic inity of Victor ia, B.C., during Febru ary, ] 93 :::: ; s pecimens \\'ere iUr\\'arcled t( I the D ivision of Entolllolog-y at Otta\\'a. and \\-e re s ub seCj ue ntly deter­ mined Ill- 1)1'. Tlarold :\ I(l rrisun o i \\'ashin~n\ln. D.C. ,-\ d clitional IlOlh' trees \\ -~ re e:'-: alllineci during the c (; urse of the 1 0:],'1 season \yhen w'e o bsen'ed the soft scale spreaciing Yer,\- r apid ly, .\ black fung-us ( pre)])­ ably Meliola camelliae Catt. \\'ith w hi c h thi:, scale is as,;ociated ) \\-as fO llnd to be present \\'here\'er the scale inie,;tatiun s occurrecl. Speci­ men s \\'Cre fo und a s far n o rth a s Duncan,

The e:'tahli slllllent I Ii the ""it scale and t h e :' o ut,\-- lll uld fungus (I n hull), in I\riti,;h Columhia is it seri, IUS menace to the [>1'Ociuction and e:'-: pll rtatio n of ho lly f()r th e Ch r istmas season. Plant quarantine,; re­ o;t ricting the free 111(J\ elllent (I f the :'i cale-infested 11CJIh', foc u ,;,; ed t h e attention of t h e cOlll111e rc ial grll \\'er:, upo n th is pC'st ;lnd created an immediate n eecl fo r inf' lrlllati( ln u po n its life hahits and c() ntr,'].

Nature and Extent of Injury Th e injur:' caus C'd iJ,I' the :,oft scal es i,; due not o nl y to th e feed in g b.l' e:,-:tracting "f the jUil'C' '; fr (1 nl t he plant hut a lso tt l the sOII(\--1l1old fungus \\'hich d e \'elop,; in t h e llO n eyde \\' that th e scales secrete. This h o neycie\\' falls up() n the uppe r s ll r rilc e o f the 1eil\'es, s tem,; and bcrrie .~ (If the Iwlh' il nd s uch area,.; eyentualh' heco m e almos t c(ll11plete h ' CO\­ ereel anci 1;lackene c1 \\-ith the ,.;oot:- ((lating' () l th e lungus. r 10'11,\' '" I ilHected i,; 11l1 ,; i.~htiy anc! i,.; not ,; aleaI Jic . "-here infestati() n" are se\erc. the :-imut-l ike c()\'e ring i:, injuriu u s to t h e tree by intericring \\ith it:-: re:; piratioll. The s ugar\' ex u cia ti" n is a1:'(l il lllC ,1I1"; of dispe r,.;al of the <;c aic, by cau,.; ing th em to a d eilre to the feet "f perching- bird,; \\'hich \\-ill thell (';1.1'1',\' the :'l'ale,; til lith er trel'S. ,\nh constant ly ,;een abli llt t he in fe,.;tnl trecs ieeding- (In the hOll e,l"l le\\ during th e sprin;:- and s um­ mer arc alsu re,.;punsihle for the rapid ,.;pread "f the :;cale \\' ithin an o rc hard.

Host Plants and Distribution

Thi" spel'ics of ,;cille , \\-hic h , \-il"; iIJr!nerl,\' placeci in the gen u :, L ecanium, has In ng- been k11U\\11 t, ) sl'i l'llC c. being o n e of the first ul the soft ,.;caics t,1 be stud ied and descrilw(i. It i,; the l'i'11111l 0 n est, nH",t \\'icie!:- spread m e m ber (If the "; UI J-i';l llli ly Coccinae (()) . (I(c urril1g Oll t ()f d O( H' s throu;:ho ll t th e \\, )rl ci in th e (ro pi cal and s u b-tropical re .~ illn ,.;,

Division of Entomology. Science Service. Dominion Departm ent of Agriculture, Victoria, B. C, B. C. EnI01ltO/ogica/ SOL"iely

alld ill :.;-ree nhouses ill the cooler regions. Originally from Europe, it is a lso r eported from Alg iers. Japan, l \u ~tra li a. New Zeala nd, C hili, Hawaiian Islands, South :\frica and ::':orth o'\11lcrica (6) . Tn ?\orth A m eri ca it is common Ull ornalllentais in the "uuth west. infesting chie fl y oleander in :\rizul1 a, Te:\as and ::.: e ll' :\Jexico; in the cuastal zO ll es of F lo rida (D ) and southern Ca li fon1 ia ( I ) it is often a to young citru s trees. 1n n orthern rcgio ns, the soft scale h as been present for a number of years as a m a jo r p est o f g r eenhou se crops. I t s estab­ li s hment o n ho lly in the "Victoria district appea r s to be the fi r s t record o f its occurrencc in Canada a s a ll econom ic pes t of plan ts g ro \\'n out ~)f cloor s. The food plants a s recorded in li teraturc number appro:\ ima t ely se\·enty-f1\·e. Those of m ost economic importance a re a s [011 0\\,5 : apple, apricot, bo:\ elder, clelllatis, , grape, h olly, Engli sh i\'y, laurel, peach, pear, phlox, p lul11. poplar. rose a nd \\' 111 0 \\'. Since February :I !J 3S. ",h en this scale I\'a s fi rst repurted infestin g E ng li s h hu ll y (!lex sp,) at Victoria. [J.e .. we ha\'e also obsen 'ed it o n s ll'eet bay (Laurus sp.) in this district. and O il a species of iyy (Hedera colchica) at Duncan. II.C. F urther sun'ey II' o rk ma\, d iscl(),;c its appearance on some o f the other h ost s m entioned. Life History and Habits There appear s to be m o re than one ;.:en eration of the scalc cach year under Victoria cunditi oll'; alld many adult::; and nymph ,.; in I";.triou s d egrees of lIlaturity a r e present th rou g h out the season Oil the ,.;a m e b ranch. ]11 the citru s a r eas in California the soft scale h a s as many a s fuur g"C nerations each year (K) a nd it is p r in cipally the trees less than ~ i :\ y ear s uld th at are attacked, In cllntrast to this \I'e lind h ull v trees 15 )'ears l) ld and nlllre are se\'erely infested. ' T he iemales of this s pecies are o\·a l. tlat. so ft, turtle-s haped scales . changing in co llll' \\'ith age, floullJ tloan sparent )'cll o \\' to d eepening shades o f bnJ\\"Il. The 111 0ther or adult female sca le lI'hich g i,oes hirth to li\'ing ,\'O Ull g is \'ery Illll ch sll'oll en . becoming a statiollary cap lilled w it.h sma ll nymphs. The you ng ny m phs a rc t h in a nd transpar en t su that they a re scarcely n oticeable on the s urface of thc leaf or branch. The Illale ,;cales are very s lender, smaller and li ghter in color than the ma­ ture fcmales. The adult mal e,; a re y ell o ll'. cxceedingly Ill inute two­ lI'in ged tli es.

These ,;u it sc,tl es :-iuck the "ap fn111l the ti ssues like the anll(>ured ,;cales do . h u t they 1ll \J I'e ahout and are able t<) \I·ithdra\\' thcir beak and in sert it at lI·ill. .\11 the imma t ure stages arc g r egariuus and mi­ grate to and attack the tender ne\l' leaf ancl s tem gTOII·th during the ,; prin g and early stl1l1m er. ])uring' t his peri cl d the del'e l

0\ concise r eport on the description and di stinguishing character­ istics of thi s "cale is contained in " Scale Jnsecb ut ::\[i ~s() uri". by H ol­ linger (5) . Proceedings, ] 939 5

Control In t il e citnh a rea:' in ';(Jllle parts oi the L ni ted State,;. natura l cn e illie:, p la.,' an illlp(li·tant part in kceping t h e sca les irU1l1 b ecom ill g a Seri(lth jle,;t. The inte r na l hylll e nopt e rl)u,; para,; ite,; Apbycu s Bavus Il n ll'anl. M'icroterys Bavus ( JT(lI\'ar cl ) . Coccopbag u s lecanii (Fitch ) ( -I ) . alld Co cc ophagus scutellarius (Dalman) ( I ) arc pro babl." t he p ri n­ c ipal olle", T h e fungu,; para,;ite C uiJall ,\ scher,;()nia ( A . cubensis I ~erk, and C urt, ) ha,; abo efiecti,'cly c()ntr u ll ecl the sl'ale in ,;el'e ra l p lace,; ill silutherll Flurida (01 . \\' here the parasi te,; cl o not check the scale in ­ ic,; ta ti u ll '; on c it ru :, trec,;. the applicati'lIl (,f o il spray s i,; recul11l11cllded as th e hest llletho d of contro l. E"tCllsil'c test:; cunducted dur in ;.,:' til e nH>nth s oi ~eptellll)Cr a nd Octulwr at thi,; labo rato ry . s holl'ed t hat an uil elll u bi()n cuntaining :! pe r cellt (Ii i ( I'iscositl' ,j.). u n,;u lf(Jl lated rc:,idue KII) in C(l mbinatio n II·ith ni cotine sulpha te I to Kilil. Il'as not injllri" lb in a n y lI'ay t u the ho lly trees. and gal'e I).) to .1111 1 p er ccnt Cllntn" of the soft scalc, Summar y The ~uft Scale ( Coccu s b esperid um ( L )) lI'as l)hsel'\'ed as an ccon(Jlnic pc:,t (If h r')I.I' in the southern r e~ i ( ' n (If \ 'ancu u I'cr lsland durin ;.,: l,'eIJruary J ~);)i-I. This is the fir st r ecurd o f its occu rre nce in Canacl a a,; an ecu n o lllic pest of plant,; gl'l' II' n (J ut oi d()or,;. I niested leal·c,;. stelll S a nd herries el'e ntua" I' hCC(llll e c()I'e red Il'ith a S(lo tl'-mold fu ngus lI' hich d el'(:)ops ill t h e hone.,'dcl" secreted by the scales,' Holly Sf) altected is un s ig htly and i,; not saleable. 1..:p to th e p rescnt tillie in this rcgion h o lly ancl Sll'ee t bay <[ r IC the o n ly plants found to be attackcd and there appears t(l he lll o r e than o n e g en era tio n !if ~c al e del'e loping, .\dditio nal sun'ey 1l'(lrk alld li fc hi ,; t u ry stucli es are re ­ qui r ed t" sen1re comple te data, Spra." ing the infcsted t rees d u rillg' the fa ll Ill( )llt h ;-; . u si ng a '2 per cent ll il ellllllsi'lll \I'ith nil'otine s ulpha te add­ ed . prul'(;d to be an elrect i \'(~ Ill etlllld lIf l· ontn l1. R eferences I, C endana, S . M . I'):; ; , ~tlldi c s on t he b iul ligy uf C o ccu pliagu ,.;. a gell u :, para"itic un no nclia" pidille Coccidac. L'nil-. o f Calil, I'uh. Ent(11ll ,. 6 ( I I-I.) ) : :,:)'1-1 U , :!, D elcurto, J. M . et a1. I ()'!.!, 'I'11c citrus illcl ustn in t he LUI\' e r J\ i() Grandc \ -allel' of Te,,\ :t ,; , TC"Cl:-i l)cpt. ,\;.,: .. ,\lls tin. T c:-;as . 1:1l1. 7!). p. ,'-' ii, :J. Essig, E. O. l ~J ·; , In jll ri u u ,; ane! h e ll e ficial insect:-; ul Cali lllrilia. ~ ec one! Edition, Sl1Ppl. t o .\ Io ntll" I~ll'-. C alil, State C (l lllll1i,; s ioll u l Il urt .. 4 ( I) . p, ] -~:; . -~ , Essig, E. O. ]~:.'(i, In ;-;e ct,; llr \\'cste rll .:\onh .\1llerica. :\iac lllillan and ClI .. :\(:1\' )'urk. p , '2 i-1 K, .,. Hollinger, A. H . 1!1'!:i. S cale in ,;ect,; 0 1 :-Li ';s(luri. ,\;":'. E.'\p, Sta .. C o ll1 lllbia. :-l issu uri. I, e:,earcli I ~lli. ;l;" . p , :JK. (i , H oward, C. W. ] \)II!I, S Cctl e illsect" " I c itrll"; trcc,;. Transl'a al J )c]> t. .\g.. I'rcturia. Fal'lllcr,; Ulll. 1-3. p, II, ? Marlatt, C. L . JD(l;L ~ca l e ill ~ e c t :--: and lll i tes {)11 citrus tr ees. L ".~ . Dept . ..\ g . [<' ar1ll c l' ': I ~u '- 17'2. p. ;)11 , ;:;. Quayle, H. J. ]93'2, i\iu lugy and con t rol ul c itrtl "; ill scct,; alld Ill it e,.;. Ag, E:-;p . Sta .. lZil Cl' s idc. Calil .. l\u1. .) I'! . pp, 1·,-:; 'I, W atson . W. R ., and B erger, E. W . I !):j'2, C itrlls in ,.;cc h and their contn>i, .\g, E"t. Sen·ice . Caineslille. Flul'ida. nul. (;7. p . :; 1.