Biology and control of the groundnut leafminer, Aproaerema modicella (Deventer) (Lepidoptera: Gelechiidae) T. G. Shanower*, J. A. Wlghtman and A. P. Gutlerrez' Legumes Entomology, ICRISAT, Patancheru PO, Andhra Pradesh 502 324, Indla and '~lvlslonof B~olog~calControl, University of California. Berkeley. 1050 San Pablo Avenue, Albany. CA 94706, USA Abstract The gr~)~~ndr~c~tI~,:~tniincr. ,.?~~rocrtr-c~rt~ri rtroclrii'l!i.r (Ilcvcntcr) (I.cpidoptera: (iclcchlldac). I\ ;In 1ri1lxnta111pC\1 of \cvcr;ll lcyl~rnccrop\ in South anil So~~th-I:a\tA\ia. For grountlnut. \iclll loh\c\ of --.511",, h;~\cIhcxcn rclx>rtc(l 11. ;~dd~t~on(1) grouriclnut and \o\hci111 (the main crops att;~ckcd).I2 ;iltcrr~;~t~\clio\~ plants h;~vct~,clr :i~por-tctl ,I, r~rr~ilrccllo IS prc\cnt thro~tgh~~~ttlic rcgioli. ;iIthough it ha\ licc~i\~LI~IL~ rr~o\t iri~cnsivrl~ in 11id1;1:11icI '~II;III~III~I I<c\c;ircti concl~~ctccl(ncr rhc p21st 10 >car\ ha\ ~>ri)\i~lctl;I g(>od untlcrsti~ndir~g of tllc hioloy!. l~fcc.\tlc and natur,~lcncnllcs of thi5 pest. Rc\carch on rnani~gcn~i~ntha\ Iocu\ctl oil chi,rriical corntrol. l'hi\ p;ipcr rcvicw thc litcr;~turcon thc hu\t plant\. rli\trit)ution. I?~trlogy;~ncl i~ontrol of .4 rr~o~lrr~rllu.cmpt~;~si;.iny rc\~,:~rch rcpt~rtcd .;lnec 1WI A\pcct\ of .,I. 11r~11!1r~~110ccoll~g\ tlli~t i~t.cd l~~itli~,~ \ILICI> ,IIL~ aI\o IIIcII~~~I~~LI. Keywords Groundnut Atachrs Aproa~remarnod~celia qroundnut leafmtner natural enemles biology host plants Taxonomy and distribution Victn;~ni. ('hin:~. the Philippines. Indonesia anrl ,M;iIi~ysi;l(hlohamm;~d. 10Sl: ('amphell. 1083: Islam r7/ The groundnu1 Izafm~ncr ((;LI\I), ,.lprotrc,r.c~rr~(~ ill.. 1083; ('SONC.1985). In India, u here GI M has hccn tnotiicc~llu(L)c\'cnter) (I cpicloptcr;~:Ciclcchiid;~c), i\ a sludicd mo\t cstcnsively. il ii found in 'I'ornil Nadu, scrious pc\t ot gr'ouridnut ;rntl \oybe;~nin So~crh:tnd Aridhra 13ratle.;h, K;~rnatak;r. Mah:~r;~hhtra.Madhy;~ South-Ea\t Asi;~(W~ghtnian (,/ (11.. IOVO). Arnln ( IOSi) F'r;ldc.hh. Ciujxrat. Punj;lb. Ilclhi. Raj;lsthan. Orissa has callcd it thC most impc~rtarit grounclnut pc.;t in and \%'cst Rcng;rl {klloliamrnad, 1081) India. Originally clcscril>ed ;i.; ilrtrrcc~rrlpsi,~ric~r/c,r.in With the esccption ,IS Rorc'ria hi.~pidti(Kuhiaccr~e). Meyr. Iron1 specimens collcctcd in India (Mcyrick. (i1.M tcc>ds onl! on leguminous host pl;lnts (7hhlc 1). 1006). five othcr binomial\ have rclcrr-cd to the silrnc pcst: Hilohri .~~rh.rc~r~i~~clltr~Zcllcr. .S/orr~optcr,~.r rtc,rtclrlci Mcyr.. S/otnol,/r.ry.\ trr,r/nrin Mqr.. S/orriop/rrv.\ Table 1. Host plants of Aproaerema modrcella .s~cOst~c~ii~c~llnZellcr. and AprcjclrrcJr7llr tir7rtcria Meyr. 'The ~~nccrtaintaxonomy was due to the euistcncc of Sc~critltli.11;lnic K~lcrcncc Iwo, nun-congcricric leaf-miners: onc from South .\tu( /ir\ /iipo,qi~~,uI bl;~xw~~ll-lct~o! ;~tl~i IiouI~Yt, IYOV Africa is now c;~llcd,S/ornol~/rry.r .snl~.rc~c~i~~c~lla (%cller) : (;I\ c itti, rti~it (I. ) bfcrr R,itn,~hr~\hn.lAy\.:ir luJ0 rhc second is the Indian-Indonesian groundnut Ic;if- 1'1gri(r~III!I(I~II (I ) Wil/i.~,k miner, Aproctercrli~u rliiodic.e~llii (Dcventcr) [J. I). ( = I'IIuY~~~111i.\(III~CII.! IJr&,id PI id/ , IV7 I ( III I , 1 hll B,~inhr~dgc-FIc~cIit~~.102(1 Drndley, British Muscum (N;ltural Ilistory) personal I.li~lill~ll,ql,\oil1 ,I I.. S,iii~lli~~,1'177 comniunic;~tior~in Mohamrnad. lOXI] Ilcvcnter (1904. /'\,>I~I/~YI ( O~\,/I~O/III L. Mi~sucll-1ctrc~! and Howlcll. 1')011 /rz~,pifi,rir/II~SIIIII I .. J,II Rao and '1't11r111ii;1I;tcli;ir.1477 in Moh;~nirn;~d.1981 ) origin;rlly described A. rrrodic~cllu I 'IXII~III~I~~I~II~I~I (Thunb.) from ;I moth collected in Java. Incloncsia. Ohui and Oli;~\hi The geographical range of A. rnoilic~lluis rcstrictcd (=Mrnrr.olir.rr~irlur.ur<~/tc\ .lai Hao :ind 'I'h~rum;il;ich;ir.1077 (;lvi~r~r.\r,/ii Sich. 't 7.iic.c L'anl~;~ll.ti)?? (in Mohanimad. IVRI) to South and South-East Asia, from Pakistan to China j111rt11111tlri11r1 I Ttion~ad,~r,;~.Jill KCio iind Kumar. and as far south as the Philippines arid Sri Lanka. It has 11)70 been rcported from Pakistan, India. Sri I.ankir. /~~rllt~11111.\i~llllfllf,\ (I . ) Sprcng 1):ih and MI~~:I,ION4 13angladesh, Myanmar, I'hailnnd. I.aos, Kampuchea, I uhl~lhj)~irlwro~(.\ l [)a\ and M~\ra.1984 KIIYIIC/r,~.sru trto~rniu I )c SII~IV;I\;I~and S~vn K;Io. lYh4 liort2r~uIIIS[IIL/~ K Sch Srin~v:~\anand Slv:~K;I<I. 1YK4 'To whom correspondence should be addressed 0261-21 94/93/01 /000348 @ 1993 Butterworth-Heinemann Ltd CROP PROTECTION Vol. 12 Februav 1993 4 B~ologyand control of Aproaerema mod~cella:T G. Shanower etal. Several are crop plants, the most important being ments indicate that, in peninsular India, GI.M larvac groundnut (Arachis hypoguea L.), soybean [Glyc-inr pass through five instars (Shanower. 1989). mux (L.) Merr.], pigeonpea [('ajanu.~ c,ujan (L.) Pupation occurs within the webbed leaflet\ and Millsp.] and alfalfa (Medicago sutiva L.). Phisitkul requires 72 degree-days above a threshold of 14.7"C (1985) tried unsuccessfully to rear GLM on a variety of (Shanower, 1989) and can be completed in .%I0 days at other plants, sunhcmp (('rotuluriu juncou I>.), winged ambient temperatures (Chcrian and Hasheer, 1942; bean [/?sophocurpus tctrugono1ob1c.s (L..) I) .C.], yard Sandhu, 1978). 'l'he egg-to-adult lifc cycle is completed long bean [Vignu sincn,si.s (L.) Saviex tlask subsp. in roughly 450 degree-days (Shanower, 1989) or 15-28 .se.squi~~edafi.sFruwirthj, siratro (Macropfilium atro- days in southern lndia (Chcrian and Basheer, 1942). In purpurcum I,.), hamata (Stylosunth~s harnutu 1,. ), northcm India. when mean temperatures rangc cowpea [Vignu sinensis (L.) Saviex Hask]. showy between 14 and 22°C'. the lifc cyclc may require 2735 crotolaria (('rotuluriu pallida Ait.), and sword bean days (Sandhu, 1978). (C'unuvulia gladiula 1) .C.). Females oviposited on these plants at a much lower rate than on groundnut and soybean, and larvae did not survivc beyond the first instar. Seasonal population dynamics A. modic,~lluhas been an important pest of groundnut Life-cycle and population dynamics in India for >?O !car5 (Amin and Mohanimad, 1980). ('ontinuous cultivation of groundnut using irrigation. Maxwcll-1,efroy and Howlett (1909) and D'tinbrtdgc- or a groundnutlsoybca~irotation. allow CiLM popula- Fletcher (1920) were among the first to dcscribc ;nd tions to build up (Wightman and Amin. 1088). Even in document the life cyclc of GLM. C'herian and Riishccr thc abscncc of groundnut or soyhcan. GLM popula- (1942), Kapadia, Bharodia and Vera (1Y83) arid tion> can persist on one 01 several wild host\ (Tuhli, I). Phisitkul (1985) also givc detailed accounts of CiLM Morc than 3000 GLM larvae havc hcen found on a biology. Small (<I .O mm) oval cggs are laid on the single P,sorulcrr c~~rvlifiiliuL. stiruh, indicating the undersides of groundnut leaflets, stems and petioles. potential of (hi\ plant as an alternate host (Manoharan Fccundltp avcrirges between 86 (1 and 185 8 cggs per and ('handramohan. 1086). Alternativcly, CiLM may female, although in one study a singlc fcnlalc pri~duced survive thc cxtrcrncl) hot, dry Indian summrr in pupal 473 eggs (Cherian and Basheer, 1942; Ciujrati, Kapoc~r diapause or acstiv;~tion (.lagtap. Rothc ant1 Deokar. and (;angrade, 1973). Egg production has been shown 1085). to be temperature dependent with significantly lower Lcafrniner populations peak in July and August in production at 15 ant1 35°C than at 30°C' (Shanower, Thailand (Campbell, 1983). although other author, 1989). The surface of the egg is covered with longi- also report high population densities in November and tudinal pits which reminded one author of the pits on December (Mohammad. 1981). In Bangladesh and groundnut pods (reference in 13ainbridge-Fletcher, India thc densest populations of GLM occur at the end 1920). Sixty degree-days above 12.4"C ;Ire required for of thc postrainy season, March and April (Amin and G1.M cgg development (Shanower, IY89). Under field Mohammad, 1980; lslam c.t al.. 1983). In India. GLM is conditions, eggs generally hatch in 3-4 days but may often a problem towards the end of the rainy season require 6-8 days at lower temperatures (Kapadia pt [I/. , (September rind October), especially in drought or low- 1982). rainfall years (Amin. 1983). G1.M populations fluctuate First-instar larvae typically chew through the epi- widely between seasons. At ICRISAT, in peninsular derm~\to reach the leaf mesophyll upon hatching India. G1,M population densities have been recorded Early instars create short serpentine mines, which regularly since 1080, in ilnsprayed groundnut (cv. widen into blotclics as the larvae grow. Later instars Kadiri 3) trials with thrcc or four observations per leavc the mine and web together two or more Ieitflets. season and up to 100 plants per sample (unpublished Final-instar larvae arc approximately 6.0 mm long and data). Population densities ranged from one to >320 very active. Males and females can be distinguished in larvae per plant. Extremely high densities (>50 larvae the larval stage by the distinctive pink gonads of the per plant) were recorded in two rainy seasons (1984 and male which are visible through the cuticle.