Monitoring resistance of Helicoverpa armigera to different insecticides used in cotton in Spain

1 Ti le: 1 Moni o ing esis ance o Helico e pa a mige a o di e en insec icides used in co on 2 in Spain. 3 4 Au ho s: Ca los A illa, José E. González-Zamo a 5 6 A ilia ions: Depa men o Ciencias Ag o o es ales, Uni e si y o Se ille. Ca e e a 7 de U e a, km 1. E-41012-Se ille (Spain) 8 9 Co esponding au ho : José E. González-Zamo a 10 zamo [email protected] 11 Phone: +34-954 486 459 12 Fax: +34-954 46 436 13 Published in: C op P o ec ion 29 (2010) 100–103 14 doi:10.1016/j.c op o.2009.09.007 15 2 Abs ac 1 Helico e pa a mige a is he key pes o co on in Spain, esul ing in many 2 insec icide ea men s agains i . The esis ance s a us o Helico e pa a mige a o 3 di e en insec icides cu en ly used in co on was e alua ed in Spain in wo di e en 4 seasons, 1999 and 2004. Fou popula ions we e es ed in o al, wo in each season. 5 Toxicological bioassays we e conduc ed in he labo a o y, and pe o med on hi d 6 ins a la ae by opical applica ion o he insec icides. LD50’s we e es ima ed by 7 p obi analysis and esis ance ac o s (RF) we e calcula ed a he LD50 le el. Fou 8 insec icides we e e alua ed, bu only endosul an eached a mode a e esis ance le el 9 (RF=11.4), and he o he s (me homyl, chlo py i os and lambda-cyhalo h in) showed 10 low esis ance (RF be ween 1.9 and 6.0). Such esul s indica e he gene ally low 11 esis ance o H. a mige a o mos o he insec icides used agains his pes in co on 12 in Spain. Possible explana ions o his si ua ion a e discussed. 13 14 Key wo ds: insec icide esis ance, co on, Helico e pa a mige a , endosul an, 15 me homyl, chlo py i os, lambda-cyhalo h in. 16 3 1. In oduc ion 1 Co on is an impo an c op in he Guadalqui i i e alley (Andalucía, sou he n 2 Spain), especially in he p o inces o Se ille, Có doba and Cádiz. One o i s main 3 economic cos s comes om insec icide ea men s agains pes s like Helico e pa 4 a mige a Hübne (Lepidop e a: Noc uidae), he key pes o co on in sou he n Spain 5 (Du án, 1999). H. a mige a can se e ely educe co on yields, mainly because i 6 eeds on lowe buds, lowe s and on he boll. I s con ol is based mainly on an IPM 7 schedule, which in ol es es ima ing popula ions o he pes and i s na u al enemies: 8 p edado y bugs (He e op e a) and lacewings (Neu op e a), and ecommending 9 insec icides only when H. a mige a popula ions su pass a h eshold and na u al 10 enemies a e sca ce (Du án, 1999; 2003). 11 12 The con ol o his pes in Spanish co on may equi e se e al applica ions 13 h ough he season ( he IPM co on is sp ayed wi h insec icides be ween 2 and 9 14 imes, ange ob ained om 23 seasons, Du án (1999; 2003)), mainly o endosul an 15 and me homyl (2-6 ea men s), complemen ed wi h o he p oduc s including 16 py e h oids (e.g. lambda-cyhalo h in), o ganophospha es (e.g. chlo py i os) o o he 17 ca bama es (e.g. hiodica b) (Du án, 2003). The con inuous use o hese p oduc s 18 can lead o he de elopmen o esis an popula ions o H. a mige a , and in he 2003 19 season impo an con ol ailu es o H. a mige a we e obse ed in co on ields. The 20 ailu e epo s in ol ed mainly he Se ille p o ince and he wo p oduc s ha we e 21 mos used agains his ca e pilla , endosul an and me homyl. The e a e many epo s 22 o he esis ance o H. a mige a (and o he Helio hinae) o insec icides a ound he 23 wo ld, especially o py e h oids, bu also o o he g oups o insec icides, like 24 4 cyclodienes (such as endosul an), ca bama es (such as me homyl and hiodica b) 1 and o ganophospha es (such as clo py iphos) (McCa e y, 1999; Bues e al., 2005; 2 Ahmad e al., 2007; Pie an onio e al., 2007; Ugu lu and Gu kan, 2007; Saleem e 3 al., 2008). 4 5 Co on is a good c op in which o s udy he p esence o esis ance o insec icides 6 due o he high numbe o ea men s ha may be applied (Deguine e al., 2008), 7 bu un il now no speci ic s udy has been done in his c op in Spain, e en hough, 8 wi h G eece and Bulga ia, i is one o he ew coun ies in he Eu opean Union whe e 9 co on is cul i a ed. On he o he hand, ou s udy complemen s o he s ca ied ou in 10 Spain o analyze he s a us o esis ance in H. a mige a in di e en c ops (To es-Vila 11 e al., 2002a,b). This s udy co e ed wo seasons: he 1999 season, in which he 12 baseline esis ance o he insec icides ha a e mos equen ly used agains H. 13 a mige a in co on was es ablished wi h a labo a o y s ain, and compa ed wi h a 14 ield popula ion, and he 2004 season, in which he e olu ion o suscep ibili y o he 15 same insec icides o e he pe iod o 5 yea s, and con ol ailu es o H. a mige a in 16 co on epo ed in he p e ious 2003 season, we e analysed. 17 18 2. Ma e ial and me hods 19 The H. a mige a popula ions used in his s udy we e ob ained om co on ields 20 in Se ille and Có doba (Andalucía, sou he n Spain) om la ae collec ed in di e en 21 plo s. In 1999, he labo a o y s ain was c ea ed om a numbe o pupae om a 22 colony ha had been main ained in he Uni e si y o Có doba by P o esso E. Va gas- 23 Osuna since 1996, wi h pe iodical ein oduc ions o indi iduals om co on ields, 24 5 and wi h no con ac wi h any kind o insec icide. The 1999 ield s ain was ob ained 1 in June by collec ing la ae om di e en co on ields om he p o ince o Se ille. 2 In he 2004 season, wo popula ions we e collec ed, he i s in June (p io o 3 applica ion o insec icides agains H. a mige a in ha season) om la ae om 4 di e en co on ields in he p o ince o Se ille in which con ol ailu es o H. 5 a mige a had been obse ed in he p e ious 2003 season, and he o he in 6 Sep embe , om he same o nea by co on plo s. 7 8 La ae we e b ough o he labo a o y and ea ed ollowing he me hodology o 9 Poi ou and Bues (1974), a 26±1 ºC and 55±10 %RH wi h a 16:8(L:D) pho ope iod. 10 Adul s we e ea ed in e ical cylind ical ubes o 11 cm in diame e and 26 cm in 11 heigh , cons uc ed om labo a o y d ying pape and co e ed wi h pape . Th ee o 12 i e pai s o adul s we e placed in each ube o ma ing and o iposi ion in he 13 condi ions desc ibed abo e, and we e ed wi h a 10% honey solu ion. Eggs we e 14 collec ed in co on bundles and placed in con aine s. A e ha ching, la ae we e ed 15 wi h a semi-syn he ic die (Poi ou and Bues, 1974) and ea ed in he condi ions 16 desc ibed abo e. Thi d ins a la ae we e ans e ed o indi idual cages o 4 cm in 17 diame e and 2 cm in heigh , wi h a po ion o die , o insec icide bioassays. 18 19 Labo a o y es ing o he insec icides was ca ied ou wi h he i s o second 20 gene a ion o la ae ea ed in he labo a o y. Toxicological bioassays we e pe o med 21 on hi d ins a la ae using he s anda d opical applica ion p ocedu e as 22 ecommended by he En omological Socie y o Ame ica (Anonymous, 1970) and 23 ollowing he guidelines o Robe son and P eisle (1992). Fou p oduc s we e used: 24 6 endosul an (Thiodan-35, 350 g l-1 a.i. om Baye C opScience), me homyl (Bonsul, 1 200 g l-1 a.i. om Baye C opScience), chlo py i os (Cuspide-48, 480 g l-1 a.i. om 2 Come cial Química Massó), and lambda-cyhalo h in (Ka a e King, 25 g l-1 a.i. om 3 Syngen a). Fo each insec icide, se ial dilu ions in ace one [o 0.075% humec an 4 (Ag idexa, om Baye C opScience) in wa e o lambda-cyhalo h in] we e p epa ed 5 so ha each was one-hal o he p e ious dose. A d op o solu ion (2 µl) was applied 6 wi h a 0.5–10 µl mic opipe e o he ho acic do sum o each hi d ins a la ae. 7 Con ols o each eplica e we e ea ed wi h ace one (o wa e wi h Ag idexa) alone. 8 The cages we e closed wi h a lid en ila ed by a hole co e ed wi h mesh, and le in 9 he same ea ing condi ions desc ibed abo e. Fo each s ain, a leas 240 la ae 10 we e ea ed pe insec icide, usually wi h 4 eplica es o 10 la ae a each o 5 o 11 mo e insec icide concen a ions. A e 48 hou s mo ali y was assessed: la ae we e 12 conside ed dead i hey we e desicca ed, o unable o mo e when dis u bed wi h a 13 b ush. 14 15 Dose-mo ali y eg essions, LD50’s and hei iducial limi s we e es ima ed by 16 p obi analysis (Finney, 1971) using he POLO Plus 1.0 so wa e (LeO a So wa e, 17 Be keley, CA, USA). Resis ance ac o s (RF) we e es ima ed a he LD50 le el as RF= 18 LD50 collec ed s ain/ LD50 e e ence s ain (ei he he 1999 labo a o y s ain o he 19 s ains collec ed in he ield in 1999 o June 2004). The insec icide esis ance le el 20 was classi ied acco ding o he c i e ia epo ed in To es-Vila e al. (2002a,b): 21 suscep ibili y (RF=1), low esis ance (RF=2–10), mode a e esis ance (RF=11–30), 22 high esis ance (RF=31–100), and e y high esis ance (RF=>100). 23 24 7 3. Resul s and Discussion 1 The esis ance in Helico e pa a mige a o di e en insec icides ha a e usually 2 applied in Spain on co on was es ed in wo seasons (Table 1). In all cases, he - 3 a io o he slope was signi ican (P<0.05), so ha a signi ican dose- esponse line 4 was ob ained. 5 6 Bo h in e -season and in a-season compa isons can be made wi h he da a. In 7 he in e -season compa ison, he esul s showed ha he LD50 o all p oduc s es ed 8 had inc eased a he end o he 2004 season (in Sep embe ), when compa ed 9 agains he LD50 o he 1999 labo a o y s ain, wi h he iducial limi s no 10 o e lapping, excep in chlo py i os. This inc emen was mos ob ious wi h 11 endosul an, which eached he ca ego y o mode a e esis ance (RF=11.4), whe eas 12 he o he p oduc s we e placed in he ca ego y o low esis ance (RF ange be ween 13 1.9 and 6.0). Compa ison o he da a om Sep embe 2004 wi h he ield popula ion 14 o 1999 p oduced RFs ha anged om 1.1 o 3.1, i.e., om suscep ibili y o low 15 esis ance, bu only endosul an had iducial limi s ha did no o e lap, indica ing an 16 inc emen in i s LD50 in his pe iod. 17 18 The second kind o compa ison is in a-season. The only compa ison ha is 19 meaning ul is o he yea 2004, when ield popula ions we e collec ed a he 20 beginning and a he end o he season. The Sep embe popula ion showed 21 suscep ibili y/low esis ance (RF be ween 0.6 and 1.7) when compa ed wi h he June 22 popula ion, bu no inc emen o he LD50 was de ec ed, wi h he iducial limi s 23 o e lapping o all he insec icides. 24 8 1 The esul s ob ained in his wo k a e simila o hose ob ained in a s udy by 2 To es-Vila e al. (2002a,b) du ing 1995 o 1999, which included he same 3 insec icides es ed he e, bu in di e en c ops (excluding co on). They ound he 4 LD50 o endosul an o be be ween 0.93 and 6.70 µg/la a, which includes ou esul . 5 In e ms o he RF, he alue ob ained in his s udy was highe (RF=11.4, included in 6 he mode a e esis ance ca ego y), bu his is p obably because i was compa ed 7 wi h a mo e suscep ible labo a o y s ain. I he less suscep ible s ain o To es-Vila 8 e al. (2002a) had been used ins ead, hen he RF would be 3 (included in he low 9 esis ance ca ego y). 10 11 The o he insec icides es ed in his s udy (i.e., me homyl, chlo py i os and 12 lambda-cyhalo h in) ollowed he same pa e n as endosul an: hei LD50 is included 13 in he ange o alues epo ed in To es-Vila e al. (2002a,b), and wi h RF alues 14 ha a e always wi hin he suscep ibili y o low esis ance ca ego y. 15 16 A clea inc emen o he LD50 has been de ec ed in mos o he insec icides es ed 17 be ween 1999 and 2004, compa ed wi h he labo a o y s ain. Only a small change 18 was obse ed in he LD50 in he pe iod om 1999 o 2004 in he ield s ains (only 19 signi ica i e in he case o endosul an), and no signi ican inc emen was de ec ed in 20 he 2004 season. O e all, ou esul s showed li le o no di e ence om he esul s 21 ob ained in he gene al s udy ca ied ou om 1995 o 1999 by To es-Vila e al. 22 (2002a,b) in Spain, e en hough he s udy p esen ed he e included wo seasons, 23 1999 and 2004, ha we e e y sepa a e in ime. Such esul s indica e a gene al 24 9 scena io o low esis ance o H. a mige a o almos all he p oduc s es ed in Spain, 1 excep o some py e h oids (cype me h in, lambda-cyhalo h in and del ame h in), 2 o which To es-Vila e al. (2002b) ound high o e y high le els o esis ance, 3 al hough only in 4 ou o 111 insec icide–s ain combina ions es ed, in ol ing 2 ou 4 o 35 H. a mige a s ains. 5 6 The le el o esis ance in H. a mige a o endosul an in ou s udy can be 7 conside ed as low o mode a e. This is simila o he si ua ion in o he co on- 8 g owing egions such as hose in Tu key (Ugu lu and Gu kan, 2007) and India 9 (K an hi e al., 2002; Su yawanshi e al., 2008). In e ms o o he insec icides, like 10 me homyl, se e al o ganophospha es, and especially py e h oids (such as 11 cype me h in, del ame h in, lambda-cyhalo h in, and o he s), he e a e many s udies 12 om di e en coun ies epo ing high le els o esis ance in his species (K an hi e 13 al., 2002; Pie an onio e al., 2007; Ugu lu and Gu kan, 2007; Su yawanshi e al., 14 2008). S udies o insec icide esis ance in Helico e pa/Helio his in Eu ope ha e no 15 been limi ed o Spain, and in F ance he e is also e idence o signi ican le els o 16 esis ance o py e h oids (del ame h in), and mode a e esis ance o me homyl in H. 17 a mige a , bu no esis ance has been de ec ed agains endosul an (Bues e al., 18 2005). 19 20 The de elopmen o insec icide esis ance is p ima ily he esul o he selec ion 21 p essu e exe ed on sp ayed popula ions, which inc eases he equency o esis an 22 indi iduals. Howe e , he co on c op in Spain is sp ayed wi h insec icides agains H. 23 a mige a om 2 o 6 imes pe season (Du án, 2003), which does no help o explain 24 16 Table 1. Toxici y o opically applied insec icides, cu en ly used in co on in 1 Spain, o di e en s ains o Helico e pa a mige a la ae (F1 and F2, hi d ins a ), in 2 wo yea s. 3 Insec icide Yea –S ain In e cep Slope±S.E. LD50 (µg/la a) 95% iducial limi s RFa Endosul an 1999–Labo a o y 6.31 2.19±0.34 0.25 0.18–0.32 -- 1999–Field 5.05 1.81±0.26 0.93 0.72–1.28 3.7 2004–June 4.54 2.11±0.27 1.64 1.30–2.05 6.6 2004–Sep embe 4.10 1.97±0.33 2.86 1.44–5.03 11.4 Me homyl 1999–Labo a o y 6.57 1.43±0.28 0.08 0.05–0.12 -- 1999–Field 6.14 1.92±0.27 0.26 0.19–0.33 3.3 2004–June 5.46 1.01±0.16 0.35 0.22–0.50 4.4 2004–Sep embe 5.47 1.48±0.22 0.48 0.19–0.90 6.0 Chlo py i os 1999–Labo a o y 7.83 3.06±0.40 0.12 0.09–0.14 -- 1999–Field 7.16 3.21±0.46 0.21 0.17–0.25 1.8 2004–June 5.88 2.21±0.28 0.40 0.32–0.50 3.3 2004–Sep embe 6.41 2.22±0.20 0.23 0.11–0.41 1.9 Lambda-Cyhalo h in 1999–Labo a o y 7.88 1.63±0.28 0.02 0.00–0.03 -- 1999–Field 7.12 1.40±0.25 0.03 0.02–0.04 1.5 2004–June 6.87 1.64±0.19 0.07 0.06–0.09 3.5 2004–Sep embe 7.08 1.85±0.27 0.08 0.05–0.12 4.0 In all s ain–insec icide combina ions he p obi dose- esponse lines we e signi ican ( - a io 4 es , P <0.05). 5 a Resis ance ac o (RF) es ima ed as RF= LD50 speci ic s ain/LD50 1999 labo a o y s ain. 6 7