BIOLOGICAL EFFICACY AND SELECTIVITY OF ACARICIDES IN
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1. Metcalf 1990 Buttler et al 1998 This is a reason to use low residual pesticides that are also selective to natural enemies Lagunes Tejeda and Villanueva Jim nez 1994 Selective pesticides allow the survival and viability of natural enemies such as predators and parasitoids Villanueva Jim nez and Hoy 2003 Collier et al 2004 found the predatory mite Neoseiulus idaeus Denmak and Muma in papaya orchards in Brazil after being subjected to continuous applications of pesticides This mite is important to control the population of red spider Tetranychus urticae Koch which makes it a good candidate for integrated management programs Two predatory mites Euseius hibisci Chant and Galendromus helveolus Chant were found in commercial orchards of papaya in Veracruz Mexico However their response to acaricides is still to be known Integrated management of pests aims to assemble both biological and chemical control in order to offer papaya farmers more sustainable choices Thus the objective of this study was to assess the biological efficacy of acaricides against pest mites and their selectivity to predators in papaya cv Maradol roja MATERIALS AND METHODS In June 2008 an experimental plot with papaya cv Maradol roja was established in 4000 m in the municipality of Manlio F Altamirano Veracruz Mexico 19 06 NL 96 20 WL As part of the integrated management of papaya s ring spot virus PRSV p at the mo2. de M xico Tesis de Doctorado Colegio de Postgraduados Montecillo Texcoco M xico SAS 2003 SAS STAT User s Guide Versi n 9 1 3 SAS Institute Cary NC USA 1028 p Sclar D C Gerace G Cranshaw W S 1998 Observations of population increases and injury by spider mites Acari Tetranychidae on ornamental plants treated with imidacloprid Journal of Economic Entomology 91 250 255 Silva F M A Rodr guez M J C D az G mez O Bautista Mart nez N 2005 Efectividad biol gica de un derivado de cido graso para el control de Macrosiphum rosae L Homoptera Aphididae y Tetranychus urticae Koch Acari Tetranychidae Agrociencia 39 319 325 Smith D Beattie G A C Broadley R eds 1997 Citrus Pest and their Natural Enemies Department of Plant Industries and Horticultural Research and Development Co Queensland Australia Stanyard M J Foster R E Gibb T J 1998 Populations dynamics of Amblyseius fallacies Acari Phytoseiidae and european red mite Acari Tetranychidae in apple trees treated with selected acaricides Journal of Economic Entomology 91 217 225 University of California 2000 Pest Notes Division of Agriculture and Natural Resources Publication 7405 www ipm ucdavis edu Consulted 1 07 2010 Villanueva Jim nez J A Hoy M A 2003 Integraci n del control biol gico con el control qu mico En Memorias del Curso de Control Biol gico Sociedad Mexican
3. 8 bdc Azadirachtin 4 5 0 6a 13a 2 94 a 13 2 a 9 5 ab Fatty acids paraffinic oil azadirachtin 1 3a 2 0a 3 94a 13 5a 4 9 bede Applications performed on dates 1 2 and 3 after sampling Means with the same letter are not significantly different Table 3 Mean number of predatory mites in five samplings in papaya before and after applying acaricide treatments Veracruz Mexico Treataments Date 1 Date 2 Date 3 Date 4 Date 5 Control 0 2 a 0 3a 0 44 a 0 6a 13a Dicofol bifenthrin 0 2a 0 la 0 31a 0 5a 0 8a Imidacloprid 0 2a 0 0a 0 19 a 0 3a 0 6 a Paraffinic oil 0 1a 0 3a 0 00 a 0 6a 0 9a Fatty acids salts 0 1a 0 1a 0 31a 0 8a 0 8a Sulphur 0 1a 0 1a 0 00 a 0 5a 0 5a Azadirachtin 1 2 96 0 3a 0 2a 0 38 a 0 8a 0 8a Azadirachtin 4 5 96 0 la 0 3a 0 13a 0 6a 0 9a Fatty acids paraffinic oil azadirachtin 0 3a 0 3a 0 00 a 0 5a 0 5a Applications performed on dates 1 2 and 3 after sampling Means with the same letter are not significantly different 120 Abato Z rate et al 2012 40 35 F 50 ms 40 Cy 5 a a m a S 25 e e uw a PEE Cw 3 2 1 J Daily rain o 3 204 a Min Temp m Mi gt e ra amp 15 20 3 o A Max Temp 3 P 10 2 i EE 5 4 Ho 0 Jl M r T 0 388 g 2 8 a 2888888888888888 83833358B e e X C a S S UU Te S SS S C U BS m eeeu eevee eevee ev 30 10 308 308 eevee 30 30 DD PD QG n oO
4. Gd OG amp d m ww d nm y SCAN AFAN gg OG d Lan mt ec Laa al rm ex m N e oy ex o ex m Sampling date Figure 1 Environmental conditions for the papaya orchard in Manlio F Altamirano Veracruz Mexico daily precipitation mm and average daily temperature C The arrows represent applications of acaricides 25 HA control 2 EH dicofol bifenthrin a 20 ENEN imidacloprid o ENEH petroleum oil 2 HA fatty acid salts 15 MEM is mmm suph r E 50000 O EE azadirachtin 1 2 5 EE azadirachtin 4 5 3 10 HA fatty ac oil aza 1 2 E 2 0 Figure 2 Means of pest mites per leaf after the third application of different acaricides treatments in papaya in Manlio F Altamirano Veracruz Mexico Selectivity of acaricides to predators The presence of predatory mites was low but persistent in all samplings performed Table 3 The population dynamics by treatment is presented in Figure 3 There was no significant difference between the different regimes of applications of acaricides in any sampling even though several selective acaricides were visually 121 as effective as dicofol Table 2 and despite the highest number of phytoseids observed in the control on the last date The ratio of predatory mites to pest mites present on average 1 5 is appropriate to keep the population of pest mites low Additionally most of the chemicals presented a certain degree of selectivity to predatory mit
5. are less toxic to predators In this study paraffinic oil was found to have a similar effect as dicofol to control T merganser with 3 9 mites per leaf According to Beattie et al 1995 Rae et al 1997 and Villanueva Jim nez et al 2000 oils are considered to be pesticides with low toxicity to predators Agnello et al 1994 and Dur n 2002 even consider that oils might not generate resistance Furthermore it is known that oils pose a low risk for human health that even the Food and Drug Administration FDA exempt them from tolerance requirements Additionally they have low prices Agnello et al 1994 On the other hand Hill and Foster 1998 found that Dormant Oil 4350 at 2 allows the survival of Amblyseius fallacis Garman in apple orchards while it is effective to control Panonychus ulmi Koch In a separate study Stanyard et al 1998 found low levels of infestation of P ulmi 146 and 213 mites day when applying Safe T Side and SunSprays 6E oils Abato Z rate et al 2012 These results were similar to the ones obtained with clofentezine dicofol and propargite 6E that also allowed the survival of predatory mites 9 2 and 9 9 mites day respectively Agnello et al 1994 were able to obtain effective control against P ulmi with three applications of oil at 2 and 3 under a two to three week program To control T urticae Koch in roses Nicetic ef al 2001 found that the applications
6. de plagas En Metcalf R L Luckman W H eds Introducci n al Manejo de Plagas de Insectos Ed Limusa M xico pp 271 344 Abato Z rate et al 2012 Nicetic O Watson D M Beattie G A C Meats A Zheng J 2001 Integrated pest management of two spotted mite Tetranychus urticae on greenhouse roses using petroleum spray oil and predatory mite Phytoseiulus persimilis Experimental and Applied Acarology 25 37 53 Pantoja A Follett P A Villanueva Jim nez J A 2002 Pests of papaya In Tropical Fruit Pests and Pollinators Biology Economic Importance Natural Enemies and Control CAB International Cambridge USA pp 131 156 Prokopy R J Coli W M Hislop R G Hauschild K J 1980 Integrated management of insect and mite pest in commercial apple orchards in Massachusetts Journal of Economic Entomology 73 529 535 Rae D J Liang W G Watson D M Beattie G A C Huang M D 1997 Evaluation of petroleum spray oils for control of the Asian citrus psylla Diaphorina citri Kuwayama Hemiptera Psyllidae in China International Journal of Pest Management 43 71 75 Raupp M J Webb R E Szczepaniec A Booth D Ahern R 2004 Incidence abundance and severity of mites on hemlocks following applications of imidaclorpid Journal of Arboriculture 30 108 113 Res ndiz G B 1998 Resistencia a acaricidas de una poblaci n de Tetranychus urticae Koch procedente de Villa Guerrero Edo
7. 26 06 09 The efficacy and selectivity of acaricides was assessed in one healthy leaf per plant in the upper layer of the four central plants in the experimental unit which was marked before the application During the sampling carried out after the applications the leaves were visually inspected to check for damages caused by plant toxicity No damage was found Due to the low level of mite infestation a non parametric analysis was performed using the Friedman test and means comparison by Least Significant Difference test LSD in SAS v 9 1 3 SAS 2003 RESULTS Efficacy of acaricides The infestation of pest mites Tetranychus merganser Boudreaux found in all the samples was low at the beginning and the means went up at the end of the experiment with values of 1 5 to 17 4 pest mites per leaf on the five sampling dates Table 2 Additionally the presence of predatory mites was low but consistent G helveolus and E hibisci on all the sampling dates with means from 0 2 to 1 3 predators per leaf in the control Table 3 This result allows us to assume that the populations were subjected to certain level of natural control No significant differences were found P 0 86 among treatments before the first application of pesticides Date 1 This indicates a similar distribution of densities all over the experimental plot No significant differences were found either P 0 44 after the first application Date 2 Despite importan
8. Information Office Florida Cooperative Extension Service Institute of Food and Agricultural Sciences University of Florida USA Castiglioni E Vendramim J D Tamai M A 2002 Evaluaci n del efecto t xico de extractos acuosos y derivados de meli ceas sobre Tetranychus urticae Koch Acari Tetranychidae Agrociencia 6 75 82 Cerna J Landeros J Guerrero E Flores A E Badii M H 2005 Detecci n de resistencia enzim tica por productos sinergistas en una l nea de campo de Tetranychus urticae Koch Acari Tetranychidae Folia Entomol gica Mexicana 44 287 295 Cerna E Ochoa Y Aguirre L Badii M Gallegos G Landeros J 2009 Niveles de resistencia en poblaciones de Tetranychus urticae en el cultivo de la fresa Revista Colombiana de Entomolog a 35 52 56 Collier K F S De la Lima J O G Alburqueque G S 2004 Predacious mites in papaya Carica papaya L orchards in search of a biological control agent of phytophagous mite pest Neotropical Entomology 33 779 803 Cranham J E Helle W 1985 Pesticide resistance in tetranychidae In Helle W Sabelis M W eds Spider Mites their Biology Natural Enemies and Control Volume 1B Elsevier New York USA pp 405 423 124 Dur n MJ 2002 BioPlaguicidas Guia de Ingredientes Activos en Am rica Central Serie T cnica Manual T cnico No 49 CATIE Turrialba Costa Rica Duso C Malagnini V Pozzebon A Castagno
9. Tropical and Subtropical Agroecosystems 15 2012 SUP 2 8118 8125 ropical and ubtropical groecosystems SHORT NOTE NOTA CORTA BIOLOGICAL EFFICACY AND SELECTIVITY OF ACARICIDES IN PAPAYA Carica papaya L EFECTIVIDAD Y SELECTIVIDAD BIOL GICA DE ACARICIDAS EN PAPAYO Carica papaya L Marycruz Abato Z rate Juan A Villanueva Jim nez Gabriel Otero Colina Catarino vila Res ndiz El as Hern ndez Castro and Noel Reyes P rez Universidad Veracruzana Facultad de Ciencias Agr colas Campus Xalapa Circuito Gonzalo Aguirre Beltr n s n CP 91090 Zona Universitaria Xalapa Veracruz M xico mabato uv mx Colegio de Postgraduados Campus Veracruz Apdo Postal 421 C P 91700 Veracruz Veracruz M xico cavire O colpos mx nreyes colpos mx Colegio de Postgraduados Campus Montecillo Fitosanidad Km 36 5 Carr M xico Texcoco CP 56230 Montecillo Texcoco Edo de M xico M xico goteroQ colpos mx Universidad Aut noma de Guerrero Corregidora 55 A Barrio de San Mateo CP 39055 Chilpancingo Guerrero M xico ehernandezcastro O yahoo com mx SUMMARY Mites are considered the second pest in importance in papaya Carica papaya L in Veracruz Mexico caused by a general increment in pesticide use that might unbalance predatory populations Efficacy of acaricides was evaluated against phytophagous mites and their selectivity to predators in papaya cv Maradol A completely randomized block d
10. a de Control Biol gico Guadalajara Jalisco M xico pp 143 15 Villanueva Jim nez J A Hoy M A Davies F S 2000 Field evaluation of integrated pest management compatible pesticides for the citrus leafminer Phyllocnistis citrella Lepidoptera Gracillariidae and its parasitoid Ageniaspis citricola Hymenoptera Encyrtidae Journal of Economic Entomology 93 357 367 Submitted March 25 2012 Accepted June 05 2012 Revised received July 30 2011 S125
11. better control for Tetranychus merganser a pest mite in papaya in Veracruz Mexico Azadirachtin 1 2 had an intermediate effect in controlling the red spider Predatory mites were alive and present in all treatments This indicates a certain level of selectivity of these chemical products which makes them appropriate to be used in integrated management programs of pest mites in papaya REFERENCES Agnello A M Reissig W H Harris T 1994 Management of summer populations of European Red Mite Acari Tetranychidae on apple with orticultural oil Journal of Economic Entomology 87 147 161 Tropical and Subtropical Agroecosystems 15 2012 SUP 2 8118 8125 Agnello A M Reissig W H Kovach J Nyrop J P 2003 Integrated apple pest management in New York State using predatory mites and selective pesticides Agriculture Ecosystems and Environment 94 183 195 Barlett R 1977 Integraci n del control qu mico y biol gico En DeBach P ed Control Biol gico de las Plagas de Insectos y Malas Hierbas Editorial CECSA M xico pp 581 604 Beattie G A C Liu Z M Watson D M Clift A D Jiang L 1995 Evaluation of petroleum spray oils and polysaccharides for control of Phyllocnistis citrella Stainton Lepidoptera Gracillariidae Australian Journal of Entomology 34 349 353 Buttler T Martinkovic W Nesheim O N 1998 Factors Influencing Pesticide Movement to Ground Water Series PI 2 Pesticide
12. es Tropical and Subtropical Agroecosystems 15 2012 SUP 2 8118 8125 Control dicofol bifenthrin imidacloprid paraffinic oil fatty acid salts sulphur azadirachtin 1 2 96 azadirachtin 4 5 96 fatty ac oil aza 1 2 Predatory mites per leaf Sampling days 6 06 to 2 07 2009 Figure 3 Population dynamics of predatory mites treated with acaricides in a papaya orchard in Manlio F Altamirano Veracruz Mexico DISCUSSION The trial took place at the end of the dry season and the beginning of rains Figure 1 This might be the right conditions for a high population of tetranychids However it was only after the beginning of rains and three applications of acaricides that the populations of both pest and predatory mites started to increase in all treatments This was most notorious in the control going beyond a high application threshold such as five mites per leaf collected on the photosynthetic side of the papaya tree Possibly this was the result of high but appropriate temperatures for the development of mites Something to be noticed was the survival of both pest mites and predators despite the applications since at least three applications were needed to start noticing a fall in the population under treatment Most likely the number of surviving mites in all treatments had to do with the number of new eggs hatched since samplings took place five to seven days after the application In relation
13. esign with nine treatments and four replications was used Significant differences P 0 005 were found in the number of phytophagous mites alive per leaf after the third weekly application The lowest populations of pest mites per leaf 2 6 3 9 3 5 and 4 9 were observed in the following treatments dicofol rotated with bifenthrin paraffinic oil alone sulphur powder alone and a weekly regime of fatty acid salts followed by paraffinic oil and azadirachtin 1 2 Azadirachtin 1 2 alone had a lower efficacy than the previous group 5 8 mites per leaf and the following pesticides were not significantly different P gt 0 05 than the control 17 4 mites per leaf fatty acids sprayed alone 6 7 azadirachtin 4 5 alone 9 5 and drenched imidacloprid 7 6 No differences were found among treatments in the number of predatory mites possibly due to the low mite densities found Key words Tetranychus merganser Galendromus helveolus Euseius hibisci S118 Corresponding Author javj colpos mx RESUMEN Los caros son considerados la segunda plaga m s importante en papayo Carica papaya L en Veracruz M xico debido al incremento en el uso de plaguicidas que pueden alterar las poblaciones de sus depredadores Se evalu la efectividad de plaguicidas contra caros fitdfagos y su selectividad a depredadores en papayo cv Maradol Se estableci un dise o experimental en bloques al azar con nueve tratamientos y cuatro repeticio
14. fenthrin 12 15 pyrethroid 0 50 L Imidacloprid applied to the stem base single Confidor imidacloprid 30 20 neonicotinoid 0 90 L application Oil applied weekly Safe T Side paraffinic oil 80 oils 9 00 L Fatty acids salts with adherent applied weekly Peak Plus B fatty acids salts 80 soap 2 00 kg Sulphur applied weekly Sulphur powder elemental sulphur 93 inorganic 50 0 kg Azadirachtin 1 2 applied weekly Azadirect azadirachtin 1 2 botanic 3 00 L Azadirachtin 4 5 applied weekly Neemix azadirachtin 4 5 botanic 0 45 L Fatty acids salts with adherent paraffinic oil Peak Plus fatty acids salts 80 2 25 kg azadirachtin 1 2 alternated fatty ac oil Safe T Side 9 paraffinic oil 9 00 L aza 1 2 Azadirect azadirachtin 1 2 botanic 3 00 L Applied to 400 L ha Adherex Experimental agricultural soap J Concepci n Rodriguez Maciel Colegio de Postgraduados Campus Montecillo Mexico Table 2 Mean number of pest mites found in five samplings in papaya before and after applying acaricide trearments Veracruz Mexico Treatments Date 1 Date 2 Date 3 Date 4 Date 5 Control 1 5 a 3 la 6 00 a 17 4a 17 4a Dicofol bifenthrin 0 4a 0 2a 0 19a 3 8a 2 6e Imidacloprid 0 3a 0 9a 2 94 a 53a 7 6 ab Paraffinic oil 0 5a 1 4a 0 44 a 49a 3 9 de Fatty acids salts 0 9a l la 1 13 a 11 3a 6 7 abc Sulphur 1 4a 0 4 a 1 44 a 12 6 a 3 5 cde Azadirachtin 1 2 0 7a 0 7a 1 25 a 12 1a 5
15. is is not consistent with other studies Stanyard et al 1998 found that M Pede a chemical based on fatty acid salts was as effective as dicofol Silva et al 2005 found that 1 to 2 kg of iodized salt from suet Peak combined with 100 L of water can have a biological efficacy of 95 2 against T urticae in roses This result was similar to the application of clofentezin Acaristo used as a regional control In this study however the fatty acid salts find its usefulness in serial applications with other pesticides Table 2 Imidacloprid is widely used because of its ample spectrum and its low toxicity on P persimilis and Typhlodromus occidentalis Nesbitt Smith et al 1997 even though it is considered a selective pesticide because it is systemic Villanueva Jim nez et al 2000 However there are reports by other authors that this chemical stimulates the surge of pest mites Sclar et al 1998 Raupp et al 2004 and the increase in fecundity in T urticae James and Price 2002 Moreover Duso et al 2008 found that P persimilis diminished egg laying in average and the survival of females after a treatment with imidacloprid Therefore this chemical is not recommended to be used against pest mites in papaya applied directly on the foliage CONCLUSION Dicofol in rotation with bifenthrin paraffinic oil alone sulphur powder alone and the regime of fatty acid salts paraffinic oil azadirachtin 1 296 achieved a
16. li M Liguori M Simmoni S 2008 Comparative toxicity of botanical and reduced risk insecticides to Mediterranean populations of Tetranychus urticae and Phytoseiulus persimilis Acari Tetranychidae Phytoseiidae Biological Control 47 16 21 Fengying G Zhi Qiang Z Zhimo Z 1998 Pesticide resistance of Tetranychus cinnabarinus Acari Tetranychidae in China a review Systematic and Applied Acarology 3 3 7 Mexicana 2009 Azadirect gowanmexicana com productosd php product o 9 amp idioma 3 amp categoria 4 Consulted 5 07 2010 Gowan Hill T A Foster R E 1998 Influence of selective insecticides on population dynamics of european red mite Acari Tetranychidae apple rust mite Acari Eriophydae and their predator Amblyseius fallacies Acari Phytoseiidae in apple Journal of Economic Entomology 91 191 199 James D G Price T S 2002 Fecundity in two spotted spider mite Acari Tetranychidae is increased by direct and systemic exposure to imidacloprid Journal of Economic Entomology 95 729 732 Jones V P Parrella M P 1983 Compatibility of six citrus pesticides with Euseius stipulatus Acari Phytoseiidae populations in Southern California Journal of Economic Entomology 76 942 944 Lagunes Tejeda A Villanueva Jim nez J A 1994 Toxicolog a y Manejo de Insecticidas Colegio de Postgraduados en Ciencias Agr colas M xico Metcalf R L 1990 Insecticidas en el manejo
17. ment of planting the experimental plot was surrounded with maize cv CP 562 This was planted at a distance of 20 cm between plants in a row separated 2 20 m from the rows of papaya and removed three months later The experiment was conducted using a completely randomized blocks design with four replications The experimental unit included 16 plants of papaya four rows with four plants each at a distance of 1 80 m between rows and 1 30 m between plants Treatments used are described in Table 1 These included chemical products alone and two regimens of applications with more than one pesticide None of the chemicals used are highly persistent in crops S119 Before the beginning of the experiment weekly sampling took place in 20 plants located in a diagonal in the plot The experimental applications began when one mite per leaf was found in the upper third of the plant on average Because of the high temperatures present at the beginning of the experiment Figure 1 the initial action threshold was low since it could have been two to five mites per leaf Agnello et al 2003 as it was the case for the following two applications Before the application and from five to seven days after it the number of pest mites and live predators per leaf were counted on the following sampling dates 06 06 09 11 06 09 15 06 09 25 06 09 and 02 07 09 Three applications took place Table 1 Figure 1 on the following dates 06 06 09 11 06 09 and
18. nes Se presentaron diferencias significativas P 0 05 en el n mero de caros plaga vivos por hoja despu s de la tercera aplicaci n Las menores poblaciones de caros por hoja 2 6 3 9 3 5 y 4 9 se obtuvieron con los tratamientos dicofol en rotaci n con bifentrina aceite paraf nico de petr leo solo azufre en polvo solo y el r gimen que combina cidos grasos seguido de aceite paraf nico de petr leo y azadiractina 1 2 La azadiractina 1 2 sola tuvo menor efectividad que el grupo anterior 5 8 caros por hoja y los siguientes plaguicidas no fueron diferentes P gt 0 05 al testigo 17 4 caros por hoja cidos grasos solos 6 7 azadiractina 4 596 sola 9 5 e imidacloprid al suelo 7 6 No hubo diferencias entre tratamientos en el n mero de caros depredadores posiblemente debido a las bajas densidades encontradas Palabras clave Tetranychus Galendromus helveolus Euseius hibisci merganser Abato Z rate et al 2012 INTRODUCTION Mites are considered a pest of the first importance in papaya Carica papaya L orchards worldwide due to the damages caused Pantoja et al 2002 In most cases farmers will choose to control mites by applying pesticides because they are easy to use effective and appealing business wise However pesticides must be used with caution they can cause pests to develop resistance to such chemicals they can also pollute the environment as well which limit their usefulness
19. of paraffinic oil 24 carbons nC24 combined with the use of the predatory mite Phytoseiulus persimilis Athias Henriot was better than only using P persimilis In a three year study on apple orchards paraffinic oil was selective to natural enemies and its use was recommended for integrated management programs Agnello et al 2003 Therefore this is one of the products that can be recommended for integrated management programs of mites in papaya Sulphur powder was also found to have a similar effect as dicofol bifenthrin and paraffinic oil Duran 2002 mentions that sulphur is an appropriate alternative to control pest mites since its toxicity is low to animals and humans and moderate to phytoseids Cranham and Helle 1985 Likewise the University of California 2000 recommends the use of sulphur powder to control pest mites since it is selective to natural enemies However Barlett 1977 mentions that sulphur presents a detrimental effect in the long run associated with the persistence of high and medium residual toxicity to species of the Phytoseiidae family In this study the presentation of sulphur in powder made its application difficult under the subhumid conditions in the area of study The powder becomes too humid even before its application Additionally it cannot be applied immediately after using oils University of California 2000 Once all of these considerations are taken into account sulphur can be recommended
20. t differences were observed among the means of pest mites populations in the second application Dates 3 and 4 Table 2 these differences were marginal on Date 4 P 0 09 and none of the two was considered significant After the third application Date 5 significant differences were found P 0 005 among treatments on the number of pest mites Figure 2 with a least significant difference of 2 8 pest mites per leaf The unapplied control presented the highest mean of pest mites per leaf 17 4 as opposed to the Tropical and Subtropical Agroecosystems 15 2012 SUP 2 8118 8125 treatment that simulates the applications used in the sulphur powder alone and the regime of fatty acids region dicofol bifenthrin with 2 6 pest mites per leaf followed by paraffinic oil and azadirachtin 1 296 on average Considering the LSD test the most which yielded the lowest population of pest mites 2 6 effective chemicals were dicofol rotated with 3 9 3 5 and 4 9 mites per leaf bifenthrin followed by paraffinic oil applied alone Table 1 Description of treatments and pesticides used in the acaricides biological efficacy trial in papaya Carica papaya in Veracruz Mexico Brand Active ingredient E al name Concentration toxicological group Dose Na Control with no application of pesticides rrr en Commercial control dicofol bifenthrin AK 200 dicofol 18 5 organochloride 0 45 L dicofol alternated weekly Talstar bi
21. to control pest mites in papaya during the dry season The combined regime of applications including fatty acid salts soaps paraffinic oil and azadirachtin 1 296 was in the first group of best treatments This regime is based on chemicals that are selective to predators The application of the combined regime was more effective than applying azadirachtin 1 2 alone or fatty acid salts alone This makes it appropriate for integrated management programs of mites in papaya The second best effective group included only Azadirachtin 1 2 The effectiveness of this acaricide was superior to the control but not better than the treatments mentioned above Azadirect amp 1 2 is a pesticide of botanic origin that acts upon contact or ingestion It is of ample spectrum and possesses trans laminar action Gowan MexicanaO 2009 Castiglioni et al 2002 found that neem oil 1 can cause 80 mortality in 7 urticae females However the brand name Nimkol at concentrations of 2 0 1 0 and 123 0 5 yielded lower mortality 51 5 41 8 and 39 7 respectively Even though this chemical is not highly effective it can help the management of pest mites when supported by the presence of predatory mites All other treatments were no different to the control Table 2 In this group are fatty acid salts applied alone imidacloprid applied to the soil and azadirachtin 4 5 Neemix 4 5 with 6 7 7 6 and 9 5 mites per leaf respectively Th
22. to the efficacy of acaricides Prokopy et al 1980 consider dicofol a pesticide that is high to moderately toxic to predators which also has an anti reproductive effect in A fallacis Jones and Parella 1984 studied the residual effect of dicofol in citrus they found that 66 days after its application the predator day numbers of Euseius stipulatus Athias Henriot McGregor was down by 72 496 and caused a reduction in their predatory potential after 83 days Stanyard et al 1998 found that the population of A fallacis in apple trees decreased sharply near to 0 2 mites per leaf over a period of two years after using dicofol Therefore it is possible that the acaricides that were more effective are also selective to predatory 122 mites present in the area of study The dicofol bifenthrin treatment includes an organochloride with higher residual activity followed by a contact pyrethroid Lagunes Tejeda and Villanueva Jim nez 1994 It has been found that Tetranychus cinnabarinus Boisduval presented resistance to dicofol in China Fengying et al 1998 just as T urticae did in Villa Guerrero Mexico on roses Res ndiz 1998 and in Guanajuato Mexico on strawberries Cerna et al 2005 Cerna et al 2009 also found resistance of T urticae to bifenthrin This is the reason why the regime dicofol bifenthrin would not be advisable to fight Tetranychus since there are other chemicals that develop resistance more slowly and
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