Spring 2003 Resistant Pest Management Newsletter Vol. 12, <strong>No.2</strong>regulate the use of insecticides by farmers. Educationof farmers and formulation of guidelines and strictcompliance can prove very useful in this direction.Based on bioassays of these compounds withDBM populations from different locations in the state,LC50s of 0.0001%, 0.00003%, and 0.0051%, forfipronil, indoxacarb, and diafenthiuron respectively,have been worked out. The baseline susceptibility datawill be very useful for monitoring of susceptibilitystatus of DBM to these insecticides in the future andmay help in early detection of resistance developmentin the pest to these compounds.ACKNOWLEDGEMENTS The present studies wereconducted under the research scheme "Insecticideresistance management in diamondback moth, Plutellaxylostella (L.) on cole crops." The authors are thankfulto the Indian Council of Agricultural Research, NewDelhi for funding the same. The authors gratefullythank Professor and Head, Department of Entomology,PAU Ludhiana for providing the necessary facilitiesand research associates and other staff for helping tocarry out various experiments during the course of thepresent studies.REFERENCES1 Argentine J.A., Jansson RK, Halliday WR, Rugg D and Jany CS 2002.Potency, spectrum and residual activity of four new insecticidesunder glasshouse conditions. Florida Entomologist 85(4): 552- 5622 Chawla R.P. and Joia B.S. 1992. Studies on the development ofresistance in diamondback moth (Plutella xylostella L.) toquinalphos in Punjab. J. Insect Sci. 5: 106-108.3 Finney, D.J. 1971. Probit Analysis: A Statistical Treatment of theSigmoid Response Curve. Cambridge <strong>University</strong> Press, Cambridge,333 p4 Georghiou G.P. 1990. Overview of insecticide resistance. P 19-41. InM.B. Green, H.M. LeBaron and W.K.K. MoBerg (eds). ManagingResistance to Agrochemicals. From Fundamental Research toPractical Strategies, ACS, Washington, DC, USA,5 Hama H. 1989 Characteristic of development of pyrethroid resistance indiamond back moth. Bull. Chugoko Ntl Agril. Expt Station 1989, 4:119-139.6 Joia B.S., Udeaan A.S. and Chawla R.P. 1996. Toxicity of cartaphydrochloride and other insecticides to multi-resistant strains of thediamondback moth, in Plutella xylostella Internat Pest Contr 38:258-597 Krishnamoorthy A. 2002. Biological control of Plutella xylostella (L.),an Indian scenario with referecne to past and future strategies.http://dbm.2002.cirad.fr/papers/krishnamorthy.doc8 Lancaster R and Burt J. 2001. Cauliflower production in WesternAustralia, Bulletin 4521.http://www.agric.wa.gov.au/agency/pubns/bulletin/bull4521/bull4521.pdf9 Mau RFL and Gusukuma-Minuto L 1999. Development of sustainablemanagement program for diamondback moth on cruciferous cropsin Hawaii. Workshop of a integrated pest management of colecrops. I. Insecticide evaluation. Proceedings of the InternationalWorkshop on Integrated Management of Cole Crops. <strong>University</strong> deCelaya, Guanjuato, Mexico, May 20-21, 1999, pp. 13-23.10 Mau RFL and Gusukuma-Minuto L 2002. Diamnondback mothresistance to spinosad (Success and Tracer, Dow AgroSciences) inHawaii: Confirmation, review of causal factors, and establishmentof a mitigation plan. http://www.inifap-gto.net/Ronaldo.PDF1111 Mehrotra K.N. and Phokela A. 2000. Insecticide resistance in insectpests: Current status and future strategies. In (eds) G.S. Dhaliwaland Balwinder Singh. <strong>Pesticide</strong>s and Environment: 39-85.12 Solang UK and Sribhuddachart J. 2002. Resistance management inPlutella xylostella on ccrucifers in southern Asia.http://www.msstate.edu/Entomology/v7n2/art14.html13 Tabashnik B.E., Cushing N.L. and Finson N. 1987. Leaf residue vstopical bioassay for assessing resistance in the diamondback moth(Lepidopetra: Plutellidae). FAO Pl. Prot. Bull. 35: 11-14.14 Talekar N.S. and Shelton A.M. 1993. Biology, ecology andmanagement of diamondback moth. Ann. Rev. Entomol. 38: 275-301.15 Umeda K., MacNeil D. and Roberts D. 2000. New insecticides fordiamondback moth control in cabbage. The <strong>University</strong> of ArizonaCollege of Agriculture 2000 vegetable report.http://ag.arizona.edu/pubs/crops/az1177/16 Zhao JZ., Zhu GR and Ju Z. 1995. Efficacy of fipronil anddiafenthiuron on the diamondback moth. Chinese vegetables. No. 2:25-27.http://www.nysaes.cornell.edu/ent/faculty/shelton/Zhao/publication.html (2002)BS Joia, KS Suri, & AS UdeaanDepartment of EntomologyPunjab Agricultural <strong>University</strong>Ludhiana, 141004IndiaArthropod ResistanceResurgence of Spider Mite Tetranychus ludeni Zacher (Acarina: Tetranychidae) Against Acaricides andBotanical <strong>Pesticide</strong>s on CowpeaABSTRACT During the summer months, spider mite(Tetranychus ludeni Zacher) is a detrimental pest ofvegetable crops, especially on cowpea in the Varanasiregion of India. Field experiments were conducted tofind out the resurgence of this mite pest against someacaricides (viz., dicofol (18.5% EC), dicofol (5%WP),abamectin (1.9%EC), phosalone (35%EC), ethion(50%EC), and sulphur (80%WP)), and botanicalpesticides (viz., pongamia oil (2%), N.S.K.E. (5%),neem oil (2%), azadirachtin (0.03%), mahua oil (2%),and PSKE (5%)) at their recommended doses oncowpea crops. The chemical solutions were preparedjust before each spray, and were sprayed every twoweeks. The mortality of spider mite was observed atdifferent intervals including pre-spray and 1, 3, 7, and14 days after spray. The last observation of theprevious spray was counted as the pre-sprayobservation of the following spray, with the rest of theobservations taken similarly. The results indicated thatno resurgence was observed with dicofol (18.5%EC),dicofol (5%WP), abamectin (1.9%EC), and phosalone(35%EC), whereas some resurgence was observed inethion (50%EC) and sulphur (35%EC) despiteencouraging performances. Resurgence was shown in32
Spring 2003 Resistant Pest Management Newsletter Vol. 12, <strong>No.2</strong>mahua oil (Madhuca indica), PSKE, pungum oil(Pomgamia pinata), neem oil, azadirachtin, and NSKE.The maximum resurgence was observed with mahuaoil, and the maximum negative resurgence wasobserved with dicofol (18.5 E.C.) in both sprays.Botanical pesticides had some resurgence but could beused as safe pesticides on vegetables, while also beingecologically friendly.KEY WORDS: Resurgence, spider mite, acaricides,botanical pesticides.INTRODUCTION In recent years spider mite, Tetranychusludeni Zacher, has been observed as a serious pest tovegetable crops, especially on cowpea, a commonvegetable of summer months in India. This hasattracted the attention of growers and acarologists inIndia's Varanasi region. Heavy populations of mitesand their profuse webs cover the plants. The regularmonoculture of cowpea without crop rotation hasaggravated the problem. It has been reported thatregular use of dimethoate (Singh et.al 1989) has alsoresulted in outbreaks of this mite. It had been earlierreported that phosphamidon, fluvalinate, fenvalerate,and dimethoate showed resurgence of this mite (Kumarand Singh, 1999). For the economic harvest of thecowpea crop, the current effective treatment is to useacaricides that can manage this mite pest.MATERALS and METHODS Field experiments wereconducted to find out the resurgence of this mite pestagainst some acaricides and botanical pesticides at theirrecommended doses on cowpea crops. The trials werereplicated four times at vegetable grower fields duringsummer months in RBD. The plot size was 3x5m androw-to-row spacing was maintained at 50 cm apart.Twelve formulations of acaricides and botanicalpesticides were taken in this trial (Tables 1 and 2). Thecontrol was treated with water + sandovit spray. Theamount of proprietary ingredient required wascalculated by using the following formula:The observations were taken from five randomlyselected tagged and numbered plants from each plot.Five leaves were plucked from the upper, middle, andlower portions of each plant and a total number oftwenty-five leaves were collected from each plot forobservation. The mite population was counted on thebasis of 2cm squared leaf areas at four spots per leaf.The mortality of spider mite was observed in differentintervals at pre-spray and at 1, 3, 7, and 14 days after.The fourteenth day observation of the first spray wastreated as the pre-spray observation of the 2nd spray,with the rest of the observations taken similarly. Thepercent mortality was calculated by using followingformula:The corrected percent mortality was calculated throughAbbot's formula (1925), which is as follows:Where:P = percent corrected mortality,P1 = percent observed mortalityC = percent mortality in control.The percent resurgence of mite population wascalculated by Henderson and Tilton's formula asfollows:Where:Ts = Number of live mite in posttreatment countTF = Number of live mite in pretreatment countCs = Number of mite in untreatedcheck (Post-treatment)CF = Number of mite in untreatedcheck (Pre-treatment)RESULTS and DISCUSSION The results indicate that somebotanical pesticides showed maximum positiveresurgence viz. mahua oil (+ 38.68 %), neem oil (+12.26 %), PSKE (+ 10.36 %), NSKE (+ 5.22 %), andpongamia oil (+ 4.68 %) (Table 1). Some acaricidesviz. sulphure (+ 6.22 %), ethion (+ 3.72 %), andbotanical pesticides i.e. azadirachtin (+ 4.66 %) hadencouraging performances but showed someresurgence, whereas resurgence was not noticed withdicofol 18.5% EC (- 26.28 %), dicofol 5 % WP (-14.22 %), abamectin (- 12.22 %), and phosalone (-10.68 %) in the first spray (Table 1). In the secondspray, the trend of maximum resurgence of somebotanical pesticides was changed, including mahua oil(+ 88.64 %), pongamia oil (+ 32.66 %), P.S.K.E. (+25.00 %), neem oil (+ 18.43 %), azadirachtin (+ 14.09%), and NSKE (+ 8.32 %) (Kumar & Singh (1998) andRai et al. (1993) supported these findings). There wasno observed change in the trend of the encouragingperformance of acaricides viz., sulphur (+ 8.32 %), andethion (+ 7.99 %) (Table 2). The same trend wasfollowed in the second spray. No resurgence wasshown with some acaricides like dicofol 18.5%EC (-74.30 %), dicofol 5% WP (- 21.65 %), abamectin (-18.02 %), and phosalone (- 12.75 %) (Table 2).Zhang and Sanderson (1990) earlier reported therelative toxicity of abamectin to Phytoseiuluspersimilis Anthias-Henriot and the spider mite33