BIOLOGY OF TWO-SPOTTED SPIDER MITE, TETRANYCHUS URTICAE KOCH (ACARI: TETRANYCHIDAE) AND IT'S FEEDING PREFERENCE ON CITRUS

Transcription

1 ISSN Jurnal f Insect Science 28 (2): (2015) 1987 BIOLOGY OF TWO-SPOTTED SPIDER MITE, TETRANYCHUS URTICAE KOCH (ACARI: TETRANYCHIDAE) AND IT'S FEEDING PREFERENCE ON CITRUS NAVJOT KAUR, MANMEET BRAR BHULLAR* AND PARAMJIT KAUR Department f Entmlgy, Punjab Agricultural University, Ludhiana , Punjab, India * manmeet@pau.edu ABSTRACT: Bilgy f tw-sptted spider mite, Tetranychus urticae Kch was studied n ventral surface f leaves f citrus (Kinnw) at 27±2 C. Mean incubatin perid was 2.52 ± 1.02 days while mean larval, prtnymphal and deutnymphal perid was 2.74 ± 0.99, 2.08 ± 0.47 and 2.40 ± 1.03 days respectively. Mean lngevity was fund t be 6.71 ± 0.67 and 9.40 ± 0.67 days fr males and females respectively whereas sex rati(female : male) was 4.33 : 1. Fecundity was fund t be lw (1.56 ± 0.74 eggs) and pre- vipsitin, vipsitin and pst-vipsitin perids were 0.96 ± 0.04, 1.78 ± 0.87 and 6.40 ± 1.67 days respectively. Studies n vipsitin respnse f tw-sptted spider mite, (T. urticae) n different citrus gentypes revealed that respnse fr vipsitin f mite was maximum n G-5 and G-4; BL-2; and SL-4 gentypes and n egg laying was bserved n SL-7. Based n feeding preference f mites n different gentypes, it was bserved that within gentypes f citrus, mites preferred gentype 'KL-7' (Kaghzi lime) the mst, but had least preference fr gentype 'G-4' (Galgal). KEY WORDS: Bilgy, citrus gentypes, Kinnw, Tetranychus urticae INTRODUCTION Citrus is the third largest fruit industry after Banana and Mang in terms f area under cultivatin in India. Over the last 30 years, the area and prductin under citrus cultivatin has increased at the rate f 11 and 9 per cent, respectively, which shws that the expansin f citrus industry was quite sustainable. In India, citrus rchards ccupy an area f 9.15 lakh ha with an annual prductin f lakh tnnes f fruits (NHB 2009). In Punjab, area under citrus is thusand ha (64.0 per cent) with ttal prductin and average prductivity f thusand tnnes and 20.1 tnnes per ha, respectively (Annymus 2013). Punjab cntributes abut per cent citrus t natin's citrus pl (Kumar et al 2010). Amng mandarins, Kinnw mandarin is the cmmercial cultivar f Nrth-West India (NHB 2009) and the area under it is increasing at a faster rate and it has emerged as the mst ppular and remunerative fruit crp due t its wider range f adaptability, preccius bearing and gd fruit quality. In spite f adptin f imprved management practices by the grwers there are reprts f decline in the yield f citrus trees after 6-7 years f prfitable prductin. Citrus cultivatin is facing several difficulties and amng them, pest attack is ne f the mst imprtant prblems which hinder the diversificatin f citriculture in the wrld. Several factrs have been cntributing fr this decline, hwever menace by different insects and mites have been cnsidered as ne f the imprtant factrs and phytphagus mites are amng the mst imprtant pests f citrus wrldwide (Jeppsn et al 1975 and Hy 2011). Frty tw species f mites, f which 25 species are phytphagus have been reprted n citrus frm India. The mites suck the sap f leaves predminantly frm the upper surface f leaves, the affected leaves turn chlrtic and finally drp ff resulting in pr plant grwth( Dhria et al 2005). The presence f tw-sptted spider mite, Tetranychus urticae Kch, n citrus nursery was detected fr the first time in Nvember 2004, in ne citrus nursery in the greenhuse in Djenvici (Bka Ktrska Bay) by Radnjic (2008) and later n in 2011 by Vacante and Bnsignre. In recent years, tw-sptted spider mite, T. urticae has been emerging as a majr pest n citrus (Kinnw) nursery plants particularly under ply/glass huse cnditins in Punjab (Annymus 2011). N infrmatin n the bilgy and varietal preference by T. urticae n citrus gentypes under Punjab cnditins is available. With change in climate patterns, the pest incidences have als been

2 Bilgy and feeding preference f tw-sptted spider mite 331 bserved t change, s keeping this factr in view, the present studies were carried ut t study the bilgy T. urticae n Kinnw and the vipsitin and feeding preference f T. urticae n different citrus gentypes. MATERIAL AND METHODS Bilgical studies: The present investigatins n the bilgy f T. urticae Kch n Kinnw and feeding preference and vipsitin respnse f T. urticae n varius citrus gentypes were carried ut under labratry cnditins in the Acarlgy Labratry and Screenhuse cnditins at the Entmlgical Research Farm, Department f Entmlgy Punjab Agricultural University, Ludhiana. Fr studying bilgy f T. urticae, pure culture f mite was raised n ptted plants f French bean, Phaselus vulgaris, and thereafter maintained n citrus (Kinnw) nursery plants under screenhuse cnditins at Entmlgical Research Farm, Punjab Agricultural University, Ludhiana during This mite culture was utilized fr different bilgical studies. The plants w e r e r e g u l a r l y m n i t r e d f r t h e r phytphagus/predatry mites, and ther insectpests. Befre using the leaves fr different experiments, the healthy tender green leaves f Kinnw selected frm ptted plants were thrughly washed with tap water, dried and examined under the sterezm micrscpe (Carl Zeiss, V-8) t remve r kill any insect r mite stages fund n them. Leaf disc technique was used fr the bilgical studies (Jeppsn et al 1975). The female mites were released with the help f '00' series hair brush n ventral surface f fresh leaves f Kinnw placed ver mist cttn swabs kept in Petri-dish (10 cm diameter). The cttn swabs were kept saturated with water frm time t time s that the leaves may remain in turgid cnditin fr lnger time. The ld leaf-discs were replaced peridically with fresh nes s as t ensure their gd quality. The develpment f tw-sptted spider mite was studied at 27±2 C temperature maintained in bilgical xygen demand (B.O.D.) incubatr. Fr recrding the incubatin perid, 10 gravid females taken frm mite culture were released n ventral surface f each leaf-disc (2.0 cm diameter) f Kinnw t btain sufficient number f eggs. After 24 hrs f releasing, females were remved and eggs were cunted and subsequently bserved daily fr their hatching. Number f eggs hatched at different intervals was cunted fr calculating the average incubatin perid. Fr studying different parameters f develpment f mite n Kinnw, ne newly emerged larva per leaf-disc was released n 30 leaf discs prepared fr studying mite develpment. The bservatins regarding larval, prt- and deutnymphal perids were recrded twice daily. Observatins regarding pre-, vi- and pstvipsitin perids, and lngevity, fecundity and sex rati were recrded daily. Fecundity was calculated by cunting the ttal number f eggs laid by a female during her life span, and the lngevity was calculated by cunting the perid between emergence f adult frm quiescent deutnymph till the last day f its survival. Sex-rati was calculated frm the ttal number f males and females that emerged. The ttal immature develpment (larval + prtnymphal + deutnymphal), and ttal life duratin (immature + adult) were als recrded. Fr all these bilgical studies, sterezm micrscpe (Carl Zeiss, V-8) was used. Measurements (µm) f the different stages were made with an cular micrmeter, munted in the bjectives f Olympus SZ40 micrscpe, and calibrated by using a stage micrmeter. Feeding preference f T. urticae: Ovipsitin respnse and feeding preference f T. urticae n twelve gentypes f citrus namely Sweet lemn, Kaghzi lime, Tahiti lime and Galgal was studied. Leaf-disc technique was used fr studying the vipsitin respnse f T. urticae n different citrus gentypes. Thirty leaf-discs f each f twelve citrus gentypes were taken and ne gravid female mite per leaf-disc was released n each gentype. Observatins regarding the number f eggs fund n each leaf-disc were recrded after 1, 2 and 3 days f releasing the mite. The experiment n feeding preference f T. urticae n fresh leaves f different citrus gentypes was cnducted using free chice methd. A thin layer f Tangleft barrier was applied in a circular fashin (15 cm diameter) n the white enamel tray t prevent the escape f mites. The circular leaf-discs f different citrus gentypes were placed in a circular manner inside the Tangleft barrier at equidistant intervals. Befre releasing, female mites were

3 332 prestarved fr 30 minutes in the Petri dish which was kept ver a blck f ice. Tw hundred (200) prestarved mites were released in the central regin f Tangleft circle and five replicatins were kept fr this experiment. Observatins regarding the number f mites fund n leaf-discs f different citrus gentypes after 6 hurs f releasing were recrded. The number f mites trapped in the Tangleft barrier, r were fund still wandering inside the enamel tray, r were fund dead in the tray were als recrded and their percentages calculated. Bth the experiments were cnducted at 27±2 C temperature maintained in B.O.D. incubatr. Mean and Standard deviatin f all the bilgical parameters was wrked ut. In case f vipsitin respnse and feeding preference by mite t different gentypes, analysis was dne by Cmplete Randmized Design. RESULTS AND DISCUSSION Studies n the bilgy f tw-sptted spider mite, T. urticae, n citrus (Kinnw); vipsitin respnse and feeding preference f T. urticae n different citrus gentypes were carried ut during and the results btained during the curse f these investigatins are presented and discussed here. Bilgy f T. urticae Kch n Kinnw Incubatin perid: Eggs were rund with mean diameter f µm. Incubatin perid varied frm 1 t 4 days (2.52 ± 1.02). Mst f the eggs successfully hatched at 27±2 C temperature (Table 1). Present findings are in cnfrmity with the bservatins f Dhria (1985) wh bserved that incubatin perid fr Eutetranychus rientalis (Klein) varied frm 4 t 5 days n mandarin at 30 ± 1 C and 70 ± 10 per cent R.H. and Matts and Feres (2009) wh reprted incubatin perid f 5.3 days fr E. banksi lvie & Barrws n Citrus sinensis at 28 ± 1 C and 70 ± 10 per cent R.H. Similarly, Wahed and Halawany (2012) bserved incubatin perid f 4.6 days fr females and 4.3 days fr males n Lacnt pear variety and 5 days fr females and 4.7 days fr males at 25 C n Hd pear variety at 25 C and Riahi et al (2013) fund mean incubatin perid f 3.90 days n peach at 27 C. In cntrast t the present findings, Badii et al (2003) fund incubatin perid f 6.21 days at Navjt Kaur, Manmeet Brar Bhullar and Paramjit Kaur 25 C and 60 ± 8 per cent R.H fr E. banksi n Sweet range while Barbsa et al (2004) reprted that incubatin perid f E. banksi varied frm 5.8 t 7.2 days n papaya and 6.6 days n lime at 26 ± 0.2 C and 65 ± 7 per cent R.H. Mnteir et al (2014) bserved that incubatin perid f T. urticae varied frm 4.17 t 4.53 days n different strawberry cultivars at 25 ± 1 C and 70 ± 10 per cent R.H. Larval perid: In the present studies, mean larval perid was fund t be 2.74 ± 0.99 days (Table 1). The mean length and width f freshly emerged larva was fund t be µm and µm, respectively (Table 2). The present studies are in accrdance with the studies f Dhria (1985) wh reprted that larval perid f E. rientalis varied frm days n lime and 1.00 t 2.37 days n mandarin, respectively and Barbsa et al (2004) wh reprted that incubatin perid f E. banksi varied frm 2.00 days n papaya and 3.90 days n lime at 26 ± 0.2 C and 65 ± 7 per cent R.H. Hwever, Badii et al (2003) and Matts and Feres (2009) fund larval perid f 1.20 days at 25 C and 60 ± 8 per cent R.H. fr E. banksi n Sweet range and 1.3 days fr E. banksi n C. sinensis at 28 ± 1 C and 70 ± 10 per cent R.H., respectively. Wahed and Halawany (2012) als bserved the larval perid f 1.8 days fr females and 1.7 days fr males at 25 C and 70 ± 5 per cent R.H n Lacnt pear variety and 2 days fr females and 1.9 days fr males n Hd pear variety at 25 C and 70 ± 5 per cent R.H. The variatin in duratin f larval perid culd be due t the effect f different hsts n Table 1. Develpmental bilgy f tw-sptted spider mite, T. urticae n Kinnw at 27±2 C Parameters Mean ± S.D (days) Incubatin perid 2.52 ± 1.02 Larval perid 2.74 ± 0.99 Prtnymphal perid 2.08 ± 0.47 Deutnymphal perid 2.40 ± 1.03 Larval + nymphal perid 7.53 ± 2.16 Pre-vipsitin perid 0.96 ± 0.04 Ovipsitin perid 1.78 ± 0.87 Pst-vipsitin perid 6.40 ± 1.67 Adult lngevity Female 9.40± 0.67 Adult lngevity Male 6.71 ± 0.74 Fecundity 1.56 ± 0.74 Sex rati (Female : male) 4.33 : 1

4 Bilgy and feeding preference f tw-sptted spider mite 333 which the studies were cnducted. Prtnymphal perid: The larvae after becming full-fed became quiescent and first stage nymph i.e. prtnymph emerged frm them. The mean ± 0.47 prtnymphal duratin was bserved t be 2.08 days (Table 1). The mean length and width f the prtnymph was 240 µm and µm (Table 2). Present findings are in cllabratin with earlier findings f Dhria (1985) wh reprted that mean prtnymphal perid f E. rientalis varied frm days n lime and 1.87 t 2.86 days n mandarin, respectively and Barbsa et al (2004) wh reprted that prtnymphal perid f E. banksi varied frm 1.6 t 2.5 days n papaya and 1.8 days n lime at 26 ± 0.2 C and 65 ± 7 per cent R.H. In cntrast t the present findings, Badii et al (2003) fund prtnymphal perid f 1.27 days at 25 C and 60 ± 8 per cent R.H. fr E. banksi n Sweet range while Matts and Feres (2009) fund prtnymphal perid f 0.7 days fr E. banksi n C. sinensis at 28 ± 1 C and 70 ± 10 per cent R.H. Riahi et al (2013) als fund prtnymphal perid f 0.76 days fr females and 1.09 days fr males at 27 C n peach leaves. The differences in the abve studies culd be due t the effect f different hsts n which the studies were cnducted. Deutnymphal perid: The prtnymphs after becming full fed entered int a quiescent stage and frm this, the secnd stage nymph i.e. the deutnymph emerged. Deutnymphal perid was fund t be 2.40 ± 1.03 days (Table 1) while the mean length and width f deutnymph was µm and µm respectively (Table 2). The present studies are in cncurrence with the earlier findings f Herbert (1981) wh reprted deutnymphal perid f 2.91 days n apple at 21 C. Dhria (1985) als reprted that deutnymphal perid f E. rientalis varied frm 1.20 t 3.00 days n lime and 2.04 t 2.71 days n mandarin, respectively. Similarly, Barbsa et al (2004) reprted that deutnymphal perid f E. banksi varied frm 2.00 t 2.6 days n papaya and 2.2 days n lime at 26 ± 0.2 C and 65 ± 7 per cent R.H., while Wahed and Halawany (2012) reprted deutnymphal perid f 2.3 days fr females and 2.1 days fr males n Hd pear variety at 25 C and 70 ± 5 per cent R.H. In variance t the present findings, Badii et al (2003) fund deutnymphal perid f 1.18 days at 25 C and 60 ± 8 per cent R.H fr E. banksi n Sweet range and Matts and Feres (2009) fund deutnymphal perid f 0.8 days fr E. banksi n C. sinensis at 28 ± 1 C and 70 ± 10 per cent R.H. Similarly, Riahi et al (2013) fund deutnymphal perid f 1.12 days fr females; 0.96 days fr males n peach leaves at 27 C while Mnteir et al (2014) fund that deutnymphal perid varied frm 0.79 t 1.12 days n different strawberry cultivars at 25 ± 1 C and 70 ± 10 per cent R.H. Less duratin f deutnymphal perid in the abve studies was attributed t be because f different hsts. Ttal larval plus nymphal perid: Data given in Table 1 revealed that n leaves f Kinnw ttal larval plus nymphal develpment was cmpleted in 7.53 ± 2.16 days. The present investigatins are in line with thse f Herbert (1981) wh reprted that the ttal immature develpment f T. urticae n apple leaves was cmpleted in 8.00 days at 21 C; Wahed and Halawany (2012) wh bserved that ttal immature develpment f T. urticae n Lacnt pear variety was 5.4 days fr females and 4.9 days fr males while n Hd pear variety it was 6.4 days fr females and 5.6 days fr males at 25 C and 70 ± 5 per cent R.H. Riahi et al (2013) als reprted ttal immature develpment f 9.43 days fr females and 9.75 days fr males n peach leaves at 27 C. Hwever, these vary frm the studies f Badii et al (2003) wh fund ttal immature develpment f days at 25 C and 60 ± 8 per cent R.H. fr E. banksi n Sweet range. Mnteir et al (2014) fund that ttal immature develpment varied frm 9.84 t 12 days n different strawberry cultivars at 25 ± 1 C and 70 ± 10 per cent R.H. The difference f duratin in these Table 2. Mrphmetric measurements f different develpmental stages f T. urticae Stage Length (µm) Width (µm) Larva ± ± 0.89 Nymph Prtnymph ± ± Deutnymph ± ± Adult Male ± ± Female ± ± 54.58

5 334 studies might be due t different temperatures and different hsts n which the studies were cnducted. Pre-vipsitin, vipsitin and pstvipsitin perid: Perusal f Table 1 revealed that mean pre-vipsitin perid f T. urticae n Kinnw leaves was 0.96 ± 0.04 days. Present findings are in cllabratin with the findings f Dhria (1985) wh fund that mean previpsitin perid f E. rientalis varied frm 0.12 t 1.33 days n lime and 0.83 days n mandarin, respectively and Barbsa et al (2004) wh reprted that pre-vipsitin perid f E. banksi varied frm 0.6 t 1.1 days n papaya and 1.00 day n lime at 26 ± 0.2 C and 65 ± 7 per cent R.H. Similarly, Matts and Feres (2009) fund pre-vipsitin perid f 0.91days fr E. banksi n C. sinensis at 28 ± 1 C and 70 ± 10 per cent R.H. and Bruessw et al (2010) als reprted that the pre-vipsitin perid f T. urticae ranged frm 0.77 days fr Trifliate range, 0.54 days fr Sur range 1.70 fr Tryer citrange, 0.14 fr Vlkamer lemn, 1.00 day fr Clepatra mandarin, 0.57 days fr Alemw rtstcks at 25 ± 1 C and per cent R.H. The present studies are in variance with thse f Badii et al (2003) wh bserved mean pre-vipsitin perid f 1.59 days fr E. banksi at 25 C and 60 ± 8 per cent R.H.; Wahed and Halawany (2012) wh fund pre-vipsitin perid f 1.2 days fr females f T. urticae n Lacnt pear variety and 1.4 days n Hd pear variety at 25 C and 75 ± 5 per cent R.H and Riahi et al (2013) wh bserved pre-vipsitin perid f 1.42 days fr females f T. urticae n peach leaves at 27 C. The mean vipsitin perid f T. urticae n Kinnw leaves was fund t be 1.78 ± 0.87 days (Table 1). The present studies are in accrdance with thse f Dhria (1985) wh fund that mean vipsitin perid f E. rientalis varied frm 1.83 t 4.58 days n lime and 3.50 days n mandarin, respectively. In cntrast t the earlier findings Badii et al (2003) bserved mean vipsitin perid f 4.93 days fr E. banksi at 25 C and 60 ± 8 per cent R.H n Sweet range; 8.6 days n lime at 26 ± 0.2 C and 65 ± 7 per cent R.H. (Barbsa et al 2004) and 7.61 days n C. sinensis at 28 ± 1 C and 70 ± 10 per cent R.H.(Matts & Feres 2009). Bruessw et al (2010) als reprted that the vipsitin perid f T. urticae ranged frm days fr Trifliate range, 8.15 days fr Sur range Navjt Kaur, Manmeet Brar Bhullar and Paramjit Kaur days fr Tryer citrange, 7.14 days fr Vlkamer lemn, days fr Clepatra mandarin, 6.07 days fr Alemw rtstcks at 25 ± 1 C and per cent R.H. Wahed and Halawany (2012) fund vipsitin perid f 14.4 days fr females f T. urticae n Lacnt pear variety and 11.8 days n Hd pear variety at 25 C and 75 ± 5 per cent R.H. while Riahi et al (2013) reprted vipsitin perid f 4.36 days fr females f T. urticae n peach leaves at 27 C. These differences may be due t difference f temperature and hsts n which develpment f mite was studied. Perusal f Table 1 als revealed that mean pst-vipsitin perid f T. urticae n Kinnw leaves was 6.40 ± 1.67 days. In cntrast t the present findings, Dhria (1985) fund that mean pst-vipsitin perid f E. rientalis varied frm 0.47 t 1.00 days n lime and 1.08 days n mandarin, respectively; 1.02 days fr E. banksi n Lime at 25 C and 60 ± 8 per cent R.H.(Badii et al 2003). Similarly, Wahed and Halawany (2012) fund pst-vipsitin perid f 1.6 days fr females f T. urticae n Lacnt pear variety and 1.3 days n Hd pear variety at 25 C and 75 ± 5 per cent R.H. and Riahi et al (2013) als reprted pstvipsitin perid f 0.37 days f T. urticae n peach leaves at 27 C. Hwever, Bruessw et al (2010) reprted that the pst-vipsitin perid f T. urticae ranged frm 3.53 days fr Tryer citrange, 2.46 days fr Trifliate range, 5.08 days fr Sur range, 2.30 days fr Tryer citrange, 0.57 days fr Vlkamer lemn, 2.73 days fr Clepatra mandarin, 0.87 days fr Alemw rtstcks at 25 ± 1 C and per cent R.H. These differences may be due t difference f temperature and hsts n which develpment f mite was studied. Fecundity: Mean maximum fecundity f 1.56 ± 0.74 eggs was fund n Kinnw in the present studies (Table 1). Present findings are in cntrary t the findings f Dhria (1985) wh reprted that mean fecundity f E. rientalis varied frm eggs n lime and 9.83 eggs n mandarin, respectively. Badii et al (2003) als reprted mean ttal fecundity/female f 9.35 eggs n sweet range fr E. banksi and 11.9 eggs/female fr E. banksi n lime (Barbsa et al 2004). Ttal mean fecundity per female f T. urticae ranged frm fr Tryer citrange, fr Trifliate range, 9.92 eggs fr Sur range 8.96 eggs fr Tryer citrange, eggs fr Vlkamer lemn,

6 Bilgy and feeding preference f tw-sptted spider mite eggs fr Clepatra mandarin and eggs fr Alemw rtstcks at 25 C and per cent R.H.( Bruessw et al 2010). Higher fecundity in the plants might be due t differential temperature and the preference fr the hst n which these studies were dne. Sex-rati: Sex-rati was taken frm the males and females that emerged frm quiescent deutnymphs. In the present findings, sex-rati (Female: Male) was fund t be 4.33: 1 (Table 1). On the whle sex rati was in favur f females. These results are in accrdance with Dhria (1985) wh bserved sex rati f female: male as 1.40: 1 n mandarin and 8.00: 1 n lime. Badii et al (2003) als reprted sex rati f female: male as 5.6: 1 fr E. banksi at 25 C. On the cntrary, Bruessw et al (2010) bserved sex rati f female/ttal as 0.83 n Tryer citrange, 0.74 n Trifliate range, 0.76 n Sur range, 0.78 n Vlkamer lemn, 0.84 n Clepatra mandarin and 0.82 n Alemw at 25 ±1 C and per cent R.H. Similarly Wahed and Halawany (2012) bserved sex rati f female/ttal as 0.70 n Lacnt and 0.60 n Hd pear variety fr T. urticae at 25 C. Lngevity: Mean lngevity f females n leaves f Kinnw was fund t be 9.40 ± 0.67 days while in case f males it was fund t be f 6.71± 0.74 days (Table 1). The length and width f adult male and female was bserved t be µm, µm and µm, µm, respectively (Table 2). Present findings are in line with the studies f Badii et al (2003) wh fund that lngevity f E. banksi was 6.86 days at 25 C n Sweet range. Hwever, Dhria (1985) reprted that mean lngevity f E. rientalis varied frm 1.50 t 5.50 n lime and 2.14 t 5.42 days n mandarin, respectively at 30 ± 0.05 C. Bruessw et al (2010) als reprted that life span f T. urticae was days n Tryer citrange, days n Trifliate range and Sur range, 7.86 days n Vlkamer lemn, days n Clepatra mandarin and 7.50 days n Alemw rtstcks f citrus. Similarly, Wahed and Halawany (2012) fund that lngevity f T. urticae varied frm 17.2 days fr females and 15 days fr males n Lacnt pear variety and 14.5 days fr females and 12.4 days fr males n Hd pear variety at 25 C and 70 ± 5 per cent R.H. Riahi et al (2013) and Barbsa et al (2004) reprted female lngevity f days and male lngevity f 6.80 days fr T. urticae n leaves f peach and mean lngevity f E. banksi t be frm 13.0 t 13.5 days n papaya and 1.00 day n lime at 26 ± 0.2 C and 65 ± 7 per cent R.H. The prlnged duratin in these studies may be due t different temperatures and different hsts n which develpment f mite was studied. Feeding preference f T. urticae Twelve citrus gentypes namely Sweet lime (Citrus limettides) (SL-3, SL-4, SL-7), Baramasi lemn (Citrus limn) ( BL-1, BL-2, BL-3, BL-5), Galgal (Citrus limn) (G-4, G-5, G-7), Kaghzi lime (Citrus aurantifila) (KL-7) and Tahiti Lime (Citrus latiflia) were screened fr vipsitin respnse and feeding preference by T. urticae. Overall cmparisn f data revealed that vipsitin after 1, 2 and 3 days interval f releasing mite was fund maximum n G-5, G-4, BL-2 and SL-4 while n egg laying was bserved n SL-7 (Table 3). Feeding preference f T. urticae n different citrus gentypes was studied thrugh free chice methd. Maximum number f mites were fund n gentype KL-7 (23.33) fllwed by SL-4 (13.67), BL-5 (13.33), BL-1 (12.33), SL-3 and G-7 (11.00), BL-2 (10.00), SL-7 and Tahiti Lime (9.69) when bserved after 6 hurs f releasing mites whereas minimum number f mites were fund n gentype G-4 (2.67). Within gentypes f citrus, mites preferred KL-7 (Kaghzi lime) the mst, but had least preference fr G-4 (Galgal) (Table 4). It was fund that mean per cent f mites were able t lcate the different gentypes successfully while mean per cent f mites were unable t settle n any f the citrus gentypes and was fund wandering in the area enclsed by Tangleft. Mean per cent f 7.84 mites were fund dead during the bservatins while 7.34 per cent were fund trapped in the Tangleft barrier. Perusal f data given in Table 4 revealed that within gentypes f citrus, mites preferred KL- 7 (Kaghzi lime) the mst, but had least preference fr G-4 (Galgal). In cntrast t the present findings, Dhria (1982) reprted that E. rientalis exhibited highest preference fr feeding n Sweet lime and Sur lemn while Kaghzi lime, Msambi had pr feeding respnse. Nt much infrmatin regarding the feeding preference f T. urticae n the abve tested gentypes f citrus was available in literature.

7 336 Navjt Kaur, Manmeet Brar Bhullar and Paramjit Kaur Table 3. Ovipsitin respnse f T. urticae n different citrus gentypes at 27±2 C Citrus gentypes Mean number f eggs laid/female 1 DAR 2 DAR 3 DAR Sweet lime (Citrus limettides) SL (1.00) 0.40 (1.14) 0.00 (1.00) SL (1.14) 0.00 (1.00) 1.00 (1.36) SL (1.00) 0.00 (1.00) 0.00 (1.00) Galgal (Citrus limn) G (1.14) 0.40 (1.16) 1.40 (1.51) G (1.08) 0.80 (1.33) 3.00 (1.98) G (1.00) 0.40 (1.14) 0.40 (1.14) Baramasi lemn (Citrus limn) BL (1.00) 0.60 (1.24) 0.60 (1.22) BL (1.08) 1.00 (1.39) 0.40 (1.16) BL (1.00) 0.20 (1.08) 0.40 (1.16) BL (1.08) 0.00 (1.00) 0.00 (1.00) Kaghzi lime (Citrus aurantifila) KL (1.00) 0.00 (1.00) 0.20 (1.08) Tahiti Lime (Citrus latiflia) 0.00 (1.00) 0.00 (1.00) 0.60 (1.24) C.D (p=0.05) N S (0.24) (0.32) DAR: Days after release ; Figures in parentheses are square rt transfrmed values Table 4. Feeding preference f T. urticae n different citrus gentypes at 27 ± 2 C Citrus gentypes Mites fund n different citrus gentypes after 6 hurs f releasing Mean number Mean Percentage Sweet lime (Citrus limettides) SL (2.98) 8.44 SL (3.46) SL (3.24) 7.42 Galgal (Citrus limn) G (1.82) 2.05 G (2.77) 5.37 G (3.16) 8.44 Baramasi lemn (Citrus limn) BL (3.60) 9.46 BL (3.20) 7.67 BL (2.60) 5.12 BL (3.65) Kaghzi lime (Citrus aurantifila) KL (4.59) Tahiti Lime (Citrus latiflia) 9.67 (3.24) 7.42 CD (p=0.05) Mean per cent f mites (a) Mites successful in finding leaves = 65.17, (b) Mites trapped in Tangleft = 7.34 (c) Mites wandering in the tray = 19.67, (d) Mites fund dead = 7.84 NS REFERENCES Annymus Biennial prgress Reprt f AINP n Agricultural Acarlgy, UAS, Bengaluru. Annymus Area, prductin and average yield f c i t r u s i n I n d i a a n d P u n j a b. Badii J, Varela M H, Flres S, and Landers A E Temperature based life histry and life table parameters f Texas citrus mite n range (Acari: Tetranychidae). Systematic and Applied Acarlgy 8: Barbsa D G F, Gndim M G C J, Barrs R, Oliveira J V and Silva F R Cmpared bilgy f Eutetranychus banksi (McGregr) (Acari : Tetranychidae) n trpical fruit species. [Prtuguese] Netrprical Entmlgy 33: Bruessw A, Asins F, Jacas M J and Urbaneja J A 2010.

8 Bilgy and feeding preference f tw-sptted spider mite 337 Replacement f CTV-susceptible sur range rtstck by CTV-tlerant nes may have triggered utbreaks f Tetranychus urticae in Spanish citrus. Agriculture, Ecsystems & Envirnment 137: Dhria Differential respnse f citrus s p e c i e s / v a r i e t i e s t i n f e s t a t i n f Eutetranychus rientalis. Indian Jurnal f Acarlgy 7 : Dhria Develpment f citrus mite, E u t e t r a n y c h u s r i e n t a l i s ( A c a r i : Tetranychidae) as influenced by age and surface f leaves f different hsts. Indian Jurnal f Acarlgy 9 : Dhria M S, Bhullar M B and Mallik B Mite pests f citrus and their management in India. 28 pp. AINP (Agricultural Acarlgy). Herbert H J Bilgy, life tables and innate capacity fr increase f the tw-sptted spider mite, Tetranychus urticae (Acarina : Tetranychidae). Canadian Entmlgist 113 : Hy M A Integrated mite management in citrus in Flrida and Califrnia. Pp In: Agicultural Acarlgy, Intrductin t integrated mite management. CRC Press Taylr and Francis Grup. Jeppsn L R, Keifer H H and Baker E W Mites injurius t ecnmic plants. Pp 614. University f Califrnia Press, Berkely, U.S.A. Kumar B, Mistry N C, Singh B and Gandhi C P Indian Hrticulture Data Base Natinal Hrticulture Bard, Gurgan, India Matts V M and Feres R J F Mrphlgical pattern and life cycle f Eutetranychus banksi (Acari : Tetranychidae) frm different lcalities and hsts. [Prtuguese]. Zlgia 26: Mnteir L B, Kuhn T M A, Mgr A F, Silva E D B Bilgy f the tw-sptted spider mite n strawberry plants. Netrpical Entmlgist 43: NHB Natinal Hrticulture Bard, Hrticulture Infrmatin Service Radnjic S The first recrd f Tetranychus urticae Kch (Acarina, Tetranychidae) n citrus in Mntenegr. IOBC/WPRS Bull 38: Riahi E, Shishehbr P, Nemati A R, and Saeidi Z Temperature Effects n Develpment and Life Table Parameters f Tetranychus urticae (Acari: Tetranychidae). Jurnal f Agricultural Science and Technlgy 15: Vacante V, Bnsignre C P Implementatin f IPM in Citriculture. In: Integrated Pest Management f Citrus. Bentham Science 3: Wahed N M and Halawany A S Effect f Temperature Degrees n the Bilgy and Life Table Parameters f Tetranychus urticae Kch n Tw Pear varieties. Egyptian Academic Jurnal f Bilgical Sciences 4: Manuscript Received: May 10, 2015 Accepted: July 07, 2014