Relationship of Broad Mite Population and Effectiveness of ... · One predatory mite per 20 broad...

www.thaiagj.org Thai Journal of Agricultural Science 2013, 46(4): 191-199

Relationship of Broad Mite Population and Effectiveness of Predatory Mite to Leaf Curl Symptoms of Chili

J. Rattanatip1, N. Siri1,2,* and A. Chandrapatya3

1Entomology Section, Department of Plant Science and Agricultural Resources

Khon Kaen University, Khon Kaen 40002, Thailand 2National Biological Control Research Center, Upper Northeastern Regional Center

P.O. Box 181 Khon Kaen University, Khon Kaen 40002, Thailand 3Department of Entomology, Kasetsart University, Bangkok 10900, Thailand

*Corresponding author, Email: [email protected]

Abstract This research is attempted to clarify the relationship between broad mite population,

Polyphagotarsonemus latus (Banks) and leaf curl symptoms in chili and evaluates the effectiveness of its natural enemy, Amblyseius cinctus Corpuz & Rimando related to leaf symptom level. The population levels of broad mite relative to leaf curl symptom were investigated on five chili cultivars; Pakpuan, Kaen-Hom 60, KKU-P33032, Super Hot and TPP034. The mite distribution was observed on 1st - 8th leaf position from the tip. The result showed that more mites were observed at the 4th - 7th leaf position than the 1st to 3rd and 8th leaf position. The appropriate leaf position for broad mite detection was suggested at the 4th leaf position for Pakpuan, Kaen-Hom 60, KKU-P33032, Super Hot cultivars and 3rd leaf position for the TPP034. Seven symptom levels (0 - 6) were developed to quantify broad mite injury to the chili plant. Different cultivars supported different amounts of broad mite, even though there were similar levels of damage across cultivars. TPP034 had significantly highest amount of broad mite than the other four cultivars. The KKU-P33032 cultivar showed no curl symptom at any broad mite infestation level. The effectiveness of A. cinctus on chili plant related to leaf curl symptom level was tested on 3 cultivars; Super Hot, Kaen-Hom 60 and TPP034. One predatory mite per 20 broad mites was released at level 3 symptom. After 1 week, the predatory mite could control the mite population on Super Hot cultivar by reducing the symptom from level 3 to zero. Keywords: broad mite, Polyphagotarsonemus latus, Amblyseius cinctus, chili, leaf curl symptom level

Introduction Chili, Capsicum annuum L., is a major cash crop

grown for domestic consumption in Thailand and exported to 27 countries with an annual value of $ 2,926,180 (Thailand trading report, 2010). However, the Department of Agriculture (DOA) had to suspend its exports of chili due to toxic residues detected in the amount greater than the allowable limits. Consequently, exports have been declined each year at least 40-50 times (Department

of Agriculture, 2004). The most important source of crop damage in chili is outbreak of major arthropod pests, especially the broad mite, Polyphagotarsonemus latus (Banks). Broad mite is a very small pest (less than 0.2 mm in length) which is difficult to observe with the naked eye. This mite typically damages plants by attacking the young leaf tissues as well as the flower and fruit buds. Common symptom induced by this pest is leaf edge curl and rolling down (Gerson, 1992). Therefore, the symptom of chili leaf curl is used

192 J. Rattanatip et al. Thai Journal of Agricultural Science

frequently to determine whether the chemical application is required.

Ali (2006) reported that an average of 21 applications was made by chili-growing countries in Asia, with the highest of 53 in Indonesia. A total of 23 pesticide applications were used for each crop in Thailand. Despite the increasing use of chemicals on chili, the yield losses due to insects and diseases, as perceived by farmers, did not decrease; rather indications were that such losses in fact increased overtime. Hence, the study of the relationship between the population of broad mite and symptomatic leaves of a chili is another important consideration to reduce chemical use in chili field. If the farmers can anticipate damaging broad mite populations on the chili based on leaf symptoms and use this information for timely and effective control actions, then this could be an effective monitoring tool for reducing the use of unnecessary chemical treatments.

Another approach is to prevent and eliminate broad mite populations through biological control agents such as the predatory mite, Neoseiulus californicus (McGregor), Neoseiulus barkeri (Hughes) and Neoseiulus cucumeris (Oudemans) (Fan and Petitt 1994b; Peña and Osbone, 1996; Weintraub et al., 2003). The predatory mite, Amblyseius cinctus Corpuz & Rimando was first detected in Thailand in the year 1977 (Ehara and Bhandhufalck, 1977) and often found in mixed populations of mites and plant pests on a wide range of host plants (Charanasri et al., 1992). Kongchoensin et al. (2005) reported that the adult female of A. cinctus consumed the larva and adult of broad mite at 19.6±0.7 and 19.4±0.8 mite day-1 when presented with 20 broad mites, and 37.2±1.3 and 30.8±2.8 per day, respectively, when 40 broad mites were provided as prey.

The Department of Agriculture of Thailand recommended farmers to spray acaricide on chili when 5-10 broad mites/leaf were found but they did not stipulate which is an appropriate leaf position to investigate. Therefore, the aim of this study was to determine the appropriate leaf position for detecting mite and evaluate the relationship of broad mite population to leaf curl symptom level including investigation of the effectiveness of A. cinctus related to leaf curl symptom level. If natural enemies effectively control the outbreak of broad

mites, causing chili leaf curl symptoms to decrease, then this will be a practical way to reduce the use of insecticides and toxic substances without the loss of chili yield.

Materials and Methods Mass Rearing of Broad Mite

Broad mite, P. latus was collected from chili field at Khon Kaen Province in 2010 and mass-reared on the cotton plant in the greenhouse. Three cotton seeds (Gossypium hirsutum L.) were grown in each plastic pot of 10-inch diameter, 50 pots per week. Fertilizer (46-0-0) was given to each pot after the cotyledon appeared. After 3 weeks, 20 adult female mites from the stock culture were transferred to each pot. New cotton plants were provided for broad mites when crowded conditions were observed. The cotton plants infested with broad miteswere then divided into 2 groups; one for broad mite rearing and one for predatory mite mass rearing.

Mass Rearing of Predatory Mite A. cinctus

Amblyseius cinctus was collected from chili plants of pesticide-free organic farmers in Banmoh Sub-District, Nampong District, Khon Kaen Province, Thailand. Adult A. cinctus female was transferred to cotton plants containing broad mite at the ratio of 1:10 predatory mite: broad mite and sprinkled with the cat-tail pollen (Typha angustifolia L.) to serve as a nutrient supplement for the predatory mite. The cotton plants were then put in a net cage of 60×60×120 cm. New broad mite-infested cotton plant pots were renewed weekly.

Study on Distribution of the Broad Mites on Leaf Surface

Five chili cultivars were used in the experiment, two were the popular planting cultivar; Pakpuan (Capsicumchinense Jacq.) and Super Hot (Capsicum annuumL.), two were from the plant breeding research center for sustainable agriculture, Khon Kaen University; Kaen-Hom 60 (Capsicum frutescens L.) and KKU-P33032 (Capsicum baccatum L.) and one was from the seed company (A.G. universal Co., Ltd.), Khon Kaen, Thailand; TPP034 (Capsicum annuum L.). Thirty-five day

Vol. 46, No. 4, 2013 Mite effects on leaf curl symptoms of chili 193

old chili plants of the five cultivars were transplanted in the screen house of 2.5 m long and 2 m wide. Four plants per cultivar were planted in row with planting space of 50×50 cm. Two screen houses were used in the experiment. Two weeks after planting, 10 female mites were released on the entire stem of each chili cultivars. The 1st to 8th leaf position of chili stem were observed where the first leaf from the apical meristem was defined as position 1. The number of mites was counted at weekly interval using a 30x hand lens until one of any cultivars showing leave distortion. Total numbers of immature and adult mites per cultivar were recorded by leaf position. There were 4 replicates for each cultivar in a Randomized Complete Block design where screen house served as block. Analysis of variance was conducted by cultivar with leaf position as the independent variable.

The Relationship of the Broad Mite Population Levels to Leaf Curl Symptoms

Preparation of the five chili cultivars infested by broad mite planting in the screen house was the same as the first experiment and three net houses were used. The mite population was investigated after one week of releasing 10 female broad mites on each chili cultivar. The number of mites was observed at the 4th leaf from the shoot tip which was the appropriate leaf position (from the first experiment). Five shoots per plant were observed at weekly interval for 8 weeks and the number of mites on each leaf was recorded (Figure 1). The leaf curl symptom level (LCL) was evaluated according to Coss-Romero and Pena (1998). The experiment went from September to November 2010.

The Effectiveness of Predatory Mite (A. cinctus) Related to the Leaf Curl Level Symptom

Kaen-Hom 60, TPP034, and Super Hot were planted in plastic pot (20 cm diameter), 4 replications per cultivar and placed in a net cage of 60×60×120 cm, one plant per cage. Six weeks after transplanting, the cotton leaf containing different stages of broad mite (approximately 50 mites leaf-1) from the stock culture were placed on the top of the chili plants. One week later, the predator was

Figure 1 Broad mite population was taken from each shoot (5 shoots per plant).

released on the chili leaves with the ratio of 1: 20 (predatory mite: broad mite). The amount of broad mite and the leaf curl symptom level (0-6) was observed at weekly interval. The experiment was terminated when the predatory mite would eradicate the broad mite in any of the three cultivars.

Results and Discussion Study on Distribution of the Broad Mites on Leaf Surface

The results on mite distribution demonstrated that the broad mite was distributed around the 3rd-7th leaf position of chili stem. However, the exact order of the leaf and amount of the broad mite depended on the cultivar of chili. The amount of the broad mite on the 8th leaf tended to decrease in some cultivar, presumably due to old age of the leaf and poorer nutrient content (Table 1). This result was supported by Smith (1935) who showed that the broad mite could not survive long on the tough, mature leaves of most plants. In addition, the 1st and 2nd leaf were too young and too small for broad mite. Therefore, the appropriate leaf position for leaf curl symptom observation were the 4th- 5th from the top except in TPP034 (Table 1). The results suggested that the 4th leaf position in Kaen-Hom 60, Pakpuan, KKU-P33032 and Super Hot cultivars is where 5-10 broad mites were found as


Table 1 Number of broad mites at the 1st-8th leaf position in 5 chili cultivars after the broad mite was released for 4 weeks.

Mites per leaf Cultivar1/

Pakpuan Kaen-Hom 60 KKU-P33032 Super Hot TPP034

1st 0.98±0.20c1/ 1.44±1.00cd 0.06±0.01b 0.44±0.20d 0.25±0.96c

2nd 0.50±1.50c 0.75±2.22d 0.31±1.00b 1.75±1.50bcd 0.044±0.00c

3rd 3.13±3.86bc 3.00±12.53bcd 3.31±1.50a 4.44±1.41bcd 9.50±1.71ab

4th 6.00±5.40ab 5.44±10.72abcd 2.50±3.20ab 5.88±8.38abc 12.81±10.50a

5th 8.25±5.85a 14.06±24.95ab 1.63±0.96ab 10.81±7.36aA 12.75±12.39a

6th 4.94±4.96abc 13.88±20.56abc 1.19±3.42ab 6.44±11.95ab 4.25±10.86bc

7th 7.13±5.50ab 12.63±16.57abc 1.25±4.36ab 3.06±4.86bcd 1.44±11.50c

8th 3.75±2.80abc 7.75±27.00abcd 0.13±1.00b 1.13±6.60cd 0.81±6.50c 1/Means in a row with different letters differed at P<0.05 as determined by Duncan’s New Multiple Range Test.

suggested by DOA whereas leaf position 3rd was most suitable for detecting mites on TPP034. Moreover, the broad mite could damage the early seedling stage, which consisted of two leaves unfolded or four leaves unfolded and the damage caused by these mites at this early stage of development reduced the plant stand and/or substantially delayed plant growth (Jovicich, et. al. 2004). Hence, we should observe broad mite on whole plant in the seedling stage.

The Relationship of the Broad Mite Population to Leaf Curl Symptom Levels

The leaf curl symptom level (LCL) in this study was simplified from Coss-Romero and Pena (1998) with some modifications. They were categorized into 7 levels of damage as follow: level 0: normal leaf, level 1: discoloration present as pale-green at the base of the leaf, unusual dark green under the leaf and the infested plants appeared pale green in color and the lower side of leaves exhibited shiny white coating (Dalaya, 1962). Level 2 showed discoloration that had advanced to green-brownish and curling appeared at the leaf tip, level 3: leaves exhibit unusual stretching and elongation of petioles as suggested by Mote (1979), level 4: extensive curling and brownish-green coloration of the top leaf, linear shape rather than round shape agreed with Dhooria and Bindra (1977) who stated that tips of infested leaves looked linear rather than round and later became necrotic and dropped. Affected leaves were dark green compared to healthy ones. Level 5: no remaining leaf at the top,

level 6: regeneration of leaf (Figures 2-3). In addition, it was observed that different cultivars supported different amounts of broad mites even though there were similar levels of damage across cultivars.

Damage did not appear right away after the pest arrived on the plant which was in agreement with Vichitbandha and Chandrapatya (2011). At level 1 damage, it was difficult to identify a clear pattern among cultivars. KKU-P33032 and TPP034 cultivars did not develop damage symptoms at this level of damage. Moreover, Kaen-Hom 60, Pakpaun, and Super Hot showed no difference in the amount of broad mite (Figure 4). The curl symptom was obvious at damage levels 2 to 3, but KKU-P33032 cultivar still showed no symptoms. In addition, the symptom color of the leaf and the amount of broad mite increased noticeably at these levels. The affected leaves became brittle with a yellowish tinge. According to Puttarudraiah (1959), the leaf curl and roughened lamina in infested plants are caused by P. latus and correspond with Nandihalla (1979) who reported that mite attack resulted in development of shiny spots on lower surface of leaves. Further, leaves exhibited downward curling all along the margin and became thick and brittle. Finally leaves turned red on both sides and had a burnt appearance. At level 4, the amount of broad mite gradually decreased, probably because of the leaf deformity which forced the broad mite to move to the upper part of the leaf. Hence, broad mites significantly reduced the increment in leaf sizes of infested


a. b. c. d.

e. f. g. h.

j. i. k. l.

Figure 2 Leaf curl symptom levels: a and b) level 0 - upper and under leaf surfaces, c and d) level 1 - upper and under leaf surfaces, e and f) level 2 - upper and under leaf surfaces, g and h) level 3 - upper and under leaf surfaces, I and j) level 4 - upper and under leaf surfaces, k) level 5, l) level 6.

Level 0 Level 1 Level 2 Level 3 Level 4 Level 5 Level 6

Figure 3 The composition of 7 leaf curl symptom levels.

plants as suggested by Cross-Romero and Pena (1998) and the plant could not support increasing numbers of broad mites, perhaps due to the low plant quality attributed to the mite damage (Jovicich et. al., 2004). At level 5, there was an even fewer broad mites because of the complete damage to the leaf and loss of terminal buds. At level 6, the new leaflet started to regenerate which indicated the broad mites had gone. Interestingly, the KKU-P33032 cultivar had no curl symptom at any broad mite infestation level. This was likely because the leaf of C. baccatum was covered with

dense trichomes which were different from the other cultivars that has no dense trichomes. Matos et al. (2009) also demonstrated that the highest values of rm were observed on Capsicum species with intermediate densities of trichomes on leaves such as C. frutescens and C. chinense and lower rm was measured in leaves of C. praetermissum which has the highest trichome density.

TPP034 had significantly highest amount of broad mite than the other four cultivars (Figure 4). The symptom was presented in 2 weeks after 10 broad mites were released/plant correspond with


Figure 4 Number of broad mites at different week on 5 chili cultivars.

Figure 5 Leaf curl symptom level at different week on 5 chili cultivars.

Ningappa (1972) and Nandihalla (1979) who stated that the mite caused downward curling of leaves and cupping of leaves on the 14th day after infestation. Furthermore, TPP034 cultivar showed the highest LCL (Level 4) within 2 weeks after mites were released. Fan and Petitt (1994a) reported new leaves of peppers inoculated with 10 adult females per plant were deformed in 2 weeks, the plants became severely stunted and the terminal growth was killed in 3 weeks which is similar to this finding.

The Effectiveness of Predatory Mite (A. cinctus) Related to the Leaf Curl Level Symptom

Amblyseius cinctus could eradicate the broad mite population on Super Hot cultivar within 2 weeks. Moreover, this cultivar showed leaf curl level 3 one week after releasing of the broad mite. Then, the symptom changed dramatically from level 3 to level 0 within one week after predatory mite was released. This result is supported by Fan and Pettii (1994) who found that the broad mite population on pepper was reduced from more than


100 mites per leaf to zero after 10 predator mite Neoseiulus barkeri adults were released for one week. On the other hand, broad mite on Kaen-Hom and TPP034 could not be controlled by A. cinctus. The two cultivars showed the leaf curl from level 1 to level 4 and level 4 to level 6, as well as the increasing of the broad mite population (Figures 6b, c). The differences in leaf morphology, the number and rate of predatory mite release may differ on difference crops (Walter and O’Dowd, 1992). This may be the reason that A. cinctus could control the broad mite on TPP034 and Kaen-Hom cultivars less than Supper Hot due to the leaf of the both cultivars which were bigger than Super Hot cultivar which meant that there was more space and more nutrients for the broad mites to develop. Furthermore, Kaen-Hom has more trichomes than TPP034 and Super Hot which served as the obstacle for A. cinctus to find the broad mite. Plant morphology traits can affect the feeding preference, oviposition choice and the vulnerability of herbivores to natural enemies (Matos et al., 2009). However, the induction of any known plant-defense mechanism against broad mite has not yet been described (Grinberg et al., 2005). Hence, the appropriate number of A. cinctus depended on cultivar, characteristic of the chili leaf, and the ability of broad mite to multiply on the host plant.

Conclusions This study found that the distribution of broad

mite was on the 1st to 8th leaf position. Observation on the 5 chili cultivars, Kaen-Hom 60, Pakpuan, KKU-P33032, Super Hot, and TPP034 indicated that the highest amount of the broad mite population was presented on the 4th to 7th leaf position and the suggesting leaf for broad mite observation was the 4th leaf position, excepted TPP034 where the 3rdleaf position was more suitable to detect the mite. The 7 leaf curl levels were developed and used to investigate the broad mite population relating to these levels. It was observed that different cultivars supported different amounts of broad mites, even though there were similar levels of damage across cultivars. The efficiency of the predatory mite A. cinctus also depended on the cultivar. The predatory mite could eradicate the mite population on Super Hot cultivar

by reducing the symptom level from 3 to zero within one week, but could not control broad mites on Kaen-Hom 60 and TPP034 since both cultivars showed leaf curl symptom at level 4 and 6 when the experiment was terminated.

Acknowledgments

This work was financial supported by the Royal

Golden Jubilee Ph D Program (grant number; PhD 0076/2550). Special thank also go to Prof. David G. Riley, The University of Georgia for advice on writing and statistic analysis.

References Ali, M. 2006. Chili (Capsicum spp.) Food Chain

Analysis: Setting Research Priorities in Asia. The World Vegetable Center, Tech. Bull. No. 38. AVRDC publication.

Charanasri, V., M. Kongchuensin, T. Kulpiyawat and C. Saringkaphaibul. 1992. Species and population density of predatory mites on durian. Thai Agric. Res. J. 10: 168-178. (in Thai)

Coss-Romero, M. and J.E. Pena. 1998. Relationship of broad mite (Acari: Tarsonemidae) to host phenology and injury levels in Capsicum annuum. Fla. Entomol. 81: 515-526.

Dalaya, V.P. 1962. Studies on the Causes of Chili Leaf Curl and Its Control by Chemicals. M.Sc. Thesis. Nagpur University. India.

Department of Agriculture (DOA). 2004. GAP: Chili. Available at www.lamphun.doae.go.th/GAP%20% 20prik.pdf . (Retrieved June 22th, 2010)

Dhooria, M.S. and O.S. Bindra. 1977. Polyphagotarsonemus latus (Banks) a mite pest of chilli and potato in Punjab. Acarol. News Lett. 4: 7-9.

Ehara, S. and A. Bhandhufalck. 1977. Phytoseiid mites of Thailand (Acarina: Mesostigmata). J. Fac. Educ. 27: 43-82.

Fan, Y. and F.L. Petitt. 1994a. Dispersal of the broad mite, Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae) on Bemisia argentifolii Bellows & Perring (Homoptera: Aleyrodidae). Exp. Appl. Acarol. 22: 411-415.

Fan, Y. and F.L. Petitt. 1994b. Biological control of broad mite, Polyphagotarsonemus latus (Banks) by Neoseiulus barkeri Hughes on pepper. Biol. Control. 4: 390-395.

Gerson, U. 1992. Biology and control of the broad mite, Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae). Exp. Appl. Acarol. 13: 163-178.

Grinberg, M., R. Perl-Treves, E. Palevsky, I. Shomer and V. Soroker. 2005. Interaction between cucumber plants and the broad mite, Polyphagotarsonemus latus: From damage to defense gene expression. Entomol. Exp. Appl. 115: 135-144.


Figure 6 Number of broad mites and leaf curl symptom level before and after released of Amblyseius cinctus in 3 chili cultivars.

Jovicich, E., D.J. Cantliffe, L.S. Osborne and P.J. Stoffella. 2004. Mite population and damage caused by broad mites (Polyphagotarsonemus latus (Banks)) infesting bell pepper at different seedling development stages. Acta. Hortic. 659: 339-344.

Kongchuensin, M., V. Charanasri, T. Kulpiyawat, P. Choawattanawong and P. Kornvipasreang. 2005. Geographic distribution, life history and effectiveness of predatory mite, Amblyseius cinctus Corpuz & Rimando (Acarina:Phytoseiidae), pp. 4-5. The 8th National Plant Protection Conference.

Matos, C.H., A. Pallini, M. Venzon, R.C. Freitas, D.D. Rezende and J.H. Schoereder. 2009. Do Capsicum spp. trichomes influence the biological aspects of the broad mite, Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae). Neotrop. Entomol. 38: 589-94.

Mote, U. N. 1979. Seasonal fluctuation in population and chemical control of chilli mites, Polyphagotarsonemus latus (Banks). J. Veg. Sci. 3: 54-61.

Nandihalla, B.S. 1979. Efficacy of Different Insecticides in the Control of Chilli Leaf Curl and Their Residues.


M.Sc. Thesis, University of Agricultural Sciences, Banglore, India.

Ningappa, M.S. 1972. Studies on the Role of Scirtothrips dorslais (Hood) (Thysonoptera: Thripidae) and Polyphagotarsonemus latus (Banks) (Acarina: Tarsonemidae) in Causing Leaf Curl and Their Control. M.Sc. Thesis, University of Agricultural Sciences, Bangalore, India.

Peña, J. E. and L. Osborne. 1996. Biological control of Polyphagotarsonemus latus (Banks) (Acarina: Tarsonemidae) in greenhouses and field trials using introductions of predacious mites (Acarina: Phytoseiidae). Entomophaga 41: 279-285.

Puttarudraiah, M. 1959. Short review on the chili leaf curl complex and the spray programme for its control. Mysore J. Agric. Sci. 34: 93-95.

Smith, F.F. 1935. Control experiments on certain Tarsonemus mites on ornamentals. J. Econ. Entomol. 28: 91-98.

Thailand trading report. 2010. Harmonize System: Export of Thailand. available at http://www2.ops3. moc.go.th/ (Retrieved September 17th, 2011)

Vichitbandha, P. and A. Chandrapatya. 2011. Broad mite effects on chili shoot damage and yields. Pak. J. Zool. 43: 637-649.

Walter, D.E. and D.J. O’Dowd. 1992. Leaf morphology and predators: effect of leaf domatia on the abundance of predatory mites (Acari Phytoseiidae). Environ. Entomol. 21: 478-484.

Weintraub, P.G., S. Kleitman, R. Mori, N. Shapira and E. Palevsky. 2003. Control of broad mite (Polyphagotarsonemus latus (Banks)) on organic greenhouse sweet peppers (Capsicum annuum L.) with the predatory mite, Neoseiulus cucumeris (Oudemans). Biol. Control. 27: 300-309.

Manuscript received 01 December 2013, accepted 28 January 2014

Now online at http://www.thaiagj.org

Relationship of Broad Mite Population and Effectiveness of ... · One predatory mite per 20 broad...

Documents

Transcript of Relationship of Broad Mite Population and Effectiveness of ... · One predatory mite per 20 broad...