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Cotton Genotypes Morpho-Physical Factors Affect Resistance Against Bemisia tabaci in Relation to Other Sucking Pests and its Associated Predators and Parasitoids.

Byline: Muhammad Naveed, Zahid Iqbal, Anjum Junaid, Ali Khan, Muhammad Rafiq and Amir Hamza

Abstract

Cotton strains having different hair length and density were evaluated for tolerance to Bemisia tabaci, Amrasca devastans and Thrips tabaci, and survival of predators and parasitoids. The seed treatment effect on the population of these insect pests and natural enemies were also studied. Population of B. tabaci was higher on the strain Cyto-46, having trichome density of 474+-12.9 per cm2 and hair length of 705+-44.8 microns and minimum on strain Cyto-12/91, having trichome density of 1011+-21.0 per cm2 and hair length of 644+-27.3 u. However, A. devastans was significantly higher on strain Cyto-12/91 whereas, thrips remained significantly less on the same strain Cyto-12/91. the total number of predators were significantly higher on strains having greater than600 trichomes per cm2 whereas the level of parasitism remained the same on all the strains. Seed treatment proved effective against A. devastans only.

However, the number of predators and percent parasitism was not significantly affected by the seed treatment. Present study revealed that the early season sucking pest complex can be managed by choosing the variety having moderate leaf hair density and if variety choice is limited then the early season sucking pest especially jassid could be managed effectively by the seed treatment.

Key words: Cotton strains, hair length and density, Bemisia tabaci, sucking pests, seed treatment.

INTRODUCTION

Bemisia tabaci has been infesting cotton in Pakistan since long but was not a major pest until the mid 1980s. It appears in cotton field after crop establishment and continues throughout season under normal environmental conditions. Farmers depend heavily on the use of pesticides for the control of whitefly. Insecticide applied to foliage occasionally provides temporary suppression of whitefly population by killing adults (Gerling, 1967). Whitefly population quickly reappear after insecticide applications because eggs and nymphs are distributed on the underside of leaves on the lower and middle crop canopy (Ohnesorge et al., 1980), and are typically not contacted by foliar application of such materials. In addition, a high level of resistance in whitefly has been recorded to organophosphate (OPs) like dimethoate, methamidophos and monocrotophos, and to pyrethroids like cypermethrin and deltamethrin in Pakistan (Ahmad, 1996).

In order to achieve an effective control of B. tabaci, devising and implementing alternative pest management strategies are inevitable. Some cotton cultivars with certain characteristics have been shown to be resistant to B. tabaci (Khalifa and Gameel, 1982; Butler and Henneberry, 1984). However, reaction of these cultivars besides whitefly should also include other cotton pests, since glabrous cottons were reported to show increased sensitivity to jassid (Meredith and Schuster, 1979; Lukefahr, 1977; Bailey, 1982). To overcome problems being posed by chemical control resistance and environmental issues, there is a need to develop some alternative control strategies. Development of cotton cultivars resistance to whitefly is one approach. Therefore, cotton cultivar selection could become an important component of an integrated pest management program to manage B. tabaci.

The mechanism of resistance in the cotton crop is sometime contradictory e.g., glabrous cotton is resistance to B. tabaci and susceptible to Empoasca spp., Heliothis spp., thrips and cotton aphid. On the other hand high gossypol cotton, which is resistance to Heliothis spp. and Spodoptera spp. was found to be susceptible to B. tabaci (Schuster, 1979). In Pakistan, we have cotton insect pest complex therefore, a thorough understanding of the interaction between the insect, natural enemies and their host plants are needed for long term solutions that offer economical and environmental advantages. Host plant resistance has potential as an integrated pest management component for suppression of sweetpotato whitefly populations (Berlinger, 1986) and may provide a more bio-rational approach for reducing the impact of sweetpotato whitefly transmitted viruses and plant disorders than reliance on pesticides.

The objectives of this study were to (i) evaluate the survival of whitefly in relation to jassid and thrips in three cotton strains having different hair length and hair density, (ii) to see the population dynamics of predators, (iii) evaluate the population trend of whitefly parasitoids, and (iv) evaluate the effect of seed treatment on the level of sucking pests, predators and parasitoids.

MATERIALS AND METHODS

The trial was conducted at the experimental area of Central Cotton Research Institute, Multan, Pakistan. Three cotton strains Cyto-46, Cyto -55 and Cyto -12/91 having different hair length and density were selected for this study. Five kgs of delinted seed of each strains were taken and treated with imidacloprid 70WS @ 8 gm/kg seed. The experiment was sown on the 9th June and laid out in factorial design. Main plots were divided into two subplots having seed treated and non-seed treated treatments. Each treatment was replicated 3 times having a plot size of 15.24 X 30.5 meter. Standard cultural practices were followed for growing healthy cotton crop. The study was carried out under unsprayed condition. Sucking pest as well as natural enemies' data was recorded after every 5 days starting from forty days to sixty five days after sowing.

Population of sucking insect pest was recorded by using leaf turn method and fifteen leaves were taken from upper, middle and lower portion of the randomly selected plants from each plot (Ellsworth et al., 1995; Naranjo et al., 1996). Arthropod predators were counted in whole plant counts in which all the plant occurring in 1.33 meter length stick section were scanned visually and the occurrence of predators were registered in each plot.

Immature and adult stages of all predator species were pooled when counted. Parasitism was recorded by taking leaves having maximum number of third instars of whitefly nymphs from the each treatment. These leaves were brought to laboratory and 10 leaf disks (each disk size= 5 cm2) from each plot were kept separately in glass petri dishes covered with lid. Adults of whitefly and its parasitoids were allowed to emerge and percent parasitism was calculated by using the following formula.

###Total number of

###parasitoids emerged

Percent parasitism=###-----------------------------------###X 100

###Total (whitefly + parasitoids)

###emerged

For determination of leaf hair density and length, ten leaves from 4th to 6th nodes from top portion were collected on 15th June and 15th August. Leaf lamina portion was cut with the help of cork borer and 25-30 leaf discs from each plot samples were kept in 70% alcohol. Hair density on 1 cm2 of leaf disc was counted with the help of binocular microscope. Hair length was measured in microns by using an ocular and a stage micrometer under microscope.

Data were statistically analyzed and means were separated with Duncan's Multiple Range Test (DMRT) (SAS Institute, 2000).

RESULTS AND DISCUSSION

Whitefly (ETL 5-6/leaf) Population of whitefly remained below ETL in all the seed treated and untreated strain's plots throughout the study period (Table II). However, seasonal means population was higher on the strain Cyto-46, having trichome density of 474+-12.9 per cm2 and hair length of 705+-44.8 microns (Table I) and minimum on Cyto- 12/91 having trichome density of 1011+-21.0 per cm2 and hair length of 644+-27.3 u. Similarly, study undertaken by Butler et al. (1991) reported that the increased whitefly population and trichome density relationship does not appear valid under extremely high trichome density and adult whitefly density decreased as trichome density increased from 467 to 847 trichome per cm2 of cotton leaf.

However, Mound (1965) and Chu et al. (2000) also did not find adult whiteflies or their eggs on the first two top leaves on some exceptionally hairy cotton plants. Contrarily, it has been well documented that hairy cotton cultivars have higher Bemisia densities compared with smooth leaf cultivars (Norman and Sparks, 1977; Sippell et al., 1983; Chu et al., 1999). Study undertaken by Van Lenteren and Noldus (1990) concluded that moderate as opposed to heavy trichome density habitats were preferred for whitefly colonization.

Table I.- Leaf hair density and hair length (Mean+-SE) of Cyto-46, Cyto-55 and Cyto-12/91.

Strains###Hair density / cm2###Hair length in (u)

Cyto-46###474+-12.85###705+-44.85

Cyto-55###633+-19.82###762+-29.93

Cyto-12/91 1011+-21.04###644+-27.30

CD 5%###120.4###44.3

Jassid (ETL 2/leaf) Population of jassid was significantly higher on strain Cyto-12/91 having higher number of hair density (1011+-21.04) with less hair length 644+-27.3 (Table III). Similarly studies undertaken by Parnell et al. (1949) concluded that length of hairs on the underside of the leaf lamina is of prime importance. High density without length is ineffective. Studies in India have also shown the importance of hair length on the under surface of the leaf in reducing oviposition, especially on cultivars on which hair length exceeded the length of the ovipositor (Khan and Agarwal, 1984). Natural enemies are not considered to have a significant effect on population of jassid. The population normally decline during the dry season. Insecticidal control measures are commonly considered necessary when the jassid population reaches two nymphs per leaf. Early sprays against jassid, however, should be avoided, if at all possible, to conserve natural enemies of the total insect pest complex.

Where resistant varieties are not sown, insecticide sprays can reduce jassid populations, but as re infestation can occur and plant growth causes rapid dilution of any spray deposits, so repeated sprays are likely to adversely affect the natural enemies of other insect pests. Bhat et al. (1984) concluded that cotton yield loss by jassid could be reduced from 25% to 12% by growing a hairy variety.

Thrips (ETL 8-10/leaf) Population of thrips remained below ETL in Cyto-12/91 in both seed treated and untreated plots throughout the study period (Table IV). Whereas, it was recorded above ETL in strains Cyto- 46 and Cyto- 55 till 55 DAP in untreated and seed treated plots. Seasonal average population was significantly higher on Cyto-55 and Cyto-46 in untreated plots. Studies undertaken by several authors (Ballard, 1951; Quisenberry and Rummel, 1979; Rummel and Quisenberry, 1979; Walker et al., 1979) reported that pubescent and pilose varieties afforded greater thrips resistance than glabrous cultivars. Similarly Zia (1994) and Aheer et al. (1999) reported that there existed a negative correlation between thrips population and leaf hair density. In Egypt, Ghabn (1948) reported that in some years T. tabaci was responsible for the loss of 50% of young cotton plants.

Several cotton cultivars have shown thrips resistance, mostly believed related to various morphological features that protect, leaves from feeding damage or prevent thrips establishment. In present study, Cyto-12/91 having hair density 1011+-21.04 have significantly less number of thrips throughout the season.

Predators Orius insidiosus, Geocorus punctipes, Chrysopa carnea, Cocinellids, and spider are the major groups of predators recorded during the study period. Number of predators was quite low till 50 DAP in all the treatments. After that, the number of predators' increased and maximum numbers of predators were recorded on Cyto-12/91 and Cyto-55 (Table V). Seasonal average number of predators was higher on Cyto-12/91 followed by Cyto-55. Overall, number of predators was higher in seed treated plots compared with untreated plots.

Predators survival, behavior and control efficacy may be affected by plant characteristics directly or indirectly through their effect on the prey. Guershon and Gerling (1999) reported no difference in prey consumption on smooth vs. pubescent cotton leaves. In the present study, strains Cyto-12/91 and Cyto-55, having greater than 600 trichomes

Table II.- Number of B. tabaci per leaf on Cyto-46, Cyto-55 and Cyto-12/91 in imidacloprid treated and untreated seed plots 40-65 days after sowing.

DAS Untreated plots###Seed treated plots###CD 5%###

###Cyto-46###Cyto-55###Cyto-12/91###Cyto-46###Cyto-55###Cyto-12/91###

40###2.1###2.2###0.5###1.6###2.5###1.1###1.78###

45###0.9###1.2###1.8###3.0###2.2###1.1###0.94###

50###2.8###2.8###1.9###3.3###2.1###2.0###0.94###

55###1.1###2.1###2.4###2.1###2.5###1.2###1.75###

60###1.9###1.3###0.9###0.8###1.1###1.2###0.49###

65###1.4###2.1###2.1###2.5###2.5###0.8###1.55###

Seasonal Mean###1.7###2.0###1.6###2.2###2.2###1.3###0.49###

Table III. Number of A. devastans per leaf on Cyto-46, Cyto-55 and Cyto-12/91 in imidacloprid -treated and untreated seed plots 40-65 days after sowing.###

DAS###Untreated plots###Seed treated plots###CD 5%###

###Cyto-46###Cyto-55###Cyto-12/91###Cyto-46###Cyto-55###Cyto-12/91###

40###0.4###0.6###1.2###0.2###0.4###0.2###0.53###

45###0.9###1.0###2.2###0.1###0.5###0.6###0.21###

50###1.8###2.3###3.3###0.7###0.5###2.2###1.13###

55###2.1###2.1###2.7###0.4###1.3###1.2###0.51###

60###1.3###2.0###2.5###0.6###1.0###0.5###0.74###

65###2.3###1.2###1.7###2.6###0.7###1.1###0.56###

Seasonal Mean###1.5###1.6###2.3###0.8###0.8###1.0###0.12###

Table IV.- Number of T. tabaci per leaf on Cyto-46, Cyto-55 and Cyto-12/91 in imidacloprid seed treated and untreated plots 40-65 days after sowing.###

DAS###Untreated plots###Seed treated plots###CD 5%###

###Cyto-46###Cyto-55###Cyto-12/91###Cyto-46###Cyto-55###Cyto-12/91###

40###0.2###0.0###0.1###0.1###0.2###0.0###0.15###

45###0.8###1.1###0.5###0.1###1.1###0.1###0.54###

50###0.0###0.9###0.1###0.3###1.3###0.1###0.26###

55###0.3###2.5###1.2###1.0###4.4###0.5###1.25###

60###15.9###16.1###1.5###9.1###8.5###2.1###4.0###

65###9.4###9.6###1.4###5.9###6.3###2.7###1.77###

Seasonal Mean###4.4###5.0###0.8###2.8###3.6###0.9###0.68###

Table V.- Number of predators per stick on Cyto-46, Cyto-55 and Cyto-12/91 in seed treated and untreated plots 40-65 days after sowing.

DAS###Untreated plots###Seed treated plots###CD 5%###

###Cyto-46###Cyto-55###Cyto-12/91###Cyto-46###Cyto-55###Cyto-12/91###

403###5###9###6###14###12###1.75###

45###12###11###14###15###16###14###3.89###

50###7###13###13###13###10###10###1.95###

55###26###36###34###18###40###43###9.36###

60###11###40###34###16###47###38###12.21###

65###29###38###70###35###41###63###19.93###

Seasonal Mean###14.7###23.8###29.0###17.2###28.0###30.0###6.62###

Table VI.- Percent parasitism on Cyto-46, Cyto-55 and Cyto-12/91 in seed treated and untreated plots 40-65 days after sowing.

DAS###Untreated plots###Seed treated plots###CD 5%###

###Cyto-46###Cyto-55###Cyto-12/91###Cyto-46###Cyto-55###Cyto-12/91###

40###57.6###77.7###72.7###38.3###75.0###73.7###12.8###

45###58.0###79.3###75.3###38.3###72.0###82.7###12.7###

50###66.7###55.0###76.7###69.0###65.0###62.3###6.9###

55###61.1###77.7###77.3###72.1###80.3###78.7###10.9###

60###75.0###74.7###65.0###56.3###75.0###73.0###8.2###

65###37.1###70.0###32.3###77.8###45.7###48.7###7.34###

Seasonal Mean###59.3###72.4###66.6###58.5###68.8###69.9###4.81###

per cm2 have significantly higher number of predators.

Many predators are general feeders, and predation is extremely difficult to positively assess in the field. Gerling et al. (2001) listed 114 arthropod predators of B. tabaci belonging to 9 orders and 31 families. Hagler and Naranjo (1994a,b) identified 9 predators feeding on B. tabaci in Arizona cotton. Study undertaken by Naranjo and Ellsworth (unpublished) in USA revealed that predation by sucking predators (primarily Heteroptera) was responsible for nearly 36% mortality of all immature stage of B. tabaci. Using immunologically based gut assays, Jones et al. (2000) describe that mortality caused in Uzbekistan by wild Chrysopa carnea and Coccinelidae (notably Coccinella septempunctata Waesmael) appeared to provide important regulation of early season sucking pests.

Parasitoids

Three species of whiteflies parasitoid (Eretmocerus mundus, Encarsia lutea and Encarsia sophia) has been recorded on cotton in Pakistan (Naveed et al., 2007, 2008). In the present study, we collectively mentioned the level of parasitism on the candidate strains. Parasitism remained significantly higher on Cyto-55 followed by Cyto-12/91 in untreated plots (Table VI). More than 60% parasitism was recorded in Cyto-55 and Cyto-12/91 in seed treated and untreated plots during 60-65 days of DAS. Apparently, we did not find any significant effect of the morphological character of the leaves on the level of parasitism. Similarly, studies undertaken by Susanne and van Lenteren (1997) on Gerbera jamesonii cultivars reported that leaf hair density varying from 80 to more than 1000 trichomes/cm2 did not affect the walking activity of the parasitoids. Contrarily, Hua et al. (1987) and McAuslane et al. (1994) found that Encarsia nigricephala are known to forage less efficiently on hairy leaves than on hairless leaves.

Effect of seed treatment

Imidacloprid was the first nicotinoid seed treatment that was registered for use against B. tabaci (Elbert et al., 1990; Mullins and Engle, 1993). As a seed treatment, Imidacloprid has excellent root systemic characteristics, absorbed by the roots and transported mainly in the xylem where it is distributed evenly throughout young, growing plant tissues (Mullins, 1993). In treated plants, the compound and its metabolites are initially toxic to feeding adults, but also repel adults and act as anti-feedants (Nauen and Elbert, 1997; Nauen et al., 1998). Consequently, establishment of immature whiteflies on plants is significantly reduced because of suppressed egg deposition. Nymphs that do emerge usually die within a week after feeding on the treated plants (Bethke and Redak, 1997; Stansly et al., 1998) . Contrarily, in the present study, population of whitefly in the treated and untreated plots were non significant for strains under test.

Indicating that imidacloprid has no significant effect on controlling the whitefly population in the field (Table II). Whereas, number of jassid was significantly lower in seed treated plots compared with untreated plots. Jassid remained below ETL in seed treated plots till 60 days after sowing (DAS) in Cyto-46, 50 DAS in Cyto-55 and only 45 DAS in Cyto-12/91. Comparatively seed treatment gave better control of jassid than untreated plots (Table III). Overall, population of thrips in the treated plots was less compared with untreated check plots (Table IV). However, number of predators were more in the seed treated plots compared with untreated plots (Table V). Level of parasitism in most of the plots were found non significant in treated and untreated plots (Table VI). It was also reported by Naveed et al. (2010) and Naranjo (2001) that the systemic application of imidacloprid is generally harmless to parasitoids of whitefly.

Cotton crop sowing normally starts from May to mid June in the major cotton growing area of the Punjab province. With the introduction of early maturing varieties fruit formation starts 40-45 days after sowing. Sucking pest like thrips, jassid and whitefly start appearing just after the emergence of the cotton plant. In normal weather conditions none of these pest become problems in the presence of natural enemies. But in case of early monsoon rains when the weather become hot and humid, the populations of jassid flare up and do considerable damage to cotton plants. On the other hand in the absence of early monsoon and in dry and hot weather conditions the thrips and whitefly population start increasing. After the disaster of cotton leaf curl virus in the mid nineties the farmers are more cautious about whitefly and the disease. In both the cases the farmers initiate spray to protect their crop from these pests.

Initiation of early spraying not only increase the number of sprays during the season but also has bad effect on the natural enemies as well and in the absence of natural enemies pest like whitefly flare up very rapidly and may even aggregate the problem as also reported in Sudan (Joyce, 1955; Eveleens, 1983); in America (Kraemer, 1966; Miller, 1986) and in Turkey (Sengonca, 1975). As demonstrated in the present study that the early season sucking pest complex can be managed by choosing the variety having moderate leaf hair density, and if variety choice is limited due to the other desirable character then the early season sucking pest especially jassid can be controlled effectively by the seed treatment. As seed treatment is more save towards the predators and parasitoids compared with foliar insecticide application.

REFERENCES

AHEER, G.M., ALI, A. AND SALEEM, M., 1999. Morpho-physical factors affect resistance in genotypes of cotton against some sucking insect pests. Pak. Entomol., 21: 43-46.

AHMAD, M., 1996. Problems and prospects of managing

Bemisia in Pakistan. Proceeding 20th International Congress of Entomology, Florence, Italy. pp. 459.

BAILEY, J. K., 1982. Influence of plant bug and leafhopper populations on glabrous and nectariless cottons. Environ. Ent., 11: 1011-1013.

BALLARD, W.W., 1951. Varietal differences in susceptibility to thrips injury in upland cotton. Agron. J., 43: 37-44.

BETHKE, J.A. AND REDAK, R.A., 1997. Effect of imidacloprid on the silverleafwhitefly , Bemisia argentifolii Bellows and Perring (Homoptera: Aleyrodidae) and whitefly parasitism. Ann. appl. Biol., 130: 397-407.

BERLINGER, M.J., 1986. Host plant resistance to Bemisia tabaci. Agric. Ecosyst.Environ., 17: 69-82.

BHAT, M.G., JOSHI, A.B. AND SINGH, M., 1984. Relative loss of seed cotton yield by jassid and bollworms in some cotton genotypes (Gossypium hirsutum L.). Indian J. Ent., 46: 169-173.

BUTLER, G.D. JR. AND HENNEBERRY, T.J., 1984. Bemisia tabaci; effect of cotton leaf pubescence on abundance. Southw. Ent., 9: 91-94.

BUTLER, G.D. JR., WILSON, F.D. AND FISHER, G., 1991. Cotton leaf trichomes and populations of Empoasca lybica and Bemisia tabaci. Crop Protect., 10: 461-464.

CHU, C.C., COHEN, A.C., NATWICK, E.T., SIMMONS, G.S. AND HENNEBERRY, T.J., 1999. Bemisia tabaci (Homoptera: Aleyrodidae) biotype B colonisation and leaf morphology relationships in upland cotton cultivars. Australian J. Ent., 38: 127- 131.

CHU, C.C., NATWICK, E.T. AND HENNEBERRY, T.J., 2000. Susceptibility of normal-leaf and okra-leaf shape cottons to silverleaf whiteflies and relationships to trichome densities. In: Proc. Beltwide Cotton Prod. Res. Conf., San Antonio, TX. 4-8 Jan. 2000. Natl. Cotton Counc. Am., Memphis, TN, pp. 1157-1158.

ELBERT, A., OVERBECK, H., IWAYA, H. AND TSUBOI, S., 1990. Imidacloprid, a novel systemic nitromethylene analogue insecticide for crop protection. In: Proceedings of Brighton Crop Protection Conference, Pests and Diseases. Brighton, England, pp. 21-28.

ELLSWORTH, P.C., DIEHL, J.W., DENNEHY, T.J. AND NARANJO, S.E., 1995. Sampling sweetpotato whiteflies in cotton, IPM Series No. 2. The University of Arizona, Cooperative Extension, Publication #194023, Tucson, AZ, 2pp.

EVELEENS, K.G., 1983. Cotton- insect control in the Sudan Gezira: analysis of a crisis. Crop. Prot., 2: 273-287.

GERLING, D., ALOMAR, O. AND ARNO, J., 2001. Biological control of Bemisia tabaci using predators and parasitoids. Crop. Prot., 20: 779-799.

GERLING, D., 1967. Bionomics of the whitefly parasite complex associated with cotton in Southern California (Homoptera: Aleyrodidae; Hymenoptera: Aphelinidae). Ann. entomol. Soc. Am., 60: 1306-1321.

GHABN, A.A.A.S., 1948. Contribution to the knowledge of the biology of Thrips tabaci in Egypt. Bull. Soc. Fouad Ent., 32: 123-174.

GUERSHON, M. AND GERLING, D., 1999. Predatory behavior of Delphastus pusillus in relation to the phenotypic plasticity of Bemisia tabaci nymphs. Ent. Exp. Appl., 92: 239-248.

HAGLER, J.R. AND NARANJO, S.E., 1994a. Determining the frequency of heteropteran predation on sweetpotato whitefly and pink bollworm using multiple ELISAs. Ent. Exp. Appl., 72: 59-66.

HAGLER, J.R. AND NARANJO, S.E., 1994b. Qualitative survey of two coleopteran predators of Bemisia tabaci (Homoptera: Aleyrodidae) and Pectinophora gossypiella (Lepidoptera: Gelechiidae) using a multiple prey gut content ELISA. Environ. Ent., 23: 193-197.

HUA, L.-Z., LAMMES, F., VAN LENTEREN, J.C., HUISMAN, P.W.T., VAN VIANEN, A. AND DE PONTI, O.M.B., 1987. The parasite-host relationship between Encarsia Formosa Gahan (Hymenoptera, Aphelinidae) and Trialeurodes vaporariorum (Westwood) (Homoptera, Aleyrodidae). XXV. Influence of leaf structure on the searching activity of Encarsia Formosa. J. appl. Ent., 104: 297-304.

JOYCE, R.J.V., 1955. Cotton spraying in the Sudan Gezira. II Entomological problems arising from spraying. FAO Pl. Protect. Bull., 3: 97-103.

JONES, K.A., VERKERK, R.H.J. AND ASANOV, K., 2000. Prospects for the integration of non-chemical and chemical pest management in cotton. Proceeding of the Brighton Crop Protection Conference 2000: Pests and Disease. British Crop Protection Council, Farnham, Surrey, pp. 199-204.

KHALIFA, H. AND GAMEEL, O.I., 1982. Control of cotton stickiness through breeding cultivars resistance to whitefly (Bemisia tabaci (Genn) infestation. In: Improvement of oil-seed and industrial crops by induced mutations. IAEA, Vienna, pp. 181-186.

KHAN, Z.R. AND AGARWAL, R.A., 1984. Oviposition preference of jassid Amrasca biguttula biguttula Ishida on cotton. J. entomol. Res., 8: 78-80.

KRAEMER, P., 1966. Serious increase of cotton whitefly and virus transmission in Central America. J. econ. Ent., 59: 1531.

LUKEFAHR, M.F., 1977. Varietal resistance to cotton insects. In: Proc. Beltwide Cotton Prod. Res. Conf., pp. 236-237.

MCAUSLANE, H.J., JOHNSON, F.A. AND KNAUFT, D. A., 1994. Population levels and parasitism of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) on peanut cultivars. Environ. Ent., 23: 1203-1210.

MEREDITH, W. R., JR. AND SCHUSTER, M.F., 1979. Tolerance of glabrous and pubescent cottons to tarnished plant bug. Crop. Sci., 19: 484-488.

MILLER, T.A., 1986. Status of resistance in the cotton insect complex. In: Proceeding Beltwide Cotton Production Conference (eds. J.M. Brown andT.C. Nelson). National Cotton Councl, Memphos, TN. pp. 162-165.

MOUND, L.A., 1965. Effect of leaf hair on cotton whitefly populations in the Sudan Gezira. Empire Cotton Grow. Rev., 42: 33-40.

MULLINS, J.W., 1993. Imidacloprid: a new nicotinoid insecticide. In: Pest control with environmental safety, American Chemical Society. Sym. Series 524. American Chemical Society, Washington, DC, pp. 184-198.

MULLINS, J.W. AND ENGLE, C.E., 1993. Imidacloprid (BAY NTN 33893): a novel chemistry for sweetpotato whitefly control in cotton. In: Proceedings Beltwide Cotton Conferences (eds. D.J. Herber and D.A. Richter). National Cotton Council, Memphis, TN, pp. 719-720.

NARANJO, S.E., FLINT, H.M. AND HENNEBERRY, T.J., 1996. Binomial sampling plans for estimating and classifying population density of adult Bemisia tabaci on cotton. Ent. Exp. Appl., 80:, 343-353.

NARANJO, S.E., 2001. Conservation and evaluation of natural enemies in IPM systems for Bemisia tabaci. Crop Protect., 20: 835-852.

NAUEN, R. AND ELBERT, A., 1997. Apparent tolerance of a field-collected strain of Myzus persicae to imidacloprid due to strong anti-feeding responses. Pestic. Sci., 49: 252-258.

NAUEN, R., TIETJEN, K., WAGNER, K. AND ELBERT, A., 1998A. Efficacy of plant metabolites of imidacloprid against Myzus persicae and Aphis gossypii (Homoptera: Aphididae). Pestic. Sci., 52: 53-57.

NAVEED, M., SALAM, A. AND SALEEM, M.A., 2007. Contribution of cultivated crops, vegetables, weeds and ornamental plants in harboring of Bemisia tabaci (Homoptera: Aleyrodidae) and associated parasitoids (Hymenoptera: Aphelinidae) in cotton agroecosystem of Pakistan. J. Pestic. Sci., 80: 191-197.

NAVEED, M., SALEEM, M.A., SALAM, A. AND ALI, S., 2008. The effects of different groups of insecticides in cotton fields on Bemisia tabaci, Genn (Homoptera: Aleyrodidae), predators and parasitoids: Implication in whitefly management. Phytoparasitica, 36: 377-387.

NAVEED, M., SALAM, M.A., SALEEM, M., RAFIQ, M. AND HAMZA, A., 2010. Toxicity of thiamethoxam and imidacloprid as seed treatments to parasitoids associated to control Bemisia tabaci. Pakistan J. Zool., 42: 559-565.

NORMAN, J.W. AND SPARKS, JR. A. N., 1977. Cotton leaf hairs and silverleaf whiteflies in the lower Rio Grande Valley of Texas three year research summary. In: Proc. Beltwide Cotton Prod. Res. Conf. (eds. P. Dugger and D. Richter), Nattional Cotton Council of America, Memphis, TN, pp.1063-1064.

OHNESORGE, B., SHARAF, N. AND ALLAW, T., 1980. Population studies on the tobacco whitefly Bemisia tabaci Genn. (Hompotera; Aleyrodidae ) during the winter season. 1. The spatial distribution on some host plants. Z. angew. Ent., 90: 226-232.

PARNELL, F.R., KING, H.E. AND RUSTON, D.F. 1949. Insect resistance and hairiness of the cotton plant. Bull. entomol. Res., 39: 539-575.

QUISENBERRY, J.E. AND RUMMEL, D. R., 1979. Natural resistance to thrips injury in cotton as measured by differential leaf area reduction. Crop. Sci., 19: 879-881.

RUMMEL, D.R. AND QUISENBERRY, J.E., 1979. Influence of thrips injury on leaf development and yield of various cotton genotypes. J. econ. Ent., 72: 706-709.

SAS INSTITUTE, 2000. JMP statistics and graphic guide, JMP version 4. SAS Institute, Cary, NC.

SCHUSTER, M.F., 1979. Insect resistance in cotton. In: Biology and breeding for resistance to arthropods and pathogens in agriculture plants (ed. M.K. Haris). pp. 101-112.

SENGONCA, C., 1975. Beitrag zum epidemischen Auftreten der Tabakmottenschildlaus, Bemisia tabaci Genn. am Baumwollpflanzen in Suedantolien (Homoptera: Aleyrodidae) Anz. Schaedlingskd. Pflanz. Umweltschutz, 48: 140-142.

SIPPELL, D.W., BINDRA, O.S. AND KHALIFA, H., 1983. Resistance to whitefly (Bemisia tabaci) in cotton. Gezira Agric. Res. Stn. Working Paper, No. 10.

STANSLY, P.A., LIU, T.X. AND VAVRINA, C.S., 1998. Response of Bemisia argentifolii (Homoptera: Aleyrodidae) to imidacloprid under greenhouse, filed, and laboratory conditions. J. econ. Ent., 91: 686-692.

SUSANNE, S. AND VAN LENTEREN, J.C., 1997. Influence of hairiness of Gerbera jamesonii leaves on the searching efficiency of the parasitoid Encarsia formosa. Biol. Cont., 9: 157-165.

VAN LENTEREN, J.C. AND NOLDUS, L.P.J.J., 1990. Whitefly plant relationship: behavioral and ecological aspects In: Whiteflies: their bionomics, pest status and management (ed. D. Gerling). Intercept. Andover, UK. , pp. 47-89.

WALKER, J.K., HART, E.R., GANNAWAY, J. R. AND NILES, G. A., 1979. Boll weevil and thrips resistance in pilose cotton. Southw. Ent., 4: 132-140.

ZIA, M.A., 1994. Resistance of cotton cultivars to thrips, Scirtothrips dorsalis Hood. J. agric. Res., 32: 303-308.

(Received 17 December 2009, revised 21 May 2010)

Muhammad Naveed, Zahid Iqbal Anjum, Junaid Ali Khan, Muhammad Rafiq and Amir Central Cotton Research Institute, Multan Pakistan Agricultural Research Council (IPM), Multan Corresponding author: naveed_ento@yahoo.com 0030-9923/2011/0002-0229 $ 8.00/0 Copyright 2011 Zoological Society of Pakistan.
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Publication:Pakistan Journal of Zoology
Article Type:Report
Geographic Code:9PAKI
Date:Apr 30, 2011
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