Printer Friendly

Control of Earias vittella (Lepidoptera: Noctuidae) by Beauveria bassiana along with Bacillus thuringiensis.

Byline: Kashif Ali, Waqas Wakil, Khurram Zia and Shahbaz Talib Sahi

Abstract

A laboratory strain of Beauveria bassiana sensu lato (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) and commercial formulation of Bacillus thuringiensis (Berliner) were assessed against three field populations of Earias vittella F. (Lepidoptera: Noctuidae) in the laboratory. Three dose rates of B. bassiana (1.5A-106, 1.5A-107 and 1.5A-108 conidia mL-1) and one of B. thuringiensis (0.5 g g-1) were applied alone and in combination against 2nd and 4th larval instars. The mortality was observed until pupation. The bioassays were carried out at 25C and 75% RH The highest larval mortality was observed in the population from Faisalabad with lowest pupation rate, adult emergence and egg eclosion treated with combined concentrations of B. bassiana and B. thuringiensis. The lowest mortality was observed in population from Pakpattan among all the tested populations.

Overall results demonstrated that all the treatments gave significant control of E. vittella and both microbial agents may become the integral part of the successful IPM program of E. vittella in okra crop.

Keywords: Entomopathogenic fungi; B. thuringiensis; E. vittella; Mortality; Populations

Introduction

Okra (Abelmoschus esculentus L.), commonly known as Bhindi" is very popular commercially grown crop among vegetables and plays a significant role in the world food security (Dilruba et al., 2009). Its annual production is 73695.6 tonnes during 2011-2012 which comprises 13,919 hectare area under cultivation in Pakistan (FAOSTAT, 2013). Okra is attacked by a number of insect pests, mites and diseases during different growth stages (Kumar et al., 2002; Gulati, 2004). Among these insect pests, Earias vittella F. and Earias insulana Boisduval (Lepidoptera: Noctuidae) are the most important and damaging (Aziz et al., 2011). According to rough estimates, the Earias sp. can cause 36-90% loss in the fruit yield of okra crop (Misra et al., 2002). The infestation of this borer can be distinguished from other phytophagous insects of Okra by their unique property of stem boring.

The larvae channel down from growing points after entering into the terminal bud of shoot, resulting in wilting of marginal leaves and stunting of the main stem (Atwal and Dhaliwal, 2009).

Farmer mainly rely on conventional chemical insecticides, like carbaryl (Kumar and Singh, 2006), endosulfan (Shukla et al., 1997; Gupta and Misra, 2006) and cypermethrin (Bagade et al., 2005) fenvalerate (Singh et al., 2005) for the control of this insect pest. An unwise use of these chemicals for the suppression of Earias sp. has posed many threats like development of insecticide resistance, environmental pollution and health hazards to mammals and amphibians (Saini and Chopra, 1988), destruction of the beneficial fauna and resurgence of minor pests (Mahapatro and Gupta, 1998).

An attractive alternative tool to control these Lepidopterous insect pests is the use of entomopathogenic fungi due to their eco-friendly and target selective characteristics (Carner and Yearian, 1989). These fungi infect the host by direct contact or via the germination of new propagules (Zimmermann, 2007). The efficacy of seven promising strains of Metarhizium anisopliae (Deuteromycotina: Hyphomycetes), Beauveria bassiana (Ascomycota: Hypocreales) and Paecilomyces fumosoroseus (Deutromycotina: Hypocreales) has been reported against different larval stages of Helicoverpa armigera HA1/4b. (Lepidoptera: Noctuidae) (Nguyen et al., 2007).

The effectiveness of fungal bio-control agents against vast range of insect pests including Spodoptera sp. is also demonstrated in number of studies (Purwar and Sachan, 2006; Lin, et al., 2007).

Bacillus thuringiensis Berliner is a spore forming gram positive bacterium considered to be an effective insecticide harmless to natural enemies, quite safe to mammals and environmentally acceptable (Entwistle et al., 1993). B. thuringiensis toxin enters the insect through ingestion and binds to glycoprotein receptors of the targeted insect midgut epithelium, where they disrupt the cytoplasmic membrane, leading to the cell lysis (Hilder and Boulter, 1999). In number of studies, B. thuringiensis intoxication enhanced the efficacy of B. bassiana especially in case of Lepidopterous insect pests when commercial formulation of B. thuringiensis was combined with B. bassiana (Gao et al., 2012; Wakil et al., 2013). The increasing interest in combining sub-lethal concentrations of B. thuringiensi with B. bassaina has stemmed from their successful control against different insect pests (Ma et al., 2008; Furlong and Groden, 2003).

Considering the significance of these promising alternatives, the present study was designed to evaluate the alone and combined effects of B. bassiana sensu lato (Balsamo) Vuillemin (Hypocreales: Clavicipitaceae) and B. thuringiensis Berliner on the mortality, pupation, adult emergence and egg eclosion of 2nd and 4th larval instars of E. vittella collected from different geographical localities of Punjab province, Pakistan.

Materials and Methods

Insect Culture

E. vittella larvae used in bioassays were collected from three different localities Faisalabad, Pakpattan and Toba Tek Singh (Punjab, Pakistan) and then taken to the IPM - Insect Pathology Laboratory, Department of Entomology, University of Agriculture, Faisalabad, Pakistan. Insects were mass cultured under laboratory conditions at 252C, 75% RH and a photoperiod of 14:10 h (L: D). The culture of E. vittella was reared following the method (PACopyrightrez-Guerrero et al., 2004) using semi-artificial diet comprising 350 ml water, 215 g dried kidney beans boiled in water, 32 g brewer's yeast, 12 g agar, 3 g ascorbic acid, 1.5 g benzoic acid, and 1.5 g nipagin (PACopyrightrez-Guerrero et al., 2004). The diet was stored at 4C until use.

B. thuringiensis Toxin

The wettable powder (WP) commercial formulation (Dipel) containing B. thuringiensis subspecies kurstaki bearing a density of active toxin 3.2% and other inert material 96.8% with the potency of 16,000 i.u. was provided by BioSciences Corporation, Libertyville, IL, USA. The B. thuringiensis toxin previously extracted (Wakil et al., 2013) was used in the bioassays @ 0.5 g g-1 against E. vittella.

Fungal Isolation

The fungus was previously isolated from soil using Galleria-bait method (Zimmermann, 1986) with larval instars of Galleria mellonella L. (Lepidoptera: Pyralidae) was used in bioassays. It was sub-cultured on Potato Dextrose Agar media and incubated at 281C and 755% RH for conidial growth. After fourteen days of incubation, culture was air dried under an inverted aluminum roasting pan (43.0A-31.7A- 6.7 cm) set on a bench and covered with aluminum foil. The harvesting of conidia was done with the help of sterilized rubber scalpel mounted on 1 mL glass pipette. Serial dilutions of the conidia were made by adding dry conidial powder in 0.05% Tween-80 solution and number of spores was counted using hemocytometer under a microscope to achieve required concentrations.

Bioassay

The mortality of 2nd and 4th instar larvae, pupation, adult emergence and egg eclosion was determined treating E. vittella with a single dose rate of B. thuringiensis (Bt: 0.5 g g-1) and three of B. bassiana (Bb1: 1.5A-106, Bb2: 1.5A-107, Bb3: 1.5A-108 conidia mL-1) individually and in their respective combinations (Bt+Bb1, Bt+Bb2 and Bt+Bb3). B. thuringiensis was applied mixed in artificial diet and B. bassiana was applied following larval immersion method (Ma et al., 2008). The artificial diet was prepared and shaken in an electric shaker for 30s in a 1 L jug for thorough mixing and even distribution of B. thuringiensis. Eight batches for 2nd and 4th instar each containing 15 larvae were prepared. Then, four batches of pre-starved (24 h) larvae for both instars were put separately in the plastic vials (base radius 2.4 cm A- height 6 cm) and allowed to feed on 1 cm3 of artificial diet for 48 h.

Three batches of Bt-mixed diet fed larvae were further immersed individually for 10s into respective concentrations of fungal solution for combined application of B. thuringiensis and B. bassiana, however, the fourth batch was left to serve as B. thuringiensis alone treatment. The remaining three batches of 2nd and 4th larval instars were only immersed in fungal solution containing three concentrations of B. bassiana. The treated larvae were put in empty petri dishes lined with filter paper to remove an excess of moisture and were released in plastic vials containing an untreated artificial diet until the larvae died or pupated. The eighth batch of larvae fed on untreated artificial diet served as control. All the bioassays were carried out at 252C, 75% RH and 14:10 (L: D) photoperiod. Each treatment was replicated three times and each bioassay was repeated thrice. The data for mortality was recorded after every 72 h and the last count noted till pupation for both larval instars.

The larvae were disturbed with a blunt needle and those unable to move in a coordinated manner were considered dead (Ma et al., 2008). The data for pupation and adult emergence was also recorded and the emerged adults were allowed to mate freely for egg hatching percentage assessment.

Statistical Analysis

The mortality in control groups was =5% and Abbott's (1925) formula was used to correct mortality in the treatments. The data was subjected to MINITAB 13.2 statistical package (Steel et al., 1997) through one way analysis of variance (ANOVA) for mortality, pupation, adult emergence and egg eclosion. The means were separated using Tukey-Kramer HSD test at 5% significance level (Sokal and Rohlf, 1995).

Results

Larval Mortality

Significant differences were found among treatments in all the populations for 2nd instar larvae of E. vittella. The highest larval mortality was observed with applications of B. thuringiensis alone in the Faisalabad (57.67%) population followed by T.T. Singh (53.43%) and Pakpattan (45.29%) populations. The highest mortalities were obtained by treatments of the highest does of B. bassiana (1.5A-108 conidia mL-1) in combination with B. thuringiensis (0.5 g g-1) with 100%, 96.08% and 89.31% mortality for populations from Faisalabad, T.T. Singh and Pakpattan, respectively (Table 1).

Similarly, significant differences were found among treatments in all the populations for 4th instar larvae of E. vittella. The highest larval mortality with applications of B. thuringiensis alone in Faisalabad (49.15%) population followed by T.T. Singh (42.22%) and was observed in the Pakpattan (36.50%) populations. The highest dose rate of B. bassiana (1.5A-108 conidia mL-1) in combination with B. thuringiensis (0.5 g g-1) resulted in 91.05%, 84.12% and 76.72% mortality for populations from Faisalabad, T.T. Singh and Pakpattan, respectively (Table 1).

Pupation and Adult Emergence

All the treatments significantly affected the pupation and adult emergence of 2nd instar of E. vittella. The maximum pupation and adult emergence was observed in populations from Pakpattan (84.44, 83.70%), T.T. Singh (80.74, 78.51%) and Faisalabad (71.85, 67.40%), respectively, where B. bassiana was applied at the dose rate of 1.5A-106 conidia ml-1 (Table 2 and 3). However, minimum pupation and adult emergence were observed where higher concentration of B. bassiana and B. thuringiensis was applied simultaneously against all of the selected populations.

The pupation and adult emergence of 4th instar of E. vittella was significantly affected in all the treatments. The maximum pupation and adult emergence was observed from Pakpattan (91.11, 90.37%), T.T. Singh (87.40, 81.48%) and Faisalabad (80.74, 77.77%) populations, respectively, where B. bassiana was applied at the dose rate of 1.5A-106 conidia ml-1 (Table 2 and 3). However, minimum pupation and adult emergence were observed where high concentration of B. bassiana and B. thuringiensis were

Table 1: Mean mortality (% SE) of Earias vittella larvae from three different field populations treated with B. bassiana (Bb1: 1.5A-106; Bb2: 1.5A-107; Bb3: 1.5A-108 conidia ml-1) and B. thuringiensis (Bt: 0.5 g g-1), individually and in combination. Means sharing same lower case letters within each population and the upper case letters among populations are significantly different from each other at 5% significance level

Treatments###Faisalabad###T.T. Singh###Pakpattan

2nd Instar

Bb-1###20.584.72Ae###15.923.12Ae###12.693.00Aef

Bb-2###35.394.00Ade###32.643.1Ad###27.034.13Ade

Bb-3###50.584.70Acd###44.923.95Acd###38.146.41Ad

Bt###57.673.05Ac###53.433.82Ac###45.293.67Acd

Bb-1+ Bt###75.074.07Ab###70.053.82Ab###62.275.35Abc

Bb-2 + Bt###84.553.81Aab###78.572.99Ab###74.185.08Aab

Bb-3 + Bt###1000.00Aa###96.081.71Aba###89.314.14Ba

Control###3.171.25Af###3.961.25Ae###1.581.04Af

F###83.3###107###47.6

df###7,71###7,71###7,71

P###less than 0.01###less than 0.01###less than 0.01

4th Instar

Bb-1###14.232.76Afg###9.681.95Afg###7.461.33Ad

Bb-2###27.833.66Aef###22.542.23ABef###15.553.51Bcd

Bb-3###41.692.86Ade###36.542.99Ade###31.273.79Abc

Bt###49.153.13Acd###42.224.26Acd###36.504.44Ab

Bb-1+ Bt###58.144.58Abc###53.175.55Abc###44.813.38Ab

Bb-2 + Bt###73.174.91Ab###67.514.32Ab###61.855.06Aa

Bb-3 + Bt###91.052.71Aa###84.123.20Aba###76.724.75Ba

Control###1.581.04Ag###2.381.19Ag###0.790.79Ad

F###75.8###66.0###51.5

df###7,71###7,71###7,71

P###less than 0.01###less than 0.01###less than 0.01

applied in combination against all the selected populations.

Egg Eclosion

The maximum egg eclosion in 2nd instar larvae of E. vittella was observed in Pakpattan (72.28%) followed by T.T. Singh (68.63%) and Faisalabad (56.29%) with the dose rate of B. bassiana alone (1.5A-106 conidia mL-1). The minimum egg eclosion was recorded in Faisalabad (0%) at the highest dose rate of B. bassiana (1.5A-108 conidia mL-1) in combination with B. thuringiensis (0.5 g g-1) (Table 4).

Similarly in 4th instar the same trend for Pakpattan (83.21%), T.T. Singh (76.46%) and Faisalabad (63.82) populations was observed, where B. bassiana was applied at the dose rates of 1.5A-106 conidia mL-1 (Table 4). Overall, eclosion rates decreased significantly in the treatments where higher concentration of B. bassiana (1.5A-108 conidia mL-1) and B. thuringiensis (0.5 g g-1) were applied simultaneously against E. vittella.

Discussion

E. vittella has attained resistance against many commonly used insecticides and the use of bio-pesticides is one way to overcome this resistance (Gao et al., 2012). The integration

Table 2: Mean pupation (% SE) of E. vittella from three different field populations treated with B. bassiana (Bb1: 1.5A-106; Bb2: 1.5A-107; Bb3: 1.5A-108 conidia ml-1) and B. thuringiensis (Bt: 0.5 g g-1), individually and in combination. Means sharing same lower case letters within each population and the upper case letters among populations are significantly different from each other at 5% significance level

Treatments###Faisalabad###T.T. Singh###Pakpattan

2nd Instar

Bb-1###71.853.09Bb###80.742.34ABb###84.442.93Aab

Bb-2###57.772.22Bc###65.924.36ABc###72.594.36Ab

Bb-3###42.224.00Ad###48.143.09Ad###54.815.53Ac

Bt###34.812.42Bd###47.43.36Ad###49.633.35Acd

Bb-1 + Bt###18.512.42Be###30.373.35Abe###34.074.64Ade

Bb-2 + Bt###12.593.22Ae###19.253.22Ae###23.74.02Aef

Bb-3 + Bt###0.000.00Bf###3.701.61ABf###7.402.34Af

Control###95.551.57Aa###94.811.85Aa###96.341.17Aa

F###145###106###65.7

df###7,71###7,71###7,71

P###less than 0.01###less than 0.01###less than 0.01

4th Instar

Bb-1###80.742.06Bb###87.401.33Aab###91.111.57Aab

Bb-2###66.662.48Bc###74.071.73ABbc###79.253.59Abc

Bb-3###52.592.34Bd###61.483.09ABcd###68.142.42Acd

Bt###48.882.48Bd###56.292.74ABd###62.224.30Ade

Bb-1+ Bt###34.073.03Be###41.484.81Abe###50.372.51Aef

Bb-2 + Bt###21.481.85Bf###30.374.17Abe###37.034.98Af

Bb-3 + Bt###8.142.15Ag###12.593.22Af###18.513.29Ag

Control###95.552.48Aa###97.031.18Aa###96.291.16Aa

F###153###87.6###69.5

df###7,71###7,71###7,71

P###less than 0.01###less than 0.01###less than 0.01

of various microbial suspensions such as B. thuringiensis and B. bassiana can increase their efficacy against voracious and polyphagous insect pests compared to the materials applied alone. The resistance to conventional insecticides in the insect pests can be overcome by integrating the microbial agents (Ma et al., 2008). Further, environmental benign characteristics makes these microbes more suitable in integrated pest management regimes against different insect pests.

The order Lepidoptera contains various insect pests which can be efficiently controlled by entomopathogenic fungi (Vega-Aquino et al., 2010). The present results showed various life stages of E. vittella have higher mortality, lower pupation, adult emergence and egg eclosion rate after the infection of B. bassiana. Likewise, similar results were observed for M. anisopliae in laboratory bioassays against different developmental stages of H. armigera (Nguyen et al., 2007). Several isolates of M. anisopliae have also shown high levels of virulence against various forest pests (Remadevi et al., 2010) and 90% mortality of Agriotes obscurus L. (Coleoptera: Elateridae) and the unidentified species of Limonius was reported (Kabaluk et al., 2001) under laboratory conditions. The decreased mortality trend was observed in the subsequent stages of various insect pests with the application of insect pathogenic fungi (Inglis et al., 2001).

Table 3: Mean adult emergence (% SE) of E. vittella from three different fferentfield populations treated with B. bassiana (Bb1: 1.5A-106; Bb2: 1.5A-107; Bb3: 1.5A-108 conidia ml-1) and B. thuringiensis (Bt: 0.5 g g-1), individually and in combination. Means sharing same lower case letters within each population and the upper case letters among populations are significantly different from each other at 5% significance level

Treatments###Faisalabad###T.T. Singh###Pakpattan

2nd Instar

Bb-1###67.403.75Bb###78.511.85Ab###83.702.51Aa

Bb-2###53.332.22Bc###62.962.96ABc###68.143.47Ab

Bb-3###36.262.97Bd###48.143.29ABd###52.594.77Ac

Bt###31.852.89Bd###42.963.53ABd###49.633.16Ac

Bb-1+ Bt###16.291.95Be###23.704.45Abe###28.883.51Ad

Bb-2 + Bt###10.373.35Bef###17.772.93Abe###22.963.70Ad

Bb-3 + Bt###0.000.00Bf###2.961.17ABf###6.672.22Ae

Control###92.592.34Aa###93.331.11Aa###94.811.85Aa

F###137###116###87.2

df###7,71###7,71###7,71

P###less than 0.01###less than 0.01###less than 0.01

4th Instar

Bb-1###77.771.92Bb###81.484.27ABab###90.371.69Aab

Bb-2###65.183.97Bc###69.632.51ABbc###78.513.81Ab

Bb-3###44.442.93Bd###58.513.29Acd###65.182.67Ac

Bt###39.253.03Bd###55.552.48Ad###57.033.16Acd

Bb-1+ Bt###27.42.82Be###36.294.02Be###49.632.74Ad

Bb-2 + Bt###16.291.95Bef###29.633.70Ae###34.073.75Ae

Bb-3 + Bt###5.181.48Bf###8.142.15ABf###14.812.89Af

Control###94.811.85Aa###94.072.06Aa###95.552.48Aa

F###136###81.8###87.3

df###7,71###7,71###7,71

P###less than 0.01###less than 0.01###less than 0.01

The virulence of entomopathogenic fungi varies greatly in different life stages of insect pests because phenoloxidase enzymes in the later stages of insects produce more melanin content in the cuticle of insects which prevents the fungal penetration (Wilson et al., 2001). The same phenomenon was observed (Hafez et al., 1997) for B. bassiana against potato tuber moth Phthorimaea operculella (Z.) (Lepidoptera: Gelechiidae). On the other hand, contradictory results were obtained (Vandenberg et al., 1998) as the 3rd and 4th instar larvae of diamond back moth Plutella xylostella L. (Lepidoptera: Plutellidae) were more susceptible to entomopathogenic fungi compared to 2nd instar larvae.

B. thuringiensis intoxication interrupted the larval feeding of early instars compared to later instars (Wraight and Ramos, 2005). The insecticidal activity of B. thuringiensis decreased with increasing larval growth of E. vittella in the present study and the results were in accordance with the findings of Herbert and Harper (1985)

who observed B. thuringiensis has no effect on the later developmental stages of Helicoverpa zea Boddie (Lepidoptera: Noctuidae). Thus they were more susceptible to B. bassiana and this interaction may be termed a synergistic effect of insect pathogens (Gao et al., 2012). Likewise, Zehnder and Gelernter (1989) recorded 40-98% mortality of 2nd instar compared with 52% mortality of 3rd

Table 4: Mean egg eclosion (% SE) of E. vittella from three different field populations treated with B. bassiana (Bb1: 1.5A-106; Bb2: 1.5A-107; Bb3: 1.5A-108 conidia ml-1) and B. thuringiensis (Bt: 0.5 g g-1), individually and in combination. Means sharing same lower case letters within each population and the upper case letters among populations are significantly different from each other at 5% significance level

Treatments###Faisalabad###T.T. Singh###Pakpattan

2nd Instar

Bb-1###56.297.45Ab###68.634.30Ab###72.284.48Aab

Bb-2###48.926.28Ab###55.395.99Abc###61.275.54Abc

Bb-2###48.926.28Ab###55.395.99Abc###61.275.54Abc

Bt###29.67.65Abcd###35.629.47Acde###39.636.05Acde

Bb-1+ Bt###13.812.94Acde###21.345.57Adef###27.65.43Adef

Bb-2 + Bt###7.283.74Ade###12.213.68Aef###18.454.42Aef

Bb-3 + Bt###0.000.00Ae###7.064.45Af###13.245.06Af

Control###93.001.42Aa###97.897.65Aa###95.001.19Aa

F###23.5###25.8###23.5

df###7,71###7,71###7,71

P###less than 0.01###less than 0.01###less than 0.01

4th Instar

Bb-1###63.8210.11Ab###76.465.22Abc###83.213.52Aab

Bb-2###54.555.48Bbc###65.963.88ABbc###72.444.59Aabc

Bb-3###43.647.24Abcd###52.438.68Abcd###54.547.12Abcd

Bt###36.637.73Acde###44.759.00Acde###50.9510.34Abcd

Bb-1+ Bt###19.684.92Adef###28.967.01Adef###35.5110.47Acd

Bb-2 + Bt###11.713.52Aef###17.147.31Aef###23.776.77Ad

Bb-3 + Bt###4.641.83Af###10.454.61Af###13.687.67Ad

Control###94.701.49Aa###91.621.83Aa###96.6017.04Aa

F###23.5###21.3###9.68

df###7,71###7,71###7,71

P###less than 0.01###less than 0.01###less than 0.01

instars of the Colorado potato beetle (Leptinotarsa decemlineata Say Coleoptera: Chrysomelidae) after 96 h with the application of B. thuringiensis var sandiego (M-ONE).

Lacey et al. (1999) reported excellent control of L. decemlineata by applying low and high recommended dose rates (1.17 and 7.01 ha-1) of B. thuringiensis. Similarly, Zehnder et al. (1992) obtained good results when application of B. thuringiensis was synchronized with the oviposition time of L. decemlineata. The ecdysis or molting enables the insects to escape from the infectious cycle of a fungus and more fungal spores rupture and penetrate the cuticle of the host during the prolonged intra-period of molting (Vey and Fargues, 1977). Similarly in our bioassays, the mortality rate was higher with the higher dose rates of B. bassiana and B. thuringiensis against 2nd and 4th instar larvae of E. vittella and these findings agree with Lacey et al. (1999). The researchers reported reduced populations of L. decemlineata when B. bassiana and B. thuringiensis were applied simultaneously in small plots.

Similarly, Wraight and Ramos (2005) observed the best control of larval populations of L. decemlineata with the combined application of B. bassiana and B. thuringiensis. Our results are more strengthened with the findings of Lewis et al. (1996) who reported the increased mortality of Ostrinia nubilalis HA1/4bner (Lepidoptera: Pyralidae) when B. bassiana and B. thuringiensis were applied in combination.

Conclusion

This is a novel study in which the effectiveness of B. bassiana and B. thuringiensis were tested against different larval instars of E. vittella populations which was originated from distinct geographical areas of Punjab province (Pakistan). The results of laboratory bioassays indicated that the combined application of B. bassiana and B. thuringiensis showed significant higher mortalities against both 2nd and 4th larval instar of E. vittella. Moreover, 4th instar larvae were less susceptible than 2nd instar larvae of E. vittella and the possible reason could be again due to the production of phenoloxidase enzyme in later developmental stages of larvae. The phenoloxidase enzyme produces toxic compounds like melanin and quinine which can resist in fugal germ tube to grow in hemolymph to deplete the nutrients (Wilson et al., 2001).

The mortality obtained in the laboratory bioassays did not predict the field mortality and there is need to conduct extensive field studies to check the combined efficacy of B. bassiana and B. thuringienis so that to develop and validate the successful IPM solution against E. vittella in vegetable growing areas.

Acknowledgments

The authors are indebted to Higher Eductaion Commission, Islamabad, Pakistan for providing financial support (Av6- 043) to first author under Indigenous PhD fellowship Program. This is contribution No. ORIC-14-05 from University of Agriculture, Faisalabad, Pakistan.

References

Abbott, W.S., 1925. A method of computing the effectiveness of an insecticide. J. Econ. Entomol., 18: 265267

Atwal, A.S. and G.S. Dhaliwal, 2009. Agricultural Pests of South Asia and their Management, 6th edition. Kalyani Publishers, New Delhi, India

Aziz, M.A., M. Hasan and A. Ali, 2011. Impact of abiotic factors on incidence of fruit and shoot damage of spotted bollworms Earias spp. on okra (Abelmoschus esculentus L.). Pak. J. Zool., 43: 863868

Bagade, A.S., J.S. Ambekar, V.Y. Bhagavati and B.A. Bade, 2005. Field efficacy of neem formulations in alternation with synthetic insecticides against okra fruit borer (Earias vittella Fab.). J. Maharashtra Agric. Univ., 30: 210212

Carner, G.R. and W.C. Yearian, 1989. Development and use of microbial agents for control of Heliothis spp. in the USA. In: Proceedings of the Workshop on Biological Control of Heliothis: Increasing the Effectiveness of Natural Enemies, 11-15 November, 1985, pp: 467481.

King, E.G. and R.D. Jackson (eds.). Far Eastern Regional Research Office, US Department of Agriculture, New Delhi, India

Dilruba, S., M. Hasanuzzaman, R. Karim and K. Nahar, 2009. Yield response of okra to different sowing time and application of growth hormones. J. Hortic. Sci. Ornamental Plants, 1: 1014

Entwistle, P.F., J.S. Cory, M. Bailey and S. Higgs, 1993. Bacillus thuringiensis, an Environmental Biopesticide: Theory and Practice. Wiley, New York, USA

FAOSTAT, 2013. FAOSTAT - Crops. Available online: http://faostat.fao.org/site/567/default.aspx#ancor; accessed on: 25.12.2013

Furlong, M.J. and E. Groden, 2003. Starvation induced stress and the susceptibilityof the Colorado potato beetle, Leptinotarsa decemlineata, to infection by Beauveria bassiana. J. Invert. Pathol., 83: 127138

Gao, Y., B. Oppert, J.C. Lord, C. Liu and Z. Lei, 2012. Bacillus thuringiensis Cry3Aa toxin increases the susceptibility of Criocerisquatuor decimpunctata to Beauveria bassiana infection. J. Invert. Pathol., 109: 260263

Gulati, R., 2004. Incidence of Tetranychuscinnabarinus infestation in different varieties of Abelmoschus esculentus. Annl. Plant Prot. Sci., 10: 239242

Gupta, S.C. and A.K. Misra, 2006. Management of okra shoot and fruit borer, Earias vittella Fab. through bio-rational insecticides. Pest. Res. J., 18: 3334

Hafez, M., F.N. Zaki, A. Moursy and M. Sabbour, 1997. Biological effects of the entomopathogenic fungus, Beauveria bassiana on the potato tuber moth Phthorimaeao perculella (Zeller). J. Pest. Sci., 70: 158159

Herbert, D.A and J.D. Harper, 1985. Bioassay of d-exotoxin of Bacillus thuringiensis against Heliothis zea larvae. J. Invert. Pathol., 46: 247250

Hilder, V.A. and D. Boulter, 1999. Genetic engineering of crop plants for insect resistance a critical review. Crop Prot., 18: 177191

Inglis, G.D., M.S. Goettel and H. Strasser, 2001. Use of hyphomycetous fungi for managing insect pests. In: Fungi as Biocontrol Agents: Progress, Problems and Potential, pp: 2370. Butt, T.M., C. Jackson and N. Magan (eds.). CABI Publishing, Wallingford, Oxon, UK

Kabaluk, T., M. Goettel, B. Vernon and C. Noronha, 2001. Evaluation of Metarhizium Anisopliae as a Biological Control for Wireworms. Organic Agriculture Center of Canada, Available online: http://www.organicagcentre.ca/ResearchDatabase/res_biol_ctrl_wire worms.asp; accessed on: 20.12.2013

Kumar, M. and A.K. Singh, 2006. Determination of economic threshold level of Earias vittella in okra. Annl. Plant Prot. Sci., 14: 226227

Kumar, S., S. Prasad and R.N. Singh, 2002. Resurgence of two spotted mite due to acaricides and botanicals on okra. Annl. Plant Prot. Sci., 10: 5154

Lacey, L.A., D.R. Horton, R.L. Chauvin and J.M. Stocker 1999. Comparative efficacy of Beauveria bassiana, Bacillus thuringiensis, and aldicarb for control of Colorado potato beetle in an irrigated desert agroecosystem and their effects on biodiversity. Entomol. Exp. Appl., 93: 189200

Lewis, L.C., E.C. Berry, J.J. Obrycki and L.A. Bing, 1996. Aptness of insecticides (Bacillus thuringiensis and carbofuran) with endophytic Beauveria bassiana in suppressing larval populations of European corn borer. Agric. Eco. Envir., 57: 2734

Lin, H.P., X.J. Yang, Y.B. Gao and S.G. Li, 2007. Pathogenicity of several fungal species on Spodoptera litura. Chin. J. Appl. Ecol., 18: 937940

Ma, X.M., X.X. Liu, X. Ning, B. Zhang, F. Han, X.M. Guan, Y.F. Tan and Q.W. Zhang, 2008. Effects of Bacillus thuringiensis toxin Cry1Ac and Beauveria bassiana on Asiatic corn borer (Lepidoptera: Crambidae). J. Invert. Pathol., 99: 123128

Mahapatro, G.K. and G.P. Gupta, 1998. Bio-potency test of some commercial formulations of Bacillus thuringiensis against spotted bollworm Earias vittella Fab. Pestology, 22: 1317

Misra, H.P., D.D. Dash and D. Mahapatro, 2002. Efficacy of some insecticide against okra' fruit borer and leaf roller. Annl. Plant Prot. Sci., 10: 5154

Nguyen, N., C. Borgemeister, H. Poehling and G. Zimmermann, 2007. Laboratory investigations on the potential of entomopathogenic fungi for biocontrol of Helicoverpa armigera (Lepidoptera: Noctuidae) larvae and pupae. Biocont. Sci. Technol., 17: 853864

PACopyrightrez-Guerrero, S., A. El-Sayed Hatem and E. Vargas-Osuna, 2004. MACopyrighttodo de cria de Earias insulana Boisduval (Lep. Noctuidae), plaga del algodon. Bol. San. Veg. Plagas, 30: 657661

Purwar, J.P. and G.C. Sachan, 2006. Synergistic effect of entomogenous fungi on some insecticides against Bihar hairy caterpillar Spilarctia oblique (Lepidoptera: Arctiidae). Microbiol. Res., 161: 3842

Remadevi, O.K., T.O. Sasidharan, J. Bhattacharya, C.R. Vossbrinck and P.D. Rajan, 2010. Some pathological effects and transmission potential of a microsporidian isolate (Nosema spp.) from the teak defoliator Hyblaeapuera puera (Lepidoptera: Hyblaeidae). Int. J. Trop. Insect Sci., 30: 138144

Saini, R.K. and N.P. Chopra, 1988. Relative toxicity of different insecticides to field collected larvae of Eaias vittella. J. Entomol. Res., 12: 169170

Shukla, A., S.C. Pathak and R.K. Agrawal, 1997. Seasonal incidence of okra' shoot and fruit borer Earias vittella (Fab.) and effect of temperature on its infestation level. Adv. Plant Sci., 10: 169172

Singh, B.K., A.K. Singh and H.M. Singh, 2005. Efficacy of certain synthetic insecticides and two botanicals against the okra fruit and shoot borer, Earias vittella (Fabr.). Pest Manage. Ecol. Zool., 13: 99103

Sokal, R. and F.J. Rohlf, 1995. Biometry, 3rd edition. W.H. Freeman and Company, New York, USA

Steel, R.G.D., J.H. Torrie and D.A. Dickey, 1997. Principles and Procedures of Statistics: A Biometrical Approach, 3rd edition. W.C.B. McGraw Hill Companies, Inc., Boston, USA

Vandenberg, J.D., A.M. Shelton, W.T. Wilsey and M. Romas, 1998. Assessment of Beauveria bassiana sprays for control of diamond back moth (Lepidoptera: Plutellidae) on crucifers. J. Econ. Entomol., 91: 624632

Vega-Aquino, P., S. Sanchez-Pena and C.A. Blanco, 2010. Activity of oil- formulated conidia of the fungal entomopathogens Nomuraea rileyi and Isaria tenuipes against lepidopterous larvae. J. Invert. Pathol., 103: 145149

Vey, A. and J. Fargues, 1977. Histological and ultrastructural studies of Beauveria bassiana infection in Leptinotarsa decemlineata larvae during ecdysis. J. Invert. Pathol., 30: 207215

Wakil, W., M.U. Ghazanfar, T. Riasat, M.A. Qayyum, S. Ahmed and M. Yasin, 2013. Effects of interactions among Metarhizium anisopliae and Bacillus thuringiensis and chlorantraniliprole on the mortality and pupation of six geographically distinct Helicoverpa armigera field populations. Phytoparasitica, 41: 221234

Wilson, K., S.C. Cotter, A.F Reeson and J.K. Pell, 2001. Melanism and disease resistance in insects. Ecol. Lett., 4: 637649

Wraight, S.P. and M.E. Ramos, 2005. Synergistic interaction between Beauveria bassiana and Bacillus thuringiensis tenebrionis-based biopesticides applied against field populations of Colorado potato beetle larvae. J. Invert. Pathol., 90: 139150

Zehnder, G.W. and W.D. Gelernter 1989. Activity of the M-One formulation of a new strain of Bacillus thuringiensis against the Colorado potato beetle (Coleoptera: Chrysomelidae): relationship between susceptibility and insect life stage. J. Econ. Entomol., 82: 756761

Zehnder, G.W., G.M. Ghidiu and J. Speese, 1992. Use of the occurrence of peak Colorado potato beetle (Coleoptera: Chrysomelidae) egg hatch for timing of Bacillus thuringiensis spray applications in potatoes. J. Econ. Entomol., 85: 281288

Zimmermann, G., 1986. Galleria-bait method for detection of entomopathogenic fungi in soil. J. Appl. Entomol., 2: 213215

Zimmermann, G., 2007. Review on safety of the entomopathogenic fungi Beauveria bassiana and Beauveria brongniartii. Biocont. Sci. Technol., 17: 553596
COPYRIGHT 2015 Asianet-Pakistan
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2015 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Ali, Kashif; Wakil, Waqas; Zia, Khurram; Sahi, Shahbaz Talib
Publication:International Journal of Agriculture and Biology
Article Type:Report
Date:Aug 31, 2015
Words:5437
Previous Article:Nutritional Evaluation of Fresh and Wilted Mixed Silage of Naked Oats (Avena nuda) and Alfalfa (Medicago sativa).
Next Article:Effects of Graded Level of Dietary L-Ascorbyl-2-Polyphosphate on Growth Performance and Some Hematological Indices of Juvenile Mahseer (Tor putitora).
Topics:

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters