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Influence of temperature and CO2 levels on growth and development of Plutella xylostella Linnaeus on cauliflower
(Punjab Agricultural University, Ludhiana, 2018) Cheema, Rupinder Singh; Sandhu, Inderpal Singh
The studies on influence of different temperature and carbon dioxide levels on biology, food consumption and nutrional indices of Plutella xylostella Linnaeus on cauliflower were conducted by collecting insect population from two locations viz. Ludhiana and Malerkotla. Study was conducted at six different combinations of temperature and CO2 levels viz. 25:11ºC and 28:14ºC at 350, 400, 450 ppm carbon dioxide concentrations. The incubation period of eggs decreased non-significantly with increase in temperature and CO2 levels in population of both the locations. In Ludhiana population total larval duration, pupal duration, female adult longevity, male adult longevity decreased from 11.68, 4.32, 14.17, 20.51, respectively at 25:11ºC to 10.02, 3.71, 11.14, 16.62 days respectively, at 28:14ºC. Similarly when CO2 levels increased from 350 ppm to 450 ppm total larval duration, pupal duration, female adult longevity, male adult longevity decreased from 11.43, 4.22, 13.85, 20.17, respectively to 10.30, 3.77, 11.37, 16.90, respectively. Whereas fecundity P. xylostella increased significantly from 165.56 to 186.00 eggs female-1 with increase in temperature and from 167.50 to 183.67 with increase in CO2 levels which indicate reduced generation time ultimately more number of generations per year. Similar results were found in Malerkotla population. Likewise food consumption, consumption index, relative growth rate, approximate digestibility, efficiency of conversion of ingested food of third instar larvae of Ludhiana population increased significantly from 5.36, 0.92, 0.47, 50.96, 45.83 to 5.59, 1.20, 0.53, 55.29, 50.71, respectively with increase in CO2 levels from 350 ppm to 450 ppm. Similarly in fourth instar larvae of both the populations, value of food consumption, CI, RGR, AD and ECI increased significantly with the increase in temperature and CO2 levels. Thus it can be concluded that elevated temperature and carbon dioxide and their interactive effect influences the different biological and nutritional indices of P. xylostella.
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Effects of double stranded RNA in Bactrocera dorsalis (Hendel) on guava
(Punjab Agricultural University, Ludhiana, 2018) Simranpreet Kaur; Sandeep Singh
The present study entitled “Effects of double stranded RNA in Bactrocera dorsalis (Hendel) on guava” was conducted in the Fruit Entomology Laboratory, Department of Fruit Science and Fruit Biotechnology Laboratory, School of Agricultural Biotechnology, Punjab Agricultural University, Ludhiana during 2016-17 and 2017-18. Evaluation of impact of two genes NOA and V-ATPase D on maggots, pupae and adults of B. dorsalis revealed that these two genes were vital for growth and survival of B. dorsalis. Bacteria (Escherchia coli HT115) expressing dsRNA was successfully delivered to maggots and adults through artificial diet containing 10g agar, 120g sucrose, 10g soya peptone, 40g dry yeast, 1g sorbic acid, 6.6g ascorbic acid, 0.1g ampicillin, 0.03g tetracycline and 1000ml water. Silencing of NOA and V-ATPase D genes resulted in mortality of different life stages of B. dorsalis in a dose-dependent manner. Maximum moratlity was observed in maggot, pupa and adult stages of B. dorsalis after feeding of bacteria expressing dsRNA at 700µl concentration followed by bacteria expressing dsRNA at 350µl and 200µl concentrations for both NOA and V-ATPase D genes as compared to control (bacteria without dsRNA). Silencing of target genes had greater impact at higher concentrations of bacteria expressing dsRNA. Thus, utilization of this novel strategy might help to manage population of B. dorsalis in guava and may further strengthen the Integrated Pest Management module for B. dorsalis in Punjab after carrying out further research on these aspects.
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Estimation of residue of diafenthiuron in brinjal (Solanum melongena L.) and cabbage (Brassica oleracea L. var. capitata)
(Punjab Agricultural University, Ludhiana, 2018) Athulya R.; Kang, B. K.
Supervised field trials were conducted to study the residues of diafenthiuron in brinjal and cabbage following application @ 300 and 600 g a.i. ha-1. The samples of cabbage and brinjal were collected at 0 (2hrs), 1, 3, 5, 7 and 10 days after the second and third application. QuEChERS sample preparation was used for the determination of diafenthiuron residues. All the samples were quantified by High Performance Liquid Chromatography (HPLC) and confirmed by Liquid Chromatograph-Mass Spectrometry (LC-MS). Mean initial deposits of diafenthiuron at 300 and 600 g a.i. ha-1 on brinjal fruits were found to be 0.26 and 0.60 mg kg-1 reached below detectable level of 0.05 mg kg-1 after 5th and 7th day at single and double dosage, respectively. The average initial deposits of diafenthiuron in cabbage were observed to be 0.60 and 1.27 mg kg-1 following third application of diafenthiuron and reduced to below its limit of quantification of 0.05 mg kg-1 after 7 and 10 days at recommended and double the recommended dosages, respectively. Diafenthiuron residue in soil samples, collected from both brinjal and cabbage fields after third application was found to be below detectable level of 0.05 mg kg-1. The half-life value (T1/2) of diafenthiuron in brinjal was calculated to be 1.28 and 1.42 days and half -life in cabbage was 1.88 and 2.15 days at single and double the recommended dosages, respectively. The initial deposits were found to be below MRL of 1 mg kg-1, so one day waiting period is suggested for safe consumption of brinjal and cabbage. Among various household processing methods, cooking removed 100 percent of diafenthiuron residues on brinjal and cabbage in both the treatments.
Open Access
Avoidable crop losses, Economic Threshold Level and management of Helicoverpa armigera (Hübner) in chickpea
(Punjab Agricultural University, Ludhiana, 2018) Akanksha; Ravinder Singh
Field studies were conducted for two years during rabi 2016-17 and 2017-18 to determine the crop losses, to establish economic threshold level (ETL) and to evaluate the efficacy of various integrated pest mangement (IPM) modules for the management of Helicoverpa armigera (Hübner) in chickpea. The avoidable yield loss of 26.27 per cent was observed in chemical method as compared to 19.59 per cent in mechanical exclusion method over unprotected method. The avoidable crop losses due to H. armigera in chickpea var. PBG 7 was recorded to be 73.50 per cent by insect density method with larval population of six larvae per meter row length. The correlation coefficient for the larval infestation level and the per cent pod damage was significantly positive. However, significantly negative correlation was observed between larval infestation level per meter row and seed yield. On the basis of regression analysis and gain threshold, the EIL and ETL were determined to be 2.086 and 1.56 larvae per meter row, respectively. Among the different IPM modules tested for two years, to test the bioefficacy against H. armigera in chickpea, the treatment with three sprays of indoxacarb 14.5 SC @ 66 g a.i. ha-1 was found to be significantly superior over all other biointensive modules and untreated control but was at par with novaluron 10 EC @ 37.5 g a.i. ha-1 > chlorantraniliprole 18.5 SC @ 25 g a.i. ha-1 > emamectin benzoate 5 SG @ 11g a.i. ha- 1. Results of the study revealed that significantly lowest larval population of zero larvae per meter row, lowest pod damage of 1.41 per cent, highest seed yield of 1950 kg ha-1 and highest C:B of 1:6.9 were found in treatment with three sprays of indoxacarb 14.5 SC @ 66 g a.i. ha-1.
Open Access
Physiological influences of pyriproxyfen on whitefly, Bemisia tabaci (Gennadius)
(Punjab Agricultural University, Ludhiana, 2018) Savinderjeet Singh; Chandi, Anureet Kaur
Pyriproxyfen, a pyridine based juvenile hormone analogue with mode of action different from the conventional insecticides, was evaluated for its physiological influences on nymphs and adults of whitefly, Bemisia tabaci (Gennadius) during 2016 and 2017. Various toxicity values i.e. LC30 (0.020, 0.021%) and LC50 (0.043, 0.048%) for first instar nymphs; LC30 (0.026, 0.029%) and LC50 (0.055, 0.060%) for fourth instar nymphs; LC30 (0.031, 0.034%) and LC50 (0.061, 0.069%) for adults were worked out by employing standard methods of bioassay. Significant increase in 50 per cent red-eyed nymph formation (14.00 and 10.50 against 7.40 and 5.90 days in control) and nymphal period (15.20 and 12.20 against 8.50 and 6.80 days in control) was registered under influence of pyriproxyfen. In contrast, when first instar nymphs were treated with pyriproxyfen, there was reduction in adult emergence (49.78 and 50.19 against 76.05 and 79.38% in control); adult longevity (3.70 and 4.40 against 5.80 and 7.40 days in the control); oviposition period (1.70 and 1.90 against 3.10 and 3.20 days in control); fecundity (10.80 and 11.83 against 19.70 and 20.85 eggs in control) and egg hatching (20.74 and 21.82 against 60.11 and 62.28% in control). Inhibition of fecundity (7.73 and 8.44 in treated; 15.48 and 15.83 in control) and curtailed egg hatching (24.56 and 26.90 in treated; 65.10 and 67.70 in control) was ascertained. Mortality of first instar nymphs (47.72 and 45.85%) on lower surface of cotton leaves indicates pronounced translaminar effect in both the years. Significant reduction in the total amino acids, increased level of total sugars and phenols of treated cotton plants could be correlated with lesser whitefly population density. Hence, pyriproxyfen, given to its several lethal and sublethal influences can be used as an effective tool for management of B. tabaci.
Open Access
Morphological and biochemical plant characters in relation to resistance against some sucking insect pests in Bt cotton
(Punjab Agricultural University, Ludhiana, 2017) Y. Krishnakumari Devi; Vijay Kumar
The studies on morphological and biochemical plant characters in relation to resistance against some sucking insect pests in Bt cotton were carried out at Entomological Research Farm, PAU, Ludhiana during 2014 and 2015. Experiment on incidence of sucking insect pests on different cotton cultivars, revealed that leafhopper population was significantly higher on Bt cotton cultivar, RCH 773 (4.70 / 3 leaves), whitefly and thrips on Bioseed 6588 (7.47 and 2.47 /3 leaves, respectively). However, lower population of leafhopper, whitefly and thrips was recorded on the desi cotton cultivar, FDK 124 (1.78, 3.25 and 0.83/ 3 leaves, respectively). Incidence of sucking insect pests was also significantly higher at 130 Kg nitrogen as compared to 100 and 65 Kg nitrogen per acre. The population of leafhopper, whitefly and thrips showed significantly positive correlation with maximum and minimum temperature whereas evening relative humidity and rainfall has significantly positive correlation with leafhopper only. However, leafhopper and whitefly showed significant positive correlation with evaporation. Sunshine hours showed significant negative correlation with thrips but positive with whitefly. In another experiment on effect of various morphological plant characters revealed significant positive correlation with leafhopper population and gossypol gland on midrib. However, leafhopper, thrips and whitefly showed significant positive correlation with leaf lamina thickness and highly significant positive correlation with leaf area. Among the biochemical plant characters revealed that higher amount of total phenol, flavonols, O-dihydroxy phenol, tannins, total sugar and reducing sugars were recorded in cultivars infested with sucking insect pests over uninfested condition. Significantly higher biochemical content were recorded at lower level of nitrogen (65 Kg) followed by 100 and 130 Kg per acre. Leafhopper population had significant positive correlation with reducing sugar whereas whitefly and thrips with total sugar. However, thrips population showed significantly negative correlation with O-dihydroxy phenol. In another experiment on detection of the presence of Cry toxin revealed that highest amount of Cry1Ac and Cry2Ab was detected at 60 days after sowing as compared to 120 days after sowing. Higher expression of Cry toxin was recorded at high level of nitrogen (130 Kg) followed by 100 and 65 Kg. ELISA analysis showed presence of Cry toxin (Cry1Ac and Cry2Ab) in leafhopper nymphs and whitefly adults fed on Bt cotton cultivars and traces in honeydew excreted by whitefly feeding on Bt cotton cultivars.
Open Access
Biological activity of horticultural mineral oils against thrips and mites on Kinnow
(Punjab Agricultural University, Ludhiana, 2018) Dhaliwal, Rajwinder Singh; Sharma, D. R.
The studies on biological activity of horticultural mineral oils against thrips and mites on Kinnow were carried out at Fruit Research Farm/Old orchard and Entomology Laboratory, Department of Fruit Science, Punjab Agricultural University, Ludhiana, during 2016 and 2017 with the objective to evaluate the biological activity and phytotoxicity of different HMOs against thrips and mites on Kinnow. Eight year old trees of Kinnow were sprayed with five different horticultural mineral oils (HMOs), viz. MAK All Season, Servo, Arbofine, Sparrow 888 Plus and HPHMO at different concentrations (0.75, 1.00, 1.25, 1.50 and 2.00% for efficacy and 3.00 and 4.00% for phytotoxicity) alongwith insecticide/acaricide i.e. triazophos 40 EC and fenazaquin 10 EC as check and untreated control (in which only water was sprayed) at 15 days interval during March, April, May and June with the help of Rocking/Foot pump sprayer. The results on the evaluation of HMOs against citrus thrips, Scirtothrips citri showed that triazophos (0.075%) was found to be the most effective treatment against thrips upto 15 days after spray. All the HMOs at different concentrations three days after spray reduced the thrips population marginally and provided about 40 per cent control of thrips upto seven days after treatment. Similarly, in case of mites, fenazaquin (0.015%) was found the most effective treatment as compared to different HMOs. As in case of thrips, HMOs also reduced the mite population by 40-50 per cent upto seven days after treatment. The results further showed that with the increase in concentration of each HMO, the efficacy against thrips and mites increased. Among different HMOs, Arbofine was found to be numerically better both against thrips and mites. Similar results were also found against predatory mite, Amblyseius spp. where population was reduced marginally with the application of HMOs. The rind scarring of fruits due to thrips and mites also decreased with the application of HMOs. Fruits free from scarring increased from 40.00-49.17 per cent at 0.75 per cent to 64.17-75.83 per cent fruits at 2.00 per cent of each HMO spray as compared to 12.50 per cent in untreated control. It was also found that with the increase in concentration of HMOs, there was an increase in the deformity of the leaves in terms of leaf hyponasty, epinasty and yellowing. Trees treated with 4.00 per cent concentration of HMOs had only 55.00-60.00 per cent normal leaves as compared to 90.00 per cent in untreated control. Thus, it is concluded that with the increase in the concentration of HMOs, though there was an increase in the efficacy against thrips and mites but there was more phytotoxic effect on leaves if the concentration of HMOs is more than 2.00 per cent.
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Diversity of natural enemies and efficacy of biopesticides for the management of Bemisia tabaci (Gennadius) in Bt cotton
(Punjab Agricultural University, Ludhiana, 2017) Khangura, Samreet Singh; Rabinder Kaur
The studies on "Diversity of natural enemies and efficacy of biopesticides for the management of Bemisia tabaci (Gennadius) in Bt cotton" were conducted during Kharif, 2016. The population of whitefly and its natural enemies were comparatively less in sprayed field as against unsprayed fields at Abohar and Muktsar. Among natural enemies of whitefly, Chrysoperla zastrowi sillemi, spiders and coccinnellids were observed in both sprayed and unsprayed fields. Diversity of natural enemies associated with whitefly in the cotton ecosystem was quite less without dominance of any particular specie. Under net house conditions, Neem oil 1 per cent @ 700 and 500 ml/acre (27.11 to 74.43 per cent reduction over control) was most effective in reducing number of nymphs of B. tabaci. It was followed by Metarhizium anisopliae @ 1200 g/acre (27.06 to 58.38 per cent reduction over control). Neem oil 1 per cent @ 700 and 500 ml/acre (32.00 to 67.54 per cent reduction over control) proved to be highly effective in minimising the population of whitefly adults under net house conditions, followed by M. anisopliae @ 1200 g/acre (23.71 to 51.01 per cent reduction over control). In field conditions, the order of efficacy of biopesticides in case of B. tabaci nymphs Neem oil 1 per cent @ 700 and 500 ml/acre (53.95 to 94.61 per cent reduction over control) ˃ M. anisopliae @ 1200 and 1000 g/acre (13.41 to 79.99 per cent reduction over control) ˃ Beauveria bassiana @ 1200, 1000 and 800 ml/acre (12.26 to 77.20 per cent reduction over control) and the order of efficacy of biopesticides in case of B. tabaci adults was Neem oil 1 per cent @ 700 and 500 ml/acre (53.12 to 95.05 per cent reduction over control) ˃ M. anisopliae @ 1200 g/acre (13.15 to 70.04 per cent reduction over control). It was concluded that Neem oil 1 per cent @ 700 and 500 ml/acre and fungal formulations (B. bassiana, M. anisopliae) being safer than chemical insecticides could be included in the IPM of whitefly in the Bt cotton in field condition.
Open Access
Evaluation and molecular characterization of hygienic traits in honey bee (Apis mellifera Linnaeus)
(Punjab Agricultural University, Ludhiana, 2017) Mohindru, Bharathi; Chhuneja, Pardeep Kumar
Studies on ‘Evaluation and molecular characterization of hygienic traits in honey bee (Apis mellifera Linnaeus)’ were conducted at PAU, Ludhiana (India), during 2015-2017. The studies included screening of 100 A. mellifera colonies for comparative hygienic behaviour response, molecular characterization through genome wide and candidate gene based markers for hygienic behaviour, and validation of the selected hygienic colonies against Varroa destructor infestation. Out of the 100 colonies screened, 45 were hygienic, and 55 were non-hygienic out of which 42 were intermediary (71-80% removal of pricked brood) and 13 were the least hygienic (<71% emptying of pricked brood). After 24 h of brood pricking, mean brood removal was 83.65 per cent (range: 80.22-91.0 %) among 45 colonies while it was 73.05 per cent (range: 46.78-79.56%) in the remaining 55 colonies. In the seven selected most hygienic colonies, after 24 h, mean of 91.40 per cent brood was removed (range: 87.22-94.89%), while it was 47.63 per cent (range: 43.56-52.44%) in the three most non-hygienic selected colonies. The hygienic colonies took 20.6 h to express the hygienic trait while the non-hygienic colonies took 44.6 h. After 24 h of V. destructor inoculation into the brood in the hygienic colonies, 93.43 and 95.23 per cent mean of brood removal was recorded during autumn and spring, while in the non-hygienic colonies, it was only 61.90 and 77.24 per cent, respectively, to achieve cent per cent cleaning of cells, the hygienic colonies took a mean of 28 and 25.71 h, while non-hygienic colonies took 50.67 and 47.33 h, during autumn and spring, respectively. The five SSR markers, reported to be linked with hygienic behaviour, showed polymorphism, and did not differentiate the colonies among hygienic and non-hygienic groups. Out of the 40 SSR markers used to study the genetic diversity between the hygienic and non-hygienic colonies, 37 markers were polymorphic; the diversity index value ranged between 0.37-0.92, marker index value between 0.24-6.41 and the PIC value between 0.23-0.77. The clustering pattern between the hygienic and non-hygienic colonies for each of the three brood cycles produced by neighbour-joining dendrogram showed that the ten colonies (7 most hygienic and 3 most non-hygienic) divided into three clusters. The clustering pattern depicting all the three brood cycles together, also consisted of three clusters; cluster I with four hygienic colonies, cluster II with 3 hygienic and 2 non-hygienic colonies and cluster III consisted of one non-hygienic colony. The grouping pattern of all the colonies varied in all the three brood cycles except for two hygienic colonies (6H and 7H) which consistently formed one group. The newly designed 34 gene specific primers amplified all 300 genomic DNA samples from both the types of colonies with no length polymorphism observed between the hygienic and non-hygienic individuals. Sequencing of the three candidate genes revealed no variation, implying these as totally conserved genes. One gene GB19509 showed six differential SNPs between hygienic and non-hygienic colonies.

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