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ThesisItem Restricted Host-parasitoid relationship between Pyrilla perpusilla (Walker) and Fulgoraecia melanoleuca (Fletcher) on sugarcane(Punjab Agricultural University, Ludhiana, 2021) Sharma, Tarun; Shera, P.S.The studies on the “Host-parasitoid relationship between Pyrilla perpusilla (Walker) and Fulgoraecia melanoleuca (Fletcher) on sugarcane” were conducted at the Punjab Agricultural University, Ludhiana during 2019 and 2020. Among the host stages, 4th instar nymphs and adult females were more suitable for the parasitoid, F. melanoleuca in terms of higher larval survival, adult emergence, more proportion of females in the progeny and higher fecundity. The exposure of 1st instar host nymphs to the parasitoid resulted in cent per cent mortality within two days before any signs of parasitism. None of the parasitized 2nd to 4th instar nymphs survived as normal adults as all the parasitized individuals died as nymphs, nymph-adult intermediates or weak adults. However, in case of parasitized 5th instar nymphs, 18.0 per cent adults were normal. The mean longevity of nymphs parasitized in the 3rd, 4th and 5th instars was prolonged significantly; maximum prolongation was in the 4th instar. However, longevity of nymphs parasitized in the 2nd instar was even less than un-parasitized ones. When host adults were offered to the parasitoid, there were significant differences in mortality of parasitized and un-parasitized adults. Further, parasitoid-induced prolongation in the longevity of the surviving parasitized adults was observed for both the sexes. Among different agro-climatic zones, population count of P. perpusilla and F. melanoleuca as well as natural parasitism was more in Jalandhar (central plain zone) as compared to Hoshiarpur (sub-mountainous undulating zone) and Fazilka (Western zone). The parasitoid remained active in overlapping stages during the months of April to November with peak activity in September month at all the locations. It overwintered in cocoon or egg stage on sugarcane trash from December to March months. Among the selected insecticides, chlorpyriphos 20 EC, imidacloprid 17.8 SL and fipronil 5 SC were comparatively toxic to the parasitoid, while pymetrozine 50 WG, chlorantraniliprole 18.5 SC, flubendiamide 480 SC and flonicamid 50 WG were harmless to moderately harmful. The prolonged pupal period, reduction in adult emergence and decreased adult longevity were the sub-lethal effects in the insecticides, chlorpyriphos 20 EC, imidacloprid 17.8 SL and fipronil 5 SC. Biopesticides (Bacillus thuringiensis var. kurstaki 0.5 WP, Metarhizium anisopliae 1.0 WP and Beauveria bassiana 1.0 WP) and botanicals (azadirachtin 1500 and 50000 ppm) were safer to all the stages of F. melanoleuca.ThesisItem Embargo Selective breeding for less stinging trait in Apis mellifera Linnaeus colonies(Punjab Agricultural University, 2022) Madaan, Anmol; Mohindru, BharthiStudies on ‘Selective breeding for less stinging trait in Apis mellifera Linnaeus colonies’ were carried out at Campus Apiary at Entomological Research Farm, Department of Entomology, Punjab Agricultural University (PAU), and at an isolated mating yard at PAU Seed Farm, Ladhowal, during 2021-2022. The studies comprised of screening 100 A. mellifera colonies for less stinging behaviour, selective breeding for development of less stinging colonies and assessment of gentle colonies for colony productivity and foraging activity. The defensive behaviour of the colonies was assessed by alarm pheromone assay. The observations recorded were time taken for the first sting (seconds), number of stings received per minute and number of bees recruited for defense per min and scores were given on a five-point scale of 1 to 5 wherein score of 1 represented the most aggressive and 5 represented the gentlest colony. Screening revealed that the mean number of stings per min, ranged between 1.33 to 22.67; depicting 23 colonies to be the gentlest (score 5) and four the most aggressive (score 1), whereas 49, 18 and 6 colonies scored 4, 3 and 2, respectively. Time taken to first sting, ranged between 3.00 to 23.00 s; two colonies took >20 s (score 5), 10 took 15-19.99 s (score 4), 26 took 10-14.99 s (score 3), 54 took 5.0-9.99 s (score 2) and 8 colonies took < 5 s (score 1) for the first sting. The number of bees recruited per min for defense ranged between 3.67 to 41.67; six colonies got score 5, 50 got score 4, 37 got score 3, five got score 2 and two colony scored 1. Based on the cumulative score from all the three parameters, 10 colonies scored 13-15, 50 got 10-12 score, 34 got 7-9 score and six got 4-6 score. From the 10 selected least stinging colonies, five daughter queens were reared from each. The comparative assessment of the defensive behaviour between selected mother colony, F1 colonies and control unselected colonies revealed that both mother and F1 colonies had lesser number of stings/min, took more time to first sting and had lesser number of bees recruited for defense thus depicting defensive behaviour to be heritable. For all the three defensive characteristics, among the 50 F1 colonies, there was 62 per cent improvement compared to just 10 per cent in the original stock of screened 100 colonies Correlation among the three defensive traits revealed that the number of stings/min was positively correlated with the number of bees recruited for defense and inversely with the time taken for first sting, implying that bees of a colony that sting more number of stings on the leather ball have more number of bees recruited for defense and take less time to initiate defense. Bee breeding for less stinging traits had no negative influence on colony growth, productivity and foraging activity. The information generated from the study on the less stinging behaviour of A. mellifera will be helpful in further bee breeding work towards developing less stinging A. mellifera strain.ThesisItem Restricted Diversity, seasonal incidence and damage assessment of Oxycarenus spp. on cotton(Punjab Agricultural University, 2023) Noor Mahammed N R; Pandher, SuneetThe study on „Diversity, seasonal incidence and damage assessment of Oxycarenus spp. on cotton‟ was conducted at PAU, RRS Faridkot during Kharif 2022-23. Increasing incidence and damage incurred due to dusky cotton bug on cotton during the last few years necessitated to conduct the present study in north India. The results of first experiment were based on collection of dusky cotton bug samples from 31 locations spread across three states of Punjab, Haryana and Rajasthan and revealed that mt-COI gene based molecular identification doesn‟t confirm Oxycarenus at species level. The second experiment on seasonal incidence of dusky cotton bug was recorded on Bt cotton hybrid G. hirsutum RCH 650, non Bt G. hirsutum var. RS 2013 and G. arboreum var. LD 1019 at weekly intervals from 20 randomly selected plants (five squares/flowers/bolls) from each cultivar starting from the appearance of bugs (June) till the harvest of the crop (December). The results revealed that population of Oxycarenus spp. started during square formation stage (July last week), reached peak (around 100 bugs per 5 bolls) during complete boll opening stage (November second week) and remained present till the harvest of crop. Among the weather variables, RH max was positively correlated with the Oxycarenus spp. population, whereas Tmax, Tmin, Tmean, RH min and RH mean were highly significant and negatively associated. Continuous heavy rainfall with non-availability of opened bolls during third week of July has high negative impact on dusky population. Using pest-weather regression models, Oxycarenus spp. incidence on RCH 650, RS 2013 and LD 1019 may be forecasted with good accuracy i.e., R²=0.86, 0.89 and 0.87, respectively. In the third experiment, study on extent of loss caused by Oxycarenus spp. was carried on Bt cotton hybrid RCH 650 under screen house conditions with five treatments (0, 25, 50, 75 and 100 bugs per boll) replicated sixteen times. Bolls of uniform size were selected and covered with perforated net sleeves/cages to prevent natural incidence of Oxycarenus spp., later bugs were released into sleeves and left for 35-40 days. The results revealed that highest damage w.r.t boll weight, seed weight, 100 seed weight and germination was observed in 100 bugs per boll treatment, whereas lint staining (brownish) was very high in 75 and 100 bugs per boll treatment. It can be concluded from the above experiment that as the bug incidence per boll increases, the seed characters are severely affected. The fourth experiment on bio efficacy of homemade neem extracts against Oxycarenus spp. was carried out on Bt cotton hybrid US 51 and dusky cotton bugs along with natural enemies count were recorded (before spray, 3, 7, and 14 days after spray) twice during the entire cropping period. The results revealed that around 50 per cent reduction over control can be achieved by spraying neem formulations, indicating effective alternative approach to synthetic insecticides in pest management. Nimbecidine @ one litre per acre and homemade neem formulations @ 1.5 litre per acre were found effective against Oxycarenus spp. up to 7 days of spraying and neem formulations‟ effect on predators and especially spider population was found to be non-significant during the spray schedule.ThesisItem Restricted Biology, population dynamics, crop losses and management of emerging pest, Spodoptera exigua (Hübner) in chickpea(Punjab Agricultural University, 2023) Sidhu, Kawartej Singh; Ravinder SinghField and laboratory studies were conducted to determine the biology, population dynamics, crop losses and management of Spodoptera exigua in chickpea during Rabi 2021-22 and 2022-23 at PAU, Ludhiana. Eggs of S. exigua were laid in masses covered with scales. The larval and pupal period lasted for 16.79 and 9.37 days on chickpea, whereas on mungbean it was 14.69 and 8.46 days, respectively. The best developmental and reproduction values were recorded on mungbean as compared to chickpea. In population dynamics, early, normal, and late sown chickpea, mean number of larvae ranged from 0.00 to 15.10, 0.00 to 13.20, and 0.40 to 11.60, respectively. As the sowing dates delayed, number of egg masses, larval number and foliar damage by S. exigua decreased. In estimation of crop losses, there was no foliar damage where the crop was protected by nylon mesh cages. Protected treatment had significantly lowest mean foliar and pod damage than unprotected treatment. In insect density method, lowest mean seed yield was recorded in treatment with highest larval infestation of seven larvae per meter row (1079 kg ha-1) as compared to control (1623 kg ha-1). In cultural and mechanical control of S. exigua, highest mean yield (1628kg ha-1) was recorded in treatment consisting of hand collection and destruction of egg masses and young larvae of S. exigua followed by where 2 rows of linseed were sown as intercrop after 10 rows of chickpea (1527 kg ha-1). Among different biopesticides/biorationals tested against S. exigua in chickpea, chlorantraniliprole 18.5 SC @ 125 ml ha-1 was found most effective over all other treatments. S. exigua is emerging as a serious pest of chickpea under Punjab conditions which can be managed by using cultural, mechanical and chemical methods.ThesisItem Embargo Management of Pyrilla perpusilla (Walker) with ecto-parasitoid, Fulgoraecia melanoleuca (Fletcher) on sugarcane(Punjab Agricultural University, 2022) Augustine, Neethu Maria; Shera, P SThe studies on “Management of Pyrilla perpusilla (Walker) with ecto-parasitoid, Fulgoraecia melanoleuca (Fletcher) on sugarcane” were conducted at the Punjab Agricultural University (PAU), Ludhiana during 2021-2022. The releases of F. melanoleuca cocoons (2000, 4000 and 6000 cocoons ha-1) and eggs (2, 4 and 6 lakh eggs ha-1) were compared with chemical control (chlorpyriphos 20 EC @ 1500 ml ha-1) and untreated control. The overall number of pyrilla nymphs and adults was significantly reduced after two releases of parasitoid eggs and cocoons. The reduction of pyrilla population creased progressively either with increase in number of released cocoons (2000, 4000 and 6000 ha-1) or with released eggs (2, 4 and 6 lakh ha-1). The nymphal and adult parasitism also increased with increase in doses and time and it was significantly higher when parasitoids were released at higher doses, i.e. 6 lakh eggs ha-1 (53.75 %) and 6000 cocoons ha-1 (50.60 %) as compared to lower ones. The augmentative releases of parasitoid eggs and cocoons plays a noteworthy role in increasing the parasitoid count (egg masses, cocoons and adults) in the released plots with time. However, chlorpyriphos 20 EC was found to be highly detrimental to the parasitoid as no parasitism and population count was observed in insecticide sprayed plots. Overall, two releases of F. melanoleuca eggs (6 lakh ha-1) or cocoons (6000 cocoons ha-1) at monthly interval (1st week of August and 1st week of September) proved better with respect to reduction in pyrilla population, increase in parasitoid population and parasitism rate and also rendered higher cane yield and better juice quality. The storage of F. melanoleuca eggs and cocoons at different temperatures (0, 5, 10 and 150C) for various durations (1, 2, 3, 4, 5 and 6 weeks) was compared with ideal temperature (270C) for the overall fitness of the parasitoid. The cocoons of F. melanoleuca can be stored at 100C for 1 week and at 150C for 1-2 weeks as these temperature regimes and storage time exhibited negligible negative effect on developmental and reproductive parameters of the parasitoid. Similarly, eggs can be stored at 150C for 1week without much negative effect on hatchability and incubation period of the parasitoid.ThesisItem Embargo Biology and management of molsari leaf webber, Nephopteryx eugraphella Ragonot (Lepidoptera : Pyralidae)(Punjab Agricultural University, 2023) Gurveer Singh; Sangha, K. S.Molsari (Mimusops elengi Linn.) is a large-sized ornamental tree with several medicinal properties. It is attacked by a number of insect-pests, the most important being the leaf webber- Nephopteryx eugraphella Ragonot. The larvae of N. eugraphella feed on leaves, apical shoots and flower buds, thereby giving a burnt appearance to the tree. In the present study, research on biology and management of molsari leaf webber, were carried out at Forest protection laboratory and forestry research area, Department of Forestry and Natural Resources, Punjab Agricultural University, Ludhiana, during 2021-2022. Biology was studied on molsari leaves with five generations (Generation I - Generation V) with a life span ranging between 32 to 45 days. Biological studies revealed that incubation period increased from 3.17 to 4.54 days, while the percent egg hatchability decreased from 90.83 to 72.99 per cent with increase in generation number. The mean duration of I, II, III and IV larval instars ranged between 2.96 to 3.92, 4.08 to 5.12, 3.56 to 4.96 and 4.69 to 5.40 days respectively during the different generations. The prepupal and pupal weight ranged between 47.20 to 55 mg and 45.20 to 60.60 mg. The length of I, II, III, IV, full grown larval instars; pre-pupa; pupa; adult female and adult male varied between 1.22 to 1.31, 4.18 to 4.48, 13.22 to 13.36, 19.22 to 19.88,19.40 to 21.61; 12.41 to 13.44; 9.72 to 10.88; 10.05 to 10.57 and 9.62 to10.32 mm respectively, whereas, breadth varied between 0.31 to 0.38, 0.46 to 0.67, 0.66 to 0.76, 0.66 to 1.11, 1.19 to1.51; 2.81 to 3.14; 2.97 to 3.23; 19.92 to 20.74 and 19.03 to 19.73 mm respectively. Duration of larval period, pre-pupa, pupa, adult female and adult male varied from 15.28 to 19.41, 0.60 to 2.11, 6.52 to 9.24, 6.00 to 9.38 and 3.86 to 6.33 days respectively. Interestingly, per cent survival of larva and pupa decreased in the successive generations. Additionally, sex ratio (male : female) ranged from 1:1.13 to 1:1.40. It was found that pre-mating, mating, pre-oviposition, oviposition and post-oviposition periods varied from 1.22 to 1.93, 0.42 to 0.62, 1.64 to 2.55, 2.28 to 3.62 and 2.08 to 3.21 days respectively. The larvae of N. eugraphella feed on leaves, apical shoots and flower buds, thereby giving a burnt appearance to the tree. Peak activity of the insect was recorded in the months of July, August and September with Tmax, RHm, RHe and rainfall showing significant positive correlation with insect infestation. Apis dorsata, Apis florea, Ischiodon scutellaris, Vespa orientalis were recorded as the casual visitors of molsari while among parasitiods Cotesia flavipes, Compislura sp, Eurytoma sp and Xanthopimpla sp were observed. Among predators, five Spiders (Marpissa mandala, Xysticus sp, Phidippus punjabensis, Rhene indicus and Sparassus sp) and one beetle (Parena nigrolineata) were recorded. Spinosad 48% SC (0.9 ml/l) proved to be the best treatment in suppressing the webs and larval population followed by Bacillus thuringiensis @ 4 g/l and Beauve ria bassiana @ 12 g/l.ThesisItem Restricted Induced host plant resistance in pigeonpea against spotted pod borer, Maruca vitrata (Fabricius)(Punjab Agricultural University, 2022) Khokhra, Shivani; Taggar, Gaurav KumarThe studies on “Induced host plant resistance in pigeonpea against spotted pod borer, Maruca vitrata (Fabricius)” were conducted during Kharif 2020 and 2021. Field screening of pigeonpea genotypes revealed that the genotype AL 1747 consistently performed better towards M. vitrata infestation during both years (Kharif 2020 and 2021). The exogenous application of Jasmonic acid (JA) (100 µM) and Salicylic acid (SA) (5.0 mM) on pigeonpea plants triggered the induction of biochemical parameters (enzymes and secondary metabolites) after 12 and 24 h of application, respectively. Pre-treatment with JA (100 µM) followed by infestation with M. vitrata after 12 h elicited a strong defense response in both the resistant (AL 1747) and susceptible (MN 1) genotypes. AL 1747 responded better to the exogenous application of elicitors and M. vitrata than the susceptible genotype MN 1. The induced effect was highest one day after the treatment (in both JA and SA) and showed a declining trend thereafter with no changes in the activities of defensive enzymes and secondary metabolites after 7 days of treatment. Both JA and SA induced an antioxidative response in pigeonpea plants against M. vitrata, which, in turn, affected the insect development, nutritional indices as well as the metabolism of M. vitrata. Imbalance in the digestive enzymes significantly reduced the nutritional indices (AD, ECI, ECD and RGR) of M. vitrata in JA-treated plants. Insect, as a counter-response to plant defense, increased the activities of glutathione-S-transferases (GST) and glucose oxidase (GOX). However, a significant negative correlation was observed between the detoxifying enzyme (GST) and larval weight (r= -0.790**). The GOX activity and larval weight exhibited a non-significant negative correlation with each other post-elicitor application. SA also led to an alteration in the activities of digestive and defense related enzymes in M. vitrata; however, the effect was not as pronounced as JA. An alteration in insect defensive and digestive enzymes and upregulation of plant secondary metabolites by exogenous application of elicitors (either in the pre-/or simultaneous application) indicates that modulation of pigeonpea defense can increase the effectiveness of the host plant to defend against M. vitrata herbivory.ThesisItem Restricted Influence of abiotic factors on development and behaviour of rice leaf folder, Cnaphalocrocis medinalis (Guenee)(Punjab Agricultural University, 2023) Simranpreet Kaur; Suri, K SThe present studies on “Influence of abiotic factors on development and behaviour of rice leaf folder, Cnaphalocrocis medinalis (Guenee)” were conducted at Punjab Agricultural University, Ludhiana during 2019-22. The impact of variable minimum:maximum temperature for 10:14 h, CO2 and RH on C. medinalis revealed that larval duration, pupal duration, adult emergence, male longevity, female longevity, incubation period and hatchability decreased, whereas female proportion and fecundity of C. medinalis increased with increase in temperature (22:32°C to 26:35°C), CO2 (400 to 450 ppm) and RH (75 to 85%). The shortest larval duration of 7.5 days, pupal duration of 6.0 days, male longevity of 4.5 days, female longevity of 7.75 days, incubation period of 2.25 days, hatchability of 47.19 per cent and least adults emergence (5.25 adults) was recorded at elevated temperature (26:35°C), CO2 (450 ppm) and RH (85%), whereas the maximum fecundity (142.25 eggs) and female proportion (0.99) was recorded at the same elevated conditions. Food consumption, CI, AD and RGR increased, whereas ECI, ECD and RCR of C. medinalis larvae decreased with increase in temperature, CO2 and RH. Maximum food consumption (0.0450 g larva-1), CI (0.0965), AD (84.43%) and RGR (0.0770 mg mg-1day-1) was recorded at elevated temperature (26:35°C), CO2 (450 ppm) and RH (85%). Leaf folding pattern, employing double and multiple leaves for feeding and pupation was witnessed at elevated temperature, CO2 and RH. Activity of enzymes viz. AChE, Esterase, GST, Proteases and SOD in C. medinalis larvae increased as 4.96 μg of free thiol formed/min/mg protein, 9.86 μg of β-napthol formed/min/mg protein, 1.81 mmole of CDNB-GSH conjugate formation/min/mg protein, 3.49 mmol of tyrosine released/min/mg protein and 3.80 units/min/mg protein, respectively, whereas activity of Catalase decreased (7.48 µmoles of H2O2 decomposed/min/mg protein) with increase in temperature from 22:32°C to 26:35°C, CO2 from 400 to 450 ppm and RH from 75 to 85 per cent. Total sugars, reducing sugars, phenols and flavonols in rice plants showed a positive linear regression equation while proteins and amino acids followed a negative linear regression equation, whereas chlorophyll showed a non-linear regression equation with temperature, CO2 and RH. The results of present study would facilitate the adoption of appropriate adaptation measures for C. medinalis management with respect to climate change.ThesisItem Restricted Biocontrol of pink stem borer, Sesamia inferens (Walker) in major cereal crops of Punjab(Punjab Agricultural University, Ludhiana, 2022) Gurpinder Singh; Sharma, SudhenduThe present study was conducted during the years 2021 and 2022 at Dr Gurcharn Singh Kalkat Laboratories, Entomological Research Farm, Punjab Agricultural University (PAU), Ludhiana and at the farmer‘s fields at Hoshiarpur, Ludhiana and Sri Muktsar Sahib districts. There were a total of three experiments where in diversity of natural enemies associated with Sesamia inferens, parasitism potential of larval parasitoid, Sturmiopsis inferens on S. inferens under laboratory conditions and evaluation of efficacy of Sturmiopsis inferens for the management of S. inferens under field conditions was studied. Among the natural enemies associated with S. inferens, two egg parasitoids (Trichogramma chilonis and Trichogramma japonicum), two larval parasitoids (Sturmiopsis inferens and Cotesia flavipes) and one pupal parasitoid (Tetrastichus israeli) were recorded. Among the three agroclimatic zones; maize, rice and wheat fields at Hoshiarpur harboured higher populations of natural enemies as compared to fields at Ludhiana and Sri Muktsar Sahib. Among different larval instars of S. inferens, the 4th and 5th instar were more suitable for Sturmiopsis inferens with higher per cent parasitism (61-65%), larval survival (50-57%), pupal survival (91-94 %) and more proportion of females in the progeny. Two intervals i.e., one at 10 days and the other at 15 days were followed for releasing different doses of Sturmiopsis inferens during August-October in rice and November-December in wheat. Among different doses (gravid females @ 75, 100, 125, 150 per ha), dose of 150 gravid females per ha showed the highest effect w.r.t. decrease in stemborer incidence and increase in yield over control in basmati rice and wheat and it was statistically at par with the lower dose of 125 gravid female per ha.
