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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.
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Selective breeding for less stinging trait in Apis mellifera Linnaeus colonies
(Punjab Agricultural University, 2022) Madaan, Anmol; Mohindru, Bharthi
Studies 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.
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Diversity, seasonal incidence and damage assessment of Oxycarenus spp. on cotton
(Punjab Agricultural University, 2023) Noor Mahammed N R; Pandher, Suneet
The 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.
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Management of Pyrilla perpusilla (Walker) with ecto-parasitoid, Fulgoraecia melanoleuca (Fletcher) on sugarcane
(Punjab Agricultural University, 2022) Augustine, Neethu Maria; Shera, P S
The 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.
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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.
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Biocontrol of pink stem borer, Sesamia inferens (Walker) in major cereal crops of Punjab
(Punjab Agricultural University, Ludhiana, 2022) Gurpinder Singh; Sharma, Sudhendu
The 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.
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Morphometric and molecular characterization of bees in Punjab (India)
(Punjab Agricultural University, Ludhiana, 2022) Mehakpreet Kaur; Choudhary, Amit
Studies on ‘Morphometric and Molecular Characterization of Bees in Punjab (India)’ were con ducted at Punjab Agricultural University, Ludhiana (India), during 2020-22. Investigations were carried out on diversity of the bee fauna and their relative abundance in six agro-climatic regions viz., Sub-Mountain Undulating region, Undulating Plain region, Central Plain region, Western Plain region, Western region and Flood plain region (Bet) over various seasons viz., Spring, Summer, Monsoon, Autumn and Winter. Morphological (40 morphometric characters) and molecular (cox1 gene) characterization of recorded bee species was also done. A total of thirty bee species were identified out of forty-nine bee species collected from Punjab. Among the various agro-climatic regions, Sub-Mountain Undulating and Undulating Plain regions were having the highest bee diversity index i.e. Shannon diversity index as 3.05 and 3.04, respectively. The lowest bee diversity index was recorded in Western region (2.66). Among the various seasons, the highest bee diversity was recorded in the summer season (2.84) followed by autumn (2.67) and spring (2.63) seasons while it was the lowest in winter (1.37) season. The family Apidae contributed the maximum abundance (>40%) across six agro-climatic regions and different seasons. In all the identified thirty bee species, six new bee species falling under three families have been recorded from Punjab for the first time viz., Amegilla cingulata, Bombus haemorrhoidalis, Halictus propinquus, Lipotriches fulvinerva, Nomia crassipes and Megachile binghami. The Bray-Curtis analysis showed the lowest dissimilarity index (0.23) between the spring and summer season. The dissimilarity indices of autumn season with summer and monsoon seasons were 0.34 and 0.24, respectively. The Bray-Curtis dissimilarity Index for different agroclimatic regions showed the lowest dissimilarity index between the Sub-Mountain Undulating region and Undulating Plain region (0.09). The highest dissimilarity indices i.e 0.39 and 0.38 were of Western region with the Sub-Mountain Undulating region and Undulating Plain region, respectively. The 40 morphological characteristics recorded for the thirty bee species revealed significant differences within and across the family groups. All the identified thirty bee species were subjected to mitochondrial cytochrome c oxidase (cox1) gene and the sequences were submitted to NCBI Genbank. The Genbank database was enriched with the submissions of eight gene sequences of Ceratina hieroglyphica, Halictus propinquus, Nomia westwoodi, Lipotriches fulvinerva, Ceylalictus punjabensis, Coelioxys decipiens, Megachile binghami and Andrena aegyptiaca for the first time. The relationships between bee species in respective families viz. Apidae, Halictidae and Megachilidae were highlighted through the construction of phylogenetic tree based on cox1 gene sequences. Present study generated a database on identified thirty bee species present in six agro-climatic regions of the Punjab state. Still, there is need to carry out further studies. Their detailed morphometric characterization and DNA barcodes will help the researchers to identify a species more accurately. This study will also help in studying the change in the apoid assemblage in the future.
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Bee venom collection and its impact on behaviour and productivity of Apis mellifera Linnaeus colonies
(Punjab Agricultural University, Ludhiana, 2022) Sidana, Vishal; Jaspal Singh
The study on ‘Bee venom collection and its impact on behaviour and productivity of Apis mellifera Linnaeus colonies’ was carried out during four seasons (monsoon and autumn in 2021, spring and summer in 2022) at Apis mellifera Apiary of Punjab Agricultural University, Ludhiana. The results revealed that the mean quantity of bee venom collection using bee venom collector model DPS-BVC01 (11.84, 18.98, 17.52 and 8.27 mg/colony/exposure during spring, summer, monsoon and autumn, respectively) was significantly higher from than with model Bee Whisper 5.0 (1.19, 2.13, 1.78 and 0.98 mg/colony/exposure in the corresponding seasons, respectively). Colonies of 16 bee-frame strength yielded significantly higher mean quantity of bee venom (8.05, 13.24, 12.62 and 5.17 mg/colony/exposure in the corresponding seasons, respectively) than 8 bee-frame strength colonies (4.90, 8.17, 6.68 and 4.07 mg/colony/exposure during spring, summer, monsoon and autumn, respectively). Increase in exposure period from 30 to 60 min significantly increased bee venom collection from 5.66, 8.70, 8.49 and 4.04 mg/colony/exposure to 7.37, 12.71, 10.82 and 5.20 mg/colony/exposure during spring, summer, monsoon and autumn, respectively. Mean adult mortality was significantly low during all the four seasons (< 2 bees/colony/exposure). Mean reduction in unsealed brood rearing by 7.90, 12.47, 13.74 and 12.70 per cent and capped brood by 5.26, 9.78, 10.42 and 9.17 per cent over control was recorded in A. mellifera colonies used for bee venom collection over the four seasons. Brood survival of the exposed colonies decreased by 1.72, 2.20, 6.19 and 5.45 per cent during spring, summer, monsoon and autumn, repectively over control. Bee venom collection impacted bee population by 1.63, 3.79, 4.27 and 1.60 per cent during spring, summer, monsoon and autumn, respectively. There was significant reduction in mean nectar foraging per min after one day of venom collection by 12.60-13.31, 16.46-16.68, 13.94-13.29, 15.75-19.27 per cent and pollen foraging by 19.23-19.72, 28.93-28.07, 33.81-30.00, 36.5630.43 per cent during spring, summer, monsoon and autumn, respectively. However, pollen and nectar foraging after three days of venom collection had been on par with pre venom collection data. Bee venom collection resulted in significant reduction in honey stores by 13.25, 14.29, 24.82 and 11.77 per cent and pollen stores by 7.69, 12.71, 20.67 and 8.83 per cent during spring, summer, monsoon and autumn, respectively. However, defensiveness of colonies one day after the venom collection increased by 9.16, 8.67, 10.34 and 11.15 per cent over pre-venom collection. Collection of bee venom from A. mellifera colonies for 60 min at weekly interval using DPS-BVC-01 resulted in improving hygienic behaviour over control by 14.48 and 18.22 per cent during spring and summer seasons, respectively. Providing pollen (100 g/colony/week) or PAU pollen subsititute (100 g/colony/week) along with sugar solution (50:50 w/w, 500 ml/colony/week) to A. mellifera colonies during floral dearth of monsoon resulted in 4.03 and 2.96 times more bee venom collection over control colonies. In view of all the factors and economics, it is concluded to use eight bee-frame strength A. mellifera colonies for weekly collection of bee venom with venom collector model DPS-BVC-01 (run once for 60 min/week).
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Studies on persistence of fenazaquin and spirotetramat in chilli and soil.
(Punjab Agricultural University, Ludhiana, 2022) Himani; Mandal, Kousik
Trials were conducted for two years for studying the dissipation and persistence of fenazaquin and spirotetramat in chilli and soil following application of Fenazaquin 10 EC @ 125, 156.25 and 250 g a.i. ha-1 and Spirotetramat 15.31 OD @ 60, 75 and 120 g a.i. ha-1. The limit of quantification (LOQ) and (LOD) were 0.01 and 0.003 mg kg-1. The residues of fenazaquin dissipated more than 90 per cent in 20 and 10 days in green chilli and soil, respectively at recommended dose. The residues of spirotetramat and its metabolites reached below the LOQ after 15 and 3 days in green chilli and soil, respectively at the recommended dose. Waiting period was calculated to be 3, 5 and 8 days for green chilli after application of fenazaquin at the 125, 156.25 and 250 g a.i. ha1 . One day waiting period is estimated after treatment of green chilli with spirotetramat at the three doses. The processing factor for fenazaquin residues in red chilli after dehydration was estimated to be 2.08 at recommended dose for both the years. Dipping of chilli fruits in baking soda (5%) and boiling proved effective in reducing the residues of fenazaquin and spirotetramat. The activity of the amylase, invertase, acidic phosphatase was not affected by these pesticides while the dehydrogenase activity was reduced. The activity of the alkaline phosphatase and urease was affected after the application of fenazaquin and spirotetramat.

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