Loading...
Theses
Browse
9 results
Search Results
ThesisItem Open Access Studies on major lepidopteran pests of mango and their management(Department of Entomology, BAU, Sabour, 2023) Krishna, Hari; Ray, S.N.Mango (Mangifera indica L.) belongs to the family Anacardiaceae. It is known as king of fruits and considered as “National fruit of India” due to its flavour, taste, nutritious value, religious and therapeutic significance. It is widely cultivated in the tropical and subtropical region in the world. Among lepidopteran insect pests of mango, mango leaf webber and fruit borers have become major threats in last few decades in Bihar. The present investigation entitled ‘Studies on major lepidopteran pests of mango and their management’ was conducted in the year 2019-20 and 2020-21 at AICRP mango orchard of Bihar Agricultural University, Sabour. Screening of cultivars, seasonal incidence of mango leaf webber, biophysical and biochemical parameters and management against mango leaf webber and mango fruit borers were carried out on mango cultivars. The mean of two consecutive years regarding screening of cultivars against mango leaf webber suggested that the number of webbed leaves per tree in Baramasia had significantly highest infestation level where as Alphonso recorded second highest infestation which was at par with Fernandin. Regarding the other cultivars, infestation in Dashehari was at par with Bombay, Mulgoa, Bangalora, Bombay Green, Kesar and SB Chausa whereas infestation level in Amrapali was at par with Bangalora, Bombay Green, Gaurjeet, Mulgoa and Prabhashankar. The cultivar Langra was found to be free from the infestation. With respect to direction preference (East, West, North and South), the mango leaf webber preferred the tree canopy of South direction followed by the West and the East direction. Therefore, the study identified the cultivar Langra as resistant to leaf webber whereas Dashehari was found as most susceptible cultivar to this pest. The present study revealed that the cultivar Mahmood Bahar and Prabhashanker were free from the infestation by red banded mango caterpillar during both the studied years. Significantly highest infested cultivar was recorded as Langra (15.90) followed by Zardalu (12.84), Keshar (11.93), Dashehari (13.05) and SB Chausa (10.23). Therefore, the present finding of Langra as highly susceptible cultivar to the RBMC where as Mahmood Bahar and Prabhashanker were free from the fruit borers. The mango leaf webber was found to be highly active (with more than 10 webs/tree) during the July to December. During rest of the periods, relatively lower activity of the pest was there with less than 1 web/tree. There were no active webs from the 2nd fortnight of February to 2nd fortnight of May. Infestation levels of mango leaf webber were different in the cultivars with different tree canopy type. Therefore, probably, the tree canopy type also played a crucial role in having variation in the level of pest infestation. Among the different canopy types (TC1 to TC7), TC3 was least preferred with mean infestation ranging from 0 to 0.61. Cultivars under this category were Prabhashankar (0), Mahmood Bahar (0.03) and Baneshan (0.61). Significant and negative correlation (r = -0.51**) of RBMC was found with peel thickness at fruit tip and significant and positive correlation (r = 45*) was found with seed length of fruits. Rest of the parameters like length of fruits, width of fruits, and width of stone/seed and thickness of mezocarp at fruit tip were not having any significant correlation. It was pertinent to notice that the highly infested cultivar Langra had 0.76 mm peel thickness in contrary to cultivar Prabhashanker (one of the least preferred cultivars) where the peel thickness was 0.86 mm at the fruit tip. The present investigation inferred that the total phenol content and mango leaf webber infestation had significantly negative correlation (r = -0.69) as presented. Significantly higher tannin contents were found in the cultivars namely, Prabhashanker, Baneshan, Mahmood Bahar, Langra and Gourjeet with the values of 17.33, 17.22, 16.67, 16.33 and 15.67 mg/g, respectively in comparison to the cultivars like Baramasia (9.00), Fernandin (9.67), Mulgoa (10.78), Kesar (11.45) and Himsagar (12.11). The formerly mentioned cultivars were among the least preferred whereas the later cultivars were among the most preferred cultivars. This parameter also had significantly negative correlation (r = -0.70) with the leaf webber infestation. The biochemical parameters such as phenol content (mg/g), tannin content (mg/g), reducing sugar (%), total sugar (%) and TSS (%), all measured separately in pulp and seed suggested that correlation coefficient values against RBMC infestation was significantly and negatively correlated with the phenol content in pulp (r = -0.56**) and seed (r = -0.42*). Against mango leaf webber, among the test insecticides, Lambda cyhalothrin 2.5 EC @ 1 ml/litre was found to be significantly superior over the other treatments containing least number of active webs per tree (along with highest percent reduction over control) followed by Indoxacarb 14.5 SC @ 0.5 ml/l of water. Against mango fruit borer complex, Chlorantraniliprole 18.5 % SC @ 0.2 ml/litre was found as the best molecule followed by Emamectin benzoate 5 SG @ 0.2 g/litre and Flubendiamide 20 % WG @ 0.3 g/litre.ThesisItem Open Access Investigation of strains, resistance level and microbial association of Spodoptera frugiperda (Smith)(Department of Entomology, BAU, Sabour, 2022) Sahani, Shrawan Kumar; Saha, TamoghnaThe present experiment was conducted in the laboratory Department of Entomology, Bihar Agricultural University, Sabour, Bhagalpur during the year from 2020 to 2022. The present investigation was aimed with the following objectives namely, (i) to find out the prevalence of strain of Spodoptera frugiperda present in Eastern India, (ii) to study the degree of resistance acquired by Spodoptera frugiperda against selected insecticides, (iii) to find out the association of microbiomes with Spodoptera frugiperda and (iv) detection of larval parasitoid of Spodoptera frugiperda. The fall armyworm (FAW) larvae had identical morphological characteristics and were identified as S. frugiperda. The present study successfully amplified S. frugiperda strains by mtCOI-5 in 18 locations in the eastern part of India (Bihar, West Bengal, Jharkhand and Orissa) and found considerable 12 nucleotide position variations when compared with ‘rice strain’ i.e. (R Strain). Similarly, variations were also observed in nucleotide positions when compared with the "corn strain," i.e. (C strain). Thus, phylogenetic analysis of the 18 fall armyworm samples revealed that the Rstrain predominated over the C-strain in the eastern part of India, with the majority of samples, i.e., twelve samples, showing a closer resemblance to the Rstrain and six samples showing a closer resemblance to the C-strain. In addition to that, the resistance levels of fall armyworm were recorded against different chemistries of newer insecticides with different modes of action. The results revealed that among the different districts of Bihar, the Munger population showed the highest resistance ratio (RR50) to sodium channel modulator groups, namely deltamethrin and lambda cyhalothrin, with 9.33fold and 7.67-fold, respectively. As far as the RR50 level of different insecticides is concerned, among the different insecticides, deltamethrin and lambda cyhalothrin showed maximum resistance, followed by chlorantraniliprole and flubendiamide, while emamectin benzoate, spinosad and spinetoram showed highly toxic, i.e., least resistance, against fall armyworm samples collected from different agro-climatic zones of Bihar. On the other hand, the experimental result revealed the composition of bacterial communities present in the larval gut of S. frugiperda and grouped them into each taxonomic category from phyla to species level. Among them, under the phyla Firmicutes and Proteobacteria, the genera Enterococcus and Klebsiella showed more dominance over other groups of bacteria associated with the different location samples of S. frugiperda. Species-level analyses revealed a total of 33 species of bacteria associated with the gut of S. frugiperda, which were collected from various locations in Bihar, West Bengal, and Jharkhand. Among the 33 species collected from various locations, Enterococcus group species are the most abundant, followed by Klebsiella sp. and Enterobacter sp., with a minor proportion of Raoultella, Citrobacter, Leclercia, and Pantoea genus were also present. As we know, biological control is the most promising and ecofriendly pest management approach in IPM, therefore, an experiment was designed to identify the larval parasitoid of S. frugiperda. The present findings revealed that lab-collected braconid parasitoid was successfully preferred for paralysed, oviposition on the metathoracic sternum of fall armyworm. Furthermore, the mean number of eggs, cocoons, and total braconid wasps emerging were also observed from S. frugiperda larvae. The different morphometric parameters like antennae, total length (mm), length of scape (mm), and width of scape (mm), although measured from single male and female individuals, showed similar trends as previously reported, i.e., the values were numerically higher in males than in females. The habitus photo of the braconid larval parasitoid, as well as the male genitalia, clearly showed its resemblance to the species Bracon (= Habrobracon) hebetor. The molecular characterization also provides strong evidence for the presence of a larval parasitoid, i.e. Bracon hebetor.ThesisItem Open Access Population dynamics and efficacy of biopesticides and entomopathogenic nematodes against Fall Armyworm, Spodoptera frugiperda (J. E. Smith) in Maize(Department of Entomology, BAU, Sabour, 2021-06) Kumar, Pintu; Kumari, KiranMaize is a staple crop in India. The recent invasion of fall armyworm, Spodoptera frugiperda (J. E. Smith) threatens the food security of millions of people. Economic damage in maize is mainly associated with defoliation of the whorl by fall armyworm larvae, although the insect also acts as a ‘cutworm’ by severing the main stem near the crown early in the growing season. It has potential to cause damage up to 100 %. Hence, in light of above facts the present study was undertaken with the following objectives: 1. Population dynamics of S. frugiperda in maize, 2. Comparative efficacy of bio-pesticides against S. frugiperda under laboratory condition, and 3. Bio-efficacy of entomopathogenic nematodes, Steinernema carpocapsae against S. frugiperda under laboratory condition. During the period of investigation it was observed that the initial average population of fall armyworm in the first week of January was 2.05 at 30 days old crop and reached to peak in the first week of March with a mean population of 22.32 at 89 days old crop, thereafter it declined and low population was found throughout the cropping season of Rabi, 2019-20 while, the activity of fall armyworm started in the last week of July with initial average population of 2.52 at 30 days old crop with maximum population in last week of August at 59 days old crop, then declined gradually and remained associated throughout the cropping season of Kharif, 2020. The correlation studies of fall armyworm and abiotic factors during Rabi, 2019-20 revealed that relative humidity was positively associated whereas rainfall and sunshine hours was negatively associated with the population build-up of fall armyworm. However, remaining parameters did not show significant correlation with fall armyworm population. During Kharif, 2020 with regards to the population of fall armyworm not any significant correlation was found with the weather parameters. Further, different bio-pesticides (mycotoxins) at three different doses and one semi synthetic biopesticide were tested against fall armyworm in vitro, the result indicated that the Emamectin benzoate @ 0.4 g/l caused highest per cent mortality (100 %) within 72 hours after treatment application. While, Metarhizium anisopliae @ 7 ml/l caused 100 per cent mortality after 96 hrs of application. Efficiency of entomopathogenic nematode, Steinernema carpocapsae was evaluated at five inoculums levels i.e., 100, 200, 300, 400 and 500 IJs against S. frugiperda. Result showed that Steinernema carpocapsae could bring 100 per cent mortality of S. frugiperda within 72 hrs, applied at 500 IJs/ petri plate. The results revealed that the mortality of S. frugiperda larvae increased due to the increase in the inoculum level and period of exposure up to certain level. The present investigation reflects that the mycotoxins of Metarhizium anisopliae can able to generate toxicity to the larval instars and their detoxifying enzymes could be suitable to replace the toxic chemicals available in the pesticide market. The results also demonstrate the possibility of using the entomopathogenic nematode (EPN) as biological control agents for S. frugiperda. Thus, the fungal bio-pesticide, Metarhizium anisopliae and the entomopathogenic nematode (EPN), Steinernema carpocapsae appeared more effective and can be alternative to chemical pesticide. Hence, these may be incorporated in Integrated Pest Management strategies against S. frugiperda.ThesisItem Open Access Study on soil surface and aquatic macrofauna in rice from rice based cropping system at Sabour(Department of Entomology, BAU, Sabour, 2018-06) Annamalai, P.; Goswami, Tarak NathThe experimental field having the rice based cropping system situated at Sabour (NL 25°14' 3" EL 87°2' 42") and which has been maintained continuously for last six years was chosen for the present investigation. All the recommended package of practices except plant protection measures have been done during the period of investigation. In the present study, the soil surface macrofauna (ground dwelling) as well as aquatic macrofauna (when available) were sampled twice a month during the study period from (July, 2017 to October, 2017). The soil surface and aquatic macrofauna found during the period of present investigation belonged to 42 species, 12 orders under five different classes among which many are going to be reported for the first time from Bihar through this investigation. Identification of two millipede species and one Orthopteran have been possible only at family level only while of two species have possible only at order level. A total of 3148 macrofauna were sampled from the paddy field during mentioned period of investigation. These whole sampled macrofauna under different insect and non insect orders indicated that the order Coleoptera recorded the highest number of individuals (957, 30%) which was followed by Littorinimorpha (Gastropoda) (740, 23%), Hymenoptera (728, 23%), Araneae (Arachnida), Hemiptera (Insecta), Polydesmida (Diplopoda), Hygrophila (Gastropoda), Orthoptera (Insecta), Dermaptera (Insecta), Caenogastropoda (Gastropoda) and Stylommatophora (Gastropoda). Coleopterans in the present investigation during the period of observation belonged to eleven families namely, Chrysomelidae, Hydrophilidae, Dytiscidae, Anthicidae, Carabidae, Staphylinidae, Malachiidae, Curculionidae, Tenebrionidae, Elateridae and Limnichidae. As far as the total numbers of individuals belonging to different families were concerned, the family Chrysomelidae was having the highest number (321) followed by Dytiscidae (252), Limnichidae (98), Hydrophilidae (97), Carabidae (50), Staphylinidae (31), Anthicidae (28), Elateridae (28), Curculionidae (19), Tenebrionidae (19) and Malachiidae (14). Individuals belonging to the family Chrysomelidae in most of the cases were having significantly higher level of population in the zero tillage plots. Regarding the aquatic macrofauna the family Gerridae was having the highest number (128) followed by Hydrometridae (33) and Nepidae (15). The Limnogonus nitidus population was significantly higher in the zero tillage plots as compared to the conventional tillage and permanent bed method. The other soil surface dwelling and aquatic macrofauna except Garstropoda and Diplopoda in most of the cases were found in higher level in the zero tillage plots. However, the cropping systems and the interaction on majority of the studied macrofauna did not show any significant differences.ThesisItem Open Access Distribution pattern and life table of stem borer Chilo partellus(Swinhoe) on maize(Department of Entomology, BAU, Sabour, 2017-07) Kumar, Devbrat; Kumari, KiranMaize (Zea mays L.) is a cereal grain, called “queen of cereal”. It is the third important cereal crop in India after rice and wheat with a share of 10 percent in total cereal production, occupying an area of 9.60 million ha with production of 26.0 million tonnes in which Bihar is contributing an area 0.70 million ha and production 2.05 million tonnes.Maize has a loss of 20 percent in yield due to insect damage. It is damaged by a large number of insect pests at different stages of crop growth. Among the insect pests, maize stem borer (ChilopartellusSwinh.) is a key pest causing losses to grain yield, which ranged between 24.3 and 36.3 percent in different agro climatic regions of India (Bhanukiran and Panwar, 2000).Keeping all these in view, the present investigation was aimed to study on “Distribution pattern and life table of stem borer Chilopartellus (Swinhoe) on maize” with the objectives: i.Seasonal Incidence of Chilopartelluson maize,ii. Determination of distribution Pattern of C. Partelluson maize, and iii. Life table study of C. Partelluson maize. The study on seasonal incidence of stem borer, C. partellusand its relationship with abiotic factors during Kharif and Rabi season, 2016-17 revealed that the incidence of stem borer started (1.67 and 2.51 percent dead heart) in the second week of July at 15 days and last week of November at 21 days old crop age, respectively and reached to its peak ( 16.67 and 11.00 percent dead heart) in the last week of August and third week of February at 57 days and 110 days old crop age during the experimentation period, respectively. Afterwards, the incidence of maize stem borer had declined gradually. The correlation studies of dead heart infestation and abiotic factors during Kharif,2016 showed that the maximum temperature was positively non-significantly correlated and minimum temperature and sunshine hours were positively significantly correlated while rainfall and relative humidity were negatively non-significantly correlated with dead heart infestation.Correlation studies for Rabi season, 2016-17 showed that the maximum temperature was positively significantly correlated, minimum temperature and sunshine hours were found to be positively non-significantly correlated while relative humidity was negatively significantly correlated with the dead heart infestation. The egg distribution within plant showed more number of eggs(107±0.55) on first leaf sheath followed by second leaf sheath (75.33±1.72) and least number on basal leaf sheath (47.10±0.55). The total oviposition period was observed to be five days with average fecundity as 220±3.76 per female moth. The distribution pattern of larvae was found in scattered fashion from seedling to initial vegetative phase of the crop while at the age of 22 to 71 days its distribution pattern was found contagious in nature. Life table study revealed that 42 percent mortality of eggs due to unknown factors whereas, 19.54 percent failed to hatch, 37 percent larval mortality was due toparasitization and 16.07 percent died due to unknown factors. Percentage mortality of pupae was 11.76 due to diseases while 15.38 percent failed to emerge into moths. Thus due to effect of biotic and abiotic factors the total mortality (K value) of Chilopartelluswas 0.88.ThesisItem Open Access Insect pest complex of linseed and management of Dasyneura lini Barnes(Department of Entomology, BAU, Sabour, 2017-07) Kunal, Gautam; AnilThe investigations on insect pests of linseed and management of D. lini were conducted at Experimental Farm, Bihar Agricultural University, Sabour during Rabi season of 2016-17. A total of nine insect pests (D. lini, Thrips palmi Karny, Frankliniella schultzei (Trybom), Agrotis ipsilon Hufnage, Helicoverpa armigera Hübner, Spilosoma obliqua Walker, Monolepta signata Olovier, unidentified aphids and wire worm) and four natural enemies (Coccinella septumpunctata L., Menochilus sexmaculatus (Fabricius), Oxyopes sp. and Paederus sp. were found to be associated with linseed. The highest population of A. ipsilon (1.00 larva/m2) and thrips (26.60 nymphs & adults/plant) were observed during 52nd and 9th SMWs, respectively. However, the highest population of aphids (2.40 aphids/plant), Helicoverpa (1.00 larvae/m2), Oxyopes (1.00 spider/plant) and coccinellids (1.0 coccinellid/plant) were observed during 8th SMW. Similarly, the maximum fresh bud fly infestation (6.12%) was also recorded during the 8th SMW. Minimum temperature had positive correlation (P=0.01) with the population of A. ipsilon, H. armigera and cumulative bud fly infestation, whereas maximum temperature showed positive correlation (P=0.01) with cumulative bud fly infestation. Minimum relative humidity and population of A. ipsilon were found to be positively correlated (P=0.01), whereas maximum relative humidity had negative correlation (P=0.01) with H. armigera and cumulative bud fly infestation. Out of 101genotypes screened for resistance against the infestation of D. lini, 12 genotypes were categorized as resistant, 65 as moderately resistant, 17 as moderately susceptible, 05 as susceptible and 02 as highly susceptible. The field trial on different dates of sowing revealed that the infestation of D. lini increased and yield decreased in all five tested varieties in progressive manner with delay in date of sowing. The lowest mean bud fly infestation (13.39%) and highest mean yield (1385.30 kg ha-1) was obtained with the crop sown on 08.11.2016, whereas the highest mean bud fly infestation (37.46%) and lowest mean yield (177.75 kg ha-1) was obtained with crop sown on 08.01.2017. The application of insecticides showed significant reduction in bud fly infestation and increased yield over untreated check. The minimum bud fly infestation (8.25%) was recorded with the application of fenvalerate 20 EC being at par with imidacloprid 17.8 SL (8.57%) followed by spinosad 45 SC (9.87%) at 15 days after second spray. Among the insecticides/bio-pesticides, the maximum infestation (16.26%) was recorded with neem leaf extract followed by fipronil 5 SC (12.31%) and dimethoate 30 EC (10.87%). The maximum incremental yield (5.21 q ha-1) was obtained with fenvalerate followed by imidacloprid (4.54 q ha-1) and spinosad (3.29 q ha-1). However, the minimum incremental yield (0.39 q ha-1) was obtained with neem leaf extract followed by fipronil (2.05 q ha-1) and dimethoate (3.06 q ha-1). The maximum benefit-cost ratio (15.12:1) was obtained with fenvalerate followed by imidacloprid (11.47:1) and dimethoate (5.92:1). However, minimum benefit-cost ratio (0.30:1) was obtained with neem leaf extract followed by fipronil (1.42:1) and spinosad (1.86:1).ThesisItem Open Access Morphological identification of cucurbitaceous fruit flies in Bihar and genetic diversity of Bactrocera cucurbitae(Department of Entomology, BAU, Sabour, 2017-07) Singh, Maneesh Pal; Saha, TamoghnaCucurbits are the major vegetable crops belonging to the family Cucurbitaceae, primarily comprising species consumed as food worldwide. The family consists of about 118 genera and 825 species (Prabhakar et al., 2012). In Bihar major growing cucurbits including bottle gourd, pointed gourd, bitter gourd and ash gourd. The production of cucurbits is hindered due to several factors like insect pests and diseases and out of those; fruit flies are one of the major limiting factor of cucurbits production occurring not only in Bihar but also in India. In India, fruit flies have been identified as one of the ten most serious problems of agriculture, because of their polyphagous nature and causes a huge economic loss to fruits and vegetables which varies from 2.50 -100 per cent depending upon the crop and season (Dhillon et al., 2005). There are approximately 4,500 species of fruit flies (Tephritidae) represented one of the largest families of Diptera and at around 243 species of fruit flies were recorded from India (Agarwal and Sueyoshi, 2005). Among those, Bactrocera cucurbitae, B. tau and Dacus ciliatus are the most diverse. Fruit flies are indeed the excellent candidates for studies on biodiversity, adaptability in changing climate and invasion to new areas because of their capability of flying long distances, polyphagous in nature, vast host range, homoplasmy in taxonomic characters, high reproductive potential, wide range of distribution due to their high adaptability and great economic importance as a pest. Proper insect pests’ management leads to better production in agroecosystem and a better management practice not supposed to be completed without proper identification of a particular pest. Therefore, the present investigation was conducted to study the morphological identification of predominant cucurbitaceous fruit flies and to find out the genetic diversity of Bactrocera cucurbitae through gene specific marker. After a roving survey at four different agroclimatic zones of Bihar, it was observed that a total of six major fruit fly species associated with cucurbitaceous crops viz. Bactrocera. (Zeugodacus) cucurbitae (Coquillett), B. (Z.) tau (Walker), B. (Z.) caudata (Fabricius), B. (Bactrocera) nigrofemoralis White & Tsuruta, B. (Hemigymnodacus) diversa (Coquillett) and Dacus (Didacus) ciliates Loew. Their distribution pattern in different agroclimatic zones with their associated hosts was also recorded. The collected fruit fly species were identified taxonomically according to keys provided by White and Elson-Harris, 1992 and Drew and Raghu, 2002. Significant achievements of our studies were i. Bactrocera (Bactrocera) nigrofemoralis White & Tsuruta will be the first report from Bihar as new fruit fly species and also identified new host of Dacus (Didacus) ciliatus Loew, Bactrocera (Hemigymnodacus) diversa (Coquillett) from pointed gourd and flowers of Cucurbita moschata respectively. On the basis of amplified PCR product of DNA of B. cucurbitae, the expected product length of MCOX-I gene was 700 bp and the product obtained was nearly between 700 to 750 bp. The expected product length of MCOX-II gene was 600 bp and the product obtained was nearly between 500 to 600 bp. It revealed that there were not much difference in the banding pattern but very small difference noticed in the bands and which would be helpful for future studies in molecular diversity analysis after getting complete sequencing.ThesisItem Open Access Studies on seasonal incidence of insect-pests and pollinators in guava and eco-friendly management of fruit fly(Department of Entomology, BAU, Sabour, 2016-09) Kumar, Chandan; Ray, S. N.The Guava (Psidium guajava) belongs to the family of Myrtaceae. It is a very rich source of vitamin C (Mahmood, 1994). Guava, the “poor man’s fruit” or “apple of the tropics” was a popular tree fruit of the tropical and subtropical climates. About 80 species of insects have been recorded on guava trees, affecting yield and quality of fruits. Fruit flies, castor capsule borer, mealy bug, whiteflies and coccids (scale insects and mealy bugs) are considered as major pest of guava, while aphids, thrips, cockchafers, stem borers and fruit borers, etc., are the minor pests (NHM, 2012). The infestation of fruit fly is a major limiting factor in production of guava. Apart from these pollinators are also playing an important role in the production of guava. Considering the above background information in view, the present experiment was undertaken on “Studies on seasonal incidence of insect-pest and pollinators in guava and eco-friendly management of fruit fly” with the objectives i. To study the seasonal infestation of insect-pests of guava, ii. To record the diversity and activity of pollinators in guava and iii. To evaluate different traps for fruit fly management. The incidence of fruit flies was recorded as high as from second week of June to August and the peak population was recorded at 32nd standard week (August). Among different species of Bactrocera, the highest population was recorded with B. dorsalis followed by B. zonata and B. correcta. The incidence of mealy bug was observed as high as from second fortnight of January to second fortnight of February, while castor capsule borer peak incidence was recorded at 49th standard week (December). Regarding diversity of pollinators are concerned, a total of four species of Apis were observed in the field pollinating the guava flower namely Little bee, Apis florea; Rock bee, A. dorsata, Italian bee, A. mellifera, Indian bee, A. cerena indica. In addition to, coccinellid and hover fly were also observed in the flowers of guava. A. mellifera was recorded as the most abundant pollinator of guava flowers based on the number of visit observed. The maximum pollinators were visited the guava flowers during 0700 hr followed by 1000 hr. Three traps viz: Sabour trap, Water trap and Nomate trap along with untreated control were taken for the management of fruit flies. Among the traps, Sabour trap performed well as compared to other traps based reduction of fruit damage both wt. and no. basis and simultaneously obtained highest yield as compared to others. The highest cost-benefit ratio was obtained with Sabour trap (1:18.71) followed by water trap (1:8.97).ThesisItem Open Access Population dynamics and management of yellow stem borer, Scirpophaga incertulas (Walker) in aromatic rice(Department of Entomology, BAU, Sabour, 2016-09) Patel, Vikas Kumar; AnilScirpophaga incertulas (Lepidoptera: Pyralidae) is one of the major insect-pests causing serious losses in rice and the incidence of insect-pests is comparatively more in aromatic rice. The investigation on population dynamics and management of S. incertulas in aromatic rice was conducted during Kharif, 2015. The adults of S. incertulas were found to be active during 29th to 44th standard meteorological weeks (SMWs), whereas infestation was noticed during 34 to 44 SMWs. The maximum pheromone trap catch (9.80 moths/trap/week) and light trap catch (46.00 moths/trap/week) were obtained during 38th SMW. Temperature (maximum & minimum), relative humidity (maximum & minimum and rainfall were found to be positively correlated with the population dynamics of S. incertulas, whereas Sunshine hours were found to be negatively correlated. All the insecticides were found to be superior in efficacy over the untreated check. Chlorantraniliprole 18.5 SC was proved to be the most effective insecticide which resulted in 4.45 per cent dead heart (DH) and 5.55 per cent white ear head (WEH) followed by fipronil 5 SC (4.79% DH, 5.92% WEH) and cartap hydrochloride 50 SP (5.09% DH, 6.74% WEH). Moderate level of efficacy (5.47% DH, 6.93% WEH) was obtained with flubendiamide 20 WG followed by indoxacarb 15.8 EC (5.65% DH, 6.97% WEH) and spinosad 45 SC (5.90% DH, 7.03% WEH). The lowest level of efficacy (7.44% DH, 8.30% WEH) was recorded in novaluron 10 EC followed by monocrotophos 36 SL (6.87% DH, 7.70% WEH) and triazophos 40 EC (6.61% DH, 7.48% WEH). Being at par with each other, all the insecticides were found to significantly reduce the mean population of natural enemies after first and second sprays over the untreated check and. Monocrotophos was found to be the relatively less toxic to the spiders followed by flubendiamide/fipronil and triazophos, whereas ii chlorantraniliprole and indoxacarb were found to be the more toxic to the spiders followed by spinosad and novaluron. However, spinosad was found to be less toxic to the dragonflies and damselflies followed by novaluron and cartap hydrochloride. Monocrotophos was found to be more toxic to the dragonflies and damselflies followed by fipronil and chlorantraniliprole. The order of persistent toxicity against neonate larvae of S. incertulas was observed as chlorantraniliprole > fipronil > flubendiamide > cartap hydrochloride > indoxacarb > triazophos > monocrotophos = spinosad > novaluron. The maximum incremental yield (6.30 q ha-1) was obtained with chlorantraniliprole followed by fipronil (5.99 q ha-1) and cartap hydrochloride (5.49 q ha-1). The minimum incremental yield (4.17 q ha-1) was obtained with novaluron followed by monocrotophos (4.32 q ha-1) and triazophos (4.50 q ha-1). However, the maximum cost-benefit ratio (1:3.05) was obtained with triazophos followed by fipronil (1:2.12), monocrotophos (1:2.09) and cartap hydrochloride (1:2.07). The cost benefit ratio was lowest (1:0.02) with novaluron followed by spinosad (1:0.42) and chlorantraniliprole (1:0.74).
