Specific identification, biology and symptoms of whitefly species infesting sunflower in South India

Whitefly species related to sunflower was identified as Bemisia tabaci (Gennadius). Further the identified whitefly species was confirmed to be indigenous B. tabaci on molecular basis by using B-biotype specific SCARs and biological silver leaf assay on sensitive pumpkin (cv Big variety). None of the whitefly samples could positive for the presence of B biotype. The results of the study on the pest life cycle under the laboratory conditions showed that, B. tabaci passed through four nymphal instars before the adult stage. The mean duration values of these stages were 5.6, 4.2, 4.4 and 5.6 days respectively. The total duration of the life cycle of B. tabaci ranged from 23- 42 days at the temperature of 29±2°C with a mean of 34.5. The damage to sunflower crop caused by the whitefly species is discussed with a special emphasis on its ability to transmit leaf curl viral disease

Built in refuge for the management of Pink Bollworm, Pectinophora gossypiella Saunders (Gelichidae: Lepidoptera) in Bt cotton

Field experiment was conducted at the Main Agricultural Research Station, University of Agricultural Sciences, Raichur during 2012-13 to identify and evaluate the suitable refuge strategy systems for pink bollworm resistance management in Bt cotton (Gossypium hirsutum L.) cultivation. The experiment was laid out in randomized complete block design with nine refuge systems : 0 % N-Bt (BIR), 5 % N-Bt (BIR), 10 % N-Bt (BIR), 15 % N-Bt (BIR), 20% N-Bt perimeter refuge, 100% Non Bt, 50% Non Bt, 10% structured refuge and 20% structured refuge as treatments with three replications in replacement series. Significantly lowest incidence (3.55 larvae/plant) and number of bolls with exit holes (11.22) due to pink bollworm was recorded in 0% BIR (41.25 q/ha) followed by 5 % N-Bt (BIR) with yield of 38.74 q/ha and this was on par with 10 % N-Bt (BIR) with yield of 37.79 is next best refuge systems with Bt cotton for higher production and greater economic benefits

1 Studies on Ruthenium and Rhodium Complexes Containing 1,2- bis (N-Methylbenzimidazolyl)Benzene and Catalytic Transfer Hydrogenation

Reactions of ruthenium(III) chloride and rhodium(III) halides with 1,2-bis(N-methylbenzimidazolyl)benzene (N-N) in stoicheiometric amounts in methanol produced binuclear complexes of the compositions [RuCl2(- Cl) (N-N)]2 and [RhX3(N-N)]2. nH2O ( n = 0, X = Br ; n = 1, X = Cl). [RhI3(N-N)]2 was prepared by stirring a mixture of rhodium trichloride with fifteen fold excess of sodium iodide and the N-heterocycle, N-N in methanol. Ruthenium chloride and rhodium halides in 2-methoxyethanol/alcohol reacted with N-N in presence of CO to produce complexes of the types [RuCl2(CO)2(N-N)], [Rh2Cl2(CO)2(N-N)] and [Rh(CO)2(N-N)]Br. The complexes were characterized by elemental analyses, molar conductivity measurements, IR, electronic, 1H- and 13C- NMR spectral studies and by mass spectra. Probable structures have been proposed for the complexes. The complex [RuCl2(-Cl)(N-N)]2 in DMF was found to reduce nitro compounds to corresponding amines using formic acid as the hydrogen donor. Keywords: 1,2-bis(N-methylbenzimidazolyl) benzene, ruthenium and rhodium complexes, carbonyl

Evidence for facultative migratory flight behavior in Helicoverpa armigera (Noctuidae: Lepidoptera) in India

Despite its deleterious impact on farming and agriculture, the physiology and energetics of insect migration is poorly understood due to our inability to track their individual movements in the field. Many insects, e.g. monarch butterflies, Danaus plexippus (L.), are facultative migrants. Hence, it is important to establish whether specific insect populations in particular areas migrate. The polyphagous insect, Helicoverpa armigera (Hubner), is especially interesting in this regard due to its impact on a variety of crops. Here, we used a laboratory based flight mill assay to show that Helicoverpa armigera populations clearly demonstrate facultative migration in South India. Based on various flight parameters, we categorized male and female moths as long, medium or short distance fliers. A significant proportion of moths exhibited long-distance flight behaviour covering more than 10 km in a single night, averaging about 8 flight hours constituting 61% flight time in the test period. The maximum and average flight speeds of these long fliers were greater than in the other categories. Flight activity across sexes also varied; male moths exhibited better performance than female moths. Wing morphometric parameters including forewing length, wing loading, and wing aspect ratio were key in influencing long-distance flight. Whereas forewing length positively correlated with flight distance and duration, wing loading was negatively correlated

Estimation of Aflatoxin Content in Chilli Samples Collected from Cold Storage and Market

Aflatoxins are toxins produced by moulds in food commodities both before and after harvest. After harvest of the produce, if the chilli fruits are not properly dried, it leads to mouldy growth and subsequent aflatoxin production. With regard to influence of storage period on aflatoxin, ten cultivars of chilli at three months interval for a period from Feb 2013 till Nov 2013 varied to an extent of 4.2 µg/kg. Among ten cultivars, Byadagi dabbi varied in aflatoxin content from three months (4.2 µg/kg) to 12 months of storage (2.5 µg/kg) interval. Similarly, cultivar Super 10 had the variation of 1.3 µg/Kg (three months) to 2.3 µg/kg (nine months), Indaf 9 had 3.2 µg/kg and Indaf 5 had 1.5 µg/kg at three month interval. Whereas the aflatoxin was not detected at all in the remaining cultivars viz., Byadagi, Number 5, Namadhari, 355, 009 and 99. Eighteen chilli samples collected from Raichur market and nineteen chilli samples from Byadagi market of Haveri district of Karnataka were analyzed for aflatoxin B1 content by ELISA technique. The average aflatoxin content of samples from Raichur market had very less quantity of aflatoxin (0.35 µg/kg) which was containing less than the permissible limit of 20 µg/kg. Similarly the samples from Byadagi market had an average aflatoxin content of 0.49 µg/kg, much below the permissible limit

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Not AvailableHelicoverpa armigera is a major pest on cotton (Gossypium spp.) and India ranks second in world production of cotton. This pest is highly adapted to different environments and abundance of this pest is due to both abiotic factors and hosts. In this study, the data mining technique based on Shannon information theory has been used for finding the significant factors that affect H. armigera incidence. This has been discussed in detail. The crop stage of cotton, season and abiotic factors like maximum temperature, minimum temperature, morning relative humidity, evening relative humidity, rainfall, number of rainy days in a week, have been considered for the analysis. The results of Shannon information theory showed that among all the factors, crop stage played a major role followed by number of rainy days in a week and relative humidity for the pest incidence and agreed well with correlation analysisNot Availabl

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Not AvailableThe mirid bug, Creontiodes biseratense (Distant) (Hemiptera: Miridae) is as a serious pest of cotton crop. Forecasting model by linking the pest incidence with season, crop phenology, biotic and abiotic factors enable to understand the dynamics of pest occurrence likely to occur. A data mining technique decision tree induction model is proposed for forecasting the pest incidence and study the population dynamics of mirid bug, C. biseratense in relation to its natural enemies viz., spider Lycosa sp. and coccinellid Cheilomenes sexmaculata Fabricius and abiotic factors. The results of the decision tree agreed well with statistical analysis.Not Availabl

Analysis of Soil Microbial Activity and Population in Rhizosphere Soil Exposed to Chlorpyrifos

Chlorpyrifos (CPF) is a popular organophosphorus pesticide that is widely employed in agricultural activities. However, we lack information regarding the relationship between soil microbial activity and population under CPF influence, which prohibits us from measuring CPF's actual impact on soil. In the present study, the effect of chlorpyrifos on soil microbial activity was assessed in an indoor pot experiment. The fertile soil was treated with 500 ppm of commercial-grade chlorpyrifos and paddy seedlings were transplanted. The soils treated with bacterial inoculants showed an increased microbial population on the 30th day after inoculation compared to soil receiving sole chlorpyrifos treatment. The same trend was followed on the 60th & 90th day as well. The combination of inoculants resulted in a maximum increase in the population compared to the single inoculants. As a result, there was an increase in soil enzymatic activities viz. dehydrogenase and phosphatase. Thus, inoculating the pesticide-degrading bacteria would lessen the detrimental effects of pesticides on the soil health

Studies on Reproductive Biology of Yellow Stem Borer, Scirpophaga incertulas Walker (Lepidoptera: Pyralidae) in the Changing Climate Scenario

Studies on reproductive biology of yellow stem borer, Scirpophaga incertulas walker in the changing climate scenario conducted at Agriculture Research Station, Gangavathi during 2020-22.Results on post eclosion behavior of yellow stem borer revealed that the maximum female moths emerged between 18:00 and 21:00 hrs from among the emerged moth the female calling was observed between 23:00 and 02:00 hrs. The time of mating commenced after the calling period and was observed between 23:00 and 03:00 hrs. The average pre-oviposition period, oviposition period and post-oviposition period were completed in 1.09 ± 0.09, 1.28 ± 0.17 and 0.85 ± 0.25 days, respectively. The longevity of adult females and males was about 3.23 ± 0.29 and 2.66 ± 0.33 days, respectively. The total number of eggs laid varied from 68 to 221 in number with an average of 146.95 ± 43.98 per female. The Operational and intrinsic sex ratio of YSB were observed to be female-biased with 1:1.35 and 1:1.44 of male to female moths, respectively

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Not AvailableStudies on the bioefficacy of dinotefuran 20 per cent SG was carried out against Bt cotton sucking pests at 15, 20, 25 and 30 g a.i/ha as compared with standard check viz., imidacloprid 17.8 SL and thiamethoxam 25 WG. Effect of treatments at 3, 7, 10 and 14 days after application differed significantly over untreated control and standard checks. At 3 days after treatment, dinotefuran 20 per cent SG @ 30 g a.i/ha performed significantly superior by recording lowest population of 1.47, 4.72, 9.10 and 0.30 leafhopper, thrips, aphids and whitefly/leaf, respectively. As the observation period progressed the pest populations though started building up, the test compound kept the sucking pest population below ETL up to 14 days. This trend was followed same in second spray also. The chemical dinotefuran 20 per cent SG @ 30 and 25 g a.i/ha dosages did not cause adverse effect on predatory population and recorded highest yield of 27.04 and 24.33 q/ha, respectively.Not Availabl