Viable mass production method for cotton pink bollworm, Pectinophora gossypiella (Saunders)

AbstractCotton seed based artificial diet has been standardized for continuous rearing of pink bollworm Pectinophora gossypiella (Saunders) at the Central Institute for Cotton Research, Regional Station, Coimbatore. The ingredients of the diet are easily available and are cost effective. Basic ingredients of the diet are cotton seed flour (processed) and chick pea flour, Carbohydrate, Protein, Fat sources, multi vitamin, antimicrobial agents and agar as thickening agent are used as other ingredients. Micro centrifuge tubes with lid were used as rearing containers. Individual neonate larvae were released on each piece of the diet inside the micro centrifuge tube and the lids were closed. This prevented larval escape, retaining them inside the tubes and also prevented diet dehydration. The recovery of insect reared on diet was recorded as 95.56%. Egg hatchability and adult emergence were 100% while pupal malformation was nil. Eggs, larval and pupal periods were recorded as 4.8±0.632, 25.10±0.994 and 7.9±0.88days, respectively. Larval and pupal weights were recorded as 21.40mg±3.63, 18.00mg±2.73, respectively

Relative toxicity of insecticides against cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera:Pseudococcidae) and its fortuous parasitod Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae)

Nineteen insecticidal formulations from 10 groups of insecticides were evaluated for their relative toxicity against cotton mealybug Phenacoccus solenopsis Tinsley and its fortuous parasitoid Aenasius bambawalei Hayat. Insects were exposed to cotton leaves dipped in insecticidal solutions and their mortality was recorded at 24-h intervals. Within 24 h of exposure, Quinalphos, Chlorpyriphos, Thiamethoxam and Profenophos have detrimental effect on both P. solenospis and A. bambawalei recorded more than 70% mortality. Thiodicarb was extremely toxic to P. solenopsis and least toxic to A. bambawalei where as Spinosad was less toxic to P. solenopsis and extremely toxic to A. bambawalei. Profenophos, Thiamethoxam and Chlorpyriphos results into > 90% mortality of P. solenospsis while 100% kill of A. bambawalei with Spinosad, Acephate and Chlorpyriphos up to 48 hours. More than 80% mortality of P. solenopsis with Chlorpyriphos, Profenophos, Monocrotophos, Thiamethoxam, Spinosad and of A. bambawalei with Profenophos, Monocrotophos, Flonicamid, Buprofezin, Imidacloprid, Thiamethoxam, Chlorantraniliprole, Flonicamid and Indoxacarb recorded 72 hours after exposure. While at 96 hours, cent per cent mortality of P. solenopsis was recorded with Monocrotophos which was equivalent to Acephate and Spinosad. Least LT50 values were found with Thiodicarb, Quinalphos and Thiamethoxam for P. solenopsis and higher in case of Thiodicarb for A. bambawalei. Spinosad, Chlorpyriphos and Quinalphos were found to be extremely toxic to A. bambawalei. Among the tested insecticides Thiodicarb was found effective against P. solenopsis and relatively safer to A. bambawalei may be used judiciously to manage P. solenopsis that have least implications on the environment

Cotton Biotechnology

Biotechnological advances have now become integral to all crop improvement strategies designed to cater to the ever-increasing challenges of the burgeoning population. Problems in cotton sustenance and development have always been a challenge to the researcher. Over the past two decades biotechnology has offered a tremendous scope primarily in the form of creating novel transgenic plants to combat biotic and abiotic stresses and molecular markers that can aid in the quicker selection of parents and progeny in conventional breeding programmes aimed at crop improvement. This bulletin makes an attempt to familiarise the reader with some basic aspects as well as the status and prospects of biotechnological research in cotton. Dealt with, in two parts the first concentrates on the development of transgenic cotton while the next focusses on the potential of biotechnological methods to assist breeding.Not AvailableNot Availabl

Overexpression of cytochrome P450 CYP6B7 mediated pyrethroid resistance in Indian strains of the cotton bollworm, Helicoverpa armigera (Hübner)

The role of cytochrome P450 monooxygenase in pyrethroid resistance was studied in different strains of the cotton bollworm, Helicoverpa armigera, from India. Filed collected strains of Nagpur and Delhi were compared to the laboratory reared population. The results showed a high resistance to deltamethrin, α-cypermethrin, and β-cyfluthrin. The results also showed that this resistance could be reduced by using piperonyl butoxide (PBO). The Nagpur and Delhi strains were found to have a 2.40 and 1.79 fold higher monooxygenase activity compared to a susceptible strain. A strong, positive correlation between monooxygenase activity and pyrethroid resistance was observed (r = 0.86 - 0.98). The relative expression of the housekeeping gene, EF-1α, and three P450 genes, was studied in the 5th instar larval midgut of the three strains. Out of the three P450 genes examined, expression of CYP6B7 mRNA was not detected in the midgut of the susceptible strain though it was highly expressed in the resistant strains. The midgut of the Nagpur strain had a 2.60 fold overexpression of CYP6B7 mRNA compared to the moderately resistant, Delhi strain. The mRNA of CYP4G8 and CYP6B2 were not overexpressed in either the Nagpur or Delhi strain. The results indicated that the elevated cytochrome P450 monooxygenase activity is associated with pyrethroid resistance in Indian strains of H. armigera, and CYP6B7 could be the P450 form responsible for pyrethroid resistance

Development of a colloidal-gold based lateral-flow immunoassay kit for ‘quality-control’ assessment of pyrethroid and endosulfan formulations in a novel single strip format

A simple lateral-flow immuno-chromatographic ‘dipstick’ kit was developed in a novel single strip format to test/verify the label claim of active ingredient in commercial insecticide formulations of endosulfan and the type-II synthetic pyrethroids, cypermethrin, deltamethrin and fenvalerate. Polyclonal antisera were raised in rabbits against immunogens developed by conjugating proteins (bovine serum albumin, BSA and keyhole limpet hemocyanin, KLH) to endosulfan-diol, 4′-hydroxy-cypermethrin and 2′-hydroxy-cypermethrin using an activated ester method through a spacer attachment. Immunoglobulin (IgG) was purified through protein-A affinity chromatography and conjugated to horse radish peroxidase (HRP) and colloidal gold. A competitive ELISA was designed to determine the ability of the test insecticides to compete with the relevant hapten–protein conjugate. A combination of antiserum-4′-OH-Cyper-KLH with the 4′-OH-Cyper-BSA as coating hapten resulted in the highest absorbance (Amax: 1.32) low background value (Amin: 0.05) and good competitive inhibition with cypermethrin (IC99: 2034 μg/L), deltamethrin (IC99: 2297 μg/L) and fenvalerate (IC99: 3546 μg/L). For endosulfan, a combination of antiserum raised against endosulfan-KLH with endosulfan-BSA as the coating hapten gave the highest absorbance (Amax: 1.42), low background value (Amin: 0.05) and good competitive inhibition with endosulfan (IC99: 2378 μg/L). A novel format was designed using the combinations for development of the lateral-flow strip, so as to enable the detection of pyrethroids and endosulfan on a single strip. The strips were designed such that two intensely coloured purple lines appeared when the strip is dipped in a solution devoid of any insecticide. The minimum concentration of the test insecticides, endosulfan (1800 μg/l), cypermethrin (800 μg/l), deltamethrin (1000 μg/l) and fenvalerate (1400 μg/l) was determined, which would be adequate to inhibit the appearance of either of the two lines, when the strip is dipped in a solution containing any one of the diluted insecticides prepared from authentic insecticide formulations. When samples of substandard insecticide formulations are diluted as per the pre-determined dilutions, the aliquots are expected to contain less than the quantity specified above, and would result in the appearance of two purple lines, with one of them at the sample line region of the membrane, the intensity of which would be inversely proportionate to the concentration of the test analyte. The strip can be considered as suitable for on-the-spot analysis of test sample formulations either by farmers, extension workers, quality control officials etc., to generate preliminary prima facie evidence in case of doubtful samples of substandard insecticide formulation

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Not AvailableBulletin documents the host plants of cotton mealybug in India and makes a comprehensive analysis that leads to the overall and zone specific information on host plant diversity along with their location in the agro ecosystem. Large number of off season hosts have been documented. Extreme severity of the pest on ornamental and vegetables in urban landscapes/backyards support evidences of invasion. Elucidated information for the location of host plants on road side and field borders in all cotton agro ecosystems largely contributing to pest build up is a revelation enforcing the essential practice of off field sanitation.Not Availabl