K. Sahayaraj
Sahayaraj Kitherian, Ph.D., D.Sc., is an Associate Professor and Head at the Department of Zoology, St. Xavier’s College of Manonmaniam Sundaranar University and a Director in the Crop Protection Research Centre in the same institution since the June 1998. Sahayaraj Kitherian received his undergraduate, post-graduate and doctoral educations at the Madurai Kamaraj University, India. Prior to his current position, he was a lecturer in the St. Joseph’s College, Trichy from 1993 to 1998. He previously held appointment at the Arulanadar College, Madurai, India. Over the past 30 years, Dr. Sahayaraj’s research efforts have been dedicated to multidisciplinary, integrated approaches to understanding how reduviids distribute and diversify in various ecosystems, and how their adaptive characters can be applied to pest management, especially through biointensive pest management. Dr. Sahayaraj has over 200 scientific papers published. He is an internationally recognized expert in many areas of advanced entomology including insect chemical ecology, artificial diet formulation, biopesticide formulation, biointensitve integrated pest management, bionanomaterial, and insect molecular biology. He is a regularly sought after and requested lecturer at the majority of science colleges at Tamil Nadu, India. Dr. Sahayaraj organized four international conferences (BIOCICON) and seven more national conferences. Dr. Sahayaraj is the Editor–in-Chief of the Journal of Biopesticides and also Editor for more than 10 reputed peer-reviewed journals. Reviewer of more than 15 journals, particularly Entomotropica, journal of Insects, Pest Management Sciences, Pesticide Biochemistry and Phytochemistry, Photobiology B: Biology etc. Recent publications of Dr. Sahayaraj deals with essential oils, seaweeds, reduviid predators, fungi for pest management
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wide range of insect pests. We investigated the responses of R. marginatus to six species of cotton pests: Spodoptera litura (F.),
Sylepta derogata (F.), Pericallia ricini (F.), Mylabris indica (Thunberg), Mylabris pustulata (Thunberg) and Dysdercus cingulatus
(F.), in terms of its predatory behaviour (approach and handling times), weight gain, macromolecular profi le (content of carbohydrates,
proteins, free aminoacids and lipids) and haemocytic profi le. We also determined the predator’s reliance on kairomones
from different species of prey. Larvae of the species of Lepidoptera studied were approached and captured more quickly than
adults of the two meloid coleo pteran and one heteropteran pest and were more benefi cial to the predator in terms of weight gain.
Predators had a higher total protein content when reared on larvae of the three lepidopteran species, higher lipid content when
reared on adults of the two meloid coleo pteran species and a higher carbohydrate content when reared on adults of one heteropteran
species. The number of haemocytes was greater in predators reared on larvae of the Lepidoptera studied, followed by those
reared on adults of the heteropteran and lowest in those reared on adults of the two meloid coleopterans. Response to kairomones
was strongest for S. litura followed by S. derogata and M. pustulata. We conclude that the Lepidoptera studied tended to be, for
this predator, superior prey, with S. litura being especially benefi cial and the prey species for which R. marginatus has the highest
kairomonal preference. Moreover, we propose that R. marginatus may be useful as a biocontrol agent against lepidopteran cotton
pests.
their applications in many areas, including agriculture. The latter topic is one of the most active areas of research in metal nanomaterials. Metal nanoparticles are traditionally synthesized by wet chemical techniques, in which the chemicals used are often toxic and flammable. We report here biosynthesis of silver nanoparticles using leaf extract of Vernonia cinerea (L.) Less. (Asteraceae). Treatment of aqueous
solution of AgNO3 with V. cinerea leaf extract resulted in rapid formation of stable silver nanoparticles. The growth of nanoparticles was monitored by UV–Visible spectrophotometry complemented by characterization using transmission electron microscopy (TEM), X-ray diffraction analysis, and Fourier-transform infrared spectroscopy. A feasible mechanism for the formation of nanomaterial and the
difference in the reduction time for silver nanoparticle synthesis is discussed. TEM
analysis revealed the presence of polydisperse silver nanoparticles with average size of 5–50 nm. X-ray diffraction studies corroborated that the biosynthesized nanoparticles were crystalline silver. Furthermore, this green biogenic approach is a rapid and simple alternative to chemical synthesis. The biologically synthesized silver nanoparticles were found to be highly effective against Xanthomonas campestris pv. malvacearum (13.00 ± 0.58 mm) with minimum inhibitory
Retz. silver nanoparticles (Ag NPs) was studied. AgNO3 (10-3 M) stock solution was prepared by dissolving 17mg of silver nitrate in 100ml of double distilled water. 10ml of gallic acid solution isolated from Terminalia chebula Retz. (Combretaceae) was added to 90ml of 10-3 M AgNO3
solution for reduction of Ag+ ions. The reduction of pure Ag+ ions was monitored by measuring in the UV-Vis Spectroscopy at 426nm. Determination of the shape and structure of silver nanoparticle was characterized by Transmission Electron Microscopic (TEM) and X-ray Diffraction studies
(XRD). The plasma resonance of the gallic acid reduced silver particle is brownish yellow. In the
light of these studies, the shape of the silver nanoparticle (spherical) and face centered cubic (FCC) structure were explained. The antibiotic experiment conducted in the present study revealed the antiphytopathogenic activity of gallic acid reduced Terminalia chebula Retz. silver nanoparticles
against the phytopathogen Xanthomonos axonopodis pv. malvacearum and also confirmed the
antiphytopathogenic activity studies based on “Broth microdilution method” against Xanthomonos
axonopodis pv. malvacearum.
P. ricini, but the uppermost concentration (2.0 x106 spores ml-1) provided maximum control within
short period of time (P<0.002) than the other spore concentrations. Mortality of P. ricini was observed
maximum on highest concentration of 2.0x106 spores ml-1. The value of LC50 lies between 2.32x102
and 13.89x107 spores ml-1. P.ricini body weight was increased at 2.0x105 (452.7±7.8 mg) spores ml-1
followed by 2.0x106 (450.9±18.9) and 2.0x104 spores ml-1 (443.8±6.2) by testing the field efficacy of B. bassiana against P. ricini, this insect pathogenic fungus can be used as potential biocontrol agent for the management of P. ricini. Results revealed that B. bassiana caused infection and caused death.
wide range of insect pests. We investigated the responses of R. marginatus to six species of cotton pests: Spodoptera litura (F.),
Sylepta derogata (F.), Pericallia ricini (F.), Mylabris indica (Thunberg), Mylabris pustulata (Thunberg) and Dysdercus cingulatus
(F.), in terms of its predatory behaviour (approach and handling times), weight gain, macromolecular profi le (content of carbohydrates,
proteins, free aminoacids and lipids) and haemocytic profi le. We also determined the predator’s reliance on kairomones
from different species of prey. Larvae of the species of Lepidoptera studied were approached and captured more quickly than
adults of the two meloid coleo pteran and one heteropteran pest and were more benefi cial to the predator in terms of weight gain.
Predators had a higher total protein content when reared on larvae of the three lepidopteran species, higher lipid content when
reared on adults of the two meloid coleo pteran species and a higher carbohydrate content when reared on adults of one heteropteran
species. The number of haemocytes was greater in predators reared on larvae of the Lepidoptera studied, followed by those
reared on adults of the heteropteran and lowest in those reared on adults of the two meloid coleopterans. Response to kairomones
was strongest for S. litura followed by S. derogata and M. pustulata. We conclude that the Lepidoptera studied tended to be, for
this predator, superior prey, with S. litura being especially benefi cial and the prey species for which R. marginatus has the highest
kairomonal preference. Moreover, we propose that R. marginatus may be useful as a biocontrol agent against lepidopteran cotton
pests.
their applications in many areas, including agriculture. The latter topic is one of the most active areas of research in metal nanomaterials. Metal nanoparticles are traditionally synthesized by wet chemical techniques, in which the chemicals used are often toxic and flammable. We report here biosynthesis of silver nanoparticles using leaf extract of Vernonia cinerea (L.) Less. (Asteraceae). Treatment of aqueous
solution of AgNO3 with V. cinerea leaf extract resulted in rapid formation of stable silver nanoparticles. The growth of nanoparticles was monitored by UV–Visible spectrophotometry complemented by characterization using transmission electron microscopy (TEM), X-ray diffraction analysis, and Fourier-transform infrared spectroscopy. A feasible mechanism for the formation of nanomaterial and the
difference in the reduction time for silver nanoparticle synthesis is discussed. TEM
analysis revealed the presence of polydisperse silver nanoparticles with average size of 5–50 nm. X-ray diffraction studies corroborated that the biosynthesized nanoparticles were crystalline silver. Furthermore, this green biogenic approach is a rapid and simple alternative to chemical synthesis. The biologically synthesized silver nanoparticles were found to be highly effective against Xanthomonas campestris pv. malvacearum (13.00 ± 0.58 mm) with minimum inhibitory
Retz. silver nanoparticles (Ag NPs) was studied. AgNO3 (10-3 M) stock solution was prepared by dissolving 17mg of silver nitrate in 100ml of double distilled water. 10ml of gallic acid solution isolated from Terminalia chebula Retz. (Combretaceae) was added to 90ml of 10-3 M AgNO3
solution for reduction of Ag+ ions. The reduction of pure Ag+ ions was monitored by measuring in the UV-Vis Spectroscopy at 426nm. Determination of the shape and structure of silver nanoparticle was characterized by Transmission Electron Microscopic (TEM) and X-ray Diffraction studies
(XRD). The plasma resonance of the gallic acid reduced silver particle is brownish yellow. In the
light of these studies, the shape of the silver nanoparticle (spherical) and face centered cubic (FCC) structure were explained. The antibiotic experiment conducted in the present study revealed the antiphytopathogenic activity of gallic acid reduced Terminalia chebula Retz. silver nanoparticles
against the phytopathogen Xanthomonos axonopodis pv. malvacearum and also confirmed the
antiphytopathogenic activity studies based on “Broth microdilution method” against Xanthomonos
axonopodis pv. malvacearum.
P. ricini, but the uppermost concentration (2.0 x106 spores ml-1) provided maximum control within
short period of time (P<0.002) than the other spore concentrations. Mortality of P. ricini was observed
maximum on highest concentration of 2.0x106 spores ml-1. The value of LC50 lies between 2.32x102
and 13.89x107 spores ml-1. P.ricini body weight was increased at 2.0x105 (452.7±7.8 mg) spores ml-1
followed by 2.0x106 (450.9±18.9) and 2.0x104 spores ml-1 (443.8±6.2) by testing the field efficacy of B. bassiana against P. ricini, this insect pathogenic fungus can be used as potential biocontrol agent for the management of P. ricini. Results revealed that B. bassiana caused infection and caused death.