285 research outputs found
World review of the natural enemies and diseases of Spodoptera litura(F.)(Lepidoptera: Noctuidae)
Published information was used to compile a summary of natural enemies(parasitoids, predatorsand diseases) reported attacking Spodoptera litirra (F) under field conditions. Species (71) of insect parasitoids in seven families of Hymenoptera and two families of Diptera were listed as
parasitoids of difTerent stages of S. litura. Predatory insects (36) belonging to 14 families and 12 species of spiders from six families have been reported to feed on this species. Four prolozoan, four fungal, seven bacterial, four each of viral and nematode species were also reported to be the pathogens of this species. Published information suggested that periodic releases of large number of egg parasites could help in suppressing populalions of this pest. There is a considerable scope for increased attention to the role of natural enemies as component of integrated pest management programmes of S. litura
Durability and Microstructure Characteristics of Concrete with Supplementary Cementitious Materials
Considering the environmental impact of cement manufacturing industries, this paper concerns the potential of using supplementary cementitious materials (SCMs), like fly ash and ground granulated blast furnace slag, as being essential to replacing the existing Ordinary Portland Cement (OPC). The objective of this paper is to study the microstructural characteristics of concrete with SCMs and improve the durability of the product to increase the lifespan of concrete structures. Replacement SCMs in OPC are 0, 40, 50, and 60 by percentage of cement weight, and we have taken a water-binder ratio of 0.40 for M40 grade and 0.28 for M60 grade concrete. The physical properties and chemical composition of OPC, Ground Granulated Blast-furnace Slag (GGBS), and fly ash were identified, and three different experiments were conducted to determine the resistance to penetration of chloride ions and corrosion processes. The rapid chloride permeability test, accelerated corrosion, and sorptivity tests were employed to measure concrete's resistance to the effects of aggressive environments and examine the durability properties. The most performed grade samples were analyzed as individual microspheres with Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDXS), and X-ray diffraction. Significant improvements in various concrete properties were achieved through the partial replacement of fly ash and GGBS with cement. Doi: 10.28991/CEJ-2022-08-04-05 Full Text: PD
Threshold Temperatures and Thermal Requirements for the Development of Spodoptera litura (Lepidoptera: Noctuidae)
Developmental thresholds and thermal requirements for different stages of Spodoptera litura (F.) fed on groundnut leaves were determined under constant laboratory conditions and in the field. An average of 64 degree-days (DD) above a threshold of 8°C was required from oviposition to egg hatch; the larval period required 303 DD and pupal stage 155 DD above a 10°C threshold; females needed 29 DD above a 10.8°C threshold from emergence to oviposition. Fifth and sixth instars accounted for about 50%of the total larval requirement under laboratory and field conditions. The response of various stages of S. litura to temperatures under constant laboratory conditions was similar to that under field conditions. The upper developmental threshold temperature of all stages was 37°C; 40°C was lethal
Status of IPM in Indian Agriculture: A Need for Better Adoption
Insect pests are well recognized as one of the major limiting factors in enhancing and sustaining agricultural production in India. Recent improvements from research brought considerable change in the cropping systems and allowed farmers to grow several crops throughout the year, which were very seasonal in the past. This also brought significant shift in the insect population dynamics and change in the status of several insect pests. Recent interactions with the farming communities revealed that 93% of the farmers in India had adopted chemical control, 51% farmers get their plant protection advice from dealers, while 22% from extension officials and majority of the farmers (73%) initiate the plant protection based on the first appearance of the pest, irrespective of their population, crop stage, and their damage relationships. The cost of plant protection on various crops ranged from 7 to 40% of the total crop production cost. Though integrated pest management (IPM) has been advocated for the past two decades, only 3.2% of the farmers adopted IPM practices in various crops. IPM research in the past decade brought out changes in the farmers’ attitude in pest management, which resulted 20100% reduction in pesticide use in different crops. The recent farmer participatory approach working in a consortium mode proved very effective in the exchange of technology. Though the results are encouraging, there is a need to further strengthen the IPM adoption in Indian agriculture through increased investments in both basic as well as applied research in plant protection to overcome the prevailing three evil “Rs” (Resistance, Resurgence, and Residues). To be more effective, readdressing the policies for encouraging eco-friendly options and strengthening extension, involving farmers should be considered as high priority
The Power of Predictions and Probabilities
Monsoon rainfall in India varies every year, and distribution is uncertain. This poses a production risk
for farmers in the semi-arid India.
Farmers tend to ignore rainfall forecasts issued by the Indian Meteorological Department (IMD) while
making crop decisions since they are made for the whole country, and could be unreliable regionally.
Recent advances in forecasting techniques improve the usefulness of forecasting seasonal rainfall.
Farmers in USA, Australia, Argentina and Brazil benefit from forecast-based cropping decision options
to enhance agricultural productivity.............
Neem: the Bitter Truth
The insecticidal properties of plants have been known through the ages. In recent years botanical
insecticides have played a critical role in the management of several insect pests. However, they have
not been fully exploited on a commercial scale. Neem (Azadirachta indica) has been the focus of
studies for over 20 years, and neem products are used as pesticides and allied chemicals against
>250 insect species all over the world
Redheads beware
The red hairy caterpillar (RHC), Amsacta albistriga, is a pest of several rainy season crops in Asia.
The RHC infestation is sporadic, but the devastation is widespread. Due to the prolonged diapause,
larval migratory behavior and irregular adult emergence, chemical protection alone is not sufficien
Survey of the Groundnut Pod-borers in South India
Groundnut pods are att~cked before harvest
by several vertebrate and invertebrate pests.
Among invertebrates, several arthropods such
as earwigs, termites, wire-worms, false wireworms,
white grubs, ted ants, Spodoptera etc.,
feed on deve1opingpotis (Wightman and
Amin, 1988). Damaged pods have little commercial
value because either the kernels are
damaged or external damage to the pod wall
renders them vulnerable to fungal infection
and aflatoxin contaminati.on (McDonald and
Harkt).ess, 1967)
Effect of helicoverpa nuclear polyhedrosis virus (HNPV) on different life stages of Helicoverpa armigera (Lepidoptera:Noctuidae)
Helicoverpa armigera Hubner, chickpea pod borer is a
serious pest of legumes, cotton and vegetables in the Indian
subcontinent. Widespread appearance of resistance to
chemical insecticides has stimulated efforts to develop
alternative control methods including the use of insect
viruses against this pest. Several workers proved the
effectiveness of HNPV under field conditions in controlling
H. armigera in chickpea (Dhamdhere and Khaire, 1986,
Jayaraj et al., 1987, Cowgill and Bhagawat, 1996). However,
there were several gaps in the utilization of HNPV and its
affects on the life stages of H. armigera. This paper discusses the quantification of various ill effects of HNPV on Helicoverpa life stages under laboratory and the effect of Robin Blue as ultraviolet protectant with NPV in enhancing its persistence in chickpea ecosyste
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