Characteristics of Armyworm Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) Occurrence and Control on Cotton | Author : Muhammad Sarwar | Abstract | Full Text | Abstract :In this paper, is examined the incidence of armyworm Spodoptera litura (Fabricius)(Lepidoptera: Noctuidae), which is a highly polyphagous pest and inflicts serious damage to a wide spectrum of crops. The ability of S. liturato thrive on diverse host plants is an adaptive advantage for its survival in the ecosystem, which is achieved by its high mobility, fecundity and capacity to develop resistance to wide spectrum of chemical insecticides. Hosts of S. litura include field crops grown for food and fiber, plantation and forestry crops, as well as certain weed species.On most crops, damage arises from extensive feeding by larvae, leading to complete stripping of the plants. On cotton, the leaves are heavily attacked, bolls have large holes in them from which yellowish-green to dark-green larval excrement protrudes and yield of the crop is severely affected. Freshly hatched S. litura scrape the leaves from ventral surface, and full grown larvae feed on the leaves voraciously and present an appearance to the field as if grazed by livestock.Marigold is identified as suitable intercrop/border crop for pest management apart from harboring activity of major parasitoids of S. litura such as Microplitis sp., Cotesiasp., Campoletischlorideae and a polyembryonic parasitoid Copidosoma sp. Also grow castor as a border or intercrop or trap crop and set up pheromone trap to monitor, attract and kill the male moths @ 12/ha.Collect egg masses and destroy, also collect the gregarious larvae as well and destroy them as soon as the early symptoms of lace-like leaves appear on crop. Avoid migration of larvae by digging a trench 30 cm deep and 25 cm wide with perpendicular sides around the infested fields.Use of synthetic pyrethroids and endosulfan alternatively is effective against S. litura at 10% visual damage threshold and for managing 1st to 3rd instars larvae spray Emamectin benzoate 5 SG @ 11gma.i./ha or Spinosad 45 SC @ 75gm. For control of the 4th to 6th instars larvae, use Indoxacarb 14.5 SC @ 75gm ha-1,Flubendiamide 480SC @ 48-60gma.i. ha-1 or Chlorantraniliprole 20 SC @30-40gm a.i. ha-1. It is concluded that a combination of biological control agents, insect growth regulators, antifeedants, a trap crop and insecticides is an ecologically sound procedure for the control of S. litura. |
| Allometric Relationships in Psychotria suterella Müll. Arg. (Rubiaceae) in a fragmented landscape of Atlantic Forest | Author : D. F. Bertani, F. A. M. Santos | Abstract | Full Text | Abstract :The allometric relationship between diameter and height was studied in populations of Psychotria suterella, a common understory species of the Atlantic Forest of southeastern Brazil, in natural situations of different density and luminosity. Nine populations were sampled including three areas of continuous forest, three connected fragments and three isolated fragments, all within a fragmented Atlantic Forest landscape. In conditions of higher density and light availability, young individuals possessed a greater increase in height per unit of diameter than adult individuals. In all the varying conditions of light and density, the allometric pattern of young growth did not change. On the other hand, adult individuals exhibited a greater increase in height in high-density conditions. There were differences among allometric coefficients of some of the populations. In fragments where the canopy openness was greater, the population possessed individuals with greater height. On a smaller scale, light and density affected the allometric relationship of individuals. On a larger scale, populations with a low density of individuals, and which were subjected to greater luminosity, varied greatly in growth form. |
| Diversity and Distribution of Ichthyofuna at Gahirmatha coast Odisha. | Author : Rajesh K. Routray, *Subrata K. Behera, Rajkishore Mohanta | Abstract | Full Text | Abstract :The ichthyofaunal diversity of Gahirmatha Marine Sanctuary was studied during June 2002 to October 2004 from seven stations. Sufficient work has not been done on the ichthyofaunal diversity from this estuary. The ichthyofaunal diversity samples were collected using different types of nets with the help of the local fishermen at monthly interval of time. There were 89 fish species observed under 40 families. The family Clupeidae was dominated contributing 30.8% followed by Sciaenidae (21.7%), Mugilidae (18.5%), Ariidae (15.4%), Carangidae (10.4%) at Dhamra estuarine, north of Gahirmatha coast. Where the percentage varied toward the south of Gahirmatha coast (Hansua). Dominance diversity index value was highest in Dhamra and lowest value was in Hansua. If we compare the temporal variation of dominance of fish species status in two estuary did not fluctuate for a greater magnitude. |
| Effect of enriched organic manures on growth and yield of Bhendi (Abelmoschus esculentus) | Author : C. Esaivani, B. Usha and K. Vasanthi* | Abstract | Full Text | Abstract :In the present study Bhendi (Lady’s finger) showed significantly higher growth in plant root length, shoot length, leaf number, leaf area index, wet weight and dry weight in the vermicompost enriched with beneficial microbes. The microbe’s works on the root zone and at the canopy space as a nutrient and mineral solubilizer and mobilizer with enhanced photosynthetic activity to overcome the nutrient disorders. The plants showed maximum growth in the above mentioned characteristics in the mixture of enriched vermicompost with a foliar application which indicated its superiority over the vermicompost prepared without bio-inoculants and even the control. Thus enriched organic manure in fluenced the development of the crop and promoted stem elongation, root initiation and root biomass which suggest the linkage between biological effects of vermicompost and microbial metabolites that influence the plant growth and development. |
| Cotton Bollworm Helicoverpa Armigera (Hubner, 1809) (Lepidoptera: Noctuidae) and Development of Integrated Pest Management Platform | Author : Muhammad Sarwar | Abstract | Full Text | Abstract :The cotton bollworm Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae),is a polyphagous and adaptive pest that
currently attacks several crops including cotton.The present article undertakes the assessment of feeding preference and
damage potential of this pest as well as better control options are made. In cotton, all stages of plant growth may be
attacked, but reproductive tissue is preferred by this pest. Seedlings can be tipped out when terminal buds are eaten,
chewing damage to squares and small bolls may cause them to shed, and injury to maturing bolls can prevent normal
development leading to secondary fungal infections such as boll rot. Consequently, cotton bollworm larvae damage to
squares, flowers, green bolls and tender shoots results in significant reduction both in yield and quality of cotton. Third
instar larvae prefer to feed more on flowerswhile fifth instars on bolls. In case of H. armigera pest’scontrol, the most
appropriate alternative to insecticidesis to adopt a system to monitor the pestilence and the level of pesticide control in
order to make a proper decision. A direct egg and first instar caterpillar count is recommended for cotton crop for two
times per week at the beginning of the plant’s germination and until 30 or 40% of the plants shown open buds. The light
traps and pheromone traps are sensitive for the detection of initial populations, they are more specific and make counting
easier and quicker.Destroy left over material from crop and use resistant materials like genetically modified plants, which
expel Bacillus thuringiensis (Bt) toxins.Biological control is mentioned as a supporter in the management of H.
armigera, wherein more than 15 species of the parasitic Trichogramma, attack to the eggs.Management of beneficial
parasites or insects and the use of microbial agents like baculovirus can be encouraged. Chemical pesticides should be
used at pest’s levels of action and use selective pesticides, with rotation of the mechanism of products action, in order to
alleviate the pressure from the selection of active ingredients. The strategy to prevent insecticide resistance includes
rotation between chemical groups with different modes of action, limiting the time period during which an insecticide
can be used and limiting the number of applications of one particular insecticide. A regional approach is suggested for
the management of H. armigera, by taking into consideration the number of generations, migration capacity and its
highly polyphagous quality. |
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