Efficacy of the botanical extract (myrrh), chemical insecticides and their combinations on the cotton leafworm,Spodoptera littoralis boisd (lepidoptera: Noctuidae)

Abstract

Effects of the botanical extract (myrrh), Commiphora molmol, and the sublethal treatments of profenofos/chlorofluazuron, fenvalerate and pyriproxyfen on the larvae of S. littoralis were investigated. The results showed that myrrh induced the highest activity after 7 days of treatment with concentration of 10000 ppm and the percentage of mortality reached 44.4%. The chemical insecticide profenofos/chlorofluazuron appeared to be the most effective treatment, giving a mortality of 54% after one day of treatment with a concentration of 100 ppm. Different treatments showed adverse effects on pupation, emerging adults and larval duration. The highest concentration of myrrh (10000 ppm) induced 35% pupation. No pupa was obtained with profenofos/chlorofluazuron while fenvalerate and pyriproxyfen gave 13.3% at 50 ppm. At 10000 ppm of myrrh, 25% adult was emerged, also fenvalerate and pyriproxyfen decreased the emerging moth to 13.3% at 50 ppm. For control there was no larval mortality at 7 days and the percentages of pupation and adult emergence were 90%. Bioassays were also conducted to test the joint action of myrrh applied in binary mixtures with each chemical insecticide on Spodoptera larvae. Results of the bioassay of mixtures indicated antagonistic effects on larval mortality. However, combination of myrrh with profenofos/chlorofluazuron showed additive effect. Also, the degree of pupation and emerging moth varied considerably when myrrh combined with the chemical insecticides. The present work shows the strong efficacy of the botanical extract (myrrh) which could be used alone or in combination with sublethal doses of certain insecticides to control the cotton leafworm.     

Zimbabwe's Child Supplementary Feeding Programme: a re-assessment using household survey data

In 1992-3 and 1995-6, Zimbabwe used a Child Supplementary Feeding Programme (CSFP) to combat child malnutrition during drought-induced emergencies. Previous evaluations of the CSFP relied on routine administrative data and key informant interviews and made only cursory use of available household survey data. These evaluations concluded that the CSFP was effective in preventing an increase in malnutrition among children under five, especially in 1992-3. The more-detailed analysis of household surveys provided in this article suggests that CSFP coverage was generally patchy and disappointingly low, especially in 1995-6. There is little evidence that children from poor or nutritionally vulnerable households got preferential access to supplementary feeding. The CSFP failed to feed many malnourished and nutritionally vulnerable children even in areas where the programme was operating. Household survey evidence suggests that the CSFP's impact on nutritional status was likely marginal, especially in 1995-6.     

Modeling Abundance Index Data from Anuran Calling Surveys

Abstract:  Evaluation of anuran populations is commonly based on calling surveys that report categorical abundance index data. I present a statistical model for abundance index data that are observations representing ordered abundance classes (e.g., none, some, many). The proposed model provides a formal treatment of detection probability, factors that affect detection, and variation in abundance. The model can be viewed as a generalization of that proposed by MacKenzie et al. (2002) for estimating site-occupancy rates in that it allows for more than two abundance classes. Because the abundance distribution is characterized by multiple abundance classes, it may be more sensitive to subtle changes in the underlying abundance that may go undetected with simple occupancy estimates under which sites are characterized merely as occupied or not. The method is most immediately applicable to surveys of anurans in which index data related to the intensity of calling activity are collected. I applied the proposed method to calling index data from the green frog (  Rana clamitans ) collected as part of the North American Amphibian Monitoring Program. The best model indicated considerable variation in detectability over time and in response to temperature. The resulting adjusted (for detectability) abundance-state distribution demonstrates the negative bias in abundance state obtained from simplistic summaries of calling index data that disregard these sources of variation in detectability.     

On the joint valuation of averting fatal and severe injuries in highway accidents

INTRODUCTION: To evaluate the benefits of road transport safety projects, planners need the monetary value of averting fatal and severe injuries. Usually, contingent valuation and risk-risk studies have been used. The contexts posed by both survey techniques do not represent the choice situation a driver faces when having to choose among alternative routes with different levels of safety. METHOD: We set up a stated choice web page survey in which individuals had to choose between two routes for a hypothetical trip between two cities; thus implicitly revealing their preferences for safety both in terms of reducing the number of fatal victims and of severely injured victims. RESULTS: For Chilean routes we were able to estimate approximate values of US$300,000 and US$140,000 for a reduction in one fatality and one severely injured victim, respectively. IMPACTS: Our evidence could be valuable for road planners in other developing nations.     

植物园数字化建设

植物园的数字化建设对植物园的发展至关重要,目前处于探索研究阶段.数字化植物园是植物园的数字模型.简要介绍了数字化植物园建设的必要性、设计实现方法及未来发展趋势,并结合我国植物园的现状分析了可能存在的问题.     

水田植物营养素的流失与控制措施

从水田流走的植物营养素在农业面源污染负荷中占主要部分,关于它们流失方式的分析是寻求适当的控制措施减少污染负荷的前提.水田植物营养素的流失途径是降雨径流和灌溉回归水,其浓度与土壤类型、作物状态和施肥等因素有关,控制它的最佳途径是改进耕作制度.     

State-of-the-art approach to hazardous waste site characterizations

A state-of-the-art characterization of a hazardous waste site provides significant benefits over a conventional program because it defines the hydrogeologic framework that governs contaminant transport, rather than merely confirming the existence of contamination State-of-the-art programs are commonly believed to be substantially more expensive than conventional programs. Such is not the case, however, for properly planned investigations Indeed, a state-of-the-art program can be substantially cheaper than a conventional one in some circumstances Costs remain comparable even under conditions unfavorable to the comparison These conclusions are illustrated by examples of field activities conducted at a variety of study sites.Publication No. 3360, Environmental Sciences Division, ORNL.Operated by Martin Marietta Energy Systems, Inc., under contract DE-AC05-840R21400 with the US Department of Energy.     

Watershed surveys to support an assessment of the regional effects of acidic deposition on surface water chemistry

Through the Direct/Delayed Response Project (DDRP), the United States Environmental Protection Agency is attempting to assess the risk to surface waters from acidic deposition in three regions of the eastern United States: the Northeast Region, the Southern Blue Ridge Province, and the Mid-Appalachian Region. The central policy question being addressed by the DDRP is: Within the regions of concern, how many surface water systems (lakes, streams) will become acidic due to current or altered levels of acidic sulfur deposition, and on what time scales? The approach taken by the DDRP is to select a statistically representative set of watersheds in each region of concern and to project the future response of each watershed to various assumed levels of acidic deposition. The probability structure will then be used to extrapolate the watershed-specific results to each region. The data will be used also for statistical investigation of hypothesized relationships between current surface water chemistry and watershed characteristics. Because the needed terrestrial data base was not available, regional watershed surveys were conducted to meet the specific data needs of the DDRP. Maps (1∶24,000) of soils, vegetation, land use, depth to bedrock, and bedrock geology were made for each watershed. The soils were grouped into sampling classes based on their hypothesized response to acidic deposition. Randomized sampling of these classes provided regional means and variances of soil properties that can be applied to individual watersheds. Because of DDRP's need for consistency within and among regions, unique quality control/quality assurance activities were developed and implemented. After verification and validation, the DDRP data base will be made publicly available. This will be a unique and useful resource for others investigating watershed relationships on a regional scale. The results of these surveys and the conclusions of the DDRP will be presented in several future papers. The current paper gives an overview of the context, rationale, logistical considerations, and implementation of these surveys, with special emphasis on the field activities of watershed mapping and soil sampling. This discussion should be useful to those planning, implementing, and managing survey activities in support of regional assessments of other environmental concerns, who are likely to face similar choices and constraints.     

ANALYSIS OF DATA FROM BIOLOGICAL SURVEYS OF STREAMS: DIVERSITY AND SAMPLE SIZE1

ABSTRACT: Brillouin's equation (H) for species diversity from information theory is to be preferred for the purposes of applied ecology over the equation of Shannon (H′) or the more commonly used approximate equation (H″). By its use, the difficult problem of delimiting the extent of the community being sampled in a stream survey can be avoided. Moreover, Brillouin's equation gives the exact diversity of the fully censused collection, whreas Shannon's diversity can only be approximated with a biased estimator. If we regard a sample as a message from the environment to the ecologist, Brillouin's equation is the proper one for computing its diversity. The product moment correlation coefficient between Brillouin's H for the total number of individuals from a group of samples and for randomly chosen subsets of 100 individuals from each sample was nearly as high as the correlation between H and H″ based on the total samples. This indicates that small sample sizes may give a useful diversity index. Replicated subsamples show that much smaller samples than are normally used can discriminate between communities from polluted and unpolluted environments. The use of smaller samples should reduce the cost of stream surveys.