Potential environmental consequences of administration of ectoparasiticides to sheep

Sheep ectoparasiticides, which include the synthetic pyrethroids, the organophosphates, the 'insect'-growth regulators, the formamidines and the spinocyns, enter into the environment primarily through disposal of dip or fleece scours, as well as with contaminated faeces and urine. Due to the large quantities of spent dip, risks associated with environmental contamination are high. Synthetic pyrethroids and organophosphates pose risks to dung, soil and aquatic fauna; concerns over potential ecotoxicity to vertebrates and invertebrates have resulted in the cessation of their use in many countries. There is very little information regarding the ecotoxicity of 'insect'-growth regulators, formamidines or spinocyns, with no studies focussing on sheep. Here, the impact of sheep ectoparasiticides is discussed in terms of their potential to enter into the environment, their toxicity and their impact on ecosystem functioning. Where there are no data for excretion or toxicity of the ectoparasiticides used in sheep production, examples to demonstrate potential impacts are taken from laboratory ecotoxicity tests and the cattle literature, as well on work with foliar insecticides. Future research priorities are suggested to allow assessment of the environmental consequences of sheep ectoparasiticide treatments, which are essential for future sustainable sheep production.     

阿坝州花椒蛀干害虫调查研究

对阿坝州花椒人工林蛀干害虫进行了较全面的调查.结果表明：阿坝州椒树受蛀干害虫危害严重,平均危害率85.2％,全州椒树平均寿命不超过8年.蛀干害虫种类复杂,主要有嫩枝天牛、虎斑天牛、台湾狭天牛、椒树长足象鼻虫等.随着海拔的不同,蛀干害虫的分布有较大差异.低海拔区以嫩枝天牛、椒树长足象鼻虫为主,高海拔区则以虎斑天牛、台湾狭天牛为主.     

Four Decades of Breeding for Varietal Improvement of Irrigated Lowland Rice in the International Rice Research Institute

Abstract

Since the establishment of the International Rice Research Institute (IRRI) in 1960, IRRI’s breeding effort in varietal improvement for irrigated lowland has passed four decades. Breeding of semi-dwarf rice varieties such as IR8 at IRRI during first decade from 1960 to 1969 resulted in quantum leaps in yield potential, which marked the green revolution in Asia. During the second decade from 1970 to 1979, the primary emphasis of rice improvement has been directed towards incorporation of multiple disease and insect resistance and shortening of growth duration. Grain quality was the main target of crop improvement at IRRI during the third decade from 1980 to 1989. The fourth decade from 1990 to 1999 and beyond was focused again on the improvement of yield potential by developing hybrid rice and new plant type. Up to 1999, 46 indica inbred varieties and 2 indica/indica hybrid rice varieties were developed by IRRI and released in the Philippines for the irrigated lowland rice systems. Large-scale adoption of these improved varieties under modern crop management practices has resulted in a dramatic increase in rice production in major rice-growing countries. The hybrid varieties between indicas increased yield potential by 9% under the tropical conditions. New plant type (NPT) breeding has not yet resulted in an increase in yield potential. The second generation NPT developed by crossing tropical japonica with indica has demonstrated some promising results in terms of improvements in yield potential, disease and insect resistance, and grain quality.     

豆谷类及其制品辐照杀虫防霉剂量要求研究

[目的]研究豆谷类及其制品辐照杀虫防霉工艺,阐述吸收剂量确定的依据。[方法]根据国内外研究结果和国际上有关辐照豆谷类及其制品杀虫防霉工艺规范中的规定,采用60Co-γ射线对豆谷类及其制品进行辐照杀虫防霉处理。[结果]试验得出,确定豆类、谷类辐照杀虫最低有效剂量为0．3kGy,豆类、谷类及其制品类辐照防霉最低有效剂量为3．0kGy,最高耐受剂量为7．0kGy。确定豆谷类及其制品辐照杀菌的适宜剂量范围为3．0～5．0kGy。[结论]研究可为提高优质谷类及其制品卫生质量品质、规范辐照加工生产提供参考依据。     

昆虫实践在生物技术专业实验教学改革中的应用

结合昆虫学领域的发展现状,将昆虫实践应用于生物技术专业实验课程的教学改革中。通过对生物技术专业实验环节进行教学改革,及时更新教育教学的发展思路,将科研与教学有机结合,昆虫实践已在教学中取得良好的反馈效果。通过对昆虫实验教学环节的改革,优化了实验指导方法,通过电化教学与昆虫学实践研究相融合,调动学生学习实验课程的主动性,激发学生的学习热情,注重学生动手能力的培养,大大提高了昆虫实验课的教学质量。     

我国虫子鸡产业的现状和展望

综述了虫子鸡的概念和发展历史,从发展规模、销售、效益、养殖模式、饲料配方等方面阐述了虫子鸡产业的现状,分析了虫子鸡产业的销售技巧和养殖效益、饲料配方和养殖成本、养殖技术和管理水平等方面的问题,并提出了相应的对策,最后展望了虫子鸡产业的发展前景。     

成都平原西缘笋用竹病虫害种类与分布

为了查明笋用竹病虫害种类及分布危害,为保障笋用竹产业发展和产品安全提供基础信息,采用踏查和标准地调查结合,并辅以灯诱的方法,对成都市主要笋用竹基地以及部分景区和社区竹林地病虫害开展了全面调查。结果显示,成都市笋用竹病虫害共45种,其中害虫38种,病害7种;对危害面积较大的病虫害分布和危害情况进行了分析,提出成都市笋用竹病虫害防控建议。     

Effect of climate change on Spodoptera litura Fab. on peanut: A life table approach

Investigations were conducted to understand the direct effects of rising temperature and the host-mediated effects of elevated CO₂ (eCO₂) on Spodoptera litura (Fabricius) (Noctuidae: Lepidoptera). This study involved i. the construction of life tables of S. litura at six constant temperatures viz., 20, 25, 27, 30, 33 and 35°C ± 0.5 °C reared on peanut (Arachis hypogaea L.) grown under eCO₂ (550 ppm) concentration in open top chambers ii. Estimation of threshold temperatures and thermal constants and iii. Prediction of the pest scenarios during near and distant future climate change periods. Significantly lower leaf nitrogen, higher carbon and a higher relative proportion of carbon to nitrogen (C:N) were observed in peanut foliage grown under eCO₂ over ambient CO₂ (aCO₂). The mean development time (days) of each stage, egg, larva, pupa, pre-oviposition and total life span decreased from 20 to 35 °C temperature on eCO₂ foliage. The thermal requirement of S. litura from egg to egg (within the range of 20 °C–35 °C) was 538.5 DD on eCO₂ as against 494.5 DD on aCO₂ foliage. Finite (λ) and intrinsic rates of increase (r_m), net reproductive rate (R_o), mean generation time (T) and doubling time (DT) of S. litura varied significantly with temperature and CO₂ and were found to have quadratic relationships with temperature. The present results on life table parameters estimated by the bootstrap technique showed that the ‘r_m’ values of S. litura on eCO₂ foliage were higher than those in the literature indicating a significant influence of eCO₂. The reduction of ‘T’ was noticed from a maximum of 50 days at 20 °C to minimum of 22 days at 35 °C and ‘λ’ which is the indicator of reproductive value of new eggs was highest at 35 °C and showed a negative relationship with temperature. The data on these life table parameters were plotted against temperature and two non-linear models developed for both CO₂ conditions and used for predicting the pest scenarios. Prediction of pest scenarios based on PRECIS A1B emission scenario data at eleven peanut growing locations of the country during near future (NF) and distant future (DF) climate change periods showed an increase of ‘r_m’ and ‘λ’ with varied ‘R_o’ and reduced ‘T’. The present results indicate that temperature and CO₂ are vital in influencing the growth and life table parameters of S. litura and that pest incidence is likely to be higher in the future.     

Movement and survival of corn rootworm in seed mixtures of SmartStax® insect-protected corn

SmartStax^® insect-protected corn (Zea mays L.) contains genes for six Bacillus thuringiensis (Bt) proteins controlling both lepidopteran pests and the corn rootworm complex (Diabrotica spp.). The properties of SmartStax, particularly the multiple effective modes of action (i.e., each Bt protein provides a high level of control of the target pests with a low probability of cross-resistance among the proteins), have provided the opportunity to add to previously approved structured refuge options by combining the non-Bt refuge seed with SmartStax seed in a seed mix. Seed mixes ensure that a refuge is present in every Bt field, remove concerns about grower compliance with refuge requirements, and provide grower convenience. However, seed mixes could increase the likelihood that larval insects move between Bt and non-Bt plants and vice versa. Assessing the insect resistance management (IRM) value of a seed mix refuge requires an assessment of the amount of larval movement, and the consequences of that movement, for the key target pests. The studies here present such data for control of corn rootworm by SmartStax corn, which contains the rootworm-active protein Cry3Bb1 and the binary protein Cry34Ab1/Cry35Ab1. In a growth chamber experiment, SmartStax was most effective against first instars and significantly effective against second instars, but did not control third instars. In a field study of movement from a heavily infested non-Bt plant onto surrounding plants, a larger percentage of insects successfully dispersed from the infested plant when the surrounding plants were non-Bt plants than when they were SmartStax plants. A paired-plant study showed that few larvae migrated from infested SmartStax plants and survived on nearby non-Bt plants; larvae that migrated from infested non-Bt plants had low survival if the adjacent plants were SmartStax. Replicated field studies of plant-to-plant movement indicated that the non-Bt plants in a 5% or 10% seed mix consistently supported large populations of susceptible insects and represented a productive refuge, whereas the SmartStax plants had few or no survivors. The timing of emergence from seed mix plots containing 5% or 10% non-Bt plants was more similar to that of the non-Bt plots than that of the SmartStax plots. Thus, the available growth chamber and field data indicate that a seed mix of 5% or more will provide an effective refuge for corn rootworm in SmartStax corn.     

昆虫多糖促进水稻生长及提高抗逆性机理分析

[目的]研究昆虫多糖促进水稻生长的作用机理。[方法]通过测定不同脱乙酰度、不同浓度昆虫多糖处理的水稻叶绿素含量、根系活力、过氧化物酶含量、可溶性糖和蛋白质含量来研究其作用机理。[结果]结果表明,昆虫多糖拌种处理水稻后叶绿素含量、根系活力、可溶性糖和可溶性蛋白质含量提高,过氧化物酶含量降低,可促进水稻的生长、增强抗逆性,提高产量。[结论]该研究为昆虫多糖的应用提供理论依据。