The ecological basis of boll weevil (Anthonomus grandis Boheman) management

The boll weevil (Anthonomus grandis Boheman), generally considered to be native to Mexico or Central America, spread into the southern United States of America in the late 1800s and seriously threatened the cotton industry. As there were no effective alternatives, pest control specialists studied the insect's ecology and advocated cultural practices that would disrupt its environment and maximize the benefits of natural biological and environmental controls. An ecologically orientated pest management scheme founded on cultural practices emerged well before suitable chemical control technology became available and allowed farmers to live with the weevil problem.Despite the ingenuity of the early management scheme, it frequently did not provide satisfactory boll weevil control gauged by present standards. Control of the pest thus shifted largely from an ecological to a chemical approach as effective synthetic organic insecticides became available after World War II. The chemical approach was successful for a number of years, but problems of insecticide-resistant strains of pests, secondary pest outbreaks, environmental quality, and increased costs of the insecticides have forced pest control specialists to re-emphasize the nonchemical techniques used widely against the boll weevil before World War II and to revive the ecological approach to weevil management.This article examines boll weevil ecology as related to management of the insect and reviews the status and prospects of ecologically-based weevil management techniques in the United States.     

A survey of the use of IPM by New York apple producers

Integrated Pest Management (IPM) was first introduced to New York apple growers in 1975 through an Extension pilot program. Since that time, growers have become aware of the methods, results and potential benefits of following an IPM approach in their orchards. Differences in pesticide use, demography and behavior between IPM users and non-users are presented in this study. Results showed that > 80% of the apple producers in New York State (NY) incorporate some aspect of IPM into their pest control strategies. IPM users were younger and better educated and had less farm experience than non-users. Cornell Cooperative Extension was considered a primary source of written pest management and pesticide information to NY growers. However, agricultural sales persons were also considered useful by the growers for making pest management decisions. Growers that employed comprehensive IPM practices used 30% less insecticides, 47% less miticides and 10% less fungicides than growers that did not use IPM practices. This resulted in 235 kg active ingredient ha⁻¹ not having to be absorbed by the environment and saved IPM apple growers an average of US$ 95.80 ha⁻¹ year⁻¹ over an 11-year period (1976–1986) without significantly affecting fruit quality.     

Inaction levels for the red imported fire ant, Solenopsis invicta (hym.: formicidae): A predator of the boll weevil, Anthonomus grandis (col.: curculionidae)

The density of red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae), necessary to limit boll weevil abundance, Anthonomus grandis Boheman (Coleoptera: Curculionidae), below the action level was determined. An inaction level of 0.4 fire ants per shake bucket sample (i.e., four ants per 10 plant terminals) will provide boll weevil control approximately 90% of the time. A dynamic inaction level is also provided. Total mortality of boll weevil developmental stages including eggs through teneral adults averaged 97.9%. Of 100 boll weevil eggs deposited in cotton squares (flower buds), an average of two adults survive of which about half are female. Thus, the net replacement rate per generation (R_o is 1.0 which, in this case, indicates a stable boll weevil population.     

农业技术推广过程中制度因素的影响——湖北省天门市棉花害虫综合防治项目案例分析报告

针对中国主产棉区在病虫害防治中大量施用化学农药加重农业污染，以及害虫产生抗药性导致防治失灵等问题，由亚洲开发银行（ＡＤＢ）资助，英联邦国际生物防治研究所（ＣＡＢＩ）负责实施，于１９９３～１９９６年在中国湖北省天门市建立害虫综合防治（ＩＰＭ）项目试点，旨在研究和开发控制病虫危害和改善生态环境的适用于中国主产棉区的ＩＰＭ技术体系。ＩＰＭ项目有两个特点：①与以往因土地、人口压力而引致的技术变革不同，ＩＰＭ项目是一项因环境压力而引致的技术变革；②以往的技术变革的阻力大多来自于乡村社会结构尤其是农民对新技术的不接受，而ＩＰＭ项目在运作层面首先遇到了高度集中的防治体系的阻碍，即受到制度因素的影响。本文着重分析高度集中的防治体系形成的过程和原因，以及制度因素影响ＩＰＭ项目实施的作用机制，并提出解决问题的政策建议。     

From IBM to IPM: Using individual-based models to design the spatial arrangement of traps and crops in integrated pest management strategies

The development of alternative pest-control strategies based on the spatial design of cropping systems requires a thorough understanding of the spatial links between the pest and its environment. Mechanistic models, especially individual-based models (IBMs), are powerful tools for integrating key behaviours, such as habitat selection and dispersal, with spatial heterogeneity. In this paper, we used an IBM calibrated and evaluated from real data to represent the spatial dynamics of the banana weevil in relation to the cropping system. We considered crop fragmentation and mass trapping as tools for suppressing pest numbers. Our simulation results showed that manipulating crop residues in the area surrounding each pheromone trap greatly improved trap efficiency. For an intensive banana plantation in fallow, traps were most effective when situated at the transition zone between banana area and fallow so as to maximize the trapping of weevils escaping the fallow. The model also showed that weevil numbers decreased when fragmentation of banana plantations was reduced.     

Impact of variable nitrogen fertilisation on arthropods in cotton in Georgia, USA

Reducing fertiliser applications can reduce production costs for cotton (Gossypium hirsutum L.) growers, as well as nitrogen (N) leaching into the soil and contamination of surface and ground water. But altered N fertilisation may also affect pests and their natural enemies. In this study, plots with four different levels of fertiliser input (0, 45, 90 and 135 kg ha⁻¹ N) were used to investigate the influence of N on cotton pest and beneficial arthropod populations, and on cotton yield in Tifton, GA, USA. We predicted that (1) N fertilisation will correlate positively with cotton plant growth; (2) increased N fertilisation will increase pest populations because plants with more N will be more nutritious for and attractive to herbivores; (3) populations of beneficial arthropods and predation of pests will decline with increased N fertilisation because of reduced plant signaling; (4) increased N fertilisation will increase pest mortality due to parasitoids because of increased host quality. Cotton plant growth was enhanced by N fertilisation but yield was unaffected. N fertilisation significantly affected some pest arthropods but inconsistently. Mirids were most abundant in the high N treatment in 1 year of the study and cotton aphids were most abundant in the highest N treatment in the other year of the study. Arthropod predators were generally more abundant in the high N treatment but only spiders and Geocoris spp. were significantly affected by N treatment, with highest numbers present in the highest N treatment but the significant differences were each only in a single year. The greatest mortality of sentinel pest eggs (Spodoptera exigua) due to predation occurred under low N conditions. N fertilisation had no significant effects on parasitism of feral or sentinel caterpillars.     

Consumer response to integrated pest management and certification

This study investigated consumer awareness of integrated pest management (IPM) and the effects of two marketing strategies. Specific objectives were to find whether eastern Massachusetts farmstand and farmers' market customers purchasing sweet corn care how their food is grown, whether they are aware of IPM, whether they would prefer to buy IPM-certified sweet corn and why, and whether the marketing methods presently available to IPM-certified growers can enhance awareness of IPM. In 1993, the Massachusetts Department of Food and Agriculture in collaboration with the IPM Program at the University of Massachusetts began a pilot IPM certification program for sweet corn and strawberries, designated ‘Partners with Nature’ (PWN). This study compared a ‘passive’ and ‘active’ PWN marketing strategy with a control that did not have any PWN publicity. The passive strategy was simply display of a PWN certificate and poster. The active strategy also included newspaper advertisements, clear labeling of corn as IPM-certified at the point of selection, a PWN sticker placed on bags of corn at payment, personally thanking customers for ‘buying our IPM-certified sweet corn’, and IPM brochures available to customers. Thirty purchasers of IPM-grown corn were interviewed at each of six farmstands and six farmers' markets.The dominant reason why customers patronize farmstands and farmers' markets was convenience. As found by other northeastern surveys, awareness of IPM was low: only 19% had heard of IPM before the survey, and only 38% of these could mention a specific method used in IPM. Although 45% of the respondents initially said that they did not care how their food is grown, 85% said that they would prefer to buy IPM-certified sweet corn after hearing a short definition. The definition gave only environmental benefits, but 74% of the customers preferring IPM-certified corn said they would buy it because it is safer or healthier. Most of the respondents claimed that they would be willing to pay 10% more for IPM-certified corn. Simply displaying an IPM poster had no significant results on consumer preference for IPM-grown produce, but active marketing significantly raised awareness of IPM and the PWN program.This study demonstrated the willingness of customers to support IPM because they believe it will have positive consequences for human health and environmental quality. It is concluded that sweet corn marketing based on IPM certification positively influenced consumer reactions to IPM; and a more extensive, diverse marketing strategy would enhance consumer awareness and support.     

1961—2012年中国棉花需水量的变化特征

利用中国三大棉区230个气象台站的地面气象资料和103个农气观测站的棉花生育期资料,采用联合国粮食与农业组织推荐的方法计算了研究区域内1961—2012年棉花全生育期和不同生育阶段的需水量,并探讨了棉花不同生育阶段缺水量和水分盈亏指数的变化。结果表明：1961—2012年我国棉花全生育期需水量和缺水量整体呈下降趋势;需水量在开花到吐絮期总体呈下降趋势,而在播种到开花、吐絮到成熟阶段基本无变化;缺水量在播种到吐絮期总体呈下降趋势,而在吐絮到成熟期基本没有变化。比较三大棉区典型站点棉花水分盈亏情况,研究区域内棉花全生育期和各生育阶段的有效降水量均不能满足棉花的需水要求,其中西北棉区棉花各生育阶段的缺水状况最为严重。研究可为中国棉花种植区域的农业用水及合理灌溉提供科学依据。     

Interaction of alfalfa plant height and insecticide carrier application rates on beneficial arthropod populations

Spray coverage, as measured by water-sensitive paper at the soil surface, indicates that plant height significantly affected coverage while spray volume had little effect. Methomyl and fenvalerate insecticides applied to different alfalfa heights at various carrier volume rates reduced arthropod populations even at lower application volumes. Carrier volume had little impact on the level of arthropod reductions in each plot. Plant height also showed little influence on arthropod mortality. Within the limits of effective pest control there appears to be little potential for reduced impact on beneficial species resulting from refined insecticide carrier volume rates in alfalfa.     

Decaleside: a new class of natural insecticide targeting tarsal gustatory sites

Natural sources for novel insecticide molecules hold promise in view of their eco-friendly nature, selectivity, and mammalian safety. Recent progress in understanding the biology of insect olfaction and taste offers new strategies for developing selective pest control agents. We have isolated two natural insecticidal molecules from edible roots of Decalepis hamiltonii named Decalesides I and II, which are novel trisaccharides, highly toxic to household insect pests and stored-product insects. We have experimentally shown that insecticidal activity requires contact with tarsi on the legs but is not toxic orally. The insecticidal activity of molecules is lost by hydrolysis, and various sugars modify toxic response, showing that the insecticidal activity is via gustatory sites on the tarsi. Selective toxicity to insects by virtue of their gustatory site of action and the mammalian safety of the new insecticides is inherent in their chemical structure with 1-4 or 1-1 α linkage that is easily hydrolyzed by digestive enzymes of mammals. Decalesides represent a new chemical class of natural insecticides with a unique mode of action targeting tarsal chemosensory/gustatory system of insects.     

不同生育期转基因抗虫棉根际土壤细菌群落特征

为深入理解转Bt基因抗虫棉对根际土壤微生物群落的影响,基于大田试验,采用高通量测序技术,研究了不同生育期(播种前期、苗期和吐絮期)转基因抗虫棉和亲本根际土壤微生物群落组成和多样性.结果表明:①转基因抗虫棉及亲本根际土壤优势菌门均为变形菌门(Proteobacteria,相对丰度为0.433 8~0.499 3)、拟杆菌门(Bacteroidetes,相对丰度为0.106 0~0.136 6)、放线菌门(Actinobacteria,相对丰度为0.074 9~0.146 4)、芽单胞菌门(Gemmatimonadetes,相对丰度为0.054 2~0.072 3)、酸杆菌门(Acidobacteria,相对丰度为0.053 8~0.089 9).不同生育期转基因抗虫棉对根际土壤细菌优势菌门相对丰度产生显著影响(P < 0.05).②不同生育期转基因抗虫棉与亲本根际土壤细菌群落的Shannon-Wiener指数、Simpson指数、Sobs指数、PD指数均无显著差异(P>0.05),但PCoA分析发现,苗期和吐絮期转基因抗虫棉和亲本的土壤微生物群落出现空间分异(P < 0.05).③转基因抗虫棉根际土壤Bt蛋白含量在不同生育期具有显著差异(P < 0.05),且苗期和吐絮期转基因抗虫棉根际土壤Bt蛋白含量显著高于亲本(P < 0.05).④根际土壤Bt蛋白含量与细菌优势菌门相对丰度呈显著相关(P < 0.05).研究显示,不同生育期转基因抗虫棉通过根际Bt蛋白对土壤细菌相对丰度及群落结构产生影响,但不影响土壤细菌的alpha多样性.      

TLC-EI测定杀虫烟剂残留量的研究

应用TLC-EI(薄层-酶抑制)技术并采用CS-910型仪,对有机磷类及氨基甲酸酯类某些农药混合组成的杀虫烟剂燃烧后的残留量进行测定,结果一般可达ng级.经测定,能把Ⅲ-SMD烟剂中的西维因、马拉硫磷、敌敌畏三种农药分开.色斑可长期保留,Rf值分别为0.710、0.875、0.538.在大气烟雾中的有效烟率分别为4.16％、2.13％、0.76％.3h内松针上最高残留量分别为102.715、19.332、6.701ppm.12h后残渣中农药残留量分别为76、13.42、4.56ppm.用大白鼠肝酯酶测定农药的最小检出量分别为1.21、7.45、0.112ng.     

Matching innovations with potential users, a case study of potato IPM practices

Through interviews and mail surveys, Ohio potato (Solanum tuberosum) growers were surveyed concerning their willingness to adopt three cultural controls being developed for management of the Colorado potato beetle, Leptinotarsa decemlineata (Say), which had become increasingly difficult to control. The principal objective of the research was to obtain a deeper understanding of how farmers make decisions to adopt or not adopt new techniques and how these decisions are related to farmers' educational backgrounds and the way they currently manage their farms. The three cultural management options emphasized ecological approaches to habitat management rather than ecologically disruptive chemical control: (1) using host plants in overwintering sites to slow the spring movement of the beetles to potato fields, (2) using larger potato plants at field borders than in the center of the field as a spring trap crop, and (3) concentrating beetles in relatively small undefoliated areas to be killed with heat in late summer. Most respondents would not adopt these alternative pest management strategies, mainly because they perceived an unsatisfactory trade-off between logistic difficulties and expenses and population suppression they would achieve compared with traditional chemical control measures. Education correlated positively and experience in farming negatively with the willingness to try new pest management techniques. Additionally, growers responding more negatively to questions regarding integrated pest management strategies were more willing to experiment with the alternative techniques, a result attributed to either the survey design or an indication of experience with the more intensive management effort required for integrated pest management. This profile of potential innovators should be used by researchers to establish partnerships with farmers that could assist with both the research and development of new farming techniques and the adoption of successful systems by other farmers.     

An environmental management system implementation model for U.S. colleges and universities

The Osnabruck model, and another under development by the South Carolina Sustainable Universities Initiative, are the only two EMS models that have been proposed specifically for colleges and universities, although several guides are now available. The Environmental Management System Implementation Model for U.S. Colleges and Universities detailed in this paper, an adaptation of the ISO 14001 standard and USEPA recommendations, has been tailored to U.S. colleges and universities for use in streamlining the implementation process. In using this three-phased implementation model created for the U.S. research and academic setting, it is hoped that these highly specialized institutions will be provided with a clearer and more cost-effective path towards the implementation of an EMS and greater compliance with local, state and federal environmental legislation.     

Changes in pest management practice in almond orchards during the rainy season in California,USA

In California, regulatory agencies are concerned about organophosphate (OP) contamination of surface water. OPs originate in part from applications on dormant almond and stone fruit orchards that are washed off during winter rainstorms. Programs conducted by the University of California Statewide Integrated Pest Management Project, University of California Cooperative Extension, and the Biologically Integrated Orchard Systems (BIOS), a coalition of public and private groups, have promoted the replacement of OPs on almonds during the rainy season with alternative practices. Data from individual applicator records from the California Pesticide Use Reports demonstrated that during 1992–1997, almond growers in all nine major almond-producing counties significantly reduced use of OPs. The area of almond orchards treated with OPs during the dormant season was reduced by 40–55%, depending upon the region. Similarly, the percentage of growers who used OPs during the dormant season was reduced by 31–48%, and the mass of OPs applied to almond orchards during the dormant season was reduced by 22–57%. During the same period, there was a significant increase in the percentage of growers who used “reduced-risk” treatments: the microbial pesticide Bacillus thuringiensis at bloom-time, oil without an insecticide during the dormant season, and no treatment during the dormant or bloom season. In addition to the decrease in OPs during the dormant season, there was a significant decrease in the area treated with OPs during the growing season. However, there was also a significant increase in the use of pyrethroids during the dormant season, a practice that might result in some surface water and sediment contamination.     

Models for pest control using food-baited traps and either insecticides or chemosterilants

Several discrete models were proposed to investigate the population dynamic consequences of trapping a pest species in traps baited with a non-sex-specific odour and containing insecticides or chemosterilants. The models indicate that density dependence has no effect on the trapping effort required to eliminate the pests and that trapping larvae, where possible, is usually more efficient than trapping adults. Chemosterilants are more efficient than insecticides, but not usually by a wide margin.When using chemosterilants, residual fertility of trapped individuals and lack of competitive ability of sterile males are much less important than they are in a sterile release program.     

害虫抗性杂合子死亡率对抗性进化的影响

通过计算机模拟,研究了在R基因频率和种群大小的三种不同组合情况下,害虫抗性杂合于在用药或不用药时对抗性进化的影响.模拟结果表明,1)在任何组合中不用药时R基因的衰退是一个缓慢的过程,除非(RR)和(RS)遗传型的生物适合度很低.若R基因的显性越高,生物适合度越低,则抗性基因衰退越快.2)用杀死全部或绝大多数杂合子的剂量,并有少量敏感个体迁入时,抗性可被控制.但抗性一旦很明显,则此策略不再有效.     

Effects of bird predation on some pest insect populations in corn

Intensive agriculture has led to a decrease in biodiversity in many areas of the world. Poisoning birds directly or eliminating habitats suitable for birds within an agricultural landscape, may remove potential control agents of insect pests. The main objective of this project was to investigate the effects of excluding avian species from portions of cornfields through the use of bird-proof netting. Although pest levels were low and exclusion nets failed to affect corn yield, some differences were seen in insect pest population levels, supporting the view that insectivorous birds play a beneficial role in corn fields. Cutworms (Agrotis spp.) and weevils (Sphenophorus spp.) were found at higher density in plots where birds were excluded, especially those situated near the field edge. Data on aphids (Rhopalosiphum maidis) and European corn borer (Ostrinia nubilalis) were more variable but tended in the same direction. Only the adult Northern corn rootworm (Diabrotica longicornis) population was clearly not reduced by birds but infestation levels were extremely low.     

The extent of monoculture and its effects on insect pest populations with particular reference to wheat and cotton

The effects of changes in region-wide cropping patterns on insect pest populations have not been well studied. This paper reviews the empirical literature and develops a theoretical framework for these effects. Changes in regional cropping patterns do affect insect populations, and in at least one case, the presence of fence rows and thickets provide a net benefit to the nearby agro-ecosystem. Of the 17 studies reviewed here, 15 discuss cotton or wheat. With cotton, increased monoculture leads to increases in 13 pest populations and a decrease in two. With wheat, increases occurred in only three populations, while seven were not affected or decreased. Most of the insect populations that were not affected or decreased are multivoltine and oligophagous or polyphagous. All of the populations that increased are monophagous on the crop in the region in which they were studied. A higher proportion of the wheat fauna is multivoltine and oligophagous or polyphagous than the cotton fauna. This may explain the difference between the response of the wheat fauna and the cotton fauna to changes in the extent of monoculture. Additional factors may be insect vagility, host-finding ability, and the response of the predators and parasitoids.     

Assessing dormant season organophosphate use in California almonds

Organophosphate (OP) pesticides were recommended during the dormant season to control overwintering insects such as peach twig borer, San Jose scale, European red mite, and brown mite in California almond and stone fruit orchards. However, since 1990, dormant OP use had fallen under increased scrutiny due to surface water contamination concerns. Studies have shown positive correlation between OP use and residue load in surface water. The purpose of this study is to assess the trends and regional patterns of OP use in almond orchards, and to identify factors that may have influenced those trends, including weather, pest pressure, and use of alternatives to OP such as pyrethroid, dormant oils, and Bacillus thuringiensis (Bt) for the assessment of the impacts to surface water quality. Pesticide use data from the California Department of Pesticide Regulation were analyzed. Regression analyses were used to assess trends from 1992 to 2000, and a geographic information system (GIS) was used to visualize the spatial variation in pesticide use. Results from this study indicated that, statewide, dormant OP use decreased while the use of some alternatives, such as dormant pyrethroid, no dormant insecticides, and in-season pyrethroid, oil alone, and Bt, increased in the last 9 years. The significant decreasing trend of OP use was observed for the measures of kilogram per hectare crop planted, percentage of total planted hectare treated, and numbers of growers who applied dormant OP. The reduction of dormant OP use appeared in all major almond-growing counties. Correlation analyses revealed that more rain was associated with less dormant OP use. A higher percent of almond damage, or rejects, was related to higher OP use in the following dormant season and in-season periods. However, the effects of weather and percent of nut rejects can only explain small portion of the variations in dormant OP use. Therefore, in addition to weather and pest pressures, economic pressures and various outreach and extension programs may also have played a role in encouraging farmers to reduce their use of dormant OP.