Effect of natural windbreaks on drift reduction in orchard spraying

In the Netherlands windbreaks are commonly grown to protect orchards against wind damage and to improve micro-climate. Natural windbreaks of broad-leaved trees can also reduce the risk of surface water contamination caused by spray drift during orchard spraying. Spray drift from pesticide applications is a major concern in the Netherlands, especially drift into water courses. So far, several drift reducing measures have been accepted by water quality control organisations and the Board for the Authorization of Pesticides (CTB), e.g. presence of a windbreak (i.e. 70% drift reduction at early season and 90% drift reduction at full leaf, respectively before and after first of May). From the experiments it was concluded that the risk of drift contamination is high during the early developmental stages of the growing season. The 70% drift reduction at early season as determined in previous experiments, appears to be valid only for windbreaks with a certain degree of developed leaves. At full leaf stage 80-90% drift reduction by the windbreak was measured. The use of evergreen windbreaks or wind-break species that develop in early season can reduce the risk of drift contamination considerably. Also, the combination of drift reducing methods, such as one-sided spraying of the last tree row and a windbreak is an effective method to reduce spray drift in the Netherlands in early season.     

A Pragmatic Approach to Assess the Exposure of the Honey Bee (Apis mellifera) When Subjected to Pesticide Spray

Plant protection spray treatments may expose non-target organisms to pesticides. In the pesticide registration procedure, the honey bee represents one of the non-target model species for which the risk posed by pesticides must be assessed on the basis of the hazard quotient (HQ). The HQ is defined as the ratio between environmental exposure and toxicity. For the honey bee, the HQ calculation is not consistent because it corresponds to the ratio between the pesticide field rate (in mass of pesticide/ha) and LD₅₀ (in mass of pesticide/bee). Thus, in contrast to all other species, the HQ can only be interpreted empirically because it corresponds to a number of bees/ha. This type of HQ calculation is due to the difficulty in transforming pesticide field rates into doses to which bees are exposed. In this study, we used a pragmatic approach to determine the apparent exposure surface area of honey bees submitted to pesticide treatments by spraying with a Potter-type tower. The doses received by the bees were quantified by very efficient chemical analyses, which enabled us to determine an apparent surface area of 1.05 cm²/bee. The apparent surface area was used to calculate the exposure levels of bees submitted to pesticide sprays and then to revisit the HQ ratios with a calculation mode similar to that used for all other living species. X-tomography was used to assess the physical surface area of a bee, which was 3.27 cm²/bee, and showed that the apparent exposure surface was not overestimated. The control experiments showed that the toxicity induced by doses calculated with the exposure surface area was similar to that induced by treatments according to the European testing procedure. This new approach to measure risk is more accurate and could become a tool to aid the decision-making process in the risk assessment of pesticides.     

Use of a model and toxicity data to predict the risks to some wild plant species from drift of four herbicides

The dose responses of 14 wild plant species (two grasses, two legumes, one annual and nine perennial dicotyledons), not usually recognised as weeds, to four herbicides (asulam, glyphosate, MCPA and mecoprop) were measured in glasshouse experiments. Glyphosate was the most toxic; seven of the species tested had EDu, values (measured as shoot dry weight) of < 1.0 μg/plant, compared with only one species for MCPA and mecoprop. Asulam was the least toxic. Results were used to indicate the risk to each species from drift damage. A model of spray drift, based on that developed by Thompson & Ley (1982) for evaporating droplets, was rescaled to allow for field application rates and used to predict the distances travelled by given doses of herbicide. This gave acceptable agreement with reports for drift damage in the field, and predicted that only glyphosate sprayed at the highest recommended concentration might be unsafe to some of the species examined. The two herbicides sometimes used as volatile formulations (MCPA and mecoprop) did not cause damage at the small doses likely to result from exposure to vapour in the field.     

Drift studies--comparison of field and wind tunnel experiments

Drift at pesticide application leads to a pollution of non-target crops, non-target species and surface water. Spray drift is influenced by many factors like environmental conditions, vegetation, technical conditions, and physical properties of the tank mixes and influenced by Chemicals. Field experiments to characterise spray drift effects with the risk of permanent changing weather conditions can be supported by wind tunnel experiments. Wind tunnel experiments do not lead to the same soil deposition curves like field experiments, but the ratio of drift reduction potential is comparable.     

In vivo genotoxicity of the pyrethroid pesticide beta-cyfluthrin using the comet assay in the fish Bryconamericus iheringii

Environmental pollution by pesticide residues is a major environmental concern due to the extensive use of these substances in agriculture. The insecticide beta-cyfluthrin is a synthetic pyrethroid widely used in agricultural and other domestic activities. The aim of the present study was to assess the genotoxic effects of a sublethal exposure of the fish Bryconamericus iheringii (Characidae) to a commercial formulation of beta-cyfluthrin using the comet assay. Fish were exposed to sublethal concentrations (4.2 and 5.6 microg/L) of beta-cyfluthrin under static conditions during 24- and 48-h exposure periods. Fish in tap water were used as negative controls. Results obtained by the comet assay revealed genotoxic effects of the pyrethroid in the higher concentration and at the longer exposure period. The mean DNA damage index of fish exposed to 5.6 microg/L beta-cyfluthrin for 48 h was significantly higher (145.9 +/- 51.8) than in the control group (69.3 +/- 39.5). These findings indicate that native fish species might be at risk for genotoxic damage in waters contaminated with beta-cyfluthrin.     

紫贻贝长期暴露于亚致死剂量的林丹和阿特拉津下的组织学反应

为开发快速、敏感的生物标记物以监测海洋贝类生物中是否存在农药,我们检测了双壳动物紫贻贝长期暴露在亚致死剂量的丙体六氯环乙烷(林丹,γ-HCH)和2-氯4-乙胺基-6异丙胺基-1,3,5-三氮苯(阿特拉津)下的组织学变化。紫贻贝容易积累环境中的杀虫剂,因此,本研究旨在阐明农药的生物积累与组织病理学效应之间的关系。利用GC/MSD分析法定期对贻贝和水样中的林丹与阿特拉津含量进行测定。将贻贝在实验室中培养21天,以使其代谢适应于带有水质控制的封闭式不间断流动系统。随后,30只贝暴露于亚致死剂量的林丹(0.9 mg/L)或阿特拉津(3.583 mg/L)溶液中56天。实验期间,控制重要的参数,比如温度和盐度分别控制在18℃和34‰。在处理28天和56天后取样,检测组织学损坏及吸收的农药量。暴露的紫贻贝每克干重分别能聚集约304.8-372.0μg/g林丹和83.3-137.4μg/g阿特拉津。组织学改变高度集中在鳃的上皮和外套膜组织;上皮与相邻的组织形成分离状态。组织病理学结果显示,抗性机制的激活使紫贻贝能在亚致死压力下存活。组织病理效应范围从浸润反应到以血淋巴细胞出现间质细胞反应为特征。因此,在农药聚集部位的组织学和超微结构的改变是敏感的,并与农药的生物积累具有正相关关系,说明这些改变可能作为农药暴露的生物标记物。     

Early pregnancy agricultural pesticide exposures and risk of gastroschisis among offspring in the San Joaquin Valley of California

Background: Prevalence of gastroschisis has inexplicably been increasing over the past few decades. Our intent was to explore whether early gestational exposures to pesticides were associated with risk of gastroschisis. Methods: We used population‐based data, accompanied by detailed information from maternal interviews as well as information on residential proximity to a large number of commercial pesticide applications during early pregnancy. The study population derived from the San Joaquin Valley of California ( ). Cases were 156 infants/fetuses with gastroschisis and controls were 785 infants without birth defects. Results: Among 22 chemical pesticide groups analyzed, none had an elevated odds ratio with an associated confidence interval that excluded 1.0, although exposure to the triazine group showed borderline significance. Among 36 specific pesticide chemicals analyzed, only exposure to petroleum distillates was associated with an elevated risk, odds ratio = 2.5 (1.1–5.6). In general, a substantially different inference was not derived when analyses were stratified by maternal age or when risk estimation included adjustment for race/ethnicity, body mass index, folic acid supplement use, and smoking. Conclusion: Our study rigorously adds to the scant literature on this topic. Our a priori expectation was that we would observe certain pesticide compounds to be particularly associated with young age owing to the disproportionate risk observed for young women to have offspring with gastroschisis. We did not observe an exposure profile unique to young women. Birth Defects Research (Part A), 100:686–694, 2014. © 2014 Wiley Periodicals, Inc.     

小型植保无人机超低量喷雾防治稻水象甲

【目的】通过建立适宜新疆荒漠绿洲特殊生态环境的稻水象甲超低量喷雾技术,为稻水象甲的大面积统防统治提供新型施药技术。【方法】以小型遥控多旋翼植保无人机(UAV)为施药机械,以稻水象甲常规喷雾防效大于90%的药剂为首选药剂,开展了药剂、施药量、助剂以及施药机型的筛选试验。【结果】施药后3、7、14和21 d虫口密度高于防治指标的样地所占比例依次为35.71%、21.43%、35.71%和78.57%。30%氯虫·噻虫嗪187.5 mL·hm~(-2)防效最佳,14 d药效高达93.43%;药后21 d,球孢白僵菌3000 mL·hm~(-2)的防效最高,达84.65%。各药剂施药量与防效呈正相关。此外,UAV喷雾防治稻水象甲时,添加助剂的平均防效可提高22.29%~28.49%。【结论】在农业精准施药、绿色生产中,综合考虑供试药剂的施药量、持效期、防效和药后存活虫量,建议以30%氯虫·噻虫嗪SC和14%氯虫·高氯氟CS作为全程以UAV为施药机械防治稻水象甲的首选药剂,在稻水象甲种群发展前中期优先考虑低浓度施药量;同时,为避免UAV在实际作业中药液雾滴发生飘失和流失问题,可以考虑添加飞防助剂提升防效。     

Pesticides in the Cagayan valley (Philippines): usage, drift patterns and the exposure of farmers differing in income and market access

Over the past ten years, the amount and number of different types of pesticides have increased significantly, which led to a growing concern about the possible adverse effects on human health and the environment. This is particularly true for countries where regulations are not strictly implemented and farmers' knowledge of safe handling is often inadequate. This paper discusses the results of a series of spray experiments to determine drift patterns along field boundaries and the exposure of farmers during their usual spraying exercises. Moreover, farmers' pesticide usage and methods of application will be described, and the effects of income and market accessibility on pesticide use patterns will be investigated. It is based on a study conducted in four villages located at increasing distance from the national highway leading to regional markets and connecting the Cagayan Valley in Northeast Luzon with Manila. The 20 pesticides encountered in this study cover 18 different active ingredients, 9 of which are classified by the WHO as 'highly hazardous' or 'moderately hazardous'. The EPA has classified at least 6 of the encountered pesticide formulations as Restricted Use Pesticides. Nevertheless, all pesticides are freely sold in stores or on markets and applied by farmers without personal protection in an unsafe manner. The farmers living nearest to the highway have the highest income and largest farms. Yet they are most at risk, having easiest access to pesticides and spraying the largest quantities of pesticides per hectare, compared to the farmers living at greater distance from the highway. It is recommended to review the list of pesticides approved for use in the Philippines and discern between Restricted and General Use Pesticides. Several recommendations for improving the implementation of pesticide policies and the IPM program are given.     

Genotoxic evaluation of workers employed in pesticide production

Pesticides are widely used throughout the world in agriculture to protect crops and in public health to control diseases. Nevertheless exposure to pesticides can represent a potential risk to humans. Pesticide manufacturing unit workers are prone to possible occupational pesticide exposure. Therefore, this study was performed to evaluate the genotoxic effect of pesticide exposure in these workers. In the present investigation 54 pesticide workers and an equal number of control subjects were assessed for genome damage in blood lymphocytes utilizing the chromosomal aberration analysis and the buccal epithelial cell by adopting the micronucleus test. The results suggested that pesticide workers had a significantly increased frequency of chromosomal aberrations when compared with controls (mean+/-S.D., 8.43+/-2.36 versus 3.32+/-1.26; P<0.05). Similarly, the pesticides exposed workers showed a significant increase in micronucleated cells compared with controls (1.24+/-0.72 versus 0.32+/-0.26; P<0.05). Analysis of variance revealed that occupational exposure to pesticides had a significant effect on frequency of micronuclei (P<0.05), whereas smoking, age, gender and alcohol consumption had no significant effect on genetic damage (P>0.05). However, no association was found between years of exposure, smoking, age, gender, alcohol consumption and higher levels of genetic damage as assessed by the chromosomal aberration assay (P>0.05). Our findings indicate that occupational exposure to pesticides could cause genome damage in somatic cells.     

Aerial ultra-low-volume application of naled: impact on nontarget imperiled butterfly larvae (Cyclargus thomasi bethunebakeri) and efficacy against adult mosquitoes (Aedes taeniorhynchus)

We assessed the exposure and acute toxicity of naled, applied aerially as an ultra-low-volume spray for mosquito control, on late instar larvae of the Miami blue (Cyclargus thomasi bethunebakeri) (Comstock and Huntington 1943) (Lepidoptera: Lycaenidae), an imperiled South Florida butterfly. We concurrently evaluated the control efficacy against caged adult female salt-marsh mosquitoes (Aedes taeniorhynchus) (Wiedemann 1821) (Diptera: Culicidae). This 3-yr study was conducted in north Key Largo (Monroe County, FL) beginning in 2006. The field trials incorporated 15 sampling stations: nine in the target spray zone, three in the spray drift zone at varying distances from the target zone, and three in the control zone not subjected to naled spray drift. A total of six field spray trials were completed, three at an altitude of 30.5 m (100 feet), and three at 45.7 m (150 feet). For all trials, the ultra-low-volume application of Trumpet EC insecticide (78% naled) at a rate of 54.8 ml/ha (0.75 fl. oz/acre) was effective in killing caged adult mosquitoes in the target zone. Butterfly larvae survival was significantly reduced in the spray zone compared with drift and control zones. Analysis of insecticide residue data revealed that the mortality of the late instar butterfly larvae was a result of exposure to excess residues of naled. Additional research is needed to determine mitigation strategies that can limit exposure of sensitive butterflies to naled while maintaining mosquito control efficacy.     

Active entry of stream benthic macroinvertebrates into the water column

Field experiments investigated the possible active entry of stream benthos into the water column. Over a 1-year period, sediment baskets were suspended for 24 hours in a stream pool so that only swimming or floating organisms, essentially unaided by current, could colonize them. A variety of benthos, including taxa characteristic of riffles, colonized the baskets, with colonization highest in late summer and negligible in winter.A modified drift net towed through the pool was used to quantitatively sample benthic animals actually in the water column. Nighttime tows captured a diverse, abundant fauna and indicated densities substantially higher than invertebrate drift densities reported in the literature. Daytime tows yielded little. Estimated percentages of the benthos in the water column at a given time were generally < 1.0%.These findings suggest that not all invertebrate drift is the result of passive mechanical removal from the substrate by current.     

Developing an ecotoxicological testing standard for predatory mites in Australia: acute and sublethal effects of fungicides on Euseius victoriensis and Galendromus occidentalis (Acarina: Phytoseiidae)

Laboratory bioassays for testing the effect of agrochemicals on Euseius victotiensis (Womersley) and Galendromus occidentalis (Nesbitt) on detached leaves of Glycine max (L.) (soybean) and Phaseolus vulgaris L. (French bean) were developed. The tests allowed standardized comparisons between mite species and leaf substrates, under "worst-case scenario" exposure, comparable with commercial pesticide application. Young juveniles, along with their initial food and the entire water supply, were sprayed to the point of runoff by using a Potter spray tower. The highest registered field rate concentration used on French bean was adjusted to deliver the same pesticide dose per higher runoff point spray volume on soybean. Cumulative mortality was assessed at 48 h, 4 d, and 7 d after spray application. Fecundity was assessed for 7 d from the onset of egg lay. Boscalid (Filan 500 WG), dithianon (Delan 700 WG), and kresoxim-methyl (Stroby 500 WG) caused no significant 7-d mortality or fecundity reduction to G. occidentalis or E. victoriensis compared with controls, and are classified as harmless to both species. Mancozeb (Mancozeb 750 WG) was highly toxic to both species, resulting in severe mortality and fecundity reduction and is considered incompatible with integrated pest management programs that use these species. Metiram (Polyram 700 WG) was highly toxic to E. victoriensis but only moderately toxic to G. occidentalis. Analyses of mortality proportions, including, and excluding unaccounted escapees, produced the same results. Test standardization on leaf substrates provides an alternative approach to standardization via residue on glass used by International Organisation for Biological and Integrated Control or Noxious Animals and Plants/West Palaearctic Regional Section regulatory testing in the European Union.     

Pesticide Residues and Bees – A Risk Assessment

Bees are essential pollinators of many plants in natural ecosystems and agricultural crops alike. In recent years the decline and disappearance of bee species in the wild and the collapse of honey bee colonies have concerned ecologists and apiculturalists, who search for causes and solutions to this problem. Whilst biological factors such as viral diseases, mite and parasite infections are undoubtedly involved, it is also evident that pesticides applied to agricultural crops have a negative impact on bees. Most risk assessments have focused on direct acute exposure of bees to agrochemicals from spray drift. However, the large number of pesticide residues found in pollen and honey demand a thorough evaluation of all residual compounds so as to identify those of highest risk to bees. Using data from recent residue surveys and toxicity of pesticides to honey and bumble bees, a comprehensive evaluation of risks under current exposure conditions is presented here. Standard risk assessments are complemented with new approaches that take into account time-cumulative effects over time, especially with dietary exposures. Whilst overall risks appear to be low, our analysis indicates that residues of pyrethroid and neonicotinoid insecticides pose the highest risk by contact exposure of bees with contaminated pollen. However, the synergism of ergosterol inhibiting fungicides with those two classes of insecticides results in much higher risks in spite of the low prevalence of their combined residues. Risks by ingestion of contaminated pollen and honey are of some concern for systemic insecticides, particularly imidacloprid and thiamethoxam, chlorpyrifos and the mixtures of cyhalothrin and ergosterol inhibiting fungicides. More attention should be paid to specific residue mixtures that may result in synergistic toxicity to bees.     

Genotoxicity biomarkers in M. galloprovincialis as indicators of marine pollutants

Many substances pollute the marine environment. There is today a growing evidence on the increased risk of disease in marine organisms, especially fish, that inhabit contaminated waters. Different types of tumours have been evidenced in fish and shellfish populations. Different short-term biomarkers are available to predict the impact of carcinogens on marine organisms. Their endpoints are different effects at the molecular and cellular level such as gene mutation, chromosome alteration and induction of DNA damage and repair. We have applied two different assays: alkaline elution to measure DNA single strand breaks and micronucleus assay as an index of a chromosomal damage. In order to select an aquatic organism as an indicator of water pollution by carcinogenic agents, we have focused on the mussel. A program of validation of genotoxicity was conducted in aquarium using DMBA. A time-dependence increase of micronuclei was evident after the exposure to 100 ppb/animal. For alkaline elution the effect was 4 times the level of the controls. Experiments in the fields were conducted on adult specimens of Mytilus gdlloprovincialis collected from natural substrates. Our sampling stations were located in the La Spezia gulf, Ligurian sea. Genotoxic effects were evaluated in gill cells. A significant increment of the two parameters in polluted, in comparison with the unpolluted sites has been observed. High frequencies of micronuclei (the highest value was 42 ± 13 with respect to control value 3 ± 2) were scored in mussels from polluted stations. The extent of DNA damage was also relevant with respect to clastogenic damage as revealed by micronucleus test. The greatest value of K (constant of elution) was 8-fold higher with respect to the value of K obtained in the same tissue of mussel from reference areas. Evidence of DNA damage could reflect a recent pollution status, since DNA strand breaks can be rapidly repaired by different mechanisms. On the contrary animals exposed to clastogenic compounds may exhibit elevated micronucleus frequency long after the exposure has ceased. The evaluation of both parameters could provide information of great significance about the pollution status of the water.     

Boll weevil (Coleoptera: Curculionidae) damage to cotton bolls under standard and proactive spraying

In some parts of the boll weevil's, Anthonomus grandis grandis (Boheman) (Coleoptera: Curculionidae), distribution from the United States to Argentina, insecticides are applied after cut-out (end of square production) when bolls are the predominant stage of fruiting body. This study demonstrates that the standard spray regime in southern Texas, which involves insecticide applications after cut-out, did not result in more bolls than a nonsprayed control. An alternative "proactive" spray regime focusing on protecting large squares before cut-out resulted in 1.9- to 2.5-fold more bolls in the lower half of the canopies than the control. At one of two experimental field locations, the percentage of damaged boll carpels was 3-fold greater in the standard spray regime's lower canopy than in the proactive spray regime, and the percentage in the control was 1.6-fold greater than in the standard regime. At both experimental field locations, the upper canopy control had 2.1- to 2.3-fold greater percentages of carpel damage than the proactive spray regime. The standard spray regime resulted in 2.3-fold greater percentage of carpel damage than the proactive regime. In the control and the standard spray regime, percentages of upper canopy nondamaged bolls were mostly lower than or not different from percentages of bolls with one, two, three, or all four carpels damaged, but in the proactive regime, percentage of nondamaged bolls in the upper canopy was greater than percentages of bolls with one or more damaged carpels. Reasons for the ineffectiveness of the standard spray regime and the benefits observed in the proactive approach are discussed.     

Polymorphisms in metabolic GSTP1 and DNA-repair XRCC1 genes with an increased risk of DNA damage in pesticide-exposed fruit growers

Pesticide exposure is associated with various neoplastic diseases and congenital malformations. Previous studies have indicated that pesticides may be metabolized by cytochrome P450 3A5 or glutathione S-transferases. DNA-repair genes, including X-ray repair cross-complementing group 1 (XRCC1) and xeroderma pigmentosum group D (XPD), may also be implicated in the process of pesticide-related carcinogenesis. Thus, we investigated whether various metabolic and DNA-repair genotypes increase the risk of DNA damage in pesticide-exposed fruit growers. Using the comet assay, the extent of DNA damage was evaluated in the peripheral blood of 135 pesticide-exposed fruit growers and 106 unexposed controls. The metabolic genotypes CYP3A5 (A(-44)G) and GSTP1 (Ile105Val) and DNA-repair genotypes XRCC1 (Arg399Gln, Arg194Trp, T(-77)C) and XPD (Asp312Asn, Lys751Gln) were identified by polymerase chain reaction. Our multiple regression model for DNA tail moment showed that age, high pesticide exposure, low pesticide exposure, GSTP1 Ile-Ile, and XRCC1 399 Arg-Arg genotype were associated with increased DNA tail moment (DNA damage). Further analysis of interaction between GSTP1 and XRCC1 genes that increase susceptibility revealed a significant difference in DNA tail moment for high pesticide-exposed subjects carrying both GSTP1 Ile-Ile with XRCC1 399 Arg-Arg genotypes (2.49+/-0.09 microm/cell; P=0.004), compared to those carrying GSTP1 Ile-Val/Val-Val with XRCC1 399 Arg-Gln/Gln-Gln genotypes (1.98+/-0.15 microm/cell). These results suggest that individuals with susceptible metabolic GSTP1 and DNA-repair XRCC1 genotypes may be at increased risk of DNA damage due to pesticide exposure.     

稻田水质模型研究和应用进展

水稻生产环境特殊、生产过程中病虫草害严重,导致农药使用品种多、频次高.部分农药会淋失到周围水体中,对水体的潜在污染风险较高.随着农药监测和田间试验成本的不断提高,数学模型已成为农药登记过程中不可或缺的一部分.稻田水质模型(RICEWQ模型)作为欧洲稻田农药暴露评估最可靠和应用最广泛的模型,主要用于预测淹水稻田土壤和积水中的农药浓度,在我国也得到了初步应用.本文简要介绍了RICEWQ模型的系统结构、农药归趋的主要过程、模型的输入输出,综述了国内外相关的研究进展,以期推进RICEWQ模型在我国的应用,并为相关研究提供参考.     

Viability of invertebrate diapausing eggs exposed to saltwater: implications for Great Lakes’ ship ballast management

International shipping has been the dominant vector of nonindigenous species introductions to the Laurentian Great Lakes over the past century. Apparent ballast-mediated invasions have been recorded in recent years, despite the implementation of voluntary ballast water exchange regulations in 1989. Since unregulated no-ballast-on-board vessels currently dominate inbound traffic to the Great Lakes, it has been proposed that live or dormant organisms contained in residual ballast of these vessels may be partially responsible for recent invasions. Alternatively, euryhaline species may pose a significant invasion threat because they can potentially survive ballast exchange. In this study, we explored whether exposure to open-ocean water (32) reduced the viability of invertebrate diapausing eggs in ballast sediments. Sediments collected from three transoceanic ships and from three freshwater habitats were exposed to open-ocean seawater. Egg viability, assessed as the abundance of taxa hatched between exposed and unexposed sediments, was not affected by saltwater exposure in any experiment. Species richness of hatched diapausing eggs was reduced by saltwater exposure in only one of seven trials. Our results indicate that oligostenohaline zooplankton may pose an invasion risk because their diapausing eggs are largely resistant to exposure to open-ocean saltwater.     

Bio-efficacy of different oil carriers in ultra low volume sprayer for management of pod borer,Helicoverpa armigera (Hübner) in pigeonpea ecosystem

A study was conducted to evaluate the bioefficacy of different oil carriers (sunflower oil, seamum oil, neem oil, mineral oil), sugar solution and water formulation to be used in ultra low volume sprayer (ULV) along with rynaxypyr 18.5 SC (Coragen) for the management of pod borer at the Agricultural Research Station, Gulbarga, Karnataka, India during the kharif season of 2011–2012. The results revealed that the sesamum oil carrier fits well with rynaxypyr 18.5 SC and recorded the lowest mean pod borer larval population after last spray (1.0 per five plants) the lowest pod damage (23.20%), grain damage (18.30%) and higher grain yield (9.43?q/ha) with a high B:C ratio of 3.64 in the plot sprayed with the sesamum oil carrier. The findings suggested that the sesamum oil carrier in ULV sprayer is suitable and practicable in pigeonpea ecosystem for effective management of pod borer with no risk of phytotoxicity, spray drift and operational difficulties. The foregoing studies indicated that the performance of sesamum oil carriers was superior to other carriers in terms of suppression of larval population, reduction in pod damage and harnessing higher yield.