Dissipation and sorption of six commonly used pesticides in two contrasting soils of New Zealand

We investigated dissipation and sorption of atrazine, terbuthylazine, bromacil, diazinon, hexazinone and procymidone in two contrasting New Zealand soils (0–10 cm and 40–50 cm) under controlled laboratory conditions. The six pesticides showed marked differences in their degradation rates in both top- and subsoils, and the estimated DT₅₀ values for the compounds were: 19–120 (atrazine), 10–36 (terbuthylazine), 12–46 (bromacil), 7–25 (diazinon), 8–92 (hexazinone) and 13–60 days for procymidone. Diazinon had the lowest range for DT₅₀ values, while bromacil and hexazinone gave the highest DT₅₀ values under any given condition on any soil type. Batch derived effective distribution coefficient (K _d ^eff) values for the pesticides varied markedly with bromacil and hexazinone exhibiting low sorption affinity for the soils at either depth, while diazinon gave high sorption values. Comparison of pesticide degradation in sterile and non-sterile soils suggests that microbial degradation was the major dissipation pathway for all six compounds, although little influence of abiotic degradation was noticeable for diazinon and procymidone.     

UPLC-线性离子阱串联质谱法测定水中新烟碱类杀虫剂

水样经离心后,采用直接进样超高效液相色谱线性离子阱串联质谱法快速测定水中9种新烟碱类杀虫剂.试验表明,该方法在20.0 ng/L～200 ng/L范围内线性良好,方法检出限为2.9 ng/L～8.4 ng/L,实际水样的加标回收率为81.2％ ～109％,测定6次结果的RSD为4.1％ ～13.9％,基质效应不明显.将...     

Toxicity of new pyrethroid in pest insects Asciamonuste and Diaphania hyalinata,predator Solenopsis saevissima and stingless bee Tetragonisca angustula

There is increasing demand for new products for vegetable pest management. Thus, the aim of this study was to assess the toxicity of pyrethroids with acid moiety modifications to measure the insecticidal activity of these compounds on the lepidopteran vegetable pests Diaphania hyalinata (L.) (Lepidoptera: Pyralidae) and Asciamonuste (Latreille) (Lepidoptera: Pieridae) and evaluate their selectivity for the predatory ant Solenopsis saevissima (F. Smith) (Hymenoptera: Formicidae) and pollinator Tetragonisca angustula (Latreille) (Hymenoptera: Apidae: Meliponinae). Racemic mixtures of five new pyrethroids (30 µg molecule mg^?1 insect body weight) resulted in high (100%) and rapid (stable LD₅₀ after 12 h) mortality in D. hyalinata and A. monuste. In A. monuste, the trans-pyrethroid [12] isomer showed similar toxicity to permethrin. For D. hyalinata, the trans-pyrethroid [9] isomer and cis-pyrethroid [10] isomer were as toxic as permethrin. Due to their low selectivity, these new pyrethroids should be applied on the basis of ecological selectivity principles to minimize impacts on nontarget organisms S. saevissima and T. angustula.     

鲫鱼(Carassius auratus)体内胆碱酯酶的组织分布及其对氨基甲酸酯类杀虫药剂的敏感度

鲫鱼(Carassius auratus Linnaeus)是重要的淡水鱼类,也是重要的食用鱼种.鱼体内胆碱酯酶(ChE)活性的降低是水体环境抗胆碱酯酶类药剂污染的重要生物化学标记.本文研究了鲫鱼体内乙酰胆碱酯酶(AChE)和丁酰胆碱酯酶(BuChE)的组织特异性分布及其对灭多威、硫双灭多威、克百威以及丁硫克百威等4种氨基甲酸酯类药剂的敏感度.AChE主要分布在鲫鱼的脑部,提取液中含有Triton X-100时,AChE的比活力要比无Triton-100时大,说明AChE是膜结合的.鲫鱼中肌肉、胰脏、肝脏、肠道中BuChE比活力较高.灭多威、硫双灭多威、克百威、丁硫克百威对鱼脑中的AChE的抑制中浓度(IC50)分别为9.47×10-7 mol/L,1.34×10-6 mol/L,2.40×10-7mol/L,2.75×10-6mol/L.上述4种氨基甲酸酯类农药对鱼脑中的AChE的抑制具有很好的剂量关系,表明鲫鱼脑AChE可以作为水体环境中氨基甲酸酯类药污染的生物化学标记.     

Comparison of gas chromatography and immunoassay methods in quantifying fenitrothion residues in grape juice processed into alcoholic drinks

Abstract

Wine and Arak, the national alcoholic drink in Lebanon, were prepared from grape juice fortified with fenitrothion to a concentration of 20ppm. Samples of the 11 fractions produced by the fermentation and distillation steps were analyzed for fenitrothion residues using gas chromatography (GC) and enzyme‐linked immunosorbent assay (ELISA). Results of residue analyses showed that the two techniques were highly correlated (r = 0.978) and indicated that fenitrothion was stable during the fermentation steps but not during distillation. The clarified wine 35 days later contained about 85% (15.3 ppm) of the fenitrothion concentration found in the juice as determined by GC analysis. Arak was prepared by a two‐steps distillation of the clarified wine. The alcohol distillate and undistilled fraction from the first distillation contained 2.5 ppm and 5.8 ppm of fenitrothion, respectively. No fenitrothion residues were detected by both techniques in the four fractions collected from the second distillation step.     

83—1除草剂和速杀威杀虫剂的小鼠耳肿致敏试验

本文采用较新的致敏性检测方法小鼠耳肿实验对８３—１除草剂和纯中药杀虫剂速杀威进行了检测。实验共设６个组，包括：速杀威原液，１０％速杀威，０．１６％８３—１，０．３２％８３—１及阴性和阳性对照组。结果显示４个受试物组在致敏后２４小时和４８小时均未观察到致敏作用，说明该受试物在此条件下不具致敏性，同时也验证了小鼠耳肿试验用于有色受试物检测致敏性的优越性。     

Priorities for forestry insecticide application technology research

Abstract

A survey was conducted to determine research priorities for forest insecticide application technology research. The target audience was persons with an interest in the topic (users, applicators, researchers, regulators). One quarter of the forestry users of insecticides felt that ground application technology research should have higher priority whereas three quarters felt that aerial application technology research should have higher priority. Five problems which ranked high for most respondent groups, were: 1) Increase the residual efficacy of Bt and viruses; 2) Determine how to develop public support for aerial application of insecticides in forestry; 3) Determine appropriate, scientifically‐based buffer zone widths required to prevent significant environmental impact in sensitive areas; 4) Develop techniques for rapid and accurate determination of Bt and virus tank mix potency; 5) Develop a practical deposit assessment technique for operational Bt and virus applications.     

Inhibition kinetics of acid and alkaline phosphatases by atrazine and methomyl pesticides

The main objective of this work was to investigate the kinetic characteristics of acid and alkaline phosphatases isolated from different sources and to study the effects of the herbicide atrazine and insecticide methomyl on the activity and kinetic properties of the enzymes. Acid phosphatase (ACP) was isolated from the tomato plant (Solanum lycopersicum L. var. lycopersicum); alkaline phosphatase (ALP) was isolated from two sources, including mature earthworms (Aporrectodea caliginosa) and larvae of the Egyptian cotton leafworm (Spodoptera littoralis). The specific activities of the enzymes were 33.31, 5.56 and 0.72 mmol substrate hydrolyzed per minute per milligram protein for plant ACP, earthworms ALP and cotton leafworm ALP, respectively. The inhibition kinetics indicated that atrazine and methomyl caused competitive–non-competitive inhibition of the enzymes. The relationships between estimates of K_m and V_max calculated from the Michaelis–Menten equation have been explored. The extent of the inhibition was different, as estimated by the values of the inhibition constant K_i that were found to be 3.34 × 10^?3, 1.12 × 10^?2 and 1.07 × 10^?2 mM for plant ACP, earthworms ALP and cotton leafworm ALP, respectively, with methomyl. In the case of atrazine, K_i were found to be 8.99 × 10^?3, 3.55 × 10^?2 and 1.36 × 10^?2 mM for plant ACP, earthworms ALP and cotton leafworm ALP, respectively.     

Etude sur l'activite initiale et la persistance d'un larvicide experimental a base de bacillus thuringiensis var. israelensis et d'une preparation commerciale contenant l'insecticide organophosphore temephos

Abstract

The larvicide activity of the experimental preparation SAN 402 I WDC containing B. Thuringiensis var. Israelensis and that of Abate 500 E (44 % temephos) were tested on the larvae of Aedes aegypti. The studies were performed on the following media : distilled water, pure and buffered at pH 9, 7 and 4 and pond water whether or not free from materials in suspension. The activity of both preparations is not influenced by the composition of the media, exception made for the presence of materials in suspension. The persistance varies according to the kind of the media and the concentration level. It is in general rather low. Both preparations behave rather similar, the microbial insecticide however is more influenced by the presence of materials in. suspension.     

Toxicity of the Mosquito Control Pesticide Scourge® to Adult and Larval Grass Shrimp (Palaemonetes pugio)

Abstract

This study investigated the toxicity of various concentrations of technical resmethrin and Scourge® on adult and larval Palaemonetes pugio, a common grass shrimp species. Two types of tests were conducted for each of the resmethrin formulations using adult and larval grass shrimp life stages, a 96-h static renewal aqueous test without sediment, and a 24-h static nonrenewal aqueous test with sediment. For resmethrin, the 96-h aqueous LC₅₀ value for adult shrimp was 0.53 μg/L (95% confidence interval (CI): 0.46–0.60 μg/L), and for larval shrimp was 0.35 μg/L (95% CI: 0.28–0.42 μg/L). In the presence of sediment, technical resmethrin produced a 24-h LC₅₀ value for adult shrimp of 5.44 μg/L (95% CI: 4.52–6.55 μg/L), and for larval shrimp of 2.15 μg/L (95% CI: 1.35–3.43 μg/L). For Scourge®, the 96-h aqueous LC₅₀ for adult shrimp was 2.08 μg/L (95% CI: 1.70–2.54 μg/L), and for larval shrimp was 0.36 μg/L (95% CI: 0.24–0.55 μg/L). The 24-h sediment test yielded an LC₅₀ value of 16.12 μg/L (95% CI: 14.79–17.57 μg/L) for adult shrimp, and 14.16 μg/L (95% CI: 12.21–16.43 μg/L) for larvae. Adjusted LC₅₀ values to reflect the 18% resmethrin concentration in Scourge® are 0.37 μg/L (adult), 0.07 μg/L (larvae) for the 96-h aqueous test, and 2.90 μg/L (adult), 2.6 μg/L (larvae) for the 24-h sediment test. Larval grass shrimp were more sensitive to technical resmethrin and Scourge® than the adult life stage. The results also demonstrate that synergized resmethrin is more toxic to P. pugio than the nonsynergized form, and that the presence of sediment decreases the toxicity of both resmethrin and Scourge®