Fumigant toxicity of<Emphasis Type="Italic">Eucalyptus blakelyi</Emphasis> and<Emphasis Type="Italic">Melaleuca fulgens</Emphasis> essential oils and 1,8-cineole against different development stages of the rice weevil<Emphasis Type="Italic">Sitophilus oryzae</Emphasis>

Essential oils extracted fromEucalyptus blakelyi (1,8-cineole, 77.5%),Melaleuca fulgens (1,8-cineole, 56.9%) and 1,8-cineole were shown to have fumigant toxicity against different development stages ofSitophilus oryzae. The eggs ofS. oryzae were the most tolerant, followed by pupae, larvae and adults in that order.M. fulgens oil,E. blakelyi oil and 1,8-cineole at 100 μl per liter of air gave, respectively, LT₅₀ values of 16.2, 17.4 and 9.1 h for adults, 31.1, 19.3 and 17.5 h for larvae, 55.6, 75.2 and 39.7 h for pupae, and required >7 days for eggs. Only 1,8-cineole (200 μl ⁻¹ air) gave a significant egg kill by 7 days and the LT₉₅ was 134.5 h. 1,8-Cineole could be a useful new fumigant. http://www.phytoparasitica.org posting Oct. 3, 2004.     

Influence of temperature on toxicity of propylene oxide at low pressure against<Emphasis Type="Italic">Tribolium castaneum</Emphasis>

Toxicity of propylene oxide (PPO) at low pressure against the most common stored-product insect,Tribolium castaneum (Herbst), over a short exposure time, was tested at three different temperatures (16°, 22° and 30°C). Toxicities of PPO at 100 mm Hg were strongly influenced by ambient temperature. LD₅₀ and LD₉₉ toxicities ranged from 4.7 to 28.9 mgl ⁻¹ and from 10.5 to 72.6 mgl ⁻¹ respectively, showing that susceptibility was positively correlated to the temperature. The LD₉₉ values for all life stages (except the larval stage) were significantly lower at 30° than those at 16° and 22°C. However, the LD₉₉ values for all life stages (except the pupal stage) at 16° were not significantly different from those at 22°C. A concentration × time (Ct) product of 291, 171 and 98 mg h/l was required to obtain complete mortality (99%) ofT. castaneum at 16°, 22° and 30°C, respectively. Thus, the efficacy of PPO at 100 mm Hg to all life stages ofT. castaneum also decreased as the temperature decreased from 30° to 16°C. http://www.phytoparasitica.org posting Sept. 28, 2004.     

Acaricidal properties of piperazine and its derivatives against house‐dust and stored‐food mites

BACKGROUND: Piperazine derivatives possess pharmacological properties, yet the acaricidal activity of these compounds has not been investigated. This study was conducted to evaluate the colour alteration and acaricidal activity of piperazine derivatives against Dermatophagoides spp. and Tyrophagus putrescentiae (Schrank) using filter paper and fumigant methods. RESULTS: In a fumigant bioassay, 1‐phenylpiperazine (7.83 µg cm^?2) against D. farinae (Hughes) was found to be 4.7 times more toxic than DEET (36.84 µg cm^?2), followed by benzyl benzoate (9.72 µg cm^?2), piperazine (11.41 µg cm^?2), 1‐ethoxycarbonylpiperazine (20.14 µg cm^?2) and 1‐(2‐methoxyphenyl)piperazine (22.14 µg cm^?2). In a filter paper bioassay, 1‐(2‐methoxyphenyl)piperazine (3.65 µg cm^?2) was 5.7 times more toxic than DEET (20.64 µg cm^?2), followed by 1‐ethoxycarbonylpiperazine (4.02 µg cm^?2), 1‐phenylpiperazine (4.75 µg cm^?2), benzyl benzoate (7.83 µg cm^?2) and piperazine (10.59 µg cm^?2). Similar results have been exhibited with piperazine derivatives against D. pteronyssinus (Troussart). However, no activity against T. putrescentiae was observed for piperazine derivatives, except for piperazine. CONCLUSIONS: These results indicate that piperazine derivatives may be suitable as vapour‐phase acaricide fumigants owing to their high volatility, acaricidal activity and safety. 1‐Phenylpiperazine was found to be an excellent mite indicator based on the colour change it induced. Taken together, these findings indicate that piperazine derivatives may be used to replace existing problematical acaricides owing to their activity and ability to act as a mite indicator. Copyright © 2009 Society of Chemical Industry     

1,3-dichloropropene distribution in soil when applied by drip irrigation or injection in pineapple culture

The fumigant nematicide, 1,3-dichloropropene (1,3-D VL; ‘Telone’ II) and a soluble liquid formulation, 1,3-D SL were tested in a pineapple field experiment to evaluate the vapor movement of the two formulations in soil gas as well as the movement and persistence of 1,3-D SL in soil profiles. Prior to planting, 1,3-D VL (407 kg ha^?1) was hand-injected into the soil in two parallel rows per planting bed to approximate the practice of chisel injection. 1,3-D SL (407 kg ha^?1) was applied with 6 mm of water by drip irrigation through a drip tube in the center of the bed. Post-plant applications of 1,3-D SL (113 kg ha^?1) were made at three-month intervals during a two-crop cycle. 1,3-D concentrations in soil gas were lower at the plant line in the drip treatment compared with the 1,3-D VL treatment, owing to differences in application method and fumigant placement. 1,3-D in the vapor phase reached peak concentrations 24 h after injection in the 1,3-D VL treatment compared with a peak at 48 h in the drip treatment. Post-plant applications of 1,3-D SL resulted in a three-fold difference in peak 1,3-D soil gas concentrations between replicate applications, the concentration being inversely related to soil moisture at the time of sampling. Drip application of 1,3-D SL resulted in a relatively uniform distribution of 1,3-D across the bed and to a depth of 45 cm. There was no effect of formulation on downward movement of 1,3-D and persistence in soil profiles sampled two weeks and one month after application. Rainfall which occurred 9 days after pre-plant 1,3-D fumigation resulted in leaching of 1,3-D to a depth of 150 cm in soil profiles. Due to the short half-life of 1,3-D, significant penetration of 1,3-D in the soil was observed only when irrigation or rainfall occurred soon after application.     

储粮熏蒸剂的发展动态与前景

本文扼要介绍了当前主要储粮熏蒸剂的发展动态与前景，包括溴甲烷的淘汰问题、磷化氢的现状与前景、熏蒸能力有限的敌敌畏、面临淘汰的氯化苦、对环境友好但应用成本较高的二氧化碳和氮气、研究中的氧硫化碳和甲基磷、重新评价的甲酸乙酸、二硫化碳、环氧乙烷等的情况，并对新熏蒸剂研究开发前景进行了简单分析。     

Effects of propylene oxide doses on Cyperus and Belonolaimus control and nutrient absorption in tomato

Among the current methyl bromide alternatives under study, propylene oxide has shown potential to control soilborne diseases, nematodes, and weeds in polyethylene-mulched tomato (Lycopersicon esculentum Mill.). Therefore, field trials were conducted to determine the most effective propylene oxide doses against populations for the nematode Belonolaimus spp. and the weed Cyperus spp. and their effect on nutrient uptake. Propylene oxide doses were 0, 190, 380, 570, 760, and 950 L/ha. Data indicated that populations of Belonolaimus and Cyperus rapidly decreased with 570 L/ha of propylene oxide. Propylene oxide doses also affected foliar concentrations of phosphorus and potassium. There was a linear increase of phosphorus concentration as dose increased, whereas potassium concentration increased rapidly after 190 L/ha of propylene oxide. The highest tomato yields were obtained with application of 760 and 950 L/ha of propylene oxide.     

Methyl bromide alternatives for strawberry and tomato pre-plant uses: A meta-analysis

This paper reports the results of a meta-analytic synthesis of information from a large number of horticultural experiments that evaluated the technical feasibility of methyl bromide alternatives as soil fumigants in strawberry (Fragaria ananassa) cultivation in California, Florida, and Spain, and in tomato (Solanum lycopersicum) cultivation in Florida. A technically feasible alternative is defined as a treatment that provides pest control and crop yields similar to methyl bromide standard fumigation. We selected papers using five criteria, which jointly ensured inclusion of field experiments that contained usable information on at least three treatments—(1) an untreated control, (2) a methyl bromide treatment, and (3) a treatment that is an alternative to methyl bromide treatment. Because of the differences in regional cropping environments, we performed separate meta-analyses for four crop/region combinations. To explore the potential effects of missing information on past fumigation history and pest pressure on the results, we performed two sensitivity analyses, in which the set of usable field experiments included only those experiments in which the improvement of the methyl bromide treatment yield over the control yield was either 15% or 50%. Finally, the definition of several potential alternative chemical treatments took into account differences in formulations and application rates. The results we obtained do not support the technical superiority of methyl bromide over its alternatives. We found several potential alternatives for which we could not reject the hypothesis of technical feasibility, based on the experimental data for strawberries in California and Spain. In particular, the results on strawberry field experiments in California indicate that the estimated effect size of the treatment using 1,3-dichloropropene/chloropicrin 65:35 formulation (applied at the standard rate) was close to the estimated effect size for methyl bromide. The results from strawberry and tomato field experiments in Florida were inconclusive. However, this does not establish that methyl bromide is technically superior to its alternatives. Given the data-related limitations of the analysis, standard protocols are necessary for conducting and reporting the experiments to allow for more meaningful synthesis of the experimental data.     

农药的混用及其在储粮害虫害螨防治中的应用

文章对储粮杀虫剂的混配基本原则，单剂的选用方法以及国内有对机农药与其它杀虫剂的混配，熏蒸剂的混用进行了介绍，并提出需对农药混剂在作用对象，效果，作用机理及毒理学方面作进一步的研究。     

甲酸乙酯对锯谷盗的熏蒸活性研究

采用密闭熏蒸法,在实验室条件下研究甲酸乙酯(EtF)对储藏物害虫锯谷盗Oryzaephilus surinamensis成虫的熏蒸活性。结果表明,熏蒸时间和温度显著影响甲酸乙酯对锯谷盗的熏蒸致死效果。甲酸乙酯在24 h内就能发挥很好的熏蒸活性,在低温条件下处理比在高温下熏蒸效果更好。在20℃、25℃和30℃条件下,熏蒸处理锯谷盗成虫24 h,其LC50分别为14.78、16.77和17.65μL/L。     

多·硫烟剂防治马尾松落针病试验初报

笔者通过采用13.0%多·硫烟剂、2.5%百菌清烟剂对马尾松落针病进行防治试验,结果表明:13.0%多·硫烟剂防治马尾松落针病的适宜用药量为1600～2000g/666.7m2,且对马尾松生态安全。