Efficacy of malathion seed treatments for chironomid control in aerially‐sown rice crops

Abstract

Malathion seed treatments were evaluated as a means of protecting aerially‐sown rice from attack by Chironomus tepperi Skuse and other chironomids in New South Wales, Australia. Four treatments were examined: malathion applied to seed at 150, 300, and 450 ga.i/ha, and malathion applied directly to water at 300 ga.i./ha. Chironominae were significantly suppressed for 10 days by all treatments, but populations were often significantly above control levels at 20 and 25 days post‐treatment. None of the treatments significantly reduced other chironomids(predominantly Tanypodinae) at any stage of the trial. Emergence trap data from control and water treatment bays showed that there was, in practical terms, only a single generation of C. tepperi during crop establishment, and that malathion applied directly to water at 300 ga.i./ha almost completely eliminated adult emergence in this species. Bioassays of field‐collected water samples showed that malathion dissipates readily from seed into the water column. Toxicity profiles over time for the 150 and 300 g a.i./ha seed treatments were statistically similar to that for the 300 ga.i./ha water treatment. Although the 450 ga.i./ha seed treatment provided slightly longer residual toxicity, control was not enhanced sufficiently to justify an increase in the existing application rate of 300 ga.i./ha.     

Pest and disease control in blackcurrants and apples by the use of overhead irrigation sprinklers

In field experiments on the effectiveness of overhead irrigation spraying of crop protection chemicals, an oscillating bar sprinkler was compared with hand spraying in post-harvest applications of protective fungicides mancozeb (0.096% a.i.) with zineb (0.022% a.i.) for the control of blackcurrant leaf spot, Pseudopeziza ribis. Twin-jet rotating sprinkler nozzles were compared with conventional automatic spraying of Cox's Orange Pippin apple trees in the application of a malathion emulsion (0.125% a.i.) for the control of apple-grass aphid, Rhopalosiphum insertum and also in applications of pre-blossom dodine emulsion (0.03% a.i.) and post-blossom captan suspension (0.09% a.i.) for control of apple scab, Venturia inaequalis. All applications were made at a nominal rate of 2250 litres/ha (200 gal/acre). On blackcurrants, the hand spraying gave much better control of leaf spot and was shown by fluorescent tracer assessment to give more cover on the lower surfaces of the leaves than the sprinkler. On apple, the rotating sprinklers gave almost as good control of apple-grass aphid and apple scab as the conventional automatic spraying. The malathion deposit levels, determined by g.l.c., on the flower trusses were also comparable, though the liquid volume distribution from the irrigation nozzles was uneven.     

The effects of helicopter applied adulticides for riverine tsetse control on Simulium populations in a West African savanna habitat. I. introduction,methods and the effect on biting adults and aquatic stages of Simulium damnosum s.l.

Abstract

Helicopter applied insecticides used for tsetse control were investigated for their potential to reduce populations of Simulium damnosum s.l. in riverine forest in the Guinea savanna zone of southwestern Upper Volta. Populations of aquatic stages and biting females were sampled before and after spraying. Deltamethrin applied at 12·5 g a.i./ha to a 30 km length of riverine vegetation almost eliminated adults for a period of about nine days. Residues which fell into the water killed all larvae in the river. Endosulfan at 100 g a.i./ha applied to a similar stretch of vegetation caused a reduction of over 60% in biting adults for 11 days, but residues falling into the river killed only young larvae. Neither dieldrin at 400 g a.i./ha, endosulfan at 10 g a.i./ha nor deltamethrin at 12.5 g a.i./ha applied to a 5 km insecticide barrier between the experimental blocks and the untreated river appeared to have much effect. This suggests that most S. damnosum were traversing the barrier without coming into contact with the insecticides.     

Reduced agent-area treatments (RAAT) for management of rangeland grasshoppers: Efficacy and economics under operational conditions

The Reduced Agent-Area Treatment (RAAT) approach involves applying low rates of insecticides in intermittent swaths to control grasshopper infestations in an effort to achieve a more economically and environmentally sound pest management strategy compared to traditional blanket applications at high rates. Operationalscale (>250 ha) insecticide tests on Wyoming rangeland grasshopper infestations (18-56 grasshoppers/m2) at two sites in 1997 revealed that carbaryl yielded 94% control as a blanket treatment (560 g/ha) and 81% control as a RAAT application (280 g/ha applied to 50% of the infested land). Malathion yielded 90% control as a blanket treatment (683 g/ha) and 91% control as an RAAT application (342 g/ha applied to 80% of the infested land), and fipronil (4 g/ha) yielded 98% control as a blanket treatment and 92% control when applied to 33% of the infested land. One year after treatment, the RAAT and blanket-treated plots had 2-4% (Pollet Ranch) of the densities in untreated plots. Economic analysis showed that the greatest benefit:cost ratio was obtained with the fipronil-RAAT method, followed by carbaryl-RAAT, malathion-RAAT, malathion-blanket, fipronil-blanket, carbaryl-blanket. The worst-case outcome of fipronil and carbaryl with a RAAT approach had a greater economic return than the best-case outcome of no treatment. Following blanket treatments, non-target arthropod abundance was highest in the fipronil plots, followed by carbaryl and malathion; arthropod biomass was higher in the carbaryl plots than fipronil and malathion. In RAAT plots, arthropods were generally less impacted than in the blanket plots, with the least reduction caused by fipronil and carbaryl. Thus, the RAAT tactic appears to be economically and environmentally superior to blanket treatments under large-scale, operational conditions.     

An Assessment of Swath Width and Frequency of Application of V.I.v. Captafol Sprays on Tomato in Northern Nigeria

Abstract

V.I.v. captafol spray treatments applied using a 1.8m swath (3.3 kg a.i./ha/application) were more effective than treatments using a 3.6 m swath (1.67 kg a.i./ha/application). At sites with more than 700 mm rainfall during the crop's field life weekly applications were more effective than spraying at 10- and 14-day intervals, but at the drier sites (< 650 mm rainfall) spraying at 10 days was adequate.     

The effects of glyphosate on the development and cell infrastructure of white mustard (Sinapis alba L.) seedlings

The phytotoxicity of glyphosate(N-(phosphonomethyl glycine) to seedlings of white mustard (Sinapis alba) cultivated indoors was studied. Yellowing and wrinkling of leaves was observed, necrotic spots appeared and the elongation of the seedlings was significantly reduced at doses 0–49 kg ai/ha and above. Only when sprayed at 4–97 kg ai/ha was the effect of glyphosate 100% lethal (5–7 days after spraying) At the highest concentration of herbicide a marked decrease in chlorophyll content was found but with 0–49 kg ai/ha the chlorophyll content was found to be higher than that in the leaves of control plants. Two and fourteen days after spraying with glyphosate and the commercial product samples of leaf and stem were harvested for electron microscopy. Cellular defects in the leaves ranging from slight swelling to complete disruption of the chloroplasts were detected at the two highest herbicide doses 48 h after spraying. These defects were intensified with time und in addition other sub-morphological changes occurred: decrease in starch grain content, an increase in the number of dictyosomes and mitochondria, disruption of tonoplasts and increase of plastoglobuli In the more central parts of stem segments the commercial product resulted in greater cellular effects than did glyphosate. It is suggested that the differences may be due to the surfactant.     

绿僵菌油剂防治东亚飞蝗田间试验

20 0 2年在天津大港以绿僵菌LA06油剂防治东亚飞蝗进行了田间试验。绿僵菌分生孢子系在实验室采用常规双相产孢系统 ,在大米固体培养基上培养产生。油剂用V(大豆油 )∶V(煤油 ) =3∶7配制。试验区选用蝗蝻相对不易迁出迁入的高密度地带 ,3龄蝗蝻占 90%,成点片状密集分布。超低量喷雾 1hm2 喷施绿僵菌油剂1.5L ,含绿僵菌干粉48g ,其分生孢子含量为1.37×10¹²个。药效调查采用全区密度级别估测法调查试验区虫口密度变化 ,并以笼罩法试验作为旁证。结果表明 ,在施药后 6～9d蝗蝻种群急剧减少 ,第 18天虫口减退率达 81.1%。田间防治与笼罩试验结果一致     

机动弥雾法施用70%吡虫啉水分散粒剂防治小麦蚜虫的雾滴沉积密度与防效的关系

田间采用背负式机动弥雾机对70%吡虫啉水分散粒剂进行喷雾试验,证明若吡虫啉喷雾雾滴在小麦穗部形成一定的沉积密度即可有效防治麦蚜。当70%吡虫啉水分散粒剂用水稀释2 333倍(有效成分300 mg/L),雾滴密度在54,133和280个/cm2条件下,施药7 d后对麦蚜的防治效果分别为83.3% ,88.7%和93.7%;当药剂稀释1 167倍(有效成分600 mg/L),雾滴密度在75,142和291个/cm2条件下,7 d后对麦蚜的防治效果分别为88.1%,94.5%和96.5%。采用背负式机动弥雾机,采用常量150 L/hm2、低浓度(300 mg/L)喷雾时,小麦穗部、旗叶上的雾滴沉积密度分别为177±12,113±8个/cm2,沉积量分别为27.4±6.8,6.6±1.6 ng/cm2,地面流失率为12.8%,7 d后的防治效果为94.0%; 当采用低容量75 L/hm2、高浓度(600 mg/L)喷雾时,小麦穗部、旗叶上的雾滴沉积密度分别为127±13,91±7个/cm2,沉积量分别为29.8±1.2, 6.7±0.6 ng/cm2,地面流失率为10.6%,7 d后的防治效果为93.8%。生产中建议采用吡虫啉低容量75 L/hm2、高浓度600 mg/L喷雾,省工、省水、省时。     

Persistence studies with [14C] 2,4-D in soils previously treated with herbicides and pesticides

The persistence of [¹⁴C] 2,4-D at a rate equivalent to 1 kg/ha was compared under laboratory conditions in samples of heavy clay, sandy loam, and clay loam at 85% of field capacity moisture and 20 ± 1°C which had either received no pre-treatment, or had been pre-treated for 7 days at the 2 μg/g level with the herbicides benzoylprop-ethyl, diclofop-methyl, dinitramine, flamprop-methyl, nitrofen, picloram, tri-allate, trifluralin, and a combination of tri-allate and trifluralin. The breakdown of [¹⁴C] 2,4-D was also studied in the same soils that had similarly received pre-treatments of 2 μg/g of the cereal seed dressing Vitaflo-DB, the insecticide, malathion, and a combination of Vitaflo-DB and malathion. In each soil type, the half-life of the 2,4-D was similar regardless of whether the soil had, or had not, received any pre-treatment, indicating that none of the chemicals investigated adversely affected the soil degradation of 2,4-D.     

Pest and disease control with low doses of pesticides in low and ultralow volumes applied to intensive apple trees

In 3 year field experiments on the development of more economical methods for pest and disease control on intensively planted dessert apple trees, low dose applications of one-tenth of the normal quantities of pesticide in one-hundredth, one-tenth and one-fifth of the normal volumes were compared with conventional high volume spraying at 2250 litres/ha. An experimental tractor-mounted mist blower, a motorised knapsack mist blower and a fan-assisted disc sprayer were each used to apply the pesticides in 225, 45 and 22.5 litres of water/ha. Control of the apple-grass aphid, Rhopalosiphum insertum, obtained by low dose spraying of demeton-S-methyl (8 g a.i./ha) combined with azinphos-methyl (37 g a.i./ha) in 225 and 22.5 litres/ha in 1971 and of fenitrothion (70 g a.i./ha) in 225, 45 and 22.5 litres/ha in 1972 and 1973 was almost equal to that obtained by the conventional high volume method. Low dose applications of benomyl fungicide programmes gave poor control of apple scab, Venturia inaequalis in 1971 when the disease incidence on the fruit was very high at 73%, but in 1972 and 1973, when it was moderately high at 42–45%, control was almost equal to that given by the conventional high volume method. Under these conditions all the low dose methods gave better control with benomyl than with dodine/captan programmes.     

Field efficacy of three insecticides against cabbage stink bugs (Heteroptera: Pentatomidae) on two cultivars of white cabbage

Abstract

In 2002 – 2003, three insecticidal substances were tested for their ability to reduce the damage inflicted on plants of white cabbage by cabbage stink bugs, Eurydema ventrale and E. oleracea (Heteroptera: Pentatomidae). The two cultivars of cabbage tested were: the early cultivar, ‘Tucana F₁’, which requires about 60 days from transplanting to harvest, and the mid-early cultivar ‘Hinova F₁’, which requires about 120 days. In a field experiment, the growth and damage on cabbage plants sprayed with malathion (two sprays), potassium soap [potassium salts of fatty acids] (five sprays), and refined rape oil (five sprays) were compared to the growth and damage on unsprayed plants. Potassium soap and refined rape oil are considered to be environmentally friendly insecticides. In 2002, plants of the cultivar ‘Tucana’, that were treated with malathion had the highest plant weights [PW], head weights [HW], HW/PW ratio, and the lowest number of frame leaves. In the drier year of 2003, there were no significant differences in damage between the three treatments for either cultivar, except during the last assessment done on 13 August. In 2003, plants of ‘Tucana’, treated with potassium soap, had the highest PW and HW. The significantly lowest PW and HW values were recorded from the untreated plants. For the cultivar ‘Hinova’, the PW and HW were heaviest from the plants treated with malathion. In both years, the HW/PW ratio of Hinova (mid-early cultivar) did not differ between treatments, while the plants of ‘Tucana’ (early cultivar) treated with malathion had the highest ratio. Of the three substances tested, malathion was the most effective at reducing the damage on white cabbage plants caused by cabbage stink bugs. However, in an attempt to reduce the use of synthetic insecticides, instead of malathion, we recommend the use of refined rape oil (49 EUR/ha), as it is as effective as potassium soap (81 EUR/ha), but much cheaper.     

Response to the insecticide chlorpyrifos by arthropods on maize canopy

We assessed the response of maize canopy arthropods to the insecticide chlorpyrifos. Four 0.3 ha (18 2 180 m) plots were divided into two subplots, a control and a treated area. During tasseling of the plants, the treated area was sprayed twice, with an interval of 3 days. Ten plants were sampled: 1 day before spraying, and 7, 14, 21 and 28 days after spraying. The insecticide had no effect on insect herbivores: a high density of Spodoptera frugiperda larvae was present in the treated plots. A few predator arthropod species were negatively affected by the insecticide, but their numbers or activity increased 2 weeks after the treatment of the plots. A canonical variate analysis showed no pronounced effect of the insecticide on arthropod communities; the largest variations on species abundance were related to sampling occasion. These results can be explained by the combination of the short period of chlorpyrifos residual activity on the plant surface and the great potential for recolonization of the areas by most of the monitored arthropods.     

Some Preliminary Findings on the Value of Granular Nematocides for Improving Banana Production in the Windward Islands

Abstract

Granular applications of prophos 5 g a.i., phenamiphos 3 g a.i., carbofuran 2.5 g a.i. and oxamy! 6 g a.i. to bananas in the planting holes and subsequent surface applications at 2, 6, 10, 14 and 18 months after planting have given good nematode control as compared with a standard DBCP (dibromochloropropane) (75% e.c.) application of 11.23 l/ha (5.7 cc per plant) every six months and untreated plots. Although the differences in plant crop yields are not statistically significant the production cycle of the granular nematocide treatments was 23–30 days faster than that of control and DBCP treatments. Production data from the ratoon crop indicates a similar pattern.     

The Use of ULV Malathion Bait Sprays for the Control of Olive Fly (Dacus oleae Gmel.) by Aerial Applications in Cyprus

Bait spraying at a rate of 1 lit./ha. (0,2 lit. of ULV Malathion at 96%+ 0,8 lit. protein hydrolysate Atropaz) gave positive results in the control of the olive fly and olive moth but was insufficient against the olive weevil. Applications at low and ultra-low volume were clearly more economical and permitted larger areas to be treated. Therefore, it is suggested that the use of malathion concentrate aerial bait spraying be expanded in Cyprus in the control of olive fly.     

A World-Wide Organization to Promote the Development of Biological Control

Abstract

Three experiments were conducted to evaluate the efficacy of metribuzin in tea fields. These were a field trial in plots infested with a wide range of weeds, a pot experiment using Paspalum conjugatum and a microplot experiment with 100 Ageratum conyzoides plants/plot. Metribuzin at 0.70, 1.05, 1.40 and 2.10 kg a.i./ha was applied in 450 l water/ha. All rates were satisfactory after 1 week but residual activity increased with application rate; metribuzin at 2.10 kg a.i./ha was significantly superior after 6 weeks. Control after 8 weeks was reduced due to the presence of resistant species. Against Paspalum conjugatum metribuzin at 1.40 kg/ha gave good control for 8 weeks but 2.10 kg/ha was necessary for 12 weeks control. All rates compared favourably with dalapon (4.48 kg a.i./ha). Against Ageratum conyzoides metribuzin at all rates gave good control for up to 12 weeks and significantly better than 2, 4-D at 1.12 kg a.i./ha. Most other grass and broadleaved weeds were satisfactorily controlled at 1.40 kg a.i./ha. Metribuzin with its marked post-emergent effect and prolonged soil residual activity from 6-12 weeks after application, depending on weed species, may become an important tool in pre-monsoon weed control programmes in tea fields. It did not induce any phytotoxic symptoms on mature tea.     

Space Treatment of Warehouses Using Dichlorvos1)

Details are given of the performance of Vapona Pest Strips and of an automatic dichlorvos sprayer developed to prevent infestation of clean or fumigated stored commodities, for infestation control on stored carobs. Air concentrations after spraying a nominal dose of 10 μg/1 of total store space averaged approximately 1.0. μ g/l after 30 minutes and less than 0.3 μ g/l after 3 hours. Residues found on carobs after daily spraying of stores at 10 μ g/1 for 96 days were in the range of 0.2 - 2.0 ppm. Ephestia cautella Walk, and Lasioderma serricorne (F.) become established in carobs after harvest and are the principle pests causing damage during storage. Effective control of E. cautella was obtained by using Shell Vapona Pest Strips at two strips/100 m³ or by daily spraying of dichlorvos at 10g/1,000 m² (10μ g/1). No effect was observed against migrating larvae of E. calidella (Guen.) or E. figulilella Greg, nor against Bracon hebetor Say., the hymenopterous parasite attacking all three Ephestia species. The automatic dichlorvos sprayer is equipped to apply a predetermined dose at time of peak flight activity, 18–20 hours each evening. On stored carobs, no spraying is needed after October because the commodity temperature falls below 20⁰C, too low for active development of the pest species. 23 automatic sprayers are now used in Cyprus to protect the whole carob crop from storage pests.     

氟铃脲在韭菜中的残留分析及膳食风险评估

为评价氟铃脲在韭菜中使用的安全性,开展氟铃脲在韭菜中的残留量及残留降解研究。进行1年4地田间试验。消解动态试验按氟铃脲11250 g/ha(562.5 g a.i/ha,推荐最高剂量的1.5倍)施药;最终残留试验按氟铃脲11250 g/ha(562.5 g a.i/ha,推荐最高剂量的1.5倍)和7500 g/ha(375 g a.i/ha,推荐最高剂量)施药,施药1~2次,施药间隔7d,1次施药按照药后间隔10、14、21d采集韭菜样品;2次施药按照末次药后间隔7、10、14d采集韭菜样品。液相色谱串联质谱法对氟铃脲进行定量分析。田间消解动态试验表明:氟铃脲在韭菜中消解较快,在山东保护地和安徽露地半衰期分别为7.7和11.5d。膳食风险评估结果表明,氟铃脲在韭菜中的残留风险处于安全水平。建议使用5%氟铃脲乳油防治韭蛆,用药量7500~11250 g/ha,韭菜收割后2~3d,根部喷淋,最多施药2次,施药间隔7d,安全间隔期为14 d。     

Studies on the Efficacy of Various Insecticides Against Mustard Aphid [Lipaphis erysimi (Kalt)]

Abstract

An experiment was designed to test the efficacy of various insecticides for the control of mustard aphid (Lipaphis erysimi (Kalt)) on mustard (Brassica juncea), variety RL 18 at the Research Farm of the Haryana Agricultural University, Hissar (India). Out of the 13 insecticides tried, each at two levels, it was found that methyldemeton 250 ml and menazon 250 g a.i. gave the maximum control of mustard aphid. Maximum yield of 1111 kg/ha was obtained with methyldemeton 250 ml (a.i./ha) against 360 kg/ha of the control.     

Comparative efficacy and economics of insecticides against chickpea semilooper,Autographa nigrisigna Walker (Noctuidae: Lepidoptera) infesting chickpea

Abstract

All fifteen insecticides tested significantly reduced pest levels. Permethrin 25 e.c. @ 150ga.i./ha proved significantly superior than other insecticides during both the years when observed 3 days after treatment but was at par with deltamethrin 2.8 e.c. and fenvalerate 20 e.c. when observed 7 and 15 days after spraying. Isofenphos was least effective, however, it did not differ significantly from phosalone during 1981–82 and fenitrothion, triazophos and phosalone during 1982–83. Maximum and the minimum cost benefit ratios of 1 : 10.6 and 1 : 4.0 were obtained in gamma BHC and fenvalerate treated plots respectively.     

N-3型无人直升机施药方式对稻飞虱和稻纵卷叶螟防治效果的影响

为了阐明喷洒药械N-3型无人直升机(N-3 UAV)对稻飞虱和稻纵卷叶螟的防治效果及应用前景,进行了飞机不同作业高度和不同喷洒浓度的田间药效试验.结果表明,在水稻分蘖后期,飞机每公顷喷洒48％毒死蜱·锐劲特EC 432 g(有效成分,下同),施药后3、5、10d对稻飞虱的防治效果为96.93％、92.21％、88.12％,对稻纵卷叶螟的保叶效果为63.29％、54.00％、58.33％,均优于传统担架式喷雾机喷洒防治效果.在水稻孕穗期,无人机在3m和5m的作业高度下,每公顷喷洒25％吡蚜酮SC 75 g,施药后10 d对稻飞虱的防治效果与每公顷喷洒60 g和52.5 g时防治效果无显著差异;每公顷施用40％二嗪·辛硫磷EC 480 g和384 g防治稻纵卷叶螟,施药后10d,3m作业高度下的杀虫效果均达90.90％,优于5m和7m的杀虫效果.