bluuebunny/crossref_metadata_2025 huggingface dataset:
Residues of carbon tetrachloride and 1,2‐dibromoethane in cereals and processed foods after liquid fumigant grain treatment for pest control
Authors: Jagielski Jan , Scudamore Keith A. , Heuser Stanley G.
Published: November 2006

Residues of halogenated hydrocarbon ‘liquid’ fumigants occurring in cereals and their products as a result of use for insect control continue to be of concern in technologically advanced as well as developing countries. Carbon tetrachloride and ethylene dibromide residues remaining in wheat, maize, barley and sorghum shortly after fumigation, during storage for periods of up to 1 year and after processing have been determined, with the fumigants applied either as liquids or vapours. Amounts of residues occurring in bread made from wheat containing residual fumigants were also measured. Current methods of use of these fumigants are discussed with reference to the results of these experiments and interim recommendations are made for post‐ treatment handling of cereals.
Plant membranes under dry conditions
Authors: Simon Eric W.
Published: November 2006

In dry seeds membrane phospholipids adopt a quite, different orientation (the hexagonal phase) to that found in the membranes of cells in growing plants (the lamellar phase). As a seed imbibes water early in germination the phospholipids must change from the hexagonal to the lamellar configuration. Biophysical and biological data indicate that this change occurs as the water content reaches 20–30% of fresh weight. During the early phase of imbibition and before membrane integrity is fully established, solutes leak out of imbibing seeds, and it is suggested that this period could be used to advantage if it is wished to insert hormones, micronutrients or pesticides into seed cells.
The detection and distribution of organophosphorus and carbamate insecticide‐resistant Myzus persicae (Sulz.) in Britain in 1976
Authors: Sawicki Roman M. , Devonshire Alan L. , Rice Adrian D. , Moores Graham D. , Petzing Stephanie M. , Cameron Anne
Published: November 2006

Examination of the enzyme that determines the level of resistance to organophosphorus insecticides and carbamates in Myzus persicae (Sulz.) and bioassays were used to establish the frequency and resistance levels of resistant aphids on outdoor crops in Britain in 1976. The biochemical tests, staining esterase‐4 after electrophoresis and total esterase determination, were more sensitive than bioassays. However the dip‐test, a simple, rapid and inexpensive bioassay designed to detect resistance and its different levels gave satisfactory results which warrant its use where biochemical detection of resistance is not possible. Carboxylesterase activities of M. persicae collected in 1976 fell into three groups: low, moderate and high, and these were correlated with differences in tolerance to dimethoate, demeton‐S‐methyl and pirimicarb. Aphids with low esterase activity were susceptible(S). Those with the moderately active enzyme (R1) had five‐ to seven‐fold resistance to the two organophosphorus insecticides and were marginally resistant (about two‐fold) to pirimicarb. The insects with the most active esterase (R2) were strongly resistant to dimethoate (resistance factor, RF × 126) and moderately resistant to demeton‐S‐methyl (RF × 17) and pirimicarb (RF × 8). Some R1, but no S aphids survived the recommended dose of demeton‐S‐methyl on field crops probably because they were under the lowest leaves and therefore protected from direct contact with the spray. Laboratory tests demonstrated that these R1 aphids tolerated the residual deposit and systemic dose present in the leaves of the treated potato‐plants. This enabled their numbers to recover in treated fields much faster than the susceptible insects which could do so by immigration only when the residual dose in the plant was no longer toxic. R1 aphids were common throughout the country particularly in eastern England where susceptible aphids were rare, but in the Shardlow area of Derbyshire susceptible aphids were in the majority throughout the summer. R2 aphids were found only in samples from the west of Scotland and northern England. The implications of the presence of aphids with different levels of resistance for aphid control are discussed.
Photolysis of dichlofluanid
Authors: Clark Terence , Watkins David A. M.
Published: November 2006

Dichlofluanid was found to be degraded by ultraviolet light in methanol, benzene and acetone solution. The products from acetone solution included N,N‐dimethyl‐N′‐phenylsulphamide, phenyl isocyanate, phenyl isothiocyanate and dimethylamidosulphonyl chloride. G.c.‐m.s. studies further indicated the presence of bis(dichlorofluoromethyl) disulphide, 1‐(dichlorofluoromethylthio)propan‐2‐one and 1‐(dichlorofluoromethylsulphonyl)propan‐2‐one. In‐vitro tests against Botrytis cinerea showed that irradiation decreased the activity of dichlofluanid and that synergism did not occur.
Pesticides in cereal production
Authors: North John J.
Published: November 2006

A cereal grower will normally attempt to maximise his returns from resources used without prejudicing the future. Historically, for the control of weeds, pests and diseases growers have preferred husbandry methods and the use of ‘resistant’ varieties. Economic pressures, technical developments and subsequent changes in farming systems demand more reliance on pesticides. The adoption of the Common Agricultural Policy and the relatively higher cereal prices improve the cost: benefit ratio from their more extensive use. Additionally, quality standards arising directly or indirectly from EEC legislation, where these can be influenced by pesticide application, will further encourage their routine application. In the longer term, increased fixed costs will encourage the grower to insure against crop losses by the use of prophylactic pesticide applications where appropriate. New systems of production to reduce fixed costs will be adopted, probably involving further use of pesticides. Growers will always wish to contain variable costs as far as is possible: as better forecasting of disease and pest epidemics is developed prophylactic treatments will be discarded. Examples of the economic benefits or penalties of adopting alternatives to pesticides are given.
Some fundamental considerations of controlled release
Authors: McFarlane Neil R. , Pedley Jeffrey B.
Published: November 2006

Several physicochemical factors which can influence the interactions between pest and pesticide are described. These relate mainly to the pesticides partition, reaction and diffusion processes. The combination of diffusion and partition processes in controlled release formulations is examined in some detail via theoretical consideration of encapsulated material. Extensive control of release can be obtained this way with the release time ranging from minutes to years. The advantages and disadvantages of controlled release are discussed and the relevance of theoretical considerations of this type to commercial objectives is touched upon.
Progress towards the integrated control of sugar cane pests
Authors: Fewkes Derek W. , Greathead David J.
Published: November 2006

Sugar cane is an important tropical and sub‐tropical crop that occupies large areas of land around sugar factories capable of processing 5000 to 15 000 tonnes of cane per day. These areas are usually kept continuously under the same crop, about one‐tenth to one‐third of the land being ploughed and replanted with sugar cane every year. The major pests of sugar cane are rats, stalk borers, white grubs and froghoppers. Other important pests include root‐feeding nematodes, top borers, scale insects, planthoppers and soldier fly. Chemical control is practised to some extent against most of these pests, although biological control is the most common method of combating stalk‐borers and has had other notable successes, particularly in Hawaii and Mauritius. Rats are controlled with baits incorporating poisons such as anticoagulants, endrin or zinc phosphide. Aerial applications of insecticide sprays, dusts or granules are used against some stalk‐borers (azinphos‐methyl), froghoppers (omethoate, propoxur, vamidothion, methidathion, monocrotophos, malathion, carbaryl, gamma‐HCH) and plant hoppers (malathion, fenitrothion, endrin). White grubs, soldier fly (crude HCH, dieldrin) and nematodes [1,2‐dibromoethane (EDB), 1,2‐dibromo‐3‐chloropropane (DBCP), aldicarb] are usually controlled with soil applications of the appropriate chemicals. The use of chemical control is restricted in some areas because it is too costly and in other areas because of its possibly adverse effects upon the natural or biological control of other pests. Historically, pest control in sugar cane has tended to develop towards a simple integrated system, making use of cultural methods in conjunction with chemicals or exotic parasites and predators. Increasingly, allowance has been made for the contribution of indigenous natural enemies to the prevention of crop losses by a more careful, selective use of insecticides.
Pest control in coffee
Authors: Bardner Richard
Published: November 2006

Coffee pests have been estimated to cause losses of about 13% of the world yield but are most serious in Africa, particularly where Arabica coffee is grown. Coffee pests are normally indigenous and except for the berry borer beetle (Hypothenemus hampei Ferrari) there has been little movement between the main production areas. There is a great variety of pests but because the crop is perennial, evergreen and only grown in areas without climatic extremes, pest populations only rarely become intolerable, being held in check for most of the time by parasites, predators and diseases. Routine spraying of insecticides in coffee plantations is undesirable for these kill parasites and predators and often result in pest outbreaks. An effective but simple integrated control system has been evolved over many decades in East Africa, using a combination of cultural, biological and chemical control. Pest numbers are monitored continuously by growers and insecticides are used as selectively as possible. The system is ideally suited to areas where labour is cheap but technology is expensive.
Response of susceptible and resistant peach‐potato aphids Myzus persicae (Sulz.) to insecticides in leaf‐dip bioassays
Authors: Sawicki Roman M. , Rice Adrian D.
Published: November 2006

The response of susceptible (S), moderately resistant (R1) and strongly resistant (R2) peach‐potato aphids, Myzus persicae (Sulz.) to organophosphorus, carbamate and pyrethroid insecticides was tested by a leaf‐dip bioassay. The aphids were placed on potato leaves (dipped in insecticide solutions 1–2 or 24 h before infestation) and their mortality examined 48 h later. R1 aphids were virtually susceptible to most of the carbamates, demephion and acephate, but were slightly to moderately resistant (2.1–9.4 times) to permethrin, cypermethrin and (S)‐α‐cyano‐3‐phenoxybenzyl (1R)‐cis‐3‐(2,2‐dibromovinyl)‐2,2‐dimethylcyclopropanecarboxylate (I), (NRDC 161), to 5,6,7,8‐tetrahydro‐2‐methylquinolin‐4‐yl dimethylcarbamate (II), (Hoechst 25 682) and demeton‐S‐methyl. R2 aphids resisted more strongly or very strongly (between 65 and 1280 times) the pyrethroids, demeton‐S‐methyl (×94), II (×83) and demephion (×9), and were slightly to moderately (2–5 times) resistant to acephate, pirimicarb, ethiofencarb and 2‐(dimethylcarbamoyloxyimino)‐3‐methoxyimino‐N,N‐ dimethylbutyramide (III), (DPX 3853). Both resistant strains were susceptible to nitrilacarb [4,4‐dimethyl‐5‐(methylcarbamoyloxyimino)pentanenitrile] complex (1:1) with zinc chloride (IV), (AC 85 258). The implications of these results in terms of practical aphid control are discussed.
Effect of temperature on the toxicity of low concentrations of methyl bromide to diapausing larvae of the warehouse moth Ephestia elutella (Hübner)
Authors: Bell Christopher H.
Published: November 2006

The performance of low concentrations of methyl bromide against diapausing larvae of Ephestia elutella at 15 and 25°C was assessed in extended exposure periods. At concentrations of 1.9 mg litre−1 and below, test batches required higher concentration‐time (ct) products for 100% kill at 25°C than at 15°C. The minimum concentration at which the concentration: time relationship still applied was between 1.3 and 1.9 mg litre−1 at 15°C, whereas at 25°C it was between 2.7 and 4.0 mg litre−1. For many individuals within each population sample, however, lower concentrations at moderate dosage levels remained lethal. At 25°C, a ct product of about 90 mg litre−1 h gave between 53 and 77% kill at 6.1, 4.0, 2.7 and 1.9 mg litre−1. The trends observed suggest that the most tolerant members of the population have an enhanced ability to detoxify methyl bromide at the higher temperature. The implications of the results for the build‐up of resistance and for practical control measures are discussed.
The structure and properties of O‐ethyl O‐isopropyl O‐(5‐methoxy‐1‐methyl‐6‐oxo‐1H‐pyridazin‐4‐yl) phosphorothioate and by‐products in the technical product
Authors: Konečný Václav , Kováč Štefan
Published: November 2006

The structure and some chemical and physical properties of a new insecticide O‐ethyl O‐isopropyl O‐(5‐methoxy‐1‐methyl‐6‐oxo‐1H‐pyridazin‐4‐yl) phosphorothioate (I) and by‐products present in the technical product are described. The structures of I and the by‐products were proved by infrared, ultraviolet, 1H‐n.m.r., Raman and mass spectrometry.
In‐vitro metabolism of O,O‐diethyl S‐(N‐methylcarbamoylmethyl) phosphorodithioate by mouse liver
Authors: El‐Oshar Mohamed A. , Dauterman Walter C.
Published: November 2006

The in‐vitro metabolism of O,O‐diethyl S‐(N‐methylcarbamoymethyl) phosphorodithioate in mouse liver was studied. The major route of metabolism was via the mixed‐function oxidases present in the microsomal fraction, which formed the oxygen analogue, O,O‐diethyl hydrogen phosphorothioate and diethyl hydrogen phosphate upon addition of nicotinamide‐adenine dinucleotide phosphate (NADPH). In the absence of NADPH, the carboxylic acid analogue (S‐carboxymethyl O,O‐diethyl phosphorodithioate) was isolated only from the microsomal fraction. Addition of glutathione to the 100 000 g supernatant resulted in no metabolism of the parent compound. However, addition of glutathione to the 10 000 g supernatant resulted in the carboxylic acid formed by amidase activity being further metabolised to O,O‐diethyl hydrogen phosphorodithioate by a glutathione‐dependent reaction.
The activity of some pyrethroids against Periplaneta americana and Blattella germanica
Authors: Chadwick Peter R.
Published: November 2006

The knockdown and contact killing actions of various pyrethroids were compared using Blattella germanica and Periplaneta americana. A wide range of knockdown activity was found; 5‐benzyl‐3‐furylmethyl (1R)‐cis‐3‐(dihydro‐2‐oxo‐3‐thienylidenemethyl)‐2,2‐dimethylcyclopropanecarboxylate (RU 15525) acted fastest, more rapidly than pyrethrins, against B. germanica as well as having a low LD50 value. Topical application and direct spray tests showed that (S)‐α‐cyano‐3‐phenoxybenzyl (1R)‐cir‐3‐(2,2‐dibromovinyl)‐2,2‐dimethylcyclopropanecarboxylate (NRDC 161) was more active as a killing agent, by an order of magnitude, than cismethrin, the next most active compound, and also had considerable knockdown activity. Piperonyl butoxide generally had little synergist effect. Female P. americana were over three times more tolerant than males to a range of insecticides applied topically. Residual knockdown action in the WHO resistance test was observed to provide baseline data. There was little overlap in speed of action between pyrethroids and other insecticides among the compounds tested.
Action of pesticides on earthworms. Part I: The toxicity of cholinesterase‐inhibiting insecticides to earthworms as evaluated by laboratory tests
Authors: Stenersen Jørgen
Published: November 2006

The action of seven cholinesterase‐inhibiting pesticides [aldicarb, carbaryl, carbofuran, oxamyl, paraoxon (diethyl 4‐nitrophenyl phosphate) parathion and trichloronate], the organochlorine insecticide, gamma‐HCH, and the nematicide potassium N‐hydroxymethyl‐N‐methyl(dithiocarbamate) (PHMD) on four earthworm species was investigated by laboratory toxicity tests. Eisenia foetida was the most tolerant species to the pesticides tested. Aldicarb was the most toxic pesticide to this species, causing severe dehydration prior to death or at sublethal concentrations. Aldicarb was also toxic to the other species (Allolobophora caliginosa, A. chlorotica and Lumbricus rubellus), while oxamyl, the other oxime carbamate, was not toxic to any of them. Carbaryl and carbofuran at low concentrations were lethal to A. caliginosa, A. chlorotica and L. rubellus, but E. foetida could tolerate high concentrations without dying, although low concentrations severely affected its ability to work the soil or to disappear from the soil surface. Paraoxon, parathion, trichloronate and gamma‐HCH were moderately toxic with low lethal effect to all species. The ability to work the soil was moderately affected by parathion, trichloronate and gamma‐HCH. PHMD was toxic to all the species. The lethal and non‐lethal effects of the pesticides are discussed in relation to their possible biochemical mode of action in earthworms, and the data are compared with published information from field trials.
Electrical theory and measurements on an experimental charged crop‐spraying system
Authors: Jones Christopher D. , Hopkinson Peter R.
Published: November 2006

A series of electric‐field measurements taken in the vicinity of spinning disc atomisers maintained at a high potential is described. Information on the space charge density, droplet mobility and droplet trajectories is deduced from a theory which is developed in the paper. Direct evidence of improved performance in strong winds compared with uncharged sprays was obtained.
Determination of the products of surface‐induced hydrolysis of organophosphorus pesticides
Authors: Mingelgrin Uri , Kljger Lilian , Saltzman Sarina
Published: November 2006

A procedure which enables the identification of the hydrolysis products of a number of phosphoric and phosphorothioic esters was developed. This procedure, which includes thin‐layer chromatography (t.l.c.), gas chromatography and u.v. spectroscopy, has been used to demonstrate that surface hydrolysis on kaolinite is a general property of bioactive phosphoric and phosphorothioic esters. The path of hydrolysis was shown to be the breakage of the PO A or PSA bond, where A is the electron attracting moiety of the organic molecule.
Effects of sodium azide and methyl bromide on soil bacterial populations, enzymic activities and other biological variables
Authors: Kelley Walter D. , Rodriguez‐Kabana Rodriguez
Published: November 2006

The application of a granular formulation of sodium azide (Smite 8G), to pine nursery beds at rates of 0, 22.4, 67.2 and 134.5 kg active ingredient ha−1 under water seal or plastic seal, was compared over a 1‐year period with methyl bromide, applied at a rate of 650 kg ha−1, to determine the effects of soil bacterial populations, soil enzymic activities, development of mycorrhizal roots, weed population and incidence of root diseases. Bacterial populations at 24 days after treatment had increased in proportion to the amount of sodium azide added; however, highest numbers of bacteria were recorded from the methyl bromide‐treated plot. At the last sampling date no significant differences were observed in bacterial populations among treatments. Neither sodium azide nor methyl bromide caused permanent changes in soil enzymic activities or adversely affected mycorrhizal root development on pine seedlings. Sodium azide at 134.5 kg ha−1 and methyl bromide both significantly decreased the number of Cyperus spp. plants in plots; however, the number of pine seedlings exhibiting a root disease was highest in plots receiving these treatments.
Time related factors in Heliothis control on cotton
Authors: Morton Neil
Published: November 2006

Most factors in Heliothis control on cotton are crucially related to time but all are interrelated one with another and form two complex interactions hinging on the pest life cycle. One is the crop‐pest interaction and the other the control strategy. This paper reviews most of the factors and reports work carried out in Swaziland to elucidate some of them. In the crop‐pest interaction the timing of the initial attack and a cue for spraying can be indicated by development of an alternate host and, in Swaziland, by reference to the average date of maize tassellation. Later infestations are measured by scouting and a comparison is made of the two main systems, the first based on a small part of many plants and used in the USA, and the second based on the whole of a few plants in Africa. Their respective purposes are discussed and economic spray thresholds based on them are presented. The compensatory ability of the plant diminishes as the season progresses but in Swaziland manual bud/flower removal experiments over 3 years on raingrown and irrigated cotton showed that prior to 12 January (9‐12 weeks from planting) removal increased the yield in half the cases whilst later removal could cause a decrease. The natural Heliothis infestation was allowed to remove fruits in an experiment by leaving spray gaps and the results confirmed those of the previous manual experiments except that damage continued for about 2 weeks after spraying restarted. This advanced the critical date to 31 December but up to three sprays could be saved without loss of yield and possibly with a yield bonus. In the control strategy the different stages of the life cycle are considered as targets but the most obvious is normally the first instar larvae. Rapid plant growth can dictate frequent spray applications regardless of deposit persistence which may need to be longer when using aircraft in spite of Heliothis oviposition occurring predominantly on exposed surfaces. Temperature‐independent or fumigant insecticides or those affecting the adult may best be sprayed in the evening when cooler and calmer post‐treatment conditions occur and adults are starting to fly.
Recent advances in biological electron microscopy
Authors: Robards Anthony W.
Published: November 2006

The main features of electron microscopy (EM) are outlined; transmission EM, high‐voltage transmission EM, scanning EM, scanning transmission EM and their uses in biological research are discussed. The use of these techniques with X‐ray analysis is mentioned and reference is made to the problems of specimen preparation.
Localisation and quantification of elements in biological tissues by electron‐microprobe analysis
Authors: Dick David A. T.
Published: November 2006

An introduction is provided to the basic ideas and theory of electron‐microprobe analysis as applied to biological tissue. The nature of characteristic and continuous X‐rays is outlined. X‐ray detectors, specimen preparation and the relative advantages and disadvantages of thick and thin section techniques are discussed.
Studies of cellular dynamics by laser Doppler microscopy
Authors: Earnshaw John C. , Steer Martin W.
Published: November 2006

The sources and magnitudes of typical molecular, macromolecular and cytoplasmic motions in cells are reviewed and compared with the ability of the conventional light microscope to detect and quantify them. The principles of laser Doppler spectroscopy are introduced; the type and range of motions detectable are reviewed and found to be superior to conventional light microscopy in certain respects. A laser Doppler microscope system has been developed that allows accurate placement of the beam within the cell and combines visual monitoring of the cellular behaviour with the superior resolution of motions from spectroscopy. The system operates with a non‐destructive, low intensity, laser beam that permits continuous monitoring of diffusive and translational motions in living cells.
Mechanism of DDT resistance in larvae of the mosquito Aedes aegypti L.; The effect of DDT selection
Authors: McDonald Alan E. , Wood Roger J.
Published: November 2006

Selection with pp'‐DDT was applied to fourth‐stage larvae of Aedes aegypti along four lines, starting with larvae of the F2 generation from crosses between a susceptible strain and each of four resistant strains (two of Trinidad origin and two of Bangkok origin). Larval resistance increased substantially along each line but there was little or no change in the percentage breakdown of DDT to 1,1‐dichloro‐2,2‐bis(4‐chloro‐phenyl)ethylene (pp'‐DDE) in vivo and in no line were these two variables significantly correlated. Percentage breakdown was generally higher at 10 mg than at 50 mg litre−1. DDT uptake (defined as content of DDT+pp'‐DDE) was generally higher after exposure to 50 mg than to 10 mg litre−1. It increased significantly with selection in the TE×NS line; it remained unchanged in the T8 × NS line; and in the other two lines (BSJ × NS and B51 × NS), it increased initially but dropped as selection progressed, the reduction being highly significant in the second of these lines. The amount of internal residual (unmetabolised) DDT tolerated by larvae of the TE × NS line also increased significantly with resistance. The levels in the other lines followed the pattern of uptake, remaining steady in T8 × NS despite the increase in survival, rising at first and then declining in the two Bangkok lines. Thus selection produced a higher tolerance to internal unmetabolised DDT in the two Trinidad lines but led ultimately to a lower content of DDT+pp'‐DDE in the two Bangkok lines. The reasons for this behaviour are discussed.
Mitotic instability in Aspergillus nidulans caused by the fungicides iprodione, procymidone and vinclozolin
Authors: Georgopoulos Spyros G. , Sarris Michael , Ziogas Basil N.
Published: November 2006

The fungicides iprodione, procymidone and vinclozolin were found to increase greatly the frequency of mitotic recombination in diploid colonies of Aspergillus niduluns. Although generally more potent, these fungicides do not appear to differ in their activity from members of a previously suggested ‚aromatic hydrocarbon group’︁ with which they should be classified in this context.
Effects of repeated applications at high rates of chlorthiamid and dichlobenil to blackcurrants
Authors: Clay David V. , McKone Colin E.
Published: November 2006

Chlorthiamid and dichlobenil were applied to blackcurrants each year for five years at doses up to 54 kg ha−1. Growth and yield were not affected but leaf margin chlorosis was caused at the higher rates. No nitrile residues of dichlobenil or chlorthiamid were found in the fruit but 2,6‐dichlorobenzamide (DCB) was present in most samples tested. There were no adverse effects of the treatments on the taste and flavour of the canned fruit. Nitrile residues in the soil were largely confined to the top 15 cm layer. Amounts detected one year after the previous application did not increase with repeated treatments and were always less than 10% of the annual doses. Nitrile residues were less from dichlobenil than chlorthiamid. The rate of disappearance of soil residues present at the end of the 5‐year treatment period was much slower than that of the freshly applied herbicide. During the period of treatment there was generally less DCB than nitrile in the 0‐15 cm layer but more was found in deeper layers and small amounts were detected at all depths sampled (up to 105 cm). These residues had largely disappeared 3.5 years after the final treatment. Test crops sown on the plots two years after the final treatment varied in susceptibility to the residues as follows; barley and cabbage (unaffected) <wheat<lettuce<carrot (most susceptible). In the following year only the treatments with chlorthiamid at 27 and 54 kg ha−1 caused a decrease in the growth of carrots but all the treatments caused skin abnormality.
Characterisation of bound residues of [3H]triforine in the straw of barley grown in the field
Authors: Rouchaud Jean , Moons Chantal , Meyer Joseph A.
Published: November 2006

Barley was grown in an experimental field and, at the growth stage J (during the stem extension stage when the second node of the stem was formed and the next‐to‐last leaf just visible), the aerial part of the plants was sprayed with an aqueous emulsion of a mixture of triforine and [3H]triforine (uniformly labelled in the piperazine ring) at the recommended rate of 250 g triforine ha−1. Barley was harvested when ripe, and the straw was analysed separately. Extraction of the straw with methanol left methanol‐insoluble solids containing an amount of radioactivity (the bound residue) which represented 88 % of the tritium (as with all the subsequently quoted percentages, relative to the total tritium incorporated into the straw). Methanol acidified with hydrochloric acid extracted a further 8% of the triforine‐derived bound residues as radioactive iminodiacetic acid (0.4%). glycine (3.2%), serine (2.0%), ethanolamine (0.2%) and unidentified compounds (2.2%); a neutral detergent solution extracted a further 3% of the radioactive triforine‐derived bound residues as unidentified compounds; these radioactive compounds, which were dissolved by the acidified methanol and by the neutral detergent solution, were thus complexed in the straw to straw constituents. An acid detergent solution extracted a further 58% of the total tritium, which was incorporated by means of σ chemical bonds into the hemicelluloses fraction. Acid hydrolysis of the hemicelluloses yielded a mixture of mono‐saccharides; these were converted into a mixture of osazones (50%), recrystallised several times, and had a constant specific radioactivity, indicating that the mono‐saccharides were tritiated. The plant solids (which contained 19% of the total tritium), left by the acid‐detergent extraction, were processed and separated into the tritium‐containing cellulose (13%) and lignin (6%) fractions. No piperazine was observed in the bound residue of straw. Biochemical pathways are suggested for the radioactive metabolites of [3H]triforine.
Determination of residues of 1‐(2‐cyano‐2‐ methoxyiminoacetyl)‐3‐ethylurea (DPX‐3217) by gas‐liquid chromatography
Authors: Holt Richard F.
Published: November 2006

Residues of the fungicide 1‐(2‐cyano‐2‐methoxyiminoacetyl)‐3‐ethylurea (DPX‐3217) in grapes, potatoes, tomatoes and wine were determined by initial extraction with ethyl acetate, clean‐up by liquid‐liquid partitioning and adsorption chromatography, and final determination by gas‐liquid chromatography with a nitrogen‐selective detector. The sensitivity of the method was 0.04 mg kg−1 based on 50‐g samples. Recoveries of the compound added to untreated substrates averaged approximately 92% in the range of 0.04‐5.0 mg kg−1.
In‐vitro metabolism of a mixture of atrazine and simazine by the soluble fraction (105000g) from goose, pig and sheep liver‐homogenates
Authors: Khan Shahamat U. , Foster Thomas S. , Akhtar M. Humayoun
Published: November 2006

The soluble fraction (105 000g) from goose, pig and sheep liver‐homogenates was found to contain an enzyme which metabolised a mixture of atrazine and simazine in in‐vitro incubations by a combination of hydrolysis and partial N‐dealkylation. Complete dealkylation was not observed as shown by the removal of only one alkyl group, but not both, from the compounds containing chlorine or hydroxyl‐groups attached to the triazine ring.
The antifungal activity of alkyl benzimidazol‐2‐ylcarbamates and related compounds
Authors: Eckert Joseph W. , Rahm Michael L.
Published: November 2006

The fungistatic activity against Penicillium digitatum and Diplodia natalensis decreased slightly in ascending a homologous series of alkyl esters of benzimidazol‐2‐ylcarbamic acid from the methyl ester (carbendazim) to the pentyl ester; the hexyl and octyl esters were inactive. 2‐(Acylamino)benzimidazoles were slightly less active than the analogous alkyl benzimidazol‐2‐ylcarbamates. Introduction of a methylene bridge between the benzimidazole ring and the 2‐methoxycarbonylamino group abolished antifungal activity. Methylation of either the carbamate nitrogen or an imidazole nitrogen of carbendazim produced inactive compounds. Replacement of the benzimidazole ring of carbendazim with various other ring systems was accompanied by marked reduction in antifungal activity.
Inhibition of oviposition in the cattle tick Boophilus microplus by certain acaricides
Authors: Mansingh Ajai , Rawlins Samuel C.
Published: November 2006

Doses of ten acaricides, ranging from 2.5 to 10 μg, induced about 10‐60% mortality and inhibited oviposition in engorged Boophilus microplus as well as preventing larval hatching from the eggs. The effects of the acaricides were dose dependent. The efficacy of acaricides in reducing the reproductive potential (inhibition of oviposition × inhibition of hatching/100) was in the following order: dimethoate > dioxathion > naled > diazinon > chlordimeform > carbaryl > trichlorphon > phosphamidon > gamma‐HCH > fenitrothion. Most of the acaricides also retarded the oviposition cycle, delaying the peak activity by 4‐8 days. The ovarian development in control ticks reached its peak between the 5th and 7th days before decreasing gradually and ceasing completely between the 16‐20th days after engorgement. The protein content of the ovaries and the rate of incorporation of [14C]glycine into the tissues followed a similar pattern. Carbaryl, fenitrothion and naled inhibited these activities. Chlordimeform stimulated [14C]glycine incorporation and increased the ovarian protein content up to the 13th day before resorption of the oocytes. The eggs from treated ticks were mostly non‐viable and contained more protein; those from dioxathion, carbaryl and chlordimeform treatments had a higher dry weight than the control.
Susceptibility of a dieldrin‐resistant and a susceptible strain of the tick Rhipicephalus evertsi evertsi Neumann, 1897 from East Africa, to carbamate and organophosphorus acaricides
Authors: Lourens Jan H. M.
Published: November 2006

A dieldrin‐resistant and a susceptible strain of the tick Rhipicephalus evertsi evertsi Neumann, 1897 from East Africa were compared for susceptibility to nine organophosphorus and a carbamate acaricides, using an internationally approved oil‐based packet test. As only minor differences in response existed between the strains, the presence of cross resistance may be excluded. For some of the acaricides, distinct susceptibility classes were recognised which were probably genetically determined. The tolerances existed independently of the organochlorine‐susceptibility status and were low (by a factor less than 3), except in the case of dimethoate for which resistance factors of up to 10 were present. As susceptibility data were not assessed prior to introduction of the compounds in the field, the lowest susceptibility classes may now be considered as providing baseline data. When compared with data from susceptible reference strains of other ticks such as Boophilus microplus from Australia and R. appendiculatus from East Africa, it is feasible that the tolerances observed in the laboratory will not interfere with practical control.
Comparative modification of insecticide‐resistance spectrum of Culex pipiens fatigans wied. By selection with temephos and temephos/synergist combinations
Authors: Ranasinghe Leonard E. , Georghiou George P.
Published: November 2006

The evolution of strong organophosphorus multiresistance, suppressible by S,S,S‐tributyl phosphorotrithioate (TBPT), in a California strain of Culex pipiens fatigans was examined by further selection with temephos, alone and in combination with the synergists TBPT or piperonyl butoxide (PB). Selection by temephos and temephos + PB increased resistance to higher levels. However, selection by temephos + TBPT virtually abolished TBPT‐suppressible resistance while preventing the emergence of significant alternative resistance mechanisms. The phenomenon of synergism may enable the extended use of an insecticide where alternative resistance mechanisms are either absent or of low efficiency in the target population.
Characterisation of bound residues of [3H]triforine in barley grain grown in the field
Authors: Rouchaud Jean , Moons Chantal , Meyer Joseph A.
Published: November 2006

Barley was grown in an experimental field and at growth stage J (during the stem extension stage when the second node of the stem was formed and the next‐to‐last leaf was just visible), the aerial part of the plants was sprayed with an aqueous emulsion of a mixture of triforine and [3H]triforine (uniformly labelled in the piperazine ring) at the normal rate of 250 g triforine ha−1. The barley was harvested when ripe, and the grain was analysed separately. Extraction of the grain with methanol left methanol‐insoluble solids containing an amount of radioactivity (the bound residue) which represented 75% of the total radioactivity incorporated into the grain. Methanol acidified with hydrochloric acid extracted a further 7% of the triforine‐derived bound residues in the form of radioactive iminodiacetic acid (1.1%), glycine (3.3 %), serine (0.9%), ethanolamine (0.2%) and unidentified compounds (1.5 %); in the grain, these compounds or their precursors had thus been complexed to grain constituents. Aqueous 0.03M sodium hydroxide extracted a further 27% of the total tritium which had been incorporated by means of α chemical bonds into the protein fraction; acid hydrolysis of the proteins yielded radioactive glycine (9.2%), serine (3.9%) and unidentified compounds (13.9%) which could have been a mixture of a large number of other amino‐acids. The plant solids (which contained 41% of the total tritium) left after the alkaline aqueous extractions, were processed and separated into tritiated cellulose (4%) and starch (37%) fractions. The starch was hydrolysed and the resulting glucose was converted into the osazone (34%). After being recrystallised several times, the osazone contained a constant specific radioactivity, indicating that [3H]glucose was present. This glucose may be considered as having a carbon skeleton mainly originating biochemically from some metabolites of [3H]triforine; this tritiated glucose may also be considered as indirect evidence of the biochemical oxidation, by transamination, of the metabolites of [3H]triforine; in barley grain, the tritiated glucose (or at least a part of it) was anabolised into proteins. No piperazine was observed in the bound residues in the grain.
Toxicology and metabolism of chloromethiuron in Boophilus microplus larvae
Authors: Schuntner Charles A. , Thompson Phillip G.
Published: November 2006

The toxicity of the acaricide chloromethiuron, 3‐(4‐chloro‐o‐tolyl)‐1,1‐dimethyl‐ (thiourea), and of nine related compounds to Boophilus microplus larvae was determined by a spray‐tower method. Four of these compounds were toxic but only chloromethiuron and its N‐demethyl derivative were of practical importance. Metabolism of [14C]chloromethiuron, in the formamidine‐susceptible but organo‐phosphorus‐resistant Mt. Alford strain, was compared with that in a chlordimeform‐selected Mt. Alford strain, which in laboratory tests was two to three times resistant to chloromethiuron, chlordimeform and amitraz. The latter strain produced smaller quantities of the toxic N‐demethyl derivative than the Mt. Alford strain; this was the only resistance mechanism determined. Rates of degradation of chloromethiuron were the same in both strains. Piperonyl butoxide strongly antagonised the toxicity of chloromethiuron by 18 to 33 times and depressed the production of the N‐demethyl derivative in both strains (0.3 times that of the control), while degradation rates of chloromethiuron itself were halved by piperonyl butoxide in both strains. These results indicated that the parent material was not toxic until oxidised to the N‐demethyl derivative. As, in addition, some symptoms of chloromethiuron toxicosis in larvae were similar to those caused by formamidine acaricides, a common mode of lethal action is suggested.
Estimation of residues of the molluscicide, niclosamide, in bananas by gas—liquid chromatography of the heptafluorobutyryl derivative of the substituted aniline moiety
Authors: Johnson John S. , Pickering Geoffrey B.
Published: November 2006

A sensitive method for the detection and estimation of residues of the molluscicide, niclosamide, in bananas is described. The procedure involves extraction of the molluscicide, purification of the extract by solvent partition and column chromatography, formation of the heptafluorobutyryl derivative of 2‐chloro‐4‐nitroaniline in 99% yield and determination of the derivative by gas—liquid chromatography with electron‐capture detection. Recoveries from fortified bananas were 89 and 79% at levels of 0.02 and 0.2 mg kg−1, respectively. The sensitivity of the method was such that 0.6 pg of the pure derivative could be detected, based on twice the background noise level on the chromatograph.
The toxic effect of diflubenzuron on Spodoptera littoralis eggs and on their respiration
Authors: Ascher K. R. Simon , Nemny Nadia E. , Ishaaya Isaac
Published: November 2006

The mortality rates of Spodoptera littoralis eggs of different ages when dipped in aqueous dilutions of a liquid diflubenzuron formulation were investigated. Eggs 2‐3 days old were less sensitive than younger eggs, 0‐1 day old. The respiratory rate of eggs 0‐1 day old, 1 or 2 days after treatment, was the same as in the control. Eggs in the control hatched on the next day; on this day, respiration in the treated eggs decreased rapidly, but further decrease was then gradual and the base line was not reached until 11 days after treatment, or 9 days after the maximum respiratory rate had been obtained. The curve with diflubenzuron resembled that obtained with parathion.
A stereoselective versatile synthesis of 3‐(2,2‐ dihalovinyl)‐2,2‐dimethylcyclopropanecarboxylic acids
Authors: Martin Pierre , Greuter Hans , Bellus Daniel
Published: November 2006

A straightforward high‐yield synthesis of cis‐3‐(2,2‐dihalovinyl)‐2,2‐dimethylcyclo‐propanecarboxylic acids is described which uses only inexpensive starting materials and reagents. The synthesis of these acids, involving a [2+2]‐cyclo‐addition of halogenated ketenes with 2‐methylpropene and two rearrangements (the ‚cine’︁ and the Favorskii rearrangements) as the key steps, exemplifies the conceptually new synthesis.
2‐anilino‐3‐methylbutyrates and 2‐(isoindolin‐2‐yl)‐3‐methylbutyrates, two novel groups of synthetic pyrethroid esters not containing a cyclopropane ring
Authors: Henrick Clive A. , Garcia Barbara A. , Staal Gerardus B. , Cerf David C. , Anderson Richard J. , Gill Karen , Chinn Henry R. , Labovitz Jeffrey N. , Leippe Michael M. , Woo Sam L. , Carney Robert L. , Gordon Douglas C. , Kohn Gustave K.
Published: November 2006

A new series of substituted 2‐anilino‐3‐methylbutyrates has been prepared; bioassay data for these compounds onHeliothis virescens, Musca domestica, Aphis fabaeandTetranychus urticaeare presented and discussed. Some unexpected relationships were observed between the nature of the substituents and the biological activity. Increases in foliar stability were noted with certain substitution patterns. Both α‐cyano‐3‐phenoxybenzyl 3‐methyl‐2‐(α, α, α,2‐tetrafluoro‐p‐toluidino)butyrate and the corresponding 2‐(2‐chloro‐α, α, α‐trifluoro‐p‐toluidino)‐3‐methylbutyrate showed good stability in air and light, and exhibited biological activities of a similar nature and potency to those of previously known synthetic pyrethroids. Esters of the (R)‐2‐ anilino‐3‐methylbutyric acids are far more active than those prepared from the (S)‐enantiomers. The (R)‐configuration at C‐2 in these acids is sterically equivalent to the active absolute configuration at the chiral carbon α to the carboxylate group in both the permethrin and the fenvalerate types of pyrethroids. A new class of insecticidal 2‐(isoindolin‐2‐yl)alkanoates is also reported. In this series the most biologically active analogue was α‐cyano‐3‐phenoxybenzyl 3‐methyl‐2‐(4,5,6,7‐tetrafluoroisoindolin‐2‐yl)butyrate. These esters were considerably less stable than the anilino analogues on exposure to air and light.
The synthesis of 3‐(2,2‐Dichlorovinyl)‐1‐ methylcyclopropane‐1,2‐dicarboxylic acid
Authors: Huff Roger K.
Published: November 2006

3‐(2,2‐Dichlorovinyl)‐1‐methylcyclopropane‐1,2‐dicarboxylic acid, a metabolite of the pyrethroid insecticide permethrin, has been synthesised as a mixture of isomers, in four stages, in high overall yield.
A novel series of O,O‐diethyl O‐(1,3‐disubstituted‐1,2,4‐triazol‐5‐yl) phosphorothioates. Part I. Synthesis and laboratory evaluation
Authors: Boschi Pier M. , Gozzo Franco , Longoni Angelo
Published: November 2006

A novel series of O,O‐diethyl O‐(1‐R′‐3‐R″‐1,2,4‐triazol‐5‐yl) phosphorothioates, in in which R″ was an alkyl group and R″ was a radical characterised by the presence of a conjugated multiple bond, generally of a vinyl nature, has been synthesised and tested in the search for new insecticides. Several of the compounds showed a broad spectrum of activity, covering important species of Orthoptera, Hemiptera, Lepidoptera, Coleoptera, Diptera and mites. At the same time they were characterised by a relatively low oral toxicity to rats.
Measured and simulated behaviour of oxamyl in fallow soils
Authors: Leistra Minze , Bromilow Richard H. , Boesten Jos J. T. I.
Published: November 2006

The movement and breakdown of the insecticide and nematicide oxamyl was monitored in fallow sandy loam soils under field conditions. Using measurements of rainfall and evaporation from a water surface, the water flow in soil was simulated by a computer model, and the results were compared with the measured soil‐moisture profiles. The model was extended to simulate the behaviour of oxamyl, using laboratory data for adsorption and rates of degradation in soil. The model generally underestimated oxamyl movement in the first month, whereas it tended to overestimate later movement. The rate of breakdown of oxamyl, as affected by soil type, temperature and soil‐moisture content, was fairly well described. After about 2 months only small amounts of oxamyl remained. Accumulation of oxamyl near the soil surface in dry periods was overestimated, indicating deficiencies in the modelling procedure under these conditions.
The effect of C‐2‐carboxyphenyl derivatives of certain heterocyclic compounds on root geotropism in cress seedlings
Authors: Harris Roger L. N. , Huppatz John L. , Teitei Tsutomu
Published: November 2006

The effects on root geotropism of 2‐carboxyphenyl derivatives of various five‐ and six‐membered heterocyclic compounds have been assessed. In an assay involving cress seedlings, appropriately substituted derivatives of isoxazole, 1,3,4‐ and 1,2,4‐ oxadiazoles, 1,3,4‐thiadiazole, 1,2,4‐triazole, thiazoie, pyridine, pyrimidine and pyridazine were highly effective in eliminating the geotropic response.
The fungitoxicity of substituted 2‐phenylbenzofurans
Authors: Chamberlain Keith , Carter Geoffrey A.
Published: November 2006

Thirty‐seven 2‐phenylbenzofurans, variously substituted in the homocyclic rings, were synthesised and assessed for antifungal activity in laboratory tests. High activity was shown only by compounds containing a hydroxy group, though amino compounds were also fungitoxic but at a lower level. Possible mechanisms by which these substitutions impart fungitoxicity are discussed with particular reference to the partitioning properties of the molecule.