摘要:

AbstractThe effects of the closely related chitin synthesis inhibitors, the nucleoside peptidyl antibiotics nikkomycin X/Z, nikkomycin Z and polyoxin D on the two‐spotted spider mite,Tetranychus urticae, have been studied by electron microscopy. The application of all three compounds, nikkomycin X/Z (95% active ingredient, ratio of components unknown), nikkomycin Z (pure component) and polyoxin D (pure component) disrupted cuticle, eggshell and yolk synthesis and influenced the silk and salivary glands. Ultrahistological patterns indicated differences in the mode of action of the three compounds which were especially evident in an alteration of the nuclear ultrastructure in the mid‐gut cells, which was only caused by polyoxin D. Mechanisms of action and their consequences on function, based on previously published information on the action of these compounds, are discus

ISSN:0031-613X    

DOI:10.1002/ps.2780170602

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractNew 2,2‐dimethylcyclopropanecarboxylic acids bearing halogenated 1,3‐alkadienyl substituents at position 3 of the cyclopropane ring were synthesised and the insecticidial activities of their 3‐phenoxybenzyl and α‐cyano‐3‐phenoxybenzyl esters against housefly (Musca domestica), Colorado potato beetle (Leptinotarsa decemlineata) and Egyptian cotton leafworm (Spodoptera littoralis) were determined. The activity of these compounds varied according to the relative position of the halogen substituents on the diene chain. The observed changes of activity with the structure of the side chain are discussed in terms of the coplanarity of the conjugated

ISSN:0031-613X    

DOI:10.1002/ps.2780170603

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe metabolism of propetamphos by insecticide‐resistant and susceptible houseflies,in vivo, was investigated. Two major pathways of propetamphos degradation were found. The first is the major route of detoxification for both resistant and susceptible strains at low doses and involves a hydrolysis of theP–O‐vinyl bond, ultimately resulting in the formation of carbon dioxide. The second major pathway involves conjugation. As the dose increases, so does the importance of this pathway. Those strains of houseflies with greater conjugative capacity are able to tolerate greater doses of propetamphos than those strains with lesser conjugative capacity. The properties exhibited by this conjugate are consistent with those of glutathione conjugates. This is further supported by a parallel between reported values of glutathioneS‐transferase activity in the houseflies tested and tolerance to prope

ISSN:0031-613X    

DOI:10.1002/ps.2780170604

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractEarthworms,Eisenia fetida, were treated by surface exposure to the fungicide benomyl at various stages of posterior segmental regeneration. Teratogenic effects of benomyl were observed when worms were treated 7–11 days after amputation (i.e. during the normal period of segmental replication), but not during days 1–5, 13–17, or 19–23. Teratogenic effects included a reduction in the number of regenerated segments, an increased frequency of segmental groove anomalies, and a variety of monstrosities. The effects of benomyl treatment on the number of regenerated segments and frequency of anomalies were dose‐dependent within a narrow concentration range (approximately 0.2–5.0 mg litre−1); at higher concentrations (e.g. 25 mg litre−1) teratogenic effects were less frequent because the onset of segmental delineation was delayed until well after exposure. Non‐invasive electrophysiological recordings from treated worms indicated that functional integrity of giant nerve fibre conduction pathways was established in all anomalously regenerated tail segments, except in a two‐tailed monstrosity. The evidence supports the hypothesis that these teratogenic effects derive from an antimitotic mode of action of benomyl on seg

ISSN:0031-613X    

DOI:10.1002/ps.2780170605

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe relative parasitic fitness of isolates ofPyricularia oryzaewith different sensitivities to isoprothiolane (di‐isopropyl 1,3‐dithiolan‐2‐ylidenemalonate) and IBP (S‐benzylO, O‐di‐isopropyl phosphorothioate) was studied in the absence of fungicides. Four field isolates (S‐1,S‐2,MR‐1 and MR‐2) and two in‐vitro mutants (Rvt‐1 and Rvt‐2) were used for disease epidemics. S‐l and S‐2 were wild types; MR‐1 and MR‐2 were sensitive to isoprothiolane and moderately resistant to IBP, and Rvt‐1 and Rvt‐2 were resistant to both fungicides. Twelve epidemics were made by inoculating rice seedlings with mixed conidial suspensions of two isolates or mutants. The value of relative parasitic fitness (W= 0‐1.0) was calculated for each isolate and epidemic. S‐l and S‐2 were stronger (W= 1.0) than MR‐2, Rvt‐1 and Rvt‐2; but weaker (W= 0.75, 0.73, respectively) than MR‐1. MR‐1 was strongest among all isolates and mutants used. MR‐2 was slightly weaker (W= 0.9‐1.0) than S‐l and S‐2, but stronger than Rvt‐1 and Rvt‐2. Rvt‐1 and Rvt‐2 had smaller values ofW, ranging from 0.25‐0.58, in the epidemics with each field isolate. These results suggest that the proportions of in‐vitro mutants do not increase unless intensive selection pressure is given, and would be expected to decrease rapidly after the selection pressure is removed. Isolates moderately resistant to IBP, such as MR‐1 and MR‐2, however, had high values ofW, suggesting that they would increase or would not decrease rapidly in the absence of selection pressure. These results may well explain why isolates highly resistant to isoprothiolane and IBP have seldom been found, and why a large number of isolates moderately r

ISSN:0031-613X    

DOI:10.1002/ps.2780170606

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe first syntheses ofsyn‐12‐hydroxydieldrin,syn‐12‐hydroxyendrin andanti‐12‐hydroxyendrin have been accomplished by debenzoylation and epoxidation of three isomeric adduction products of hexachlorocyclopentadiene and 1,7,7‐trinorborna‐2,5‐dien‐7‐yl benzoate. A third known metabolite of endrin, 12‐ketoendrin, and a putative metabolite of dieldrin, 12‐ketodieldrin, were prepared from the corresponding alcohols by oxidation with chromium trioxide. Characterisation of the three debenzoylated intermediates assyn‐12‐hydroxyaldrin, andsyn‐ andanti‐12‐hydroxyisodrin constitutes the first syntheses of these three possibl

ISSN:0031-613X    

DOI:10.1002/ps.2780170607

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe active ingredient of the fungicide ‘Panoctine’ is a standardised mixture of guanidated amine acetates (GTA). This mixture was degraded in German standard soils with half‐lives of 400–600 days. GTA dressed on to wheat seed at 0.75 g kg−had a half‐life of 20 days when seed was incubated in Petri dishes at 25°C and of 80 days on seed sown in pots of soil stored outside. These results demonstrate a substantial influence of the test system on the degradation times of guanidated am

ISSN:0031-613X    

DOI:10.1002/ps.2780170608

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

ISSN:0031-613X    

DOI:10.1002/ps.2780170609

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractAn attempt has been made to link the results of laboratory toxicological studies on tsetse flies to the specification of application requirements for control or eradication of tsetse flies in the field. Relevant parameters have been identified and a consideration of their physical interactions has provided the basis for predicting the effect of changes in the operational variables on the efficiency of kill. Some implications for future developments in application techniques and for requirements in research and development have been recognised.

ISSN:0031-613X    

DOI:10.1002/ps.2780170610

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe fungicidal activity of a series of 2‐(1‐alkenyl)‐3‐hydroxy‐1,4‐naphthoquinones and their acetates has been assessed against various fungiin vitroand against others, notably powdery mildews,in vivo, and the activity compared with that of analogous compounds bearing saturated side chains. Several of the compounds demonstrated a broad spectrum of activityin vitro. Whereas the presence of α‐unsaturation in the side chain is essential for the in‐vitro activity against the non‐obligate fungi tested, it is of virtually no importance for the curative effect againstErysiphe graminison barley. Only the corresponding acetates had activity against t

ISSN:0031-613X    

DOI:10.1002/ps.2780170611

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY