Modelling pesticide residues on greasy wool: surveys of the insect growth regulators triflumuron and diflubenzuron

Surveys have examined the relationship between louse and flystrike treatments on farms and the resulting residues of insect growth regulators on greasy wool. These results have been summarised using a model of the on-farm survey data. The model estimated the amount of chemical taken up by the wool at application. This was based on experimental breakdown rates of these insecticides on wool determined in controlled trials. The data indicated that the backliner, triflumuron, when used off-shears within 24 h of shearing, was normally applied at slightly higher than the recommended rate on-farm and left an average residue of 30 mg/kg greasy wool at the following shearing 12 months later. Diflubenzuron, applied by dipping or jetting, was usually applied at lower than the recommended rates, and left an average residue of 40 mg/kg on the wool at shearing 12 months later. When treatment was applied to very short wool (<3 weeks after shearing) the residue was only about 20 mg/kg, but when applied at later times after shearing the residue at the following shearing was not closely related to the time of treatment. The model can be used to estimate the expected residue level and likely range of results from most standard insect growth regulator treatments. This will improve advice to producers so most can meet specified industry standards.

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Modelling pesticide residues on greasy wool: using organophosphate and synthetic pyrethroid survey data

Australian Journal of Experimental Agriculture ◽

10.1071/ea98094 ◽

1999 ◽

Vol 39 (1) ◽

pp. 9 ◽

Cited By ~ 3

Author(s):

J. W. Plant ◽

B. J. Horton ◽

R. T. F. Armstrong ◽

N. J. Campbell

Keyword(s):

Survey Data ◽

Synthetic Pyrethroid ◽

Breakdown Rate ◽

Delayed Treatment ◽

Dose Rates ◽

Industry Standards ◽

Breakdown Rates ◽

Average Residue ◽

Survey Results ◽

On Farm

Summary. Several surveys have examined the relationship between organophosphate and synthetic pyrethroid residues in wool and associated treatments. These have been combined and summarised using a model of on-farm survey data. The model estimated the amount of chemical taken up by the wool at application. This was based on experimental breakdown rates of these pesticides on wool determined in controlled trials. For about 10% of survey results the chemical measured on the wool did not match the chemical the producer said was applied. A further 5% of results were excluded because the amount of chemical detected on the wool was inconsistent with the stated time of treatment and shearing. With the remaining results there was a very high variation in residues resulting from the same (stated) treatment. It is clear that many producers do not know what chemicals they have used or how much they applied. The wide variation in results suggests that some producers may apply excessive amounts of pesticides while others use too little to have a useful effect. The model estimated the amount of pesticide taken up by the fleece using the residue left at shearing and the known breakdown rate for a given method and chemical group. When organophosphates were applied by dipping, the amount of chemical taken up by the fleece appeared to increase as the length of the wool increased. This was generally higher than would be anticipated from label dose rates but was consistent with the stripping characteristics of these chemicals. Therefore dipping as soon as possible after shearing left much lower residues (<10 mg/kg wool) than delayed treatment (often 10–30 mg/kg wool). In contrast the survey results suggest that the amount retained by sheep as a result of jetting decreased in longer wool. Jetting treatment rates appear to be lower than recommended, particularly for sheep with more than 6 months wool. Therefore jetting (as used by producers) left much lower residues in wool than dipping (with similar length wool) and was usually only above 10 mg/kg wool if carried out in the last 5 months before shearing, or if the same sheep received repeated treatments. The residue of synthetic pyrethroid retained in the fleece after dipping or long wool backliner application increased as the length of the wool increased at treatment, and appeared generally consistent with label recommendations. Current long wool backline products usually left residues of synthetic pyrethroid above 10 mg/kg on the wool. Short wool dipping left less than 10 mg/kg wool while off-shears backliners usually left average residue concentrations of about 2 mg/kg wool. Although the actual on-farm results vary 4-fold above and below the average, the model can be used to estimate the expected residue concentration and likely range of results from most standard on-farm organophosphate and synthetic pyrethroid treatments. This will allow improved provision of advice so that most producers can meet specified industry standards. It will allow wool buyers to estimate the risk of purchasing high residue wool based on producers’ statements about treatments applied.

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Efficacy of the insect growth regulators tebufenozide and fenoxycarb for lepidopteran pest control in apples, and their compatibility with biological control for integrated pest management

Australian Journal of Experimental Agriculture ◽

10.1071/ea9960501 ◽

1996 ◽

Vol 36 (4) ◽

pp. 501 ◽

Cited By ~ 13

Author(s):

BJ Valentine ◽

GM Gurr ◽

WG Thwaite

Keyword(s):

Biological Control ◽

Growth Regulators ◽

Growth Regulator ◽

Codling Moth ◽

Pheromone Trap ◽

Insect Growth Regulator ◽

Panonychus Ulmi ◽

Insect Growth Regulators ◽

Insect Growth ◽

Azinphos Methyl

The insect growth regulators tebufenozide and fenoxycarb were compared with the industry standard organophosphate, azinphos-methyl, in a replicated field trial. In both the 1992-93 and 1993-94 seasons, the 2 insect growth regulators maintained damage levels to harvested and windfall apples below 1% for both codling moth (Cydia pornonella L.) and lightbrown apple moth (Epiphyas postvittana Walker). This was despite considerable pest pressure as indicated by pheromone trap catches of both species. In the first season of the trial, E. postvittana was controlled more effectively (P<0.05) by tebufenozide than by fenoxycarb. In both seasons, populations of two-spotted mite, Tetranychus urticae Koch, and European red mite, Panonychus ulmi Koch, were higher in plots under azinphos-methyl treatment than in either insect growth regulator treatment. Neither insect growth regulator appeared to suppress populations of the phytoseiids Typhlodromus pyri Scheuten and Typhlodromus occidentalis Nesbitt. Limb jarring in the second season showed statistically significant (P<0.05) differences in populations of other predators which may have contributed to the biological control of phytophagous mites in the insect growth regulator treatments. Numbers of spiders, Stethorus spp., and apple dimpling bug (Carnpylomma liebknechti Girault) nymphs were all lower in the azinphos-methyl treatment. Results are discussed in relation to reducing dependence on conventional pesticides by use of more target-specific compounds which may be more compatible with biological control.

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Effect of insect growth regulators and fertilizers applied as foliar sprays during the egg stage of the sawfly Neodiprionsertifer

Canadian Journal of Forest Research ◽

10.1139/x76-072 ◽

1976 ◽

Vol 6 (4) ◽

pp. 523-531 ◽

Cited By ~ 2

Author(s):

W. H. Fogal ◽

C. R. Sullivan

Keyword(s):

Growth Regulators ◽

Larval Mortality ◽

Field Trials ◽

Insect Growth Regulator ◽

Red Pine ◽

Ovicidal Activity ◽

Insect Growth Regulators ◽

Geometrical Isomers ◽

Egg Hatch ◽

Insect Growth

Two insect growth regulators, a mixture containing about 25% Cecropia juvenile hormone with its geometrical isomers (AY-22342-3: Ayerst Research Laboratories, Saint-Laurent, Quebec) and a preparation containing 75% of the aromatic terpenoid ether, 4-ethylphenyl-6,7-epoxygeranyl ether (R-20458-B: Stauffer Chemical Co., Mountain View, California), were tested under field conditions for ovicidal activity against eggs of Neodiprionsertifer (Geoff.). Single egg clusters on Scots pine (Pinussylvestris L.) and whole red pine (P. resinosa Ait.) trees were sprayed to the drip point with formulations containing 0.1, 1, or 10 g/litre of insect growth regulator. AY-22342-3 reduced egg hatch at 10 g/litre on both tree species but was more effective in the red pine trial. R-20458-B did not reduce egg hatch significantly. Results with AY-22342-3 in the laboratory were about twice as effective as field trials. The application of fertilizers (urea, KNO3, or NH4NO3) accompanying a spray of AY-22342-3 on whole red pine trees does not enhance larval mortality. For trees receiving relatively intensive care, notably ornamentals and Christmas trees, the ovicidal activity of insect growth regulators might be useful as a means of preventing sawfly defoliation.

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THE RELATIONSHIP BETWEEN INSECT GROWTH REGULATORS WITH JUVENILE HORMONE ACTIVITY AND INSECT FEEDING BEHAVIOURAL RESPONSE

Insect Science ◽

10.1111/j.1744-7917.1999.tb00012.x ◽

1999 ◽

Vol 6 (1) ◽

pp. 71-76 ◽

Cited By ~ 1

Author(s):

Zhisheng Jiang ◽

Zhizhen Shang ◽

Shanhuan Zhao ◽

Shinfoon Chiu

Keyword(s):

Juvenile Hormone ◽

Growth Regulators ◽

Behavioural Response ◽

Insect Feeding ◽

Hormone Activity ◽

Insect Growth Regulators ◽

Insect Growth ◽

Juvenile Hormone Activity ◽

The Relationship

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Modelling pesticide residues on greasy wool: experimental studies

Australian Journal of Experimental Agriculture ◽

10.1071/ea98047 ◽

1998 ◽

Vol 38 (5) ◽

pp. 441 ◽

Cited By ~ 5

Author(s):

N. J. Campbell ◽

P. D. Hanrahan ◽

I. M. Russell ◽

G. S. Roberts ◽

B. J. Horton

Keyword(s):

Genetic Algorithm ◽

Growth Regulators ◽

Experimental Studies ◽

The Other ◽

Synthetic Pyrethroids ◽

Insect Growth Regulators ◽

Insect Growth ◽

Experimental Application ◽

Wool Growth ◽

Breakdown Rates

Summary. A model has been fitted to results from experimental application of organophosphates, synthetic pyrethroids and insect growth regulators to sheep mostly in long wool. The model relates the rate of breakdown of pesticide to the chemical used, the method of application and the length of wool at the time of treatment. A genetic algorithm was used to combine a range of experimental results for each chemical group to determine the rate of breakdown, and also the effect of application method and length of wool on breakdown. Organophosphates break down very quickly when applied to the surface of the wool (initial half-lives of 9–12 days), but the rate of breakdown gradually slows as the proportion of pesticide near the surface of the wool decreases. When the pesticide is applied deep into the wool by hand jetting or dipping, the rate of breakdown is slower (average half-lives of 27–42 days) and more uniform. Synthetic pyrethroids applied by hand jetting or backliner to sheep with 6–9 months wool growth initially break down with half-lives of 32–39 days, but the rate of breakdown decreases to 59–215 days giving average half-lives of 48–103 days over the 3–6 months between application and shearing. Cyromazine applied by hand jetting to sheep with 6–8 months wool growth has an average half-life of 79–96 days, but less if applied by automatic jetting race. The other insect growth regulators have longer half-lives: triflumuron, off-shears backliner, 119 days; and diflubenzuron, long wool jetting on to 7–9 months wool, >119 days. The model allows for different breakdown rates due to the method of application and length of wool and for changes in the rate of breakdown between application and shearing. It can be used to estimate the expected residue on wool at any time after a specified treatment, provided the amount of chemical applied is known. Conversely, the amount applied can be estimated from the residue and treatment details.

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Effect of Insect Growth Regulators on Citrus Mealybug [Planococcus citri (Homoptera: Pseudococcidae)] Egg Production

HortScience ◽

10.21273/hortsci.38.7.1397 ◽

2003 ◽

Vol 38 (7) ◽

pp. 1397-1399 ◽

Cited By ~ 4

Author(s):

Raymond A. Cloyd

Keyword(s):

Growth Regulators ◽

Indirect Effects ◽

Egg Production ◽

Isopropyl Alcohol ◽

Insect Growth Regulator ◽

Planococcus Citri ◽

Insect Growth Regulators ◽

Citrus Mealybug ◽

Insect Growth ◽

Solenostemon Scutellarioides

Greenhouse trials were conducted in 2000-2001 to evaluate the indirect effects of insect growth regulators, whether stimulatory or inhibitory, on the egg production of female citrus mealybug [Planococcus citri (Risso)]. Green coleus [Solenostemon scutellarioides (L.) Codd] were infested with 10 late third instar female citrus mealybugs. The insect growth regulators kinoprene, pyriproxyfen, azadirachtin, buprofezin, and novaluron were applied to infested plants at both the high and low manufacturer recommended rates. Beginning two days after treatments were applied, plants were monitored daily to determine when female mealybugs began to oviposit. Individual mealybugs were removed from plants, placed into glass vials containing 70% isopropyl alcohol when female mealybugs started to oviposit, and dissected to determine the number of eggs. Overall, there were no consistent patterns to suggest that the insect growth regulators and different rates tested had any effect on the egg production of citrus mealybug females. Although, in one instance, the insect growth regulators kinoprene and pyriproxyfen actually lowered citrus mealybug egg production. In addition, the insect growth regulator buprofezin numerically increased female citrus mealybug egg production.

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