Mite testing

Regression Equations. Elements of four regression equations. Equations 1-4, embodying the structure/activity relationships inherent in the Phase I dataset are illustrated in Table V. Equations 1 and 2 were derived from all the observations in the 202 compound Phase I dataset except five compounds inactive at 500 ppm in the mite test and six compounds inactive at 500 ppm in the egg test. The r terms, in each case the fraction of biological data variation in the regression datasets accounted for by the model, are satisfactory considering the precision of the test protocols and the size and diversity of the datasets ... 

A detailed overview of the major residuals is beyond the scope of this report highlights of such an overview, however, include the following points (1) the compounds inactive at 500 ppm fit predictions well if their observed LC50 is assigned as 550 ppm (2) extreme residuals occur more frequently in the egg test than in the mite test and activity less than predicted... 

European Red Mite Tests. The European red mite eggs used occurred as natural infestations on apple wood. Branches were collected in March, and from... 

Repellents Tested with Animal Attractants. Numerous methods have iavolved the use of animals as attractants, foUowed by evaluation of repeUents as skin treatments or attached cloth treatments, often against crawling arthropods such as fleas, ticks, and mites. Animals such as gerbUs, guiaea pigs, camels, mice, shaved rabbits, and hairless dogs have been used, particularly when the toxicity is unknown. 

Van der Veen MJ. Mulder M. Witteman AM. van Ree R. Aalberse RC. Jansen HM. van der Zee JS False-positive skin prick test responses to commercially available dog dander extracts caused by contamination with house dust mite (Dermatophagoides pteronyssimus) allergens. J Allergy Clin Immunol 1996 98 1028-1034... 

Denneman, C.A.J. and N.M. van Straalen. 1991. The toxicity of lead and copper in reproduction tests using the oribatid mite Platynothrus peltifer. Pedobiol. 35 305-311. 

Langer K, Breuer K, Kapp A, Werfel T Staphylococcus aureus-derived entero-toxins enhance house dust mite-induced patch test reactions in atopic dermatitis. Exp Dermatol 2007 16 124-129. 

Results from these laboratory studies demonstrated that avermectin Bj had high toxicity for the twospotted spider mite (Tetranychus urticae) on bean plants. When applied in solution directly onto adult and nymphal spider mite populations on foliage, avermectin Bj was shown to be 50-200 times as potent as commercially available acaricides, with an LC q of 0.02-0.03 ppm. Additional tests on foliage with insects in the order Lepidoptera, Coleoptera, Homoptera, Orthoptera, Diptera, Isoptera and Hymenoptera confirmed the broad spectrum activity and potency of the avermectin family of compounds and avermectin Bj in particular. Table II provides LC q values for avermectin Bj for the control of larval forms of several of these insects in foliar residue assays (18). 

Optimization of biological properties in a series of miticidal and mite ovicidal 2-aryl-l,3-cycloalkanediones, Ia,b, and enol esters, II, was achieved through analog synthesis and testing supported by the development of quantitative structure/ activity trends during the course of the project. QSAR equations developed during an initial phase provided the basis for both... 

In the early 1970 s potent acaricidal activity in 3-aryl-4-hy-droxy-coumarins. III, and 2-aryl-l,3-indanediones, IV, and their enol esters was discovered at Union Carbide (1,2). Extensive synthesis and screening of analogs in the dione and enol ester series led to the field test candidates Va and Vb, active against both motile forms (mite) and eggs. Va and Vb embodied certain structural and physicochemical features shown by published QSAR studies (2,3) to be important in determining the level of activity in the 1,3-indanedione series (1) the dimension D2 across the aryl ring must be near 7A and symmetry is preferred (2) the... 

Methods. Synthetic methods used to create the compounds described in this study and protocols used in the determination of toxicity to motile forms (mites) and eggs (activity expressed as LC50, ppm of foliar spray) have been published (6-10 1). The test organism was Tetranychus urticae (two-spotted mite). 

An electrochemical sensor using an array microelectrode was tested for the detection of allergens such as mite and cedar pollen (Okochi et ah, 1999). Blood was used in the assay and the release of serotonin, a chemical mediator of allergic response, which is electrochemically oxidized at the potential around 300 mV, was monitored for electrochemical detection by cyclic voltammetry. 

All test treatments were applied approximately 1 month ahead of hatching and over a 2-day period. The writers (5) have shown that mite winter eggs become increasingly more susceptible to oil sprays as the hatching time approaches. Possible errors arising from this cause were avoided in these studies by limiting treating time to a 48-hour period. 

In the tests with both California red scale and citrus red mite, untreated lots of fruit selected at random from infested fruit prepared for a given day were held with the treated lots and counted for natural mortality. The corrected percentage of kill for each treatment was calculated by means of the Abbott equation (Jf). 

Mortalities observed in tests of a series of oil dosages against adult female California red scale or eggs of the citrus red mite indicated a positive relation between increased dosage and increased kill. The fit of the points to the line was much better for oil dosages expressed as deposit than for those expressed as spray concentration. However, the variance observed indicated that statistical procedures would be required to arrive at the best fit for a line through the observed points. The method of probit analysis chosen was that proposed by Bliss (2) and modified by Finney (11) for data adjusted for mortality in the controls. 

Field tests of the value of the relationships observed in the laboratory studies of petroleum fractions against the Califomia red scale and the citrus red mite are planned for the Califomia red scale and are in progress for the citrus red mite. In addition, field experiments offer opportimities to observe the response of citms trees to differences in molecular size and to paraffinic vs. naphthenic composition of the oils. 

In early studies, the criterion for pheromonal activity was designated as the lowest concentration (ppm) of the candidate compound in a 10-fold dilution series that elicited a demonstrable response from test mites. Activity was expressed in terms of the dose of the test compound applied to the filter paper dispenser. More recently, more sophisticated bioassays using arenas have been developed, in which the movements of mites toward or away from test stimuli can be quantified (Nishimura et al., 2002). 

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