Pinitol, a larval growth inhibitor for Heliothis zea in soybeans

A search for insect growth inhibitors in methanol extracts of soybean leaves resulted in isolation of pinitol. Pinitol caused a 50% reduction in weight gain (ED50) of Heliothis zea larvae at about 0.7% when added to a synthetic diet. Although myo-inositol is a normal component of the insect diet, it also caused growth inhibition at higher concentrations; ED50 4%.

Isolation and concentration of organophosphorus pesticides from drinking water at the ng/L level, using macroreticular resin

A screening method has been developed for determining organophosphorus pesticides at ng/L levels in drinking water. Sixteen organophosphorus pesticides, diazinon, diazinon-oxon, dimethoate, ronnel, beta-phosphamidon, methyl parathion, ethyl parathion, malathion, chlorpyrifos, fenitrothion, ruelene, methidathion, ethion, EPN, phosalone, and phosmet, were extracted by Amberlite XAD-2 resin from 100 and 200 L drinking water previously spiked with these pesticides. The pesticides were eluted from the XAD-2 resin with acetone-hexane (15+85). The concentrated extract was analyzed by gas chromatography using a nitrogen-phosphorus selective detector and by gas chromatography-mass spectrometry using selected ion monitoring. Recoveries at the 10 and 100 ng/L spiking levels were greater than 90%, except recoveries for dimethoate and phosphamidon were 37 and 42%, respectively. The analysis of 300 L Ottawa tap water showed no detectable amounts (less than 1 ng/L) of any of the 16 organophosphorus pesticides.

Method for the separation of organochlorine residues before gas-liquid chromatographic analysis

The adsorption characteristics of alumina and silica for column chromatography have been assessed to develop a method, using a single solvent, for the separation of seventeen organochlorine residues into four eluates prior to gas-liquid chromatographic analysis. The effects on the adsorbents of thermal activation and subsequent deactivation with water, variation of column size and choice of eluents have been critically examined. The lipid capacity of the alumina and the effect of co-extracted materials from animal tissue upon the elution profile of the organochlorines have been determined.

Isolation and determination of chlorinated organic pesticides by thin-layer chromatography and the application to toxicological analysis

A sensitive method for the isolation and clean-up of chlorinated organic pesticides from tissues and biological materials is discussed. RF values of the pesticides in 26 solvent systems, and colours of the spots given with various chromogenic reagents, are reported. The limits of detection, and densitometric measurements, are also discussed. The average recovery has been found to be 94%. The distribution of endrin in different autopsy tissues from five different victims has been studied by the proposed technique.

Discovery of insect anti-juvenile hormones in plants.?2U

Two simple chromenes with anti-JH activity have been isolated and identified from the bedding plant Ageratum houstoianum. By contact and fumigation these compounds induce precocious metamorphosis and sterilization in several hemipteran species of insects. Certain holometabolous species are sterilized, forced into diapause, or both. Each of these biological actions is equivalent to removal of the corpora allata, which produce the JH's, and is reversible by treatment with exogenous JH. Thus, the action of these compounds is to stop the production or depress the titer of the JH's. To our knowledge, this is the first discovery of anti-JH, and we hope it will guide the way to the emergence of a fourth generation of safe and insect-specific pesticides.