Selective Acaricides Research Articles

Two new acaricides of the bi-(pchlorophenyl)-carbinol group

The 2 compounds ethoxymethyl-di-(p-chlorophenyl)-carbinol and 4,4′-dichlorobenzilicacid-ethylester were tested in the laboratory againstTetranychus urticae and in field trials againstMetatetranychus ulmi andTetranychus urticae. Both compounds are selective acaricides, which show a contact action against all stages of development of red spiders and which also have a residual action.

A guide to the spider mites of deciduous fruit trees

The recent development of highly selective acaricides for spider mite control has made it necessary for the economic entomologist to know the particular species he is dealing with. This report, a guide to the spider mites known to occur on deciduous fruit trees in the United States and Canada, is intended to aid him in making determinations in the field and in the laboratory. Included are a taxonomic key to the species, a field guide, and instructions for sampling, slide preparation, and recognition of diagnostic characters. Of special interest are three new combinations, one new species, four new synonyms, and new information on color forms and seasonal phases of Tetranychus bimaculatus. The following twelve species of spider mites are treated: Bryobia praetiosa Koch (p. 259) Metatetranychus ulmi (Koch) (p. 260) Paratetranychus newcomeri McGregor (p. 261) Eotetranychus carpini borealis (Ewing), new combination (p. 261) Eotetranychus willamettei (McGregor), new combination (p. 263) Eotetranychus uncatus Garman, new species (p. 263) Tetranychus pacificus McGregor (p. 265) Tetranychus mcdanieli McGregor (p. 266) Tetranychus schoenei McGregor (p. 266) Tetranychus canadensis (McGregor), new combination (p. 267) Tetranychus bimaculatus Harvey (p. 268) Tetranychus atlanticus McGregor (p. 271)