The cyclamen mite,Tarsonemus pallidus, and its control on field strawberries

Abstract

does not appear. First page follows. Introduction During the past several years, strawberry fields in California have shown an increasing decadence, until, at the present time, a commercial planting may be expected to produce a crop of fruit for two years, or in some cases only one year, and then become commercially unproductive. This is strikingly in contrast with the conditions which existed 15 or 20 years ago, when, according to reports, strawberry plantings produced crops for 4 to 6 years. This decadence may be caused by one or more relatively obscure factors, of which the most important is, no doubt, in certain varieties at least, the virus disease known as yellows or xanthosis. In addition, strawberries suffer from accumulation of salts in the surface soil, and from root diseases of obscure etiology. Recently Thomas (1932) has discovered that the causal agent of a hitherto puzzling wilt disease is a fungus belonging to the genus Verticillium. Among the animal parasites of strawberries are the cyclamen mite, red spider, the strawberry root-worm, white grubs (larvae of various scarabaeid beetles), the stem nematode, the root-knot nematode, and aphids. The most important economically of these parasites of strawberries at the present time is the cyclamen mite, Tarsonemus pallidus Banks.