Thrips of economic importance in California /

Abstract

The insects known as thrips constitute an important group of crop pests deserving much more attention than has been given them in the past. The increasing demand for higher-quality fruits and vegetables, free from blemish, has directed attention to the silvering and small scars usually produced by the rasping-sucking feeding process of thrips. Also, during the dry seasons recently experienced in this state (1929)(1930)(1931)(1932)(1933)(1934),The adult male bean thrips. thrips injured many crops through defoliation and through bud and flower injury. During this period the gladiolus thrips, an entirely new species, became the most serious pest of gladiolus in North America. In southern California the greenhouse thrips has so increased out-of-doors on avocados and citrus that control measures have become necessary.Another major outbreak of the pear thrips has forcefully recalled to mind an old pest in this group. Likewise the bean thrips for some time known as injurious to beans, cotton, and alfalfa, has become of concern

Population Dynamics of Western Flower Thrips (Thysanoptera: Thripidae) in Nectarine Orchards in British Columbia

“…Western ßower thrips are believed to overwinter as sexually mature females in soil, curled leaves, evergreen plants, and protected places, such as under bark (Bailey 1938). In the Okanagan and Similkameen Valleys, western ßower thrips are likely to overwinter without reproduction in areas of sagebrush, Artemisia tridentata Nutt., and areas not previously used for agriculture (wild areas) bordering orchards (Venables 1925, Madsen andJack 1966).…”

Resistance to Onion Thrips (Thysanoptera: Thripidae) in Onion Cultivars does not Prevent Infection byIris Yellow SpotVirusFollowing Vector-Mediated Transmission

“…T. tabaci is a widely distributed pest of onions wherever they are grown (Lewis 1997), including New York State where a total of 4,330 ha were planted in 2010 (NASS 2011). T. tabaci feeding on onion causes silvery leaf spots that turn into white blotches and silvery patches along the leaves (Bailey 1938). This damage reduces the photosynthetic ability of the plant (Parrella & Lewis 1997) and results in reduction of onion bulb weight (Kendall & Capinera 1987;Rueda et al 2007) and yield loss from 50% (Fournier et al 1995) to 60% (Waiganjo et al 2008).…”

Determination of soil depth inhabited by Frankliniella occidentalis (Pergande) and Thrips tabaci Lindeman (Thysan., Thripidae) under greenhouse cultivation

“…Some species enter the soil beneath their host plant as fully grown stage II larvae and crawl downwards through cracks, old root channels and worm holes searching for suitable sites. The depth in which thrips penetrate into the soil mostly depends on the species, the stage of the thrips, and the soil condition ( Bailey , 1934, 1938, 1944; Grivanov , 1939; Franssen and Huisman , 1958; Franssen , 1960; Shurovenkov , 1961; Bonnemaison and Bournier , 1964; Lewis , 1973). Most terebrantian larvae move into the soil, usually concentrating beneath the food plants.…”