Damage to Nectarines by the Western Flower Thrips (Thysanoptera: Thripidae) in the Interior of British Columbia, Canada

Abstract

The phenology of damage by the western flower thrips, Frankliniella occidentalis (Pergande), on nectarines was investigated using sticky cards and direct sampling of buds between 1993 and 1995 in the interior of British Columbia, the most susceptible period for damage by western flower thrips to nectarines. The life stage responsible for damage and variation in susceptibility to damage of 11 different nectarine varieties were determined. To evaluate the predictive ability of 2 sampling methods, thrips were counted from both buds and sticky cards before petal fall and correlated to damage levels at husk drop. Damage to nectarines was caused almost entirely by larval feeding at petal fall. No predictive relationships between adult or larval densities of western flower thrips and subsequent damage to fruit were apparent. Varieties did not differ in terms of larval densities at petal fall or the subsequent damage to fruit. Female western flower thrips oviposit in nectarine buds from dormant through bloom stages primarily in sepal tissues in the early buds, and in filaments and petals as these become available.

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

“…A separate study found that damage to nectarines by thrips is caused by feeding larvae rather than by oviposition activity or feeding by adult females (Pearsall 1999). The relationship between adult and larval densities and subsequent fruit damage in each orchard was also examined during that study.…”

Daily flight activity of the western flower thrips (Thysan., Thripidae) in nectarine orchards in British Columbia, Canada

“…Their patterns of flight behaviour have not been studied to the extent of other insects such as aphids or locusts but, because of their growing economic importance in western Canada and also worldwide, it is important to examine their movement patterns more critically. Previous work identified that the western flower thrips is the most abundant species of thrips entering nectarine orchards in early spring in the interior of British Columbia, and the species to which the scarring of fruit may be solely attributed (P earsall , 2000; P earsall and M yers , 2001). Wild land which extends over vast areas of hillsides adjacent to orchards in this region is dominated by sagebrush ( Artemisia tridentata Nutt.)…”

Predatory mites double the economic injury level of Frankliniella occidentalis in strawberry

“…2), as found in other crops, such as nectarines (Pearsall 2000), presumably because they feed more. The large reduction in damage (>90 %) in the presence of N. cucumeris (Fig.…”