Ia. Pearsall et Jh. Myers, Spatial and temporal patterns of dispersal of western flower thrips (Thysanoptera : Thripidae) in nectarine orchards in British Columbia, J ECON ENT, 94(4), 2001, pp. 831-843
Thrips were sampled from six nectarine orchards in the Dry Central Interior
, British Columbia, Canada, between April and June 1993 using yellow sticky
cards on posts spaced around the perimeter of each orchard, Although 12 id
entified species of thrips were captured, > 90% of individuals were the wes
tern flower thrips, Frankliniella occidentalis (Pergande). The flight patte
rns and abundances of western flower thrips were compared between orchards
located in two. differently oriented valleys (N-S and E-W) and between orch
ards located close to or far from areas of wild land. Results indicate that
densities of western flower thrips entering orchards, and their direction
of movement, were related more to the external vegetation than either locat
ion within the two different valleys or general wind flow patterns. Western
flower thrips tended to move into orchards close to ground level in early
spring (late April and early May) but flew higher as ground cover grew tall
er and temperatures increased, Densities of western flower thrips at ground
level were highest in an orchard with the densest dandelion ground cover.
We conclude that the location of nectarine orchards in relation to wild are
as is a major determinate of western flower thrips densities.