|
Peach
Twig Borer
Insect Biology
Monitoring Info
Omnivorous
Leafroller
Insect Biology
Oriental Fruit Moth
Insect Biology
Monitoring
Info
San Jose Scale
Insect Biology
Western Flower
Thrips
Insect Biology
Site designed and maintained by
UC Kearney Agricultural Center; last update:
04/10/07
ŠThe Regents of the University of California, 4/1/00 |
|
WESTERN
FLOWER THRIPS
Frankliniella
occidentalis
DESCRIPTION OF THE PEST
Western flower thrips (see photo above) are minute insects,
about 0.03 inch long, with two pairs of fringed wings. The adult has three color
forms that vary in abundance depending on the time of year. There is a pale form
that is white and yellow, except for slight brown spots or blemishes on the top
of the abdomen; an intermediate color form with an orange thorax and brown
abdomen; and a dark form that is dark brown. The intermediate form is present
throughout the year, but in spring the dark form predominates while the pale
form is most abundant at other times throughout the year.
First instar nymphs are opaque or light yellow, turning to golden yellow
after the first molt. The
nymphal
stage [82K] lasts from 5 to 20 days.
Western flower thrips overwinter as adults in weeds, grasses, alfalfa, and
other hosts, either in the orchard floor or nearby. In early spring, if
overwintering sites are disturbed or dry up, thrips migrate to flowering trees
and plants and deposit eggs in the tender portions of the host plant, e.g.
shoots, buds, and flower parts. The peak infestation is usually reached in May
or June.
(Description from
UC Pest Management Guidelines)
Back to Research & Extension Programs |