Frankliniella bispinosa (Morgan) is also known as the Florida
flower thrips, although this common name has not yet been accepted
by the Entomological Society of America. It is a common thrips
species throughout southern Florida,
and is increasingly common in northern Florida and southern Georgia.
Frankliniella bispinosa (Morgan)
Florida flower thrips
Distribution
Description (click here for drawing
)
The female Florida flower thrips is about 1 mm long and her basic
body color is yellow. The male is pale yellow or white and is
smaller than the female. Females often have pale gray bands or
blotches on each segment of the abdomen.
The postocular seta
is about half as long as the interocellar
seta. The pedicel of the third
antennal segment
has a sharp-edged flange.
The anteroangular and anteromarginal
setae are well developed, with the anteromarginal shorter than
the anteroangular.
The comb on abdominal segment
VIII is incomplete.
Frankliniella bispinosa infests a wide range of crops and
uncultivated hosts. Major population peaks in vegetables coincide
with or follow closely the blooming of such hosts
as oaks, pines, and citrus, suggesting that immigration from these
sources is a major factor in vegetable infestations (Glades Crop
Care unpublished data). Vegetable crops infested include tomato,
pepper, eggplant, potato, tomatillo, cucumber, watermelon, squash,
beans. strawberry, and sweet corn. Cut flowers, such as chrysanthemum
and baby's breath, are also favored, especially varieties with
white or yellow flowers (Frantz & Mellinger 1990).
Frankliniella bispinosa feeds primarily in blooms. It can
infest the foliage or feed externally on the fruit when its population
is high. Its feeding damage, either by itself or in conjunction
with the fungal pathogen, Colletotrichum acutatum, can
significantly reduce citrus yields (Childers 1992). Most problems
with the Florida flower thrips in vegetable crops occur seasonally,
when large numbers of thrips migrate from blooming citrus groves,
or from other hosts, such as oaks.
In tomatoes, thrips oviposition wounds
result in pin-prick dimples in the mature fruits. These are not
a serious problem, unless the number of dimples is high. Feeding
and oviposition damage to pepper
fruits is also not a problem, unless very high numbers of thrips
are present for an extended period.
High numbers of thrips migrating from citrus groves can inundate
nearby vegetable crops. If these migrating populations are not
accompanied by sufficient numbers of predators,
such as the minute pirate bug, Orius
insidious (Say), they can cause direct feeding damage to tender
young foliage, fruits, or blooms. If scouting reports indicate
F. bispinosa numbers less than 10/bloom in peppers, 2-3/bloom
in tomatoes, or 10/growing point in cucurbits, crop damage should
be tolerable. When counts exceed these levels, insecticide
applications may be needed, unless predators are also present.
Generally, insecticide applications specifically for control of
the Florida flower thrips are made sparingly. The reasons for
this are:
When insecticides are used, the lowest rates of insecticides with
short residual activity, such as
methomyl, are usually efficient to bring Florida flower thrips
under control. Follow-up applications may be needed during the
blooming periods of oaks and citrus.