TARNISHED
PLANT BUG - Lygus lineolaris occurs throughout
North America. (The Tarnished Plant Bug in Europe
is Lygus rugulipennis, this family of bugs
often being known there as capsid bugs). Lygus
lineolaris is around a quarter inch in length;
the adult is often seen on or in daylily flowers and on leaves, frequently
ducking underneath the bloom or
leaf rapidly when approached. While the adult is
usually yellowish brown with an obvious triangle
shape on its back, the young nymphs are green and
resemble aphids when small
except that they move much more quickly. The adults
overwinter under leaves and other garden debris,
stones or bark. They emerge early in spring on warmer
days and are active in the garden into the fall.
Eggs are inserted into plant tissue. There are three
to five generations a year, and in the south they
may be active year round. TPB's are damaging to a
wide range of plants including agricultural crops
and vegetables as well as ornamentals; they feed
by inserting a beak into the plant tissues, injecting
a toxin, and sucking up the plant juices. While the
extent of the damage they do to daylilies is uncertain,
in other plants their feeding can result in injury
to flower buds, causing them to abort and drop, or
the blooms not to open properly. Seed pods may be
attacked, causing seeds to shrivel or be non-viable,
and younger pods may drop. Feeding on other plant
parts may result in distortion, stunting and dieback.
The adults are highly mobile, which makes them difficult
to control. TPB's are particularly partial to alfalfa,
and after this is cut for hay will often then move
into neighboring gardens to find alternative food.
They also tend to be more of a problem in dry years.
Clean up leaves and other garden debris in the fall
to remove overwintering places. Control weeds which
can provide food and hiding places. If necessary,
spray with insecticidal soap early in the morning
when the bugs are still sluggish from the cooler
temperatures. |
