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Bridal creeper leafhopper
Zygina sp.
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In July 1999 the bridal creeper leafhopper Zygina
sp. (Hemiptera: Cicadellidae) was approved for release as
a biocontrol agent for bridal creeper.
The leafhopper is a small white insect approximately 2mm
long and damages bridal creeper by sucking the photosynthetic
cells of the leaf. Feeding damage appears as white spots,
often in a zig-zag pattern visible from the upper leaf surface.
Females lay their eggs into the bridal creeper leaves which
hatch into nymphs (juveniles) which also feed on the photosynthetic
cells. There are five nymphal stages, each stage is preceded
by a "moult" where the exoskeleton is shed to enable
the nymph to grow. Nymphs are wingless and walk from leaf
to leaf. When the final moult occurs the leafhopper becomes
adult with wings enabling it to move considerable distances.
The leafhopper has been released onto bridal creeper infestations
across temperate Australia between 1999 and 2003. Whilst the
leafhopper readily establishes at most release sites, their
performance is highly variable. In many places they simply
establish and populations stay in numbers too low to make
any impact on bridal creeper. At other sites they perform
extremely well, spreading considerable distances and causing
early defoliation of bridal creeper.
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