View pictures: Bing Images Google Images Yahoo Images
Common names: Avocado Thrip
Scientific name: Scirtothrips
Region: This insect pest is found
throughout the avocado growing regions of California. Its native region
is Mexico to Guatemala.
When this insect was discovered in 1996, causing havoc on
California Avocado orchard in Ventura County, California, it was
species new to science.
cycle: The Avocado-Thrip lays eggs, singly
into the soft tissue of leaves. These thrips produce numerous
generations each year. A new generation
emerges every two to three weeks. When
the eggs hatch, they undergo two larvae stages that actively feed on
plant tissue. Thrip larvae are often found on the underside of leaves.
During the pupae stage, they will drop below the host plant
into the soil and leaf litter. As adults (after pupation), the adult
thrips migrate back into the host tree to continue feeding and
They breed year round.
Physical Description: Male thrips
are smaller than the female, and unlike many thrip species, the males
are found throughout the general population. The adults are light
yellow, and have thin dark lines running across the upper area of the
abdomen. Their wings are brown. Larvae are light yellow in color.
Feeding characteristics: This
pest is only known to attack avocados. This pest damages foliage
and is found on upper and lower leaf surfaces. The leaf damage is a
bronze colored between the leaf veins. The adult and larvae Thrips feed
on developing fruit.
Once the fruit is past the size of a golf ball, it is less
susceptible to damage. Feeding scars develop on the fruit, resulting in
an "alligator skin" like appearance.
Controls: It has been found that
high temperatures, 86°F (30°C) and low humidity (<50%)
significantly reduce this insect pest populations.
Avocado orchards have natural subtropical biodiversity. This
biodiversity encourages many natural predators
that will help to control thrip populations.
Wasps, Predatory Thrips, Predatory
and Pirate Bugs
are a natural predators
and can help to control populations.
For serious infestations,
dust with Diatomaceous
Hoddle, Mark S. "The Biology and Management of the Avocado
Thrips, Scirtothrips perseae Nakahara (Thysanoptera: Thripidae)." 1999.
Department of Entomology, University of California, Riverside, CA 92521
Return from Avocado Thrip to Insects A-D Encyclopedia of Garden Insects