South African bean thrips

Scientific name

Scirtothrips aurantii (Thysanoptera: Thripidae)

Other common names

South African citrus thrips

Similar species

other species of Scirtothrips

Distribution

United States: not known to occur.

Worldwide: Africa, Australia, and Yemen.

Native to Africa and Yemen.

Diagnostic characteristics

Adults

• Yellow body, small brown area medially.
• Bottom of abdominal segments covered with minute hairs.
• Females measure 0.6 - 0.9 mm (0.02 - 0.04 in.) in length.
• Males are similar in appearance but somewhat smaller.
• Head head:
  one of the three main body segments in insects; the anterior-most segment containing the many sensory structures including the eyes, antennae, and mouthparts
  is wider than long.

Immatures

• Two larval instars, pre-pupapre-pupa:
  the non-feeding last instar larva of insects that undergo complete metamorphosis
  (3rd instarinstar:
  immature stages (larva or nymph) of insects in between molts
  ), and pupa (4th instarinstar:
  immature stages (larva or nymph) of insects in between molts
  ).
• Light orangeish-yellow to white body.
• Body surface is rough and grainy.
• Larvae resemble adults, but wingless.

Eggs

• 0.2 mm (0.008 in.).
• Elongate, bean-shaped.

Hosts

Citrus hosts

All Citrus species and their hybrids, but particularly destructive to sweet orange, Citrus sinensis.

Non-citrus hosts

Diverse host rangehost range:
the range of species that a particular organism can feed on to achieve successful growth and reproduction
including over 50 species from a wide range of plant families. Hosts include both weeds and economically-important crops. A partial list includes:

• Acacia spp.
• Asparagus spp.
• banana, Musa spp.
• bean, Phaseolus vulgaris
• cashew, Anacardium occidentale
• cassava, Manihot esculenta
• castor oil plant, Ricinus communis
• cotton, Gossypium spp.
• grape, Vitis spp.
• mango, Mangifera indica
• peanut, Arachis hypogaea
• pepper, Capsicum spp.
• tea, Camellia sinensis

Host damage

Fruits

• Feeding punctures young fruit leaving characteristic ring of grey scarring on the rind.

Leaves

• Damages young leaves resulting in leaf distortion.
• Silvering on leaf surface.
• Brown frassfrass:
  pellets of very dry excreta produced by some insects
  markings.

Biology

Eggs are deposited within young growing leaves, stems, or fruit. Females are capable of laying up to 250 eggs. Eggs deposited in the fall can overwinter. First and second instars feed on leaves and young fruit. The feeding on young fruit results in cosmetic scarring of the rind. Third and fourth instars are quiescent "pupal" phases that do not feed and may leave the plant to develop in the litter or soil. Breeding is continuous, so there are many generations possible annually.

References

(EPPO) European and Mediterranean Plant Protection Organization. 2005. Diagnostics: Scirtothrips aurantii, Scirtothrips citri, Scirtothrips dorsalis. Bulletin 35: 353–356. (http://archives.eppo.org/EPPOStandards/PM7_DIAGNOS/pm7-56%281%29%20SCITSP%20web.pdf).

(EPPO) European and Mediterranean Plant Protection Organization. 2009. PQR database. Paris, France: European and Mediterranean Plant Protection Organization. (www.eppo.org).

(CABI) Centre for Agricultural Bioscience International. 2012. Invasiveinvasive:
term used to describe species that are not native and have the ability to adversely effect habitats they invade either ecologically or economically
species compendium (beta).(http://www.cabi.org/isc/?compid=5&dsid=49061&loadmodule=datasheet&page=481&site=144).

Hoddle, M.S., L.A. Mound, and D. Pena. Thrips of California. CBIT Publishing, Queensland. (http://keys.lucidcentral.org/keys/v3/thrips_of_california/Thrips_of_California.html).

Authors

Weeks, J.A., A.C. Hodges, and N.C. Leppla