Figures
Fig. 1: Antenna (inset: III. and IV. antennal segment)
Fig. 2: Head dorsal with ocellar triangle
Fig. 3: Pronotum
Fig. 4: Meso- and metanotum
Fig. 5: Fore- and hindwing
Fig. 6: Sternites V and VI
Fig. 7: Tergites VII and VIII
Fig. 8: Tergite VIII
Taxonomic Information
Species:
Thrips australis (Bagnall, 1915)
Synonyms:
Isoneurothrips marisabelae Ortiz, 1973
Anomalothrips amygdali Morgan, 1929
Thrips lacteicorpus Girault, 1926
Thrips mediolineus Girault, 1926
Isoneurothrips australis Bagnall, 1915
Common name:
Gum tree-flower thrips
Eucalyptus thrips
Present taxonomic position:
Family: Thripidae Stephens, 1829
Subfamily: Thripinae (Stephens) Karny, 1921
Genus: Thrips Linneaeus, 1758
Species Recognition
General information about the genus Thrips:There are about 280 species currently recognized in the genus Thrips making this genus one of the largest groups within the Thysanoptera. They are separated from other genera in having the following characters, antenna comprising 7 or 8 segments with segments III and IV containing forked sense cones, the head has two pairs of ocellar setae (II and III), pair I is missing, the pronotum with four long setae on the posterior margin, forewing 1st vein usually has a row of setae interrupted by gaps, on lateral sides of abdominal tergites V to VIII there are paired ctenidia, abdominal tergite VIII with ctenidia posterior to the spiracles.
Typical character states of Thrips australis:
Body color
Mainly brown or mainly pale or yellow, with some darker markings or bicolored
Antennae
Number of antennal segments: 7
Segment IV - forked sensorium: scarcely extending beyond base of segment V
Segments II and III shape: more or less symmetric
Segments III & IV sensoria: emergent and forked
Base of sensorium on antennal segment VI: no more than 2 times as wide as base of nearest seta
Terminal antennal segments: rarely elongate
Head:
Distance between bases of ocellar setae III: greater than width of first ocellus
Head shape between compound eyes: not prolonged
Ocellar setae III on head: arising on anterior margin of, or in front of, ocellar triangle
Postocular setae I: absent
Surface of head, pronotum and fore legs: without strong reticulate sculpture
Ocellar setae I in front of anterior ocellus: absent
Prothorax
Number of pairs of elongate pronotal setae: 0-3
Number of pairs of elongate posteroangular pronotal setae: 2
Pronotum shape: rectangular
Number of pairs of pronotum posteromarginal minor setae: 3-4
Number of pairs of pronotum anteromarginal minor setae: 3-5
Mesothorax
Mesothoracic endofurca: with median spinula
Metathorax
Metanotal median area sculptured lines: with mainly equiangular reticulation
Metanotal median setae length: shorter than lateral metanotal setae
Metanotal median setae position: arising behind anterior margin
Metanotum: without campaniform sensilla
Metanotum major sclerite: with two major sclerites, metascutum and metascutellum
Metanotum sculpture: without dominant sculptured triangle medially
Metathoracic endofurca: transverse, sometimes with simple median spinula
Wings
Wings: present and more than half as long as abdomen
First vein of forewing: distinct from costal vein
Forewing anterior margin: with setae and cilia but cilia longer than setae
Forewing clavus: terminal veinal seta longer than subterminal seta
Forewing color: uniformly pale or weakly shaded
Forewing costal fringe of cilia: arising at anterior margin of wing
Forewing costal setae at middle of wing: shorter than median width of wing
Forewing first vein setal row: complete, with setae closely and uniformly spaced
Forewing posterior margin cilia: undulated near apex
Forewing second vein setal row: complete, with setae closely and uniformly spaced
Forewing surface: not reticulate
Forewings: with veins, setae and microtrichia
Legs
Fore tarsus inner apex: without tooth
Fore tibial apex: not extending around fore tarsus - with small curved claw ventrolaterally
Mid and hind tarsi: with two segments
Abdomen:
Pleurotergal discal setae: absent
Abdominal pleurotergites: not covered in microtrichia
Abdominal segment X: never tubular, longitudinally incomplete ventrally in both sexes
Abdominal sternite II: with marginal setae but no discal setae
Abdominal sternite III of female: without glandular areas
Abdominal sternite VII: with discal setae present on median area
Abdominal sternite VII median marginal setae: arising at margin or in front of margin
Abdominal sternites IV , V and VI: with discal setae present medially as well as marginal setae
Number of lateral marginal setae on abdominal tergite II: 4
Abdominal tergites: without curved wing-retaining setae
Abdominal tergites IV & V median setal pair: much shorter than distance between their bases
Abdominal tergites V-VII: with pair of ctenidia laterally
Number of discal setae on sternite V: 14-20
Setae on abdominal tergite X: slender
Surface of lateral thirds of abdominal tergites: without regular rows of fine microtrichia
Ctenidia on tergite VIII: posteromesad to spiracle
Tergite VIII posteromarginal comb of microtrichia: present laterally, incomplete medially
Tergite VIII posteromarginal microtrichia: short and irregular in length
Biology
Life history:
As with other thrips species the life cycle from egg to adult is dependent on temperature. The full cycle can take about 15 days (Lewis, 1973) to over a month and adults may live for more than one month producing several generations in one year depending on seasonal weather. With greenhouse temperatures the developmental time from egg to adult can decrease to about one week.
Host plants:
Eucalyptus flowerers, also
other Myrtaceae
Vector capacity:
None identified
Current known distribution:
Africa, Australia, New Zealand, Central and South America, Europe, North America
Additional notes:
This species has not been reported as a major pest but has been introduced around the world where ever Eucalyptus has been distributed.
Bibliography
Bailey, SF (1957): The thrips of California
Part I: Suborder Terebrantia. Bulletin of the California Insect Survey 4, no.
5: 143-220.
Boulter, SL, Kitching, RL, Howlett, BG & Goodall, K (2005): Any which way will do - the pollination biology of a northern Australian rainforest canopy tree (Syzygium sayeri; Myrtaceae). Botanical Journal of the Linnean Society, 149, 69-84.
Cavalleri, A, Rornanowski, HP & Redaelli, LR (2006): Thrips species (Insecta, Thysanoptera) inhabiting plants of the Parque Estadual de Itapua, Viamao, Rio Grande do Sul state, Brazil. Revista Brasileira De Zoologia, 23, 367-374.
de Borbon, CM (2007): A key for the identification of second instar larvae of some common thrips (Thysanoptera : Thripidae). Mendoza, Argentina. Revista De La Facultad De Ciencias Agrarias, 39, 69-81.
Greber, RS, Klose, MJ, Milne, JR & Teakle, DS (1991): Transmission
of Prunus Necrotic Ringspot Virus Using Plum Pollen and Thrips. - Annals
of Applied Biology 118 (3): 589-593.
Laughlin, R (1977): Gum Tree Thrips Isoneurothrips australis Bagnall - Survival at different temperatures and humidities and its relation to capacity for dispersal. Australian Journal of Ecology, 2, 391-398.
Lewis, T (1973): Thrips their biology, ecology and economic
importance. Academic Press Inc., London Ltd. 349 pp.
Milne, JR, Milne, M & Walter, GH (1997): A key to larval thrips (Thysanoptera) from granite belt stonefruit trees and a first description of Pseudanaphothrips achaetus (Bagnall) larvae. Australian Journal of Entomology, 36, 319-326.
Moritz G, Morris DC, Mound LA (2001): ThripsID -
Pest thrips of the world. ACIAR
and CSIRO Publishing Collingwood, Victoria, Australia, CDROM ISBN 1 86320
296 X.
Moritz G, Mound LA, Morris DC, Goldarazena A (2004): Pest
thrips of the world - an identification and information system using molecular
and microscopial methods. CBIT, University of Queensland,CDROM ISBN 1-86499-781-8.
Mound, LA & Kibby, G (1998): Thysanoptera: An identification
guide, (2nd edition). CAB International, Wallingford and New York,
70pp.
Mound, LA & Marullo, R (1996): The
thrips of Central and South America: An Introduction (Insecta: Thysanoptera).
Associated Publishers, Gainesville.
Nakahara, S (1994): The Genus Thrips Linnaeus (Thysanoptera: Thripidae) of the New World. USDA Agricultural Research Service Technical bulletin No. 1822.
Nickle, DA (2006): A review of the species of Thrips Linnaeus, 1758 (Thysanoptera : Thripidae) from Africa, Europe, and the Mediterranean region. Proceedings of the Entomological Society of Washington, 108, 443-466.
Nickle, DA (2008): Commonly intercepted thrips at US ports-of-entry from Africa, Europe, and the Mediterranean. III. The genus Thrips Linnaeus, 1758 (Thysanoptera : Thripidae). Proceedings of the Entomological Society of Washington, 110, 165-185.
Stannard, LJ (1968): The thrips, or Thysanoptera, of Illinois. Illinois Natural History Survey Bulletin 29: 215-552.
Links:
Mound, LA (2005): Thysanoptera (Thrips) of the World
- A Checklist. http://www.ento.csiro.au/thysanoptera/worldthrips.html