Distinguishing features

Both sexes fully winged. Female yellow to brown, typically yellow with brown postoccipital ridge on head, brown markings medially on each tergite, and tergites IX–X brown; fore wings pale but shaded along veins, major setae often dark. Antennae 7-segmented, VI large and bullet-shaped with the basal two-thirds brown and the apical third lighter, often greyish-brown. Head with ocellar setae III arising inside ocellar triangle near the anterior ocellus. Pronotal posteromarginal transverse apodeme usually stout, postero-angular setae relatively short. Metanotum reticulate, reticles without internal markings, median setae arising behind anterior margin, campaniform sensilla present. Fore wing with first vein setal row almost uninterrupted, consisting of closely-spaced, shortish, dark setae; clavus with 6 marginal setae. Abdominal tergite II with 4 lateral setae, VIII with marginal comb not developed medially. Sternites with 15–40 discal setae arranged in irregular double rows, 3 pairs of marginal setae, sternite VII setae S1 arise on the margin; pleurotergites with 6–10 discal setae.
Male similar to female in structure, but smaller and paler; tergite VIII with no comb; tergite IX with 4 setae close set in a transverse row; sternites III–VII with small transverse pore plate anterior to about 10 discal setae.

Related species

Thrips australis is an Australian species, and has the unusual characteristic of bearing 6, instead of 5, marginal setae on the fore wing clavus. This, together with the highly setose pleurotergites and the distinctive large, bullet-shaped, antennal segment VI, distinguishes the species from all other British species of Thrips. This species has been treated as the type species of the monotypic genus Isoneurothrips Bagnall, but that is now considered a junior synonym of Thrips L., for reasons outlined by Mound & Masumoto (2005). The larvae of australis are essentially similar to those of other members of the genus Thrips (Vierbergen et al., 2010). The genus Thrips is the second largest genus in the Thysanoptera, and currently includes, worldwide, over 300 species. All members of this genus lack ocellar setae I on the head, and they all have ctenidia on tergite VIII posteromesad to the spiracles. Other characters, such as number of antennal segments, number of setae on the fore wing veins, and number of discal setae on the sternites are variable between species (Palmer, 1992; Nakahara, 1994; Mound & Masumoto, 2005).

Biological data

Breeding in the flowers of Eucalyptus species, particularly in white flowers, but also in the flowers of related Myrtaceae such as Melaleuca species. However, as the flowers on such host plants die off, large numbers of adult australis disperse and can then be found in the flowers of a very wide range of unrelated plants - resulting in many "host records" that are largely spurious.

Distribution data

A single adult female of australis was found on the South Downs, West Sussex, in 2017 (Collins, 2019) despite the nearest outdoor record being in the extreme southeast of France (Pizzol et al., 2014). This species is now widely distributed in the Mediterranean region and also found on the Atlantic islands. Native to Australia, and widespread across that continent, it is common in New Zealand, and is now also found worldwide having been transported widely by the international trade in ornamental Eucalyptus plants.

Family name

THRIPIDAE - THRIPINAE

Species name

Thrips australis (Bagnall)

Original name and synonyms

Isoneurothrips australis Bagnall, 1915: 592
Thrips lacteicorpus Girault, 1926: 17
Thrips mediolineus Girault, 1926a: 18
Anomalothrips amygdali Morgan, 1929: 5
Isoneurothrips marisabelae Ortiz, 1973: 119

References

Collins DW (2019) The first British records for two species of Thrips (Thysanoptera: Thripidae): the European species T. linariae and the Australian adventive species T. australis. British Journal of Entomology and Natural History 32: 1–8.

Mound LA & Masumoto M (2005) The genus Thrips (Thysanoptera, Thripidae) in Australia, New Caledonia and New Zealand. Zootaxa 1020: 1–64.

Nakahara S (1994) The genus Thrips Linnaeus (Thysanoptera: Thripidae) of the New World. United States Department of Agriculture. Technical Bulletin 1822: 1–183.

Palmer JM (1992) Thrips (Thysanoptera) from Pakistan to the Pacific: a review. Bulletin of the British Museum (Natural History) Entomology Series 61 (1): 1–76.

Pizzol J, Nammour D, Rabasse JM, Parolin P, Desneux N, Poncet C & Reynaud P (2014) Species and population dynamics of thrips occurring inside and outside greenhouses cultivated with roses in southern France. International Journal of Agricultural Policy and Research 2: 141–153.

Vierbergen G, Kucharczyk H & Kirk WDJ (2010) A key to the second instar larvae of the Thripidae of the Western Palaearctic. Tijdschrift voor Entomologie 153 (1): 99–160.