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Print Fact SheetAeolothripidae

Link to genera and species of Australian Aeolothripidae

Australian fauna

Ten genera and 31 species of Aeolothripidae are known from Australia, and all but five of the species are endemic to this continent (Mound & Marullo, 1998).

 

Biology

Adults and larvae of many species of Aeolothripidae appear to be facultative predators of other small arthropods, in that they feed on both floral tissues as well as on thrips and mites that live in flowers. However, some species are solely phytophagous, a few being univoltine in flowers of particular plant species (Tyagi et al., 2008), whereas in the warmer parts of the world, a considerable number of species are obligate predators (Hoddle, 2003). In Australia, the main aeolothripid genus, Desmothrips, includes many species that are common in a wide range of flowers, and most of these seem to be facultative predators. This also appears to be true of the many species in the northern hemisphere genus Aeolothrips. However, in both of these genera some species appear to be predatory, and a few of them are distinctive ant-mimics. These include Aeolothrips albicinctus in Europe, Aeolothrips bicintus and related species in North America, as well as  Desmothrips reedi in southern Australia. Ant-mimicry has also arisen amongst other members of this family, including  Gelothrips cinctus in South East Asia and tropical Australia (Mound & Marullo, 1998), Stomatothrips species in Central and South America (Mound & Marullo, 1996), and Franklinothrips species throughout the tropics (Mound & Reynaud, 2005). Franklinothrips orizabensis has been employed as a biocontrol agent against thrips pests in European greenhouses. Species of the tropical genus Mymarothrips are also obligate predators, but have a body form and wings that resemble those of small chalcid wasps. In contrast, Cycadothrips species are phytophagous, breeding only in Australia in the male cones of Macrozamia cycads (Mound & Terry, 2001), and Dactuliothrips species also seem to be phytophagous breeding in California particularly in the flowers of Yucca species (Mound et al., 2019). It is probable that in all species of Aeolothripidae the second instar larva produces a silken cocoon within which to pupate (Hoddle et al., 2001), and such cocoons usually occur at ground level.

Geographic distribution

The family Aeolothripidae is found worldwide. However, the 112 species recognised in Aeolothrips are almost entirely Holarctic, and the six species of Rhipidothrips are Palearctic, although a few species in both genera are widely introduced around the world, including Australia and North America. Five of the 24 recognised genera are endemic to the Americas, four to the Afrotropical region, three to India and five to Australia. Desmothrips is known only from Australia, with 18 described species, and a closely related Australian species is placed in a genus Andrewarthaia. Also known only from Australia, Cycadothrips includes three described species, and the Australian genera Erythridothrips and Lamprothrips each include a single species. Three genera in the Americas have diversified, Erythrothrips with 14 species, and Dactuliothrips and Stomatothrips each with six or seven species, and in the Afrotropical region Allelothrips includes seven species. Similarly, Franklinothrips includes 16 tropical species, with one from Central America now widespread around the tropics but the others locally endemic including two in Australia. Several genera remain known from only one or two species, indeed, Euceratothrips is known only from a single male taken in Peru. Although a few genera are of doubtful significance, Orothrips is a particularly interesting genus with two species in California and one in southern Europe.

Recognition

Species of Aeolothripidae all have nine antennal segments, with the exception of a single species known only from Iran. Moreover, at least segments VII-IX are broadly connate and form a single unit. The sensoria on segments III and IV are generally linear and longitudinal in the apical portion of these segments but often curling around the segmental apex. Exceptions to this occur in Rhipidothrips, in which the sensoria are interpreted as being reduced to the apical curve, although essentially linear in R. gratiosus. Antennal segments III and IV each bear two sensoria in Orothrips, Dactuliothrips and Cycadothrips species. Aeolothripidae are distinguished from Melanthripidae by the complete loss of sternite VIII. The pair of lobes that represent this sternite in Melanthripidae each bear two setae, and these two pairs of setae are represented on sternite VII of Aeolothripidae by two pairs of submarginal accessory setae. In the head, the tentorial bridge is well-developed, but the anterior tentorial arms are weaker than in Melanthripidae. The fore wings often have transverse or longitudinal dark bands, and are broadly rounded at the apex, with several cross-veins. Most Aeolothripidae have only short setae on the head and pronotum, but Dactuliothrips species have many prominent setae similar to those found in many Melanthripidae.

Genus and species diversity

Worldwide, the Aeolothripidae comprises about 215 species and 24 genera, with a further 7 genera and 15 species known only from fossils. The genus Aeolothrips includes more than 50% of the species in this family, with three genera that each have between 10 and 15 species, eight genera that each include less than five species, and eight genera each with a single species. The genus Aeolothrips is sometimes restricted (Bhatti, 2006) to a single ground-living species, A. albicinctus, in which the first abdominal tergite is narrowed and bears numerous transverse striae; the other species being treated in Coleothrips. However, a similar transversely striate first abdominal tergite occurs in Desmothrips reedi, a ground-living species in this Australian genus. This body form seems to be part of the ant-mimicry syndrome that recurs amongst Aeolothripidae, and is insufficient to consider A. albicinctus as sister species to all the other members of Aeolothrips. Species of Stomatothrips and Franklinothrips also have a "wasp-waist", and the behaviour of some species is remarkably like that of small Hymenoptera.

Family relationships

Members of the Aeolothripidae are distinguished from those of the Melanthripidae and Merothripidae by the complete loss in females of the eighth abdominal sternite and its two pairs of setae. However, in female Aeolothripidae there are two pairs of accessory setae submarginally on the seventh sternite that are considered to represent the paired setae of the lost eighth sternite. The sensoria on antennal segments III and IV are linear in most Aeolothripidae with a slight curve around the apex of the segments. The antennal sensoria of Rhipidothrips are interpreted as having almost lost the linear portion and retained only the distal curved portion, but R. gratiosus retains the linear portion of both sensoria as a series of isolated areas (Mound et al., 2019). Species in three genera do not have linear sensoria, these being Cycadothrips in Australia, and Dactuliothrips and Orothrips in western USA. 

Thysanoptera systematics

The classification adopted here is a compromise between practicality and the ideal of a classification based on phylogenetic relationships. The two sub-orders, Terebrantia and Tubulifera, are probably sister-groups (Buckman et al., 2013), but relationships among the eight families of Terebrantia remain far from clear (and there are also five families based on fossils - see ThripsWiki 2020). A radically different classification was proposed by Bhatti (1994, 1998, 2006) that recognised two Orders, 10 superfamilies and 40 families, but that classification is based on autapomorphies rather than synapomorphies, and is thus essentially phenetic rather than phylogenetic.  

References

Bhatti JS (1994) Phylogenetic relationships among Thysanoptera (Insecta) with particular reference to the families of the Order Tubulifera. Zoology (Journal of Pure and Applied Zoology) 4 (1993): 93–130.

Bhatti JS (1998) New structural features in the Order Tubulifera (Insecta). 1. Amalgamation of labro-maxillary complex with cranium and other cephalic structures. Zoology (Journal of Pure and Applied Zoology) 5: 147–176.

Bhatti JS (2006) The classification of Terebrantia (Insecta) into families. Oriental Insects 40: 339–375.

Buckman RS, Mound LA & Whiting MF (2013) Phylogeny of thrips (Insecta: Thysanoptera) based on five molecular loci. Systematic Entomology 38: 123–133.

Hoddle MS (2003) Predation behaviours of Franklinothrips orizabensis (Thysanoptera: Aeolothripidae) towards Scirtothrips perseae and Heliothrips haemorroidalis (Thysanoptera: Thripidae). Biological Control 27: 323–328.

Hoddle MS, Oishi K & Morgan D (2001) Pupation biology of Franklinothrips orizabensis (Thysanoptera: Aeolothripidae) and harvesting and shipping of this predator. Florida Entomologist 84 (2): 272–281.

Mound L, Hoddle MS & Hastings A (2019) Thysanoptera Californica. An identification and information system to thrips in California. Lucidcentral.org, Identic Pty Ltd, Queensland, Australia. https://keys.lucidcentral.org/keys/v3/thrips_of_california_2019/

Mound LA & Marullo R (1996) The Thrips of Central and South America: An Introduction. Memoirs on Entomology, International 6: 1–488.

Mound LA & Marullo R (1998) Biology and identification of Aeolothripidae (Thysanoptera) in Australia. Invertebrate Taxonomy 12: 929–950.

Mound LA & Reynaud P (2005) Franklinothrips; a pantropical Thysanoptera genus of ant-mimicking obligate predators (Aeolothripidae). Zootaxa 864: 1–16.

Mound LA & Terry I (2001) Thrips pollination of the central Australian cycad, Macrozamia macdonnellii, by a new species of basal clade thrips (Thysanoptera). International Journal of Plant Sciences 162: 147–154. http://www.journals.uchicago.edu/doi/pdf/10.1086/317899

ThripsWiki (2020) ThripsWiki - providing information on the World's thrips. Available from: http://thrips.info/wiki/Main_Page [accessed 29.x.2019].

Tyagi K, Kumar V & Mound LA (2008) Sexual dimorphism among Thysanoptera Terebrantia, with a new species from Malaysia and remarkable species from India in Aeolothripidae and Thripidae. Insect Systematics & Evolution 39 (2): 155–170.