Idolothripinae

 Male Dinothrips sumatrensis, from CSIRO.

Belongs within: Phlaeothripidae.
Contains: Allothripina, Phaulothrips, Gastrothrips, Compsothrips, Bolothrips, Carientothrips, Pygothripina, Diceratothripina, Macrothripina, Elaphrothrips, Mecynothrips, Ophthalmothrips, AnactinothripsIdolothripina, Actinothrips, Bactrothrips, Zeugmatothrips.

The Idolothripini is a lineage of fungus-feeding thrips, characterised by the absence of metathoracic sternopleural sutures, and usually by the presence on the tergites of two or more pairs of wing-retaining setae. Within the Idolothripini, the subtribes Idolothripina and Hystricothripina are united by the presence of conspicuous lateral setae on the anal tube, and shortened metathoracic anapleural sutures. The Elaphrothripina, in contrast, lack conspicuous hairs on the tube and have the anapleural sutures complete (Mound & Palmer 1983).

A vision of thrips
Published 17 March 2011
The giant thrips Idolothrips spectrum, drawn by Geoff Thompson.

The thrips are one of the more undeservedly obscure groups of insects, largely because of their generally small size. When they do get attention, it is usually as horticultural pests, living amongst fresh growth of garden plants, and causing unsightly blemishes to form on flowers and fruit due to their feeding. However, the thrips are more than just nuisances, and include many forms for which the gardener’s ire would be unwarranted. For instance, consider today’s subject, the Idolothripini, which do not feed on young shoots but on fungal spores, hunting them down amongst leaf litter and under bark.

As a whole, thrips have a very characteristic form that makes them readily distinguishable from other insects. Their wings (at least in those species that have them) are relatively long and strap-like, with few or no veins and a long fringe of hairs. The mouthparts are long and tubular, as well as asymmetrical with the mandible being developed on only one side, and feeding is down via a long pair of maxillary stylets that are retracted into the head when resting. Thrips are also one of the groups of insects that lead themselves most readily to anthropomorphisation, with the framing of the head by the forelegs when slide-mounted (the usual method of studying these small insects) often giving the impression of waving, shaking of fists, or other expressions. Such impressions are accentuated by the fact that the normal insect claws on each foot are replaced by an adhesive bladder. Idolothripini belong to the thrips family Phlaeothripidae, distinguished from other families by the complete absence of veins in the wings and the development of the final abdominal segment into a long tube, often used for the secretion of protective chemicals*. Large phlaeothripids (I can’t say exactly which species) become very visible here in Perth when dispersing at certain times of year; when they land, their long mobile abdomens give them an almost reptilian appearance. Phlaeothripids are in turn divided between the Phlaeothripinae and Idolothripinae on the basis of the appearance of the maxillary stylets: very narrow in Phlaeothripinae, broader in Idolothripinae. Mound and Palmer (1983) expressed the view that the Phlaeothripinae are probably paraphyletic with regard to the Idolothripinae, and though the basis for this proposal was not clear it is consistent with the (admittedly limited) available molecular data (Mound & Morris 2007). Mound and Palmer (1983) divided the Idolothripinae into the tribes Idolothripini and Pygothripini, though Pygothripini was explicitly paraphyletic to Idolothripini.

*I’ve seen specimens of the phlaeothripine Gynaikothrips curl their abdomen above their thorax like miniature scorpions and move it back and forth in a manner suggesting that they were releasing some offensive spray that I was not sensitive enough to detect.

Head (antennae removed) and pronotum of Lasiothrips perplexus, showing the broad maxillary stylets outlined by dashes. Figure from Mound and Palmer (1983) via World Thysanoptera.

As defined by Mound and Palmer (1983), Idolothripini lacked sutures in the metathoracic sternopleuron, one of the plates of the exoskeleton on the underside of the thorax. Most Idolothripini also had at least two pairs of wing-retaining setae on each abdominal segment, specialised hooked setae on the backs of phlaeothripids that hold the wings back when at rest* (due to the absence of veins, phlaeothripid wings are very floppy), but Mound and Palmer also included some species with only single pairs of wing-retaining setae that they regarded as more generally similar to other Idolothripini. These single-paired taxa have been referred by Retana-Salazar (2009) to a new tribe Anactinothripini.

*The wing-retaining setae can make slide-mounting phlaeothripids a little trickier than other thrips, as the wings must often be unhooked from the setae before being spread on the slide. This can be even trickier than it sounds, because even once unhooked the wings have a definite tendency to simply reattach themselves to the setae like the opposing sides of a strip of velcro.

Head and pronotum of Hartwigia tumiceps. Figure from Mound and Palmer (1983), via World Thysanoptera.

Within the Idolothripini, a range of morphologies can also be found. Many species have the part of the head bearing the antennae protruding noticeably in front of the eyes. This is taken to its most extreme form in the Indian Tiarothrips subramanii, in which the preocular head process is nearly as long as the remainder of the head. Mecynothrips kraussi from the Solomon Islands has a comparable process, but with an apparently different derivation: in Tiarothrips, the process has mostly formed from the parts of the head in front of the ocelli, with the median ocellus only a little in front of the eyes, but in M. kraussi the median ocellus is located well in front of the eyes, more than half-way down the extended process. Another particularly notable species is the South African Hartwigia tumiceps, a thrips which has evolved into an ant-mimic. Hartwigia has a remarkably swollen head: in most phlaeothripids, the head is roughly oblong in shape and distinctly narrower than the pronotum (the first thoracic segment), but that of Hartwigia is almost globular and wider than the pronotum, as well as being covered by an abundance of small setae. It also has white markings on the bases of its legs that make the thorax appear narrower, and a raised section towards the end of the thorax that mimics the node of an ant’s petiole (Stannard 1976).

Systematics of Idolothripinae
<==Idolothripinae [Cryptothripini, Idolothripidae, Idolothripini, Megathripidae, Megathripinae, Pygothripini]BMW13
    |  i. s.: Pinaceothrips Yakhontov 1956MP83
    |         AllothripinaMP83
    |         Hoodia Karny 1910K10
    |           `--*H. austriaca Karny 1910K10
    |--+--PhaulothripsBMW13
    |  `--+--GastrothripsMP83
    |     `--Compsothripina [Compsothripinae, Compsothripini]MP83
    |          |--CompsothripsBMW13
    |          |--BolothripsMP83
    |          |--Anaglyptothrips Mound & Palmer 1983MP83
    |          |    `--*A. dugdalei Mound & Palmer 1983MP83
    |          |--Illinothrips Stannard 1954MP83, MM96
    |          |    `--*I. rossi Stannard 1954MM96
    |          `--Loyolaia Ananthakrishnan 1964MP83
    |               `--*L. indica Ananthakrishnan 1964MP83
    `--+--CarientothripsBMW13
       `--+--+--+--PygothripinaBMW13
          |  |  `--DiceratothripinaBMW13
          |  `--+--MacrothripinaBMW13
          |     `--ElaphrothripinaMP83
          |          |--ElaphrothripsMP83
          |          |--MecynothripsMP83
          |          |--OphthalmothripsBMW13
          |          |--AnactinothripsMP83
          |          |--Tiarothrips Priesner 1935MP83
          |          |    `--*T. subramanii (Ramakrishna 1925) [=Kleothrips subramanii]MP83
          |          |--Hartwigia Faure 1949MP83
          |          |    `--*H. tumiceps Faure 1949MP83
          |          |--Dermothrips Bagnall 1910MP83
          |          |    `--*D. hawaiiensis Bagnall 1910MP83
          |          |--Lamillothrips Bagnall 1923 [incl. Hylothrips Priesner 1932]MP83
          |          |    |--*L. typicus Bagnall 1923 (see below for synonymy)MP83
          |          |    |--L. aethiopicus (Priesner 1932) [=*Hylothrips aethiopicus]MP83
          |          |    `--L. vitulus (Karny 1920) [=Macrothrips vitulus]MP83
          |          |--Malesiathrips Palmer & Mound 1978MP83
          |          |    |--*M. malayensis Palmer & Mound 1978MP83
          |          |    |--M. guamensis Palmer & Mound 1978MP83
          |          |    `--M. solomoni (Mound 1970) [=Atractothrips solomoni]MP83
          |          `--Dinothrips Bagnall 1908 [incl. Paxillothrips Ananthakrishnan 1961]MP83
          |               |--*D. sumatrensis Bagnall 1908 [incl. D. fulmeki Priesner 1959, D. furcifer Schmutz 1913]MP83
          |               |--D. juglandis Moulton 1933MP83
          |               |--D. longicauda (Ananthakrishnan 1961) [=*Paxillothrips longicauda]MP83
          |               |--D. monodon Karny 1920MP83
          |               `--D. spinosus (Schmutz 1913) (see below for synonymy)MP83
          `--+--IdolothripinaBMW13
             `--Hystricothripina [Hystrichothripidae, Megathripina, Megathripini, Zeugmatothripina]MM96
                  |--ActinothripsMM96
                  |--BactrothripsBMW13
                  |--ZeugmatothripsMM96
                  |--Hybridothrips Stannard 1954MM96
                  |    `--*H. oneillae (Stannard 1954) (see below for synonymy)MM96
                  |--Saurothrips Hood 1952MM96
                  |    `--*S. assai Hood 1952MM96
                  |--Cyphothrips Hood 1952MM96
                  |    `--*C. dorsalis Hood 1952MM96
                  |--Ceuthothrips Hood 1938MM96
                  |    `--*C. timuqua Hood 1938MM96
                  |--Zeuglothrips Hood 1936MM96
                  |    `--*Z. echinus Hood 1936MM96
                  |--Neatractothrips Mound & Palmer 1983MP83
                  |    `--*N. macrurus (Okajima 1975) [=Atractothrips macrurus]MP83
                  |--Paractinothrips Mound & Palmer 1983MP83
                  |    `--*P. peratus Mound & Palmer 1983MP83
                  |--Atractothrips Hood 1938 [Atractothripina]MM96
                  |    |--*A. bradleyi Hood 1938MM96
                  |    `--A. mockfordi Stannard 1974MM96
                  |--Zactinothrips Hood 1936MM96
                  |    |--*Z. elegans Hood 1936MM96
                  |    `--Z. modestus Hood 1941MM96
                  |--Azeugmatothrips Mound & Palmer 1983MM96
                  |    |--*A. rectus Mound & Palmer 1983MM96
                  |    `--A. obrieni (Johansen & Garcia 1980) [=Zeuglothrips obrieni]MM96
                  |--Hystricothrips Karny 1912 [incl. Zeugmatothripoides Bagnall 1929]MP83
                  |    |--*H. phasgonura Karny 1912 [incl. H. hystrix Priesner 1932]MP83
                  |    `--H. africanus (Bagnall 1929) [=*Zeugmatothripoides africanus]MP83
                  |--Holurothrips Bagnall 1914MP83
                  |    |--*H. ornatus Bagnall 1914 [incl. H. leeuweni Priesner 1934]MP83
                  |    |--H. collessi Mound 1974MP83
                  |    `--H. morikawai Kurosawa 1968MP83
                  |--Megathrips Targioni-Tozzetti 1881MM96 [incl. Siphonothrips Buffa 1908MP83]
                  |    |--M. lativentris (Heeger 1852) (see below for synonymy)MP83
                  |    |--M. brevis (Bagnall 1914) [=Siphonothrips brevis]MP83
                  |    |--M. elegans (Buffa 1908) [=*Siphonothrips elegans]MP83
                  |    |--M. flavipes (Reuter 1901) [=Cryptothrips flavipes]MP83
                  |    |--M. inermis Priesner 1937MP83
                  |    `--M. timidus Cott 1956MM96
                  `--Megalothrips Uzel 1895MM96
                       |--*M. bonannii Uzel 1895MM96
                       |--M. andrei Mound & Palmer 1983MP83
                       |--M. delmasi Bournier 1956MP83
                       |--M. picticornis Hood 1927 [incl. M. animus Moulton 1929]MP83
                       |--M. schuhi Crawford 1947MP83
                       `--M. spinosus Hood 1908 [incl. M. fuscus Watson 1921]MP83

Dinothrips spinosus (Schmutz 1913) [=Ischyrothrips spinosus; incl. Din. affinis Bagnall 1915, Din. anodon Karny 1923, Din. celebensis Bagnall 1934, Dicaiothrips crassiceps Bagnall 1921, Din. gardneri Moulton 1928, Din. jacobsoni Karny 1921, Din. kenneri Karny 1923, Din. malloti Moulton 1933]MP83

*Hybridothrips oneillae (Stannard 1954) [=Actinothrips (*Hybridothrips) oneillae; incl. Zeuglothrips guerreronis Johansen & Garcia 1973]MM96

*Lamillothrips typicus Bagnall 1923 [incl. Machatothrips longidens Bagnall 1934, L. pennicollis Bagnall 1923]MP83

Megathrips lativentris (Heeger 1852) [=Phloeothrips lativentris; incl. P. longispina Reuter 1879, Megalothrips niger Schmutz 1909, Bacillothrips padewiethi Karny 1919, *Megathrips piccioli Targioni-Tozzetti 1881, Phloeothrips tibialis Reuter 1879]MP83

*Type species of generic name indicated

References

Buckman, R. S., L. A. Mound & M. F. Whiting. 2013. Phylogeny of thrips (Insecta: Thysanoptera) based on five molecular loci. Systematic Entomology 38: 123-133.

Karny, H. 1910. Neue Thysanopteren die Wiener Gegend. Mitteilungen des Naturwissenschaftlichen Vereines an der Universität Wiens 8 (2): 41–57.

[MM96] Mound, L. A., & R. Marullo. 1996. The thrips of Central and South America: an introduction (Insecta: Thysanoptera). Memoirs on Entomology, International 6: 1-487.

Mound, L. A., & D. C. Morris. 2007. The insect order Thysanoptera: classification versus systematics. Zootaxa 1668: 395–411.

[MP83] Mound, L. A. & J. M. Palmer. 1983. The generic and tribal classification of spore-feeding Thysanoptera (Phlaeothripidae: Idolothripinae). Bulletin of the British Museum (Natural History): Entomology series 46 (1): 1-174.

Retana-Salazar, A. P. 2009. Monografía de los grupos genéricos: AnactinothripsZeugmatothrips (Tubulifera: Idolothripinae). ECIBRC: San Jose (Costa Rica).

Stannard, L. J., Jr. 1976. A synopsis of some ant-mimicking thrips, with special reference to the American fauna(Thysanoptera: Phlaeothripidae: Idolothripinae). Journal of the Kansas Entomological Society 49 (4): 492–508.

Leave a comment

Your email address will not be published. Required fields are marked *