Distinguishing features

Both sexes fully winged. Body colour variable, mainly brown but head and thorax sometimes paler; femora light brown, tibiae often yellow; major setae brown; antennal segment III mainly yellow, IV shaded at apex, V brown at least on distal half, VI–VII brown; fore wings pale to very weakly shaded. Antennae 7-segmented; III–IV each with forked sense cone. Head with 2 pairs of ocellar setae; pair III no longer than distance between 2 ocelli, arising just outside triangle; postocular setae pairs I & III slightly longer than ocellar setae III, postocular setae pair II smaller. Pronotum with 2 pairs of posteroangular setae; posterior margin with 3 pairs of setae; discal area with widely spaced irregular transverse striae. Mesonotum with paired anterior campaniform sensilla; median setae arise well in front of posterior margin. Metanotum with irregular, usually longitudinal, reticulation medially; median setae arising behind anterior margin; campaniform sensilla absent or present. Fore wing first vein with 3 setae on distal half; second vein with 12–15 setae. Abdominal tergite II with 3 lateral marginal setae; tergites V–VIII with paired ctenidia, on VIII posteromesad to spiracles; tergite VIII posteromarginal comb absent medially, with several microtrichia laterally; pleurotergites with no discal setae, sculpture lines with many ciliate microtrichia, posterior margin with microtrichia; tergite IX with 2 pairs of campaniform sensilla, X with median split. Sternites with no discal setae; sternite I with no small setae between hind coxae; sternite VII marginal setae S1 arise in front of margin.
Male smaller than female and yellow; tergite VIII with no posteromarginal comb; tergite IX median setae slender, median pair arising anterior to lateral pair and anterior to campaniform sensilla; sternites III–VII with broad transverse pore plate. 

Related species

Thrips major is one of the two most common flower-living thrips in Europe. It is distinguished from the other abundant flower-living species, Thrips fuscipennis, by the combination of having 3 lateral marginal setae on tergite II, and ciliate, rather than dentate, microtrichia on the pleurotergites. The genus Thrips is the second largest genus in the Thysanoptera, and currently includes, worldwide, over 300 species. All members of genus Thrips 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

Feeding and breeding on leaves and in the flowers of its host plants, this polyphagous species is often associated with species of Rosaceae, and is also sometimes found in leaf buds. The species has been shown to be an important pollinator of common elder, Sambuscus nigra [Viburnaceae], an interaction in which the thrips’ behaviour is influenced by temporal changes in the plant’s biochemical signalling (Scott-Brown et al., 2019). 

Distribution data

Widely distributed and very common throughout Britain, particularly in southern England, and is also recorded from across the island of Ireland (Mound et al., 1976). Since the middle of the twentieth century, it has expanded its range northwards through Scotland and is now present in Aberdeenshire (Collins, 2022). This species occurs throughout the Palaearctic as far south as Iran.

Family name

THRIPIDAE - THRIPINAE

Species name

Thrips major  Uzel

Original name and synonyms

Thrips major  Uzel, 1895: 179
Thrips major var. gracilicornis Uzel, 1895: 180
Thrips major var. adusta Uzel, 1895: 180
Thrips sarothamni Priesner, 1925: 149
Thrips fuscipennis f. corticina Priesner, 1925: 369
Thrips fuscipennis var. banatica Priesner, 1927: 370
Thrips fuscipennis f. ustulata Priesner, 1927: 371
Thrips fuscipennis f. dorsimaculata Priesner, 1927: 371
Physothrips inaequalis Bagnall, 1928: 98
Thrips phytolaccae Priesner, 1951: 256
Thrips ponticus zur Strassen, 1970: 374
Thrips permutatus zur Strassen, 1971: 249

References

Collins DW (2022) Range expansion of Thrips major Uzel (Thysanoptera: Thripidae) north through Scotland into Aberdeenshire. British Journal of Entomology and Natural History 34: 335–336.

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

Mound LA, Morison GD, Pitkin BR & Palmer JM (1976) Thysanoptera. Handbooks for the Identification of British Insects 1 (11): 1–79.

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.

Scott-Brown AS, Arnold S, Kite G, Farrell IW, Farman DI, Collins DW & Stevenson PC (2019) Mechanisms in mutualisms: A chemically mediated thrips pollination strategy in common elder. Planta 250: 367–379.