Synaptothrips distinctus (Bagnall, 1915)

Thripinae, Thripidae, Terebrantia, Thysanoptera

Figures

Fig. 1: 9-segmented antenna, terminal segments V-IX
Fig. 2: Dark head, dorsal with ocellar triangle
Fig. 3: Pale head, dorsal with ocellar triangle
Fig. 4: Pronotum
Fig. 5: Pronotum, a bit paler
Fig. 6: Meso- and metanotum
Fig. 7: Fore wing and fore wing distal region
Fig. 8: Sternites V-VII
Fig. 9: Tergites VIII and IX
Fig. 10: Tergites IX and X (male)

Synaptothrips distinctus breeds in the flowers of certain Protea species (sugar bushes). Female macropterous. Body mainly yellow; head with median area of vertex brown, pronotum with transverse brown band on posterior half (Fig. 4 and 5), meso- and metanotum with brown markings; apex of antennae pale brown; fore wings pale. Antennae 9-segmented; segment VI with apex separated by complete suture, segments III & IV with forked sense cone (Fig. 1). Head slightly wider than long; without sculpture between eyes; 3 pairs of ocellar setae present, pair III arising almost lateral to first ocellus and close to compound eyes, pair III as long as distance between compound eyes, pair I & II arising anterior to first ocellus and close to the base of antennae, pair I & II as long as side of ocellar triangle; postocular setae in a single row and about as long as hind ocellus (Fig. 2 and 3). Pronotum with many discal setae and 2 pairs of long posteroangular setae; posterior margin with 5 pairs of setae (Fig. 4 and 5). Mesofurca with weak spinula. Metanotum closely striate, transverse at anterior and longitudinal at posterior; median setae short and arising close to posterior margin; campaniform sensilla present (Fig. 6). Mid and hind tarsi 2-segmented. Fore wing first and second vein with complete row of setae (Fig. 7). Tergite VIII with group of microtrichia anteromesad to spiracle, but no posteromarginal comb (Fig. 9); on tergite X all setae slender. Sternite II with 1 discal seta medially, remaining sternites without discal setae; sternite II with 3 or 4 pairs of marginal setae, III-VI with 4 or 5 pairs, VII with 3 pairs of which pair S1 arises in front of margin (Fig. 8).
Male yellow with the apical antennal segments pale brown; thorn-like setae on tergite IX dark brown (Fig. 10).

The genus Synaptothrips Trybom, 1910
This genus includes 11 species, all from southern Africa (Mound 1968). A first description is given by Trybom (1910). They have been collected mainly within Cape Province, and are possibly all associated with members of the flowering plant family Proteaceae. Members of the genus have 7-9 antennal segments (depending on a partial or complete suture of antennal segment VI), antennal segments III & IV with forked sense cone, head with 3 pairs of ocellar setae, pronotum with 2 pairs of posteroangular setae, fore wings with an almost complete row of setae on both veins, sternites II-VI with 3 or more pairs of posteromarginal setae, and several species have a single discal seta on sternite II (Mound 1968). The members of Synaptothrips are unusual in having the median pair of metanotal setae arising on the posterior half of this notum, in contrast to almost all other Thripidae.

It differs from the related species Synaptothrips paradoxus in having a mainly pale or yellow body color, uniformly pale fore wings, ocellar setae II on head arising anterior to first ocellus close to the base of antennae and they are as long as side of ocellar triangle, ocellar setae III arising outside ocellar triangle and almost lateral to first ocellus and they are as long as distance between compound eyes, and all setae on tergite X are elongate and slender. Synaptothrips paradoxus has a mainly brown body color, light brown fore wings, ocellar setae II on head arising almost lateral to first ocellus and they are not as long as side of ocellar triangle, ocellar setae III arising on anterior margin of ocellar triangle and posterior to first ocellus, ocellar setae III are as long as side of ocellar triangle, and the median dorsal setae on tergite X are stout and thorn-like.
Compared to the species of Synaptothrips with 9-segmented antennae and median pair of metanotal setae arising on the posterior half of this sclerite, all other Thripidae have 7- or 8-segmented antennae (except Anaphothrips obscurus with 8- or 9-segmented antennae) and metanotal median setae arising at anterior margin or on the anterior half of this sclerite.

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
Protea sp. (sugarbushes) - Protea barbigera, Protea laurifolia. In Ethiopia, thrips belonging to genus Synaptothrips are reported as pest of Niger (Bayeh & Gebrre Medhin 1992).

Vector capacity
None identified, but possible mechanical distribution of phytopathogenic fungi and bacteria.

Damage and symptoms
-

Detection and control strategies
-

Biogeography
South Africa (Western Cape: Gordon's Bay, Cape Town, Kirstenbosch, Du Toits Peak - 1995m, Rawsonville).

Bagnall RS (1915). Brief descriptions of new Thysanoptera - VI. Annals and Magazine of Natural History, Zoology, Botany and Geology. (Serie 8) 15: 588-597

Bayeh M & Gebre Medhin T. (1992). Insect pests of Niger, linseed and Brassica. pp. 174-177 in Oilseed Research and Development in Ethiopia. Proceedings of the First National Oilseed Workshop, 3-5 December 1991, Addis Abeba

Lewis T (1973). Thrips: their biology, ecology and economic importance. Academic Press Inc., London Ltd., 349 pp

Moritz G (2006). Thripse. Pflanzensaftsaugende Insekten, Bd. 1, (1. Auflage). Westarp, Hohenwarsleben, 384 pp. ISBN-13: 978 3 89432 891 7

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 microscopical methods. Centre for Biological Information Technology, University of Queensland, Australia, CDROM ISBN 1 86499 781 8

Moritz G, O'Donnell C & Parrella M (2009). Pest thrips of North America. Centre for Biological Information Technology, University of Queensland, Australia, CDROM ISBN-13: 978 1 86499 940 2

Mound LA (1968). A review of R. S. Bagnalľs Thysanoptera collections. Bulletin of the British Museum (Natural History), Entomology. Supplement 11: 1-181

Mound LA (1968). New synonymy in the South African genus Synaptothrips Trybom (Thysanoptera) with a key to the species. Journal of the Entomological Society of South Africa. 31 (1): 87-95

Nickle DA (2009). Commonly intercepted thrips at U.S. ports-of-entry from Africa, Europe, and the Mediterranean. IV. Miscellaneous thripine genera excluding Frankliniella, Iridothrips, and Thrips (Thysanoptera: Thripidae). Proceedings of the Entomological Society of Washington. 111 (1): 215-238

Trybom F (1910). Physapoda. In Denkschriften der Medizinisch-Naturwissenschaflichen Gesellschaft zu Jena. Bd. 16, Schultze L. Zoologische und anthropologische Ergebnisse einer Forschungreise im westlichen und zentralen Südafrika (1903-1905). 4: 147-174 (pp 156-158)

zur Strassen R (1960). Catalogue of the known species of South African Thysanoptera. Journal of the Entomological Society of Southern Africa. 23 (2): 321-367

zur Strassen R (1968). New records of South African Thysanoptera with description of a new Phlaeothripid genus. Journal of the Entomological Society of Southern Africa. 31 (2): 365-372