
Large sized, dark brown, macropterous Idolothripinae, male abdomen with pair of lateral tergal tubercles. Head longer than wide, elevated dorsally, with maxillary stylets retracted to eyes and close together medially; one pair of prominent postocellar setae; eyes small, postocular setae varying in length; genae weakly convex; mouth-cone short and rounded; maxillary bridge absent. Antennae 8-segmented; segment III with 2 sense cones, IV with 4 major sense cones; VIII slender and narrowed to base. Pronotum short; notopleural sutures incomplete or absent; with 5 pairs of major setae but epimerals much longer than other pairs. Prosternal basantra present; ferna large, almost meeting medially; mesopresternum complete; metathoracic sternopleural sutures absent. Fore tarsal tooth absent in both sexes. Fore wings not constricted medially, with many duplicated cilia. Pelta broadly rounded medially with long slender lateral lobes; tergites II‒VII each with 2 pairs of sigmoid wing-retaining setae; tergite IX setae shorter than tube; tube slightly shorter than head, with prominent setae laterally. Male tergite VI with pair of lateral stout horn-like tubercles; tergite IX setae S1 and S2 similar; sternite VIII without pore plate.
This genus is one of 10 genera in the mainly Old World Idolothripina, a subtribe of the Idolothripini in the Idolothripinae (Mound & Palmer, 1983). The eight species listed in Megalothrips worldwide are similar to each other in structure, with each one distinguished on relatively insignificant character states of setal lengths and antennal colour (Mound & Palmer, 1983; Okajima, 2006). The genus Bacillothrips, that comprises only three species, is distinguished from Megalothrips on a relatively insignificant difference in the position of the maxillary stylets.
The species are spore feeding on dead branches. Morison (1949: 108) reported that bonannii was found in the burrows of caterpillars on dead Salix branches, and Bournier (1956) indicated a similar habit for delmasi in burrows on Quercus.
Of the eight species in this genus three are from North America, three from southeastern Asian countries, and the other two listed below from Central and southern Europe.
Megalothrips Uzel, 1895: 224. Type species Megalothrips bonannii Uzel, by subsequent designation.
Eight species are listed in this genus (ThripsWiki, 2022).
Euro-Mediterranean species
Megalothrips bonannii Uzel, 1895
Megalothrips delmasi Bournier, 1956
Bournier A (1956) Trois espèces nouvelles de Phloeothripidae. Bulletin de la Société entomologique de France 61: 160–174.
Morison GD (1949) Thysanoptera of the London Area. Part III. Supplement to London Naturalist 28: 76–131.
Mound LA & Palmer JM (1983) The generic and tribal classification of spore-feeding Thysanoptera (Phlaeothripidae: Idolothripinae). Bulletin of the British Museum (Natural History). Entomology 46: 1–174.
Okajima S (2006) The Suborder Tubulifera (Thysanoptera). The Insects of Japan 2: 1-720. The Entomological Society of Japan, Touka Shobo Co. Ltd., Fukuoka.