Both sexes fully winged. Body, legs and antennae brown to dark brown; antennal segments III–V bicoloured, yellow with apices brown; fore wings pale; major setae pale but setae on tergite IX and anal setae all brown. Antennae 8-segmented, segment III with 2 slender sense cones, IV with 4 similar sense cones; VIII with narrow pedicel. Head elongate, slightly elevated in midline, cheeks weakly convex, with one pair of short stout setae behind eyes; one pair of long setae on anterior margins of ocellar triangle, 3 pairs of shorter setae on vertex (postocellar,postocular and midvertex); maxillary stylets close together medially in head, retracted to compound eyes. Pronotum with no epimeral sutures; epimeral setae as long as antennal segment III with apices bluntly pointed, remaining major setae shorter; prosternal basantra present, mesopresternum transverse. Fore tarsus with no tooth. Fore wing broad, parallel sided, with about 30 duplicated cilia. First abdominal segment, pelta, with slender lateral wings; tube long with prominent setae along lateral margins.
Male with no fore tarsal tooth; abdominal tergite VI laterally with pair of drepanae extending beyond segment VII; tube similar to female.
The genus Megalothrips comprises eight species; three from North America, three from eastern Asia, and two from Europe. It is closely related to Megathrips and Bacillothrips, but has much longer maxillary stylets than species in either of those genera. Together with the tropical species-rich genus Bactrothrips it seems likely that these represent a single clade, within which recognition of smaller genera has limited phylogenetic significance. M. bonannii is closely related to delmasi, the other European species of Megalothrips (Mound & Palmer, 1983). A large thrips species for Britain, it is slightly smaller than Bacillothrips nobilis.
Feeding on the spores of unidentified fungi on Salix [Salicaceae] and Pinus [Pinaceae] in Europe, and breeding on dead branches.
Mostly recorded across central Europe, but also known from Spain and Italy (Marullo & zur Strassen, 1994), this species was taken in Britain on five occasions between 1935 and 1947, all at Wood Walton Fen in Cambridgeshire (Mound et al., 1976).
PHLAEOTHRIPIDAE - IDOLOTHRIPINAE
Megalothrips bonanni Uzel
Megalothrips bonanni Uzel, 1895: 227
Marullo R & zur Strassen R (1994) Thysanoptera. In: Checklist delle specie della fauna italiana 40: 1–7. Eds: Minelli A., Ruffo S. & La Posta S. - Calderini, Bologna, Italy.
Mound LA, Morison GD, Pitkin BR & Palmer JM (1976) Thysanoptera. Handbooks for the Identification of British Insects 1 (11): 1–79.
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.