Print Fact SheetMegathrips timidus

Distinguishing features

Female short winged, sometimes fully winged. Body dark brown, legs yellow, all tibiae yellow at base and apex; antennal segment III yellow with apex brown, IV–VI yellow in basal half or more; major setae and fore wing pale. Antennae 8-segmented; segment III with 2 long slender sense cones, IV with 4 similar sense cones; segment VIII slender and narrowed to base. Head much longer than wide, projecting in front of eyes, cheeks sinuate with pair of prominent setae behind large eyes; ocellar, postocular and mid-vertex setae finely pointed, shorter than eyes; maxillary stylets broad, retracted almost to postocular setae, about one-third of head width apart. Pronotum with 5 pairs of broadly blunt major setae; epimeral sutures usually incomplete; basantra weakly sclerotized, ferna and mesopresternum transverse. Fore tarsi with no tooth. Metanotum reticulate, with one pair of long setae. Fore wing parallel sided, broad, with about 15 duplicated cilia. Pelta broad with prominent lateral wings; short-winged female with anterior pair of sigmoid wing-retaining setae weak on each tergite; tergite IX setae blunt, shorter than tube; tube slightly shorter than head, with several prominent lateral setae.
Male short winged; tergite VI with pair of elongate lateral tubercles bearing a terminal seta, tergites VII and VIII each with smaller lateral tubercles.

Related species

The genus Megathrips includes five species from Europe in addition to this one from California. The genus is probably merely an Holarctic subgroup derived from the large genus Bactrothrips that is widespread across the Old World tropics, and M. timidus could equally well be considered a member of Bactrothrips together with the Californian species B. hesperus (see Mound & Tree, 2011). All these species are unusual amongst Phlaeothripidae in having the abdominal tube with prominent lateral setae, and the males commonly have one or more abdominal segments bearing a pair of prominent tubercles laterally (Mound & Palmer, 1983).

Biological data

Breeding on dead leaves, and feeding by imbibing fungal spores.

Distribution data

Known only from California.

Family name


Species name

Megathrips timidus Cott

Original name and synonyms

Megathrips timidus Cott, 1956: 177


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.

Mound LA & Tree DJ (2011) Australian spore-feeding Thysanoptera of the genus Bactrothrips (Phlaeothripidae – Idolothripinae). Zootaxa 3087: 56–65.