Ankothrips gracilisAnkothrips gracilisFemale fully winged. Body and legs largely yellow; antennal segments IV–IX light brown, I–III paler with apex shaded; fore wings clear. Antennae 9-segmented, IX longer than VIII, sensoria transverse on III & IV, segment II apex prolonged ventro-laterally into small serrate lobe. Head with ocellar setae I arising on slightly bifurcate tubercle, setae III arise just within ocellar triangle. Head with one pair of long postocular setae and two shorter pairs. Pronotum trasversely striate, posterior margin with 7–8 pairs of prominent setae, one posteroangular pair at least three times as long as discal setae. Mesonotum closely transversely striate, with no microtrichia on sculpture lines. Metanotum closely longitudinally striate, with no microtrichia, median setae near posterior margin. Abdominal tergite VIII median setae more than 0.7 as long as tergite; tergite X with paired trichobothria well developed. Sternite VII posterior margin with pair of lobes each bearing two setae at base.
This species is distinguished by the closely spaced lines of sculpture on the mesonotum and metanotum that lack microtrichia. Currently there are 13 species listed in the genus Ankothrips, seven of which are from western USA, with five recorded from California (Bailey, 1957). Of the others, one is from SW Africa, one from Iran, and four from southern or eastern Europe. Although at one time considered members of the Aeolothripidae, all females of Melanthripidae have a pair of lobes at the posterior margin of sternite VII, a condition that is otherwise found only in females of Merothripidae.
Bailey (1957: 165) states that this species is widespread along the Californian coastal mountains in the flowers of Adenostoma fasciculatum [Rosaceae]. It is flower-living with one generation each year.
Known only from California.
MELANTHRIPIDAE
Ankothrips gracilis Moulton
Ankothrips gracilis Moulton, 1926: 19
Bailey SF (1940) A review of the genus Ankothrips D.L.Crawford (Thysanoptera). Pan-Pacific Entomologist 16: 97–106.
