Distinguishing features

Female fully winged, or with wings shorter than thorax width. Body and legs brown, tarsi and apices of fore tibiae yellow; antennal segments III–VII largely yellow, VII shaded at apex, VIII light brown; fore wings pale. Antennae 8-segmented; segment III with 2 (or 3) sense cones, IV with 4 (2 or 3) sense cones; segment VIII narrowed to base. Head longer than wide; cheeks confluent with eyes, with small grooves anterolaterally; postocular setae wide apart, bluntly pointed; dorsal surface with little sculpture; maxillary stylets retracted to eyes, about one fifth of head width apart. Pronotum with little sculpture; 3 pairs of prominent, almost capitate, major setae; anteromarginals minute, midlaterals variable but never as long as epimerals; paired prosternal basantra well developed, mesopresternum slender at mid-point. Fore tarsus with minute tooth. Metanotum faintly reticulate. Fore wings weakly constricted medially; 5 duplicated cilia present. Pelta almost without sculpture, D-shaped; tergites II–VII with two pairs of sigmoid wing-retaining setae; tergite IX setae S1 almost pointed, as long as tube.
Male similar to female, but fore tarsal tooth slightly larger; tergite IX setae S2 short and stout.

Related species

Nine species are listed in the genus Bagnalliella. Seven of these are from Yucca plants in southwestern USA and are clearly closely related in structure, whereas the other two (from New Guinea and South Africa) should probably be placed in other genera. B. yuccae has been distributed widely around the world in association with its cultivated host-plant. Cott (1956) distinguished the three species of Bagnalliella recorded from California on the following basis: B. yuccae with two sense cones on antennal segment III and four on IV; B. mojave Hood with one sense cone on antennal segment III and two on IV; B. desertae Hood with one sense cone on antennal segment III and three (? four) on IV. Tree (2010) noted that in a population of B. yuccae introduced to Australia the number of sensoria on antennal segment III varied from 2–3, and the number on segment IV varied from 2–4. Thus the species separations given by Cott require further study in natural populations.

Biological data

Colonies of adults together with larvae and pupae occur on leaf bases of Yucca spp., sometimes inducing mottling of these leaf bases.

Distribution data

Originally from Western USA, but now widespread around the world on cultivated Yucca plants.

Family name

PHLAEOTHRIPIDAE, PHLAEOTHRIPINAE

Species name

Bagnalliella yuccae (Hinds)

Original name and synonyms

Cephalothrips yuccae Hinds, 1902: 194
Haplothrips ryani Moulton, 1929: 131
Haplothrips yuccae Savenko, 1944: 1005.

References

Cott HE (1956) Systematics of the suborder Tubulifera (Thysanoptera) in California. University of California, Berkeley, Publications in Entomology 13: 1–216.

Tree DJ (2010) Intrapopulation Variation in an Australian Population of the North American Thrips, Bagnalliella yuccae (Thysanoptera: Phlaeothripidae), A New Record from Australia. Florida Entomologist 93: 346–351.

Thysanoptera Californica