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Thrips of California 2012

Thrips palmi

Recognition data

Distinguishing features

Both sexes fully winged. Body and legs yellow, major setae light brown; antennal segments IV–V brown distally, VI–VII brown; fore wings pale. Head wider than long; 2 pairs of ocellar setae; pair III small, arising just outside the ocellar triangle; postocular setae pair I slightly longer than ocellar setae III. Antennae 7-segmented; segments III–IV with short forked sensorium; VII short. Pronotum with 2 pairs of long posteroangular setae; posterior margin with 3 pairs of setae. Metanotum with irregular longitudinal lines converging to posterior margin, at anterior with curving transverse lines; median setae arising behind anterior margin; campaniform sensilla present. Fore wing first vein with 3 (sometimes 2) setae on distal half; second vein with row of about 15 setae. Abdominal tergite II with 4 lateral marginal setae; tergites V–VIII with paired ctenidia laterally, on VIII posteromesad to spiracles; tergite VIII posteromarginal comb complete, microtrichia long and slender; pleurotergites without discal setae. Sternite II with 2 pairs of marginal setae, III–VII with 3 pairs; sternites without discal setae.

Male smaller than female; tergite VIII with marginal comb complete medially; sternites III–VII with narrow transverse pore plate.

Related and similar species

Thrips palmi is a widespread pest in tropical countries, and although present in Florida it has not yet been found in California.Populations in southern China and the mountains of southern Asia seem to represent a separate species, T. alatus Bhatti. Also remarkably similar in structure is T. flavus Schrank, a species that is widespread from Europe across Asia, but with ocellar setae III arising within the ocellar triangle just behind the first ocellus. The genus Thrips is the second largest genus in the Thysanoptera, and currently includes, worldwide, about 285 species. All members of genus Thrips lack ocellar setae I on the head, and they all have ctenidia on tergite VIII posteromesad to the spiracles. Other characters, such as number of antennal segments, number of setae on the fore wing veins, and number of discal setae on the sternites are variable between species (Palmer, 1992; Nakahara, 1994; Mound & Masumoto, 2005).

Taxonomic data

Current valid name

Thrips palmi Karny

Original name and synonyms

  • Thrips palmi Karny, 1925: 10
  • Thrips clarus Moulton, 1928: 294
  • Thrips leucadophilus Priesner, 1936: 91
  • Thrips gossypicola Priesner, 1939: 41
  • Chloethrips aureus Ananthakrishnan & Jagadish, 1967: 381
  • Thrips gracilis Ananthakrishnan & Jagadish, 1968: 361

Family placement

Thripidae, Thripinae

Common names

Melon thrips [This species does not live on any palm plants – it was named originally after a Dr Palm and should NOT be called “Palm Thrips” ]

Biological data

Life history

Breeding in flowers and on leaves.

Host plants

Highly polyphagous, particularly Cucurbitaceae and Solanaceae.

Tospoviruses vectored

WSMV, GBNV

Crop damage

Serious damage to several food crops, including aubergines and potatoes.

Distribution data

Area of origin

Southeast Asia

Distribution

Throughout Asia, locally in northern Australia, widespread in tropical countries, including Caribbean and southern Florida. [not recorded in California]