Scolothrips ochoa, Mound, Laurence A., Tree, Desley J. & Goldarazena, Arturo, 2010

Mound, Laurence A., Tree, Desley J. & Goldarazena, Arturo, 2010, A new species of predatory Scolothrips (Thysanoptera, Thripidae) feeding on Raoiella mites (Tenuipalpidae) in Australia, Zootaxa 2620, pp. 63-68 : 64-66

Scolothrips ochoa sp. n.

Female macroptera. Body mainly brown with red internal pigment ( Fig. 3 ); tarsi and apices of tibiae yellow; head, metanotum and abdominal segments brown, pronotum and mesonotum paler; abdominal segments III– VI with clear areas laterally, VIII–IX darkest; antennal segments IV–V much paler than remaining segments ( Fig. 4 ); major setae hyaline, but dark on pigmented areas of forewings; forewings with two dark transverse bands.

Head wider than long, cheeks short and slightly incut behind large eyes. Ocellar triangle strongly elevated; ocellar setae pairs I and II, also postocular setae, absent; ocellar setae III long and finely barbed, arising within triangle; vertex transversely reticulate ( Fig. 8 ). Compound eyes each with four pigmented facets ventrally; frons with seven pairs of setae; maxillary palps 2-segmented ( Fig. 9 ).

Antennae 8-segmented ( Fig. 10 ), with few or no microtrichia; segment I without paired dorso-apical setae; III–IV also V–VI broadly joined; III and IV each with forked sensorium.

Prosternal basantra without setae, ferna slender and widely separated, prospinasternum reduced to small median triangle ( Fig. 13 ); meso and metafurca each with strong median spinula.

Pronotum transverse, surface transversely but irregularly reticulate ( Fig. 8 ), with no discal setae; five pairs of long, barbed major setae present (anteromarginal, anteroangular, posteromarginal, and two pairs posteroangular); four pairs of minor, weakly barbed, setae present (two pairs of anteromarginals, one (or two) pair of posteromarginals, one pair of midlaterals).

Mesonotum transversely striate/reticulate; no anterior campaniform sensilla; median setal pair arising near middle of sclerite, lateral pair small. Metanotum longitudinally and narrowly reticulate; median setal pair wide apart near lateral pair and at anterior margin; campaniform sensilla absent ( Fig. 14 ).

Forewing relatively broad with apex pointed; dark areas finely tuberculate ( Fig. 11 ); costal setae long with apices barbed, costal cilia small and present only medially; first vein with 10–11 long barbed setae in irregular continuous row, second vein with 6–8 long barbed setae; clavus with 3 veinal and 1 discal barbed setae; posteromarginal cilia strongly undulated.

Tergites without craspedum; tergite I transversely reticulate ( Fig. 15 ), II–VIII with sculpture markings only laterally and not extending to campaniform sensilla; median setae small and wide apart; VIII with neither comb nor craspedum. Suture between tergites and pleurotergites weakly developed, pleurosternites weakly sclerotised. Tergite IX elongate ( Fig. 12 ), without anterior pair of campaniform sensilla, mid-dorsal paired setae well developed; tergite X short with no longitudinal split.

Sternites reticulate laterally, with three pairs of marginal setae, no discal setae; sternite VII posterior margin eroded medially. Ovipositor well developed and serrated.

Measurements of holotype female in microns. Body length 1150. Head, length 65; width 150; ocellar setae III 65. Pronotum, length 75; width 200; major setae 60–65. Forewing length 750. Tergite IX setae, S1 55; S2 75. Antennal segments I–VIII length 15, 30, 25, 18, 20, 48, 15, 15.

Male not known.

Larva II. In life with red-brown body contents ( Fig. 5 ); cleared specimens with no cuticular pigment, except faintly grey at base of all femora and tibiae, and base of antennal segments I–IV. Major setae all long, weakly capitate and barbed; 2 pairs on head, 6 pairs on pronotum; thorax and abdominal tergites with finely tuberculate sculpture.

Specimens studied. Holotype female, Australia, Queensland, Brisbane, The Gap, Walton Bridge Reserve, from Lophostemon suaveolens (Myrtaceae) in association with an unidentified Raoiella species, 14.vi.2009 (D.J.Tree 945).

Paratypes: 2 females taken with holotype, also 3 larvae; same locality, 2 females with one larva, Lophostemon confertus , 16.v.2009 (Jenny Beard); same locality, 1 female from Lophostemon confertus , 15.v.2008 (Beard & Ochoa ). Western Australia, 27km north of Narrogin, 1 female from Eucalyptus wandoo (Myrtaceae) , 9.v.2008 (Beard & Ochoa ). New South Wales, 20km west of Narrandera, 1 female from Callitris glaucophylla (Cupressaceae) , 25.iv.1995 (LAM 2647).

Relationships. Adult females of this new species share most character states with the other species of Scolothrips . Moreover, the body colour, and the sculpture of the metanotum and first abdominal tergite are similar to that of S. asura ( Figs 17–18 ). The major structural differences from previously described Scolothrips species are (1) loss of the two pairs of pre-ocellar setae, (2) reduction of the paired pronotal midlateral setae, and (3) compact form of the antennal segments (cf. Figs 10 , 16 ). Although these character state differences are striking, most details of the body structure, the long barbed setae, the fasciate forewings, as well as the biology of this species as a mite predator, are strikingly similar to those found in the other Scolothrips species. It seems more likely that S. ochoa evolved within this genus, rather than that it is sistergenus to Scolothrips or even more distantly related. We therefore conclude that a new genus is not warranted.

Figures

FIGURES 1 – 4. Scolothrips ochoa sp. n. (1) Host tree, Lophostemon suaveolens; (2) Adult female feeding on Raoiella egg; (3) Slide mounted adult female; (4) Female head and antennae.

FIGURES 8 – 15. Scolothrips ochoa sp. n. female illuminated with Differential Interference Contrast (8) Head & pronotum; (9) Ventral surface of head; (10) Antenna; (11) Forewing dark area; (12) Tergites VIII – X; (13) Thoracic sternites; (14) Meso and metanota; (15) Tergites I – III.

FIGURES 5 – 7. Scolothrips ochoa sp. n. (5) Larva feeding on larval Raoiella; (6) Pupa with Raoiella eggs and nymphal skins; (7) Four images from cine film of pupa and emerging adult (note white cast cuticle: (a) Start of filming; (b) at 6 minutes; (c) at 11 minutes; (d) at 94 minutes).

FIGURES 16 – 18. Scolothrips asura female. (16) Antenna; (17) Pro, meso and metanota; (18) Tergites I – III.