Heterothrips pilarae, Borbón, Carlos Manuel De, 2010

Borbón, Carlos Manuel De, 2010, The Heterothrips species of Argentina, with two new species and biological notes (Thysanoptera, Heterothripidae), Zootaxa 2562, pp. 45-56 : 48-50

Heterothrips pilarae sp. n.

Female macropterous ( Fig. 33 ): Color: Body uniformly brown., fore tibiae, apex of fore femur and all tarsi yellowish, antennal segments I and II dark brown, apex of II, segment III and IV yellowish brown, V–IX brown ( Fig. 2 ); forewing shaded greyish brown with basal 2/5 clearer ( Fig. 31 ).

Structure: Head ( Fig.1 ) wider than long and broader at base, with three pairs of ocellar setae, pair III arising between the lines that connect fore and hind ocelli; with five pairs of postocular setae, three arising near to hind ocelli and two near to cheek. Antennal segment III tripartite with short pedicel; segments III and IV with a sensorial band, apparently a simple row of pores at apex ( Fig. 2 , 30 ). Pronotum with transverse sculpture lines and about 34 discal setae ( Fig.1 ). Mesonotum with transverse lines and with pair of more developed setae placed at posterior third of sclerite ( Fig. 3 ). Metanotum with concentric lines of structure covered with microtrichia, with two pairs of setae, the external pair located at anterior margin and the inner pair at posterior margin, campaniform sensilla present ( Fig. 3 ). Tergites ( Figs 4, 5 , 8, 9, 10, 11 and 12) II–VII with one pair of well developed setae medially, with reticulation at middle zone and more strongly on lateral third, with several discal setae laterally. Tergites II–VIII with microtrichia at posterior margin, forming a complete comb on tergites VI–VIII, the rest of these tergites with microtrichia at middle and laterally on posterior margin; tergites VIII–IX with discal microtrichia. Sternites (Figs 7, 26) with weak reticulation, I with minute setae at anterior ridge, II–VI with spaced setae and microtrichia on posterior margin, VII with few short microtrichia arising at posterior margin. Pleurites II–VII with posteromaginal microtrichia. Some specimens presented anomalies, such as the first tergite with only one seta medially; the comb of microtrichia on tergite VI is variable, sometimes incomplete.

Measurements in microns Holotype female: Length 1290. Head length (width) 102 (173). Pronotum length (width) 129 (244). Forewing length 650. Tergite lengths, IX 73, X 73. Antennal segments I–IX length (width) 22 (24), 34 (22), 46 (20), 27 (20), 24 (17), 24 (15), 22 (11), 17 (10), 11 (5).

Male macropterous ( Fig. 34 )): Similar to female in colour and structure, but smaller and more slender. Sternites III–VIII with irregular pore plate at centre of anterior third ( Fig. 6 ).

Measurements in microns Paratype male: Length 1050. Head length (width) 90 (146). Forewing length 570. Sternite VIII width of pore plate 34.

Material examined. Female holotype, ARGENTINA, El Carrizal, Mendoza (S 33°17’; W 68°43’), 18.xi.2007, on flowers of Tricomaria usillo (Malpighiaceae) , collected by de Borbón, in Museo de Ciencias Naturales de La Plata.

Paratypes, 13 females, 2 males collected with holotype, 27 females, 6 males with similar data but 11.xi.2007; 15 females, 1 male with similar data but 14.xi.2007, collected by de Borbón, in Museo de La Plata and Laboratorio de Fitovirología EEA Mendoza INTA.

Comments. Using the key by Mound & Marullo (1996), several species can be discounted such as all species with craspeda, lobes or plaques, also several species with different colour of body, antennal segments, legs and wings, also presence of discal setae on sternites, sculpture of pronotum absent, length ratio of antennal segments, antennal segment III partitions, length ratio of abdominal segments IX/X. Using the key, this species runs to H. vitis , with which it has several characters in common. Judging from the original description of H. vitis given by Hood (1916), pilarae differs because it has antennal segment III length/width ratio around 2.3 whereas in vitis this ratio is about 2.8. Also it differs in the presence of microtrichia medially on the posterior ridge of tergites II–V, whereas in vitis microtrichia are present laterally but absent medially on these tergites. Moreover, vitis is found on native Vitis species in the Eastern United States, whereas pilarae occurs on a Malpighiaceae in South America. H. pilarae has the same disposition of tergal marginal microtrichia that is recorded in H. johanseni Berzosa & Maroto , but pilarae has only one row of sensorial pores on antennal segments III–IV, whereas johanseni has two rows. These two species also differ in forewing colour. Another similar species is H. araucaniae Berzosa et Maroto (1999) , collected on Quinchamalium chilense (Santalaceae) , but tergites II–V of that species have no microtrichia medially on the posterior ridge. Two further species recorded from Malpighiaceae , H. peixotoa Del Claro et al. (1997) and H. nouragnensis Ulitzka (2004) , also have a double row of pores on antennal segments III–IV, in contrast to the single row found in pilarae .

FIGURES 7–12. H. pilarae : 7 Sternite V; 8 Tergite V; 9 Tergite VI; 10 Tergite VIII; 11 Tergite IX; 12 Tergite X.

Figures

FIGURES 33 – 37. H. pilarae: 33 Female; 34 Male. H. stellae: 35 Female; 36 Male. 37 H.? flavitibia

FIGURES 1 – 6. H. pilarae: 1 Head and Pronotum; 2 Antenna; 3 Meso and Metanotum; 4 Tergites V – VI; 5 Tergites IX –

FIGURES 24 – 32. H. marginatus: 24 tergite. H. moestus: 25 tergite. H. pilarae: 26 Sternites. H. cacti: 27 Sternites; 28 Antenna. H. myrceugenellae: 29. Antennal segment III – IV. H. pilarae: 30 Antennal segments III – IV; 31 Right forewing. H. stellae: 32 Right forewing.