Aulacothrips amazonicus, Cavalleri, Adriano, Kaminski, Lucas A. & Mendonça, Milton S., 2012

Cavalleri, Adriano, Kaminski, Lucas A. & Mendonça, Milton S., 2012, A new ectoparasitic Aulacothrips (Thysanoptera: Heterothripidae) from Amazon rainforest and the significance of variation in antennal sensoria, Zootaxa 3438, pp. 62-68 : 63-66

Aulacothrips amazonicus sp.n.

( Figs 2–11 )

Female macroptera. Body brown ( Fig. 2 ); all legs yellow; antennae extensively brown, segment II darker and III paler in basal third; fore wings blackish brown with a dark basal line; major setae light brown; abdominal tergites VII–VIII somewhat paler in lateral thirds.

Head about 1.2 times wider than long ( Fig. 4 ); three pairs of ocellar setae, pair II long and capitate, arising close to eye inner margin; postocular setal pair II expanded at tip and well developed; pair III small and within ocellar triangle; ocellar area reticulate; antennae 9-segmented, III & IV enlarged and with continuous porous sensoria, curved laterally toward base and extending to segment midpoint ( Fig. 5 ). Mouth-cone short and rounded at tip, extending 53 microns beyond posterior dorsal margin of head.

Pronotum transverse and reticulated, except a small area medially ( Fig. 6 ); six pairs of long and capitate setae (two specimens with seven pairs on only one side) and one pair arising well behind the anterior margin; about 30 small and finely acute discal setae; mesonotum reticulate; metascutum triangular, polygonally reticulate, faintly sculptured medially and without internal markings, remaining metanotal area also sculptured and covered by numerous microtrichia; paired metanotal campaniform sensillae placed at posterior third. Abdominal tergites with strong polygonal reticulation ( Fig. 8 ), with well-developed craspedum bearing stout teeth; tergite I without long setae, II–VIII with median furrow bearing pair of long and pointed setae medially, lateral margin of furrow with two pairs of stout setae, posterior margin with fringe of small microtrichia medially and three pairs of long discal setae, median pair arising in line with wing-retaining setae; IX with numerous long and pointed discal setae ( Fig. 11 ); long setae on X weakly expanded at apex. Abdominal sternites II–VIII with about five pairs of stout and flattened setae placed laterally, IX with two rows of five such setae each side ( Fig. 10 ).

Measurements of female holotype, in microns: Length about 1,520 (distended); head length 150, greatest width across cheeks 167; ocellar setae II length 43, interval 55; postocular setae pair II 52, interval 55; eye dorsal length 70; pronotum median length 175, width 250; mesonotum width 190; fore wing length 780, median width 20; metascutal triangle length 75, major width 92; tergite IX length 130, basal width 167; tergite X length 73, basal width 68; major setae on X 98; antennal segments III–IX length (width): 80 (basal width 30, apical width 41), 82 (35), 8 (18), 8 (15), 10 (8), 10 (8), 12 (5).

Male macroptera. Smaller and paler than female ( Fig. 3 ); body largely yellowish brown, anterior margin of mesonotum and abdominal tergites IX–X darker; lateral thirds and furrow on abdominal tergites II–VIII also darkened; posterior margin of abdominal tergite VIII with only one pair of long and capitate setae; tergite IX posterior margin not extending toward X; tergite X with two pairs of long, curved and weakly expanded setae; sternite VII antecostal ridge with small circular pore plate, diameter about 11 microns, covered by a posterior extension of sternite VI bearing several long and pointed setae ( Fig. 9 ); IX with several stout and hyaline setae laterally.

Measurements of paratype male, in microns: Length about 1,240; head length 105, greatest width across cheeks 140; pronotum median length 165, width 213; mesonotum width 158; metascutal triangle length 65, maximum width 82; tergite IX length 70, basal width 122; tergite X length 55, basal width 55; curved setae on X 93; genitalia length 178; major width 47, aedeagus length 145; antennal segments III–IX length (width): 65 (basal width 22, apical width 33), 70 (33), 8 (15), 11 (12), 11 (8), 10 (7), 12 (5).

Material examined. Holotype female, Brazil: Par, Ilha de Jurupari (0136’S, 5249’W), 04.vii.2010, associated with Ramedia sp. ( Membracidae ) aggregation on Solanum sp. branches (L.A. Kaminski). Paratypes: 10 males and 11 females collected with holotype.

Comments. This new species was found infesting Ramedia (Membracidae) treehoppers on Solanum shrubs in Amazon rainforest. Larvae, 17 females and 12 males were found living together, most of them attached to the bodies of the hemipterans. These bugs were tended by ants of the species Dolichoderus bispinosus ( Formicidae : Dolichoderinae ). Although very distinct on its lighter colouration, Au. amazonicus is possibly closely related to A.

minor due to its host preference and general morphology. Both species have abdominal sternite IX with several small flattened setae laterally in one or two rows, and the conical format of antennal segment III is also similar. Despite this, the sensorial areas on antennal segments III and IV are remarkably reduced in Au. amazonicus , and are similar to those of Lenkothrips species ( Fig. 14 ). However, as in Au. dictyotus , males of this new species also have the posterior margin of abdominal sternite VI prolonged, and bearing several setae, thus covering the minute pore plate on the antecostal ridge of sternite VII.

Figures

FIGURES 1 – 7. Aulacothrips amazonicus sp. n. and its host. (1) Ramedia treehoppers tended by Dolichoderus bispinosus ants on Solanum shrub; (2) Female; (3) Male; (4) Head; (5) Antenna in dorsal view; (6) Pronotum; (7) Mesonotum and Metanotum.

FIGURES 8 – 11. Aulacothrips amazonicus sp. n.; (8) Male abdominal tergites II – IV; (9) Male abdominal sternites VI – VIII (arrow indicates the minute pore plate); (10) Female abdominal sternites VIII – IX (arrows indicate flattened and hyaline lateral setae on IX); (11) Female abdominal tergites VIII – X.

FIGURES 12 – 14. Dorsal view of antennae in Heterothripidae species. (12) Aulacothrips dictyotus; (13) Aulacothrips minor; (14) Lenkothrips sp.