Holopothrips molzi, Lindner, Mariana Flores, Jr, Milton De Souza Mendonça & Cavalleri, Adriano, 2016

Lindner, Mariana Flores, Jr, Milton De Souza Mendonça & Cavalleri, Adriano, 2016, Holopothrips molzi sp. n. (Thysanoptera, Phlaeothripidae): natural history and interactions in Myrtaceae galls, Zootaxa 4114 (2), pp. 139-148 : 141-143

Holopothrips molzi sp.n.

( Figs 5 ̶10)

Macropterous female: Body uniformly dark brown, with fore tibia and all tarsi slightly lighter, red internal pigmentation present. Antennal segment I concolorous with head, II brown at base and yellowish at tip, III–VI yellow, VII yellow at base and brown at tip, and VIII brown. Fore wings pale and without median dark line; major body setae yellow, tergite X very dark medially and light brown at base and apex.

Head about 1.2 times as long as greatest width, but variation was observed among specimens from 1.1 to 1.5 times, cheeks slightly curved, eyes large but not holoptic; po acute and very small (as long as the diameter of an ocellus). Maxillary stylets retracted close to po and about 0.5 of head width apart. Antennae slender and 8- segmented, III with 2 sense cones and IV with 2 sense cones + 1 additional small sense cone. Mouth cone short (not reaching probasisternum) and rounded at tip. Fore tarsal hamus not enlarged.

Pronotum trapezoidal and with weak lines of sculpture near margins; two pairs of long and slightly capitate setae on epimera; aa, ml and pa well developed but shorter, all with blunt apexes; am not developed or no longer than discal setae. Epimeral sutures incomplete; prosternal ferna well developed; basantra absent but sometimes faintly indicated. Mesonotum with transversally elongate reticles, metanotum with longitudinally elongate reticulation, two pairs of small median setae present. Fore wings with 7 to 12 duplicated cilia.

Pelta bell-shaped with paired campaniform sensilla, with reticulate lines of sculpture covering the entire structure. Tergite II with well-defined transverse striations, which become less defined on further tergites. Tergites II–VII with three pairs of wing-retaining setae. Tergite IX setae S1, S2 and S3 finely acute; tube about 0.7 of head length and about 2.0 times as long as greatest width near base, apical width about 0.4 of basal width. Spermatheca S-shaped but not enlarged medially.

Measurements (female holotype in microns): Length about 1,640; head length 220, greatest width across cheeks 180, po length 16, eye dorsal length 82; median length of pronotum 187, width 242, am 3, aa 15, ml 25, ep 77 and 71, pa 7; width of mesonotum 225; fore wing length 730; tergite IX setae S1 127, S2 162, S3 140; tergite X length 162, basal width 80, apical width 35; length(width) of antennal segments III–VIII 53 (30), 43(32), 45(31), 47(28), 50(25), 25(14), respectively.

Macropterous male: Similar to female in both colouration and structure, but slightly smaller; sternites without pore plates, S3 on tergite IX shorter and more slender than S1 and S2.

Measurements (male paratype in microns): Length about 1,580; head length 218, greatest width across cheeks 173, po length 21, eye dorsal length 83; median length of pronotum 165, width 250, am 7, aa 8, ml 30, ep 73 and 75, pa 20; width of mesonotum 225; fore wing length 720; tergite IX setae S1 102, S2 135, S3 47; tergite X length 128, basal width 75, apical width 35; length(width) of antennal segments III–VIII 53 (28), 43(30), 50(28), 48(25), 52(22), 27(12), respectively.

Larva I: About 820 microns long when distended; body colour white with small bands of reddish-orange pigment on abdomen, abdominal segments IX and X brown. Antennae 7-segmented, with segments circular to oval in shape. All dorsal setae are finely acute, with one pair of anal setae longer than the other pairs.

Larva II: Approximately 1,460 microns long when distended (range 1,200–1,740); body colour white with small bands of reddish-orange pigment on abdomen, sometimes also on thorax; abdominal segments IX and X brown. Antennae 7-segmented, segment I concolorous with head, II–VII brown, segments III–VII elongated. Three pairs of setae dorsally on head, two of them finely acute; pronotum with am and aa setae short and acute, ml long and capitate, ep and pa long and acute, and a pair of long and capitate discal setae. Anal setae acute, with one pair longer than the tube. All other setae capitate.

Pupa I: About 1,670 microns long when distended. Body colour white, with red internal pigmentation present in small granules across the body. Wing buds reaching the second abdominal segment.

Pupa II: About 1,890 microns long when distended. Body colour white, extensively filled with internal red pigment, including eyes. Wing buds reaching the fourth abdominal segment.

Material studied: Holotype female, Brazil, Rio Grande do Sul, São Francisco de Paula (S29’29”16° W50’12”04°), in Myrcia guianensis leaf-galls, 17.ii.2014 (Cavalleri, A.), at UFRGS ( Brazil).

Paratypes: 8 males, 83 females collected with holotype, from three different galls; 2 males, 9 females from same locality and plant species, 9.ix.2011 (Toma, T.); 1 female from same locality and plant species, 21.ix.2011 (Toma, T.); 1 male, 10 females from same locality and plant species, 18.iii.2014 (Lindner, M.F.). Brazil, Cambará do Sul (Aparados da Serra), 21 females in M. guianensis leaf-galls, 27.i.2013 (Cavalleri, A.).

Etymology. The species described here is dedicated to our botanist colleague Martin Molz, for his constant help in the identification of thrips host plants.

Comments. Holopothrips molzi shares with other members of the genus two essential character states, the presence of an enlarged S-shaped spermatheca in females, and the presence of an additional pair of tergal wingretaining setae. It has two pairs of epimeral setae ( Fig. 7 ), a character state that is shared with some other species of the genus, such as the South American H. conducans (Priesner) and H. tillandsiae Mound & Marullo , also H. chaconi Zamora et al. from Costa Rica ( Zamora et al. 2015). This characteristic, however, might not be a good indicator of phylogenetic relationship, and is known to vary within H. mariae Mound & Marullo , with some individuals bearing only one pair of epimeral setae, and others two pairs. Holopothrips molzi also differs from its congeners because males do not have pore plates on any sternite ( Fig. 10 ), while in other species (except H. tillandsiae ) these are present at least on sternite VIII ( Mound & Marullo 1996; Cavalleri & Kaminski 2007). This species is possibly related to other Holopothrips species that induce galls in Myrtaceae , such as H. conducans and H. jaboticabae (Hood) , which have antennal segments shaped similarly to H. molzi and male pore plates small or very reduced.

The immature stages of this species are easily differentiated from immatures of M. variabilis by their body colour: H. molzi larvae have the body mainly white with red internal pigmentation forming rings around the thorax and abdomen, while the immatures of the invader are completely red in colour ( Fig. 3 ).

Figures

FIGURES 5 – 10. Holopothrips molzi sp. n. (5) Female body; (6) Ventral view of head and prosternum; (7) Pronotum; (8) Antenna; (9) Mesonotum, metanotum and pelta; (10) Male abdominal sternites V – X, showing the absence of pore plates.

FIGURES 1 – 4. Holopothrips molzi sp. n. galls on Myrcia guianensis and its invaders. (1) Green and intact gall; (2) Green and damaged gall (perforated); (3) Dissected gall, showing the immatures of H. molzi (white arrows) and Myrciathrips variabilis (black arrow); (4) Eulophidae larva feeding on H. molzi.