Haplothrips euphorbiae Priesner, 2025

Rousse, Pascal & Reynaud, Philippe, 2025, Ananthakrishnana syn. n. of Haplothrips, with redescription of H. euphorbiae adult and larva (Thysanoptera), Zootaxa 5583 (3), pp. 589-596 : 591-594

Haplothrips euphorbiae Priesner stat. rev.

( Figs 2 –6)

Haplothrips euphorbiae Priesner, 1931: 1–4

Ananthakrishnana indica Bhatti, 1967: 22 , synonimised by Bhatti 1979: 310.

Priesner described this species from specimens collected at Medan, Sumatra, whereas Bhatti described indica on specimens from Delhi, India. There are subsequent records of the species from southern India —Andra Pradesh and Maharashtra ( Tyagi & Kumar 2016), Pakistan ( Saeed & Yousuf 1994), Thailand (Masumoto et al. 2021), Philippines ( Reyes 2021), Mauritius ( Ulitzka 2022), and Cape Verde ( Berzosa et al. 2005). It is here newly recorded from Reunion Island, with the details of specimens collected given below. In contrast, there are no records of the species from tropical Australia or the continent of Africa. These collecting records suggest that this thrips species is probably widespread across the south-Asian tropics.

Redescription

Female macroptera. Body length 1600–1840 microns ( Fig. 2A ), antenna and legs brown to dark brown, abdomen sometimes lighter than remainder of body; fore wing pale with extreme base and clavus shaded. Head dorsally with transverse wavy striations and reticulate in ocellar area ( Fig. 3A ), distinctly protruding between antennal bases, about 1.4 times longer than wide; eye less prolonged ventrally than dorsally; cheeks parallel, slightly tapering towards base; maxillary stylets ( Fig. 3B ) retracted beyond mid-length of head and posterior eye margin, 13–20 microns distant from each other, maxillary bridge ( Fig. 3B ) present (sometimes hardly distinct); posterior ocellus contiguous to eye; post-ocular setae minute. Antenna 8-segmented ( Fig. 3C ), segments III–VII constricted at base, segment II with campaniform sensorium on apical half, segment III with two sense cones, IV with four sense cones, segment III short, 0.8x as long as IV and about 1.3 times as long as segment VIII, segment IV rounded in shape. Pronotum ( Fig. 4A ) with similar transverse and wavy striations, only epimeral seta developed, capitate, anteromarginal and mid-lateral setae no longer than discal setae, notopleural sutures complete, basantra and ferna transverse and large; mesopresternum transverse and eroded medially; mesonotum transversally reticulate with laterally three pairs of campaniform sensilla and four pairs of posterior setae; metanotum ( Fig. 4B ) reticulate with a median pair of setae and three pairs of small antero-lateral setae. Fore tarsal tooth present ( Fig. 5B ), sometimes reduced to weak lateral protuberance. Fore wing moderately constricted medially, without duplicated cilia on posterior margin; fore wing cilia smooth; all three sub-basal setae short with apex expanded. Pelta broadly triangular and reticulate ( Fig. 4B ); tergites transversely striate-reticulate, sculpture stronger laterally and anteriorly; tergites II–VII with two pairs of wing-retaining setae, lateral setae S1 hyaline, flattened with apex slightly expanded; tergite IX with S1 blunt and 0.5 times as long as tergite X, S2 thinner, blunt and 0.7 times as long as S1; tube with straight sides, 0.5 times as long as head and about twice as long as its basal width.

Male macroptera. Body length 1280–1320 microns ( Fig. 2B ). Similar to female but: maxillary stylets farther apart (30–40 microns); fore tarsal claw more distinct, broad and blunt; sternite VIII without pore plate; aedeagus slender and narrowed to apex ( Fig. 5A ), total length 40 microns, maximum width 11 microns distance between gonopore and tip of aedeagus 11 microns.

Second instar larva. Body length 1100–1450 µm ( Fig. 5C ). Live specimens red; mounted specimens whitish but head, legs, antennae, prothorax and tip of abdomen light to dark brownish. Head with two lateral and one anterior plates, central oval small plate on frons (10x6 µm); antenna 7-segmented, (175 µm long), segment III 1.70x longer than wide and tapering basally, segment VII 2.75x longer than wide; D1 seta (20 µm) with expanded apice, other setae smaller and acute; maxillary stylets retracted to D1 seta.

Thorax. Dorsal setae with indistinct basal sclerotization; prothorax smooth with two large dorsal plates and seven pairs of setae: D1, D6 and D7 setae strongly expanded, D2 to D4 small and acute (D3 vestigial); D1 17–22 µm, D6 32–40 µm, D7 25–35µm; pronotal dorsal plates with posterior margins are medially reduced, setae D1 situated close to their edges; meso- and metanotum with a single sclerite pair reduced to small transversal plates (10 µm) with microseta, second and third sclerites pairs entirely lacking; spiracles of metanotum with about 13 cells, without pore; apical setae on all tibiae pointed.

Abdomen. Smooth with some microtrichiae on segments VIII–X; dorsal setae with expanded apex and without basal sclerotization; spiracle of segment II with eight cells, without pore; spiracle of tergite VIII with 11 cells, without pore, and small lateral plates reaching at least D2 seta but not beyond D1; tergite IX with D1 setae long and expanded, D2 and D3 very small and acute; sternite IX with D1 seta long (43–55 µm) and pointed, D2 (27–38 µm) expanded; segment X cone-shaped, 1.25x longer than wide with apical setae pointed, about 1.7x longer than tube.

Host plants. Euphorbia hirta ( Priesner 1931) . Euphorbia heyneana , E. goliana , Euphorbia sp. var. Pointe au Sel. Also associated with Chenopodium sp. ( Amaranthaceae ) ( Bhatti 1967), Oriza sativa , ( Poaceae ) ( Reyes 2021), Parthenium hysterophorus ( Asteraceae ) (M. Ulitzka, pers. com.), and Vappodes phalenopsis ( Orchidaceae ) ( Masumoto et al. 2012).

Material examined. All from Reunion and all in Laboratoire de Santé des Végétaux-Entomologie: 5♂♂ 4♀♀ [slide-mounted], from Euphorbia (Chamaesyce) sp., 3.i.2022 ; 22♂ ♀ [ethanol 96%], from Euphorbia (Chamaesyce) sp., 3.i.2022; 6 second instar [slide-mounted], Euphorbia (Chamaesyce) sp., 12.v.2022; 4♂♂ 4♀♀ [slide-mounted] , from Euphorbia goliana , 7.ii.23; 3♂ ♀ 11 larvae [ethanol 96%], from Euphorbia goliana , 7.ii.2023.

Figures

FIGURE 2. Adult H. euphorbiae, habitus (Canada balsam after KOH treatment). A: female; B: male.

FIGURE 3. Adult H. euphorbiae female, details. A: dorsal view of head showing the transversely striate sculpture fading to reticulate in ocellar area; B: internal view of head showing the maxillary stylets (ms) and bridge (mb); C: complete antenna.

FIGURE 4. Adult H. euphorbiae female, details. A: pronotum, the arrows point on epimeral setae; B: metanotum (MtN) and pelta (T1).

FIGURE 5. Adult H. euphorbiae. A: male aedeagus; B: female fore tarsus; C: larva II habitus, H. euphorbiae (in Hoyer fluid).