Omophoita personata (Illiger, 1807)

Antonio, Anderson Igomar, Rech, Tarcila & Linzmeier, Adelita Maria, 2022, Description of the immature stages of the flea beetle Omophoita personata (Coleoptera: Chrysomelidae: Galerucinae: Alticini), Zoologia (e 21024) 39, pp. 1-9 : 2-6

Omophoita personata (Illiger, 1807)

Figs 1–11

Egg (measurements in mm). Length 2.55 (2.26–2.66; N = 18), width 0.75 (0.64–0.87; N = 18). Color light brown, darker at the apex, elongated, fusiform, wider medially, narrower at the apex. Presence of micropyle at the apex. Chorion with grainy texture.

Third instar larva (measurements in mm). Body length: 12.93 (11.56–13.82; N = 4). Body width: 3.36 (3.22–3.52; N = 4).

Coloration. Head and legs black. All thoracic and abdominal segments orange in vivo, cream in AGA.

Head ( Fig. 1 ). Hypognathous, rounded in frontal view, well sclerotized; slightly inserted into prothorax; epicranial suture Y-shaped; coronal suture short; frontal sutures pale, reaching antennal sockets. Endocarina long, robust, extending from base of frontal sutures to clypeus, externally represented by a slight depression, internally ridge-shaped. Each epicranial plate with one pair of filiform setae medially (eps1–2) and two pairs of filiform setae near antenna (eps3–6). Frons with three pairs of filiform setae (frs1–3), one pair near antenna (frs1), one pair medially (frs2), and one medially, near the frontoclypeal suture (frs3). Antennae small, glabrous, two-segmented; antennal sockets membranous, well-developed; base of first antennomere well sclerotized, wider than long; second antennomere cylindrical with conical apex. Stemmata absent. Clypeus transverse, sclerotized basally, membranous apically mainly in the median region. Labrum sclerotized, transverse, slightly wider than clypeus, with four pairs of filiform setae: two pairs of long setae, one laterally (lbs1) and one medially (lbs2), and two pairs of short setae (lbs3–4) near the anterior margin; anterior angles rounded, anterior margin notched medially. Mandibles ( Fig. 2 ) symmetrical, palmate, strongly sclerotized, with five teeth: teeth 1 and 2 the longest, similar in length, teeth 3 and 4 slightly serrated, teeth 4 and 5 short; external face with two prominent filiform setae, one near tooth 1 (mds1) and other dorsomedially (mds2); condyle present, well developed; penicillus with a row of 14 short and thick setae. Maxilla ( Fig. 3 ): cardo narrow, transverse, with one filiform setae (cas1) near outer margin; stipes elongated, wider basally, sclerotized, apically membranous, with two filiform setae (sts1–2); palpiger with two setae ventrally (pas1); mala pronounced, basally sclerotized, with a projection palpiform containing two segments, surrounded by six thick setae, followed by a line of flattened setae on the internal region; maxillary palp three-segmented: first palpomere glabrous, second palpomere with one ventral seta (mps1) and one ventrolateral seta (mps2); third palpomere with one ventral filiform microseta (mps3). Labium: postmentum greater than the prementum, weakly sclerotized, with two pairs of long filiform setae, one in the anterior region (mes1) and one in the posterolateral region (mes2), and one pair of short filiform setae anterolaterally (mms1); prementum basally sclerotized, with one pair of filiform setae near the base (prs1), three pairs of short setae (prs2–4) between the labial palps and two pairs of sensilla between the labial palps; labial palpi two-segmented. Hypopharynx densely covered with short and wide setae. Epipharynx ( Fig. 4 ) with four pairs of thick and short setae (epis1–4) in the anterior angles and a dense set of thin setae in anterior margin, medially.

Prothorax ( Fig. 5 ). Slightly smaller than following thoracic segments; pronotum with 20 short tubercles, each bearing one filiform setae, distributed as follows: two rows in the pronotum, one row on anterior margin with 12 tubercles (apt1–6) followed by one row with four tubercles (ppt1–2) ( Fig. 5 ), one lateral pair (lpt) and one anteroventrolateral pair (alt); prosternum with median Y-inverted-shaped sclerotization, containing two pairs of short setae (vpt1–2) medially ( Fig. 7 ).

Mesothorax and metathorax ( Figs 5 , 7 ). With one pair of dorsolateral digitiform tubercles (mdt), bearing two filiform setae (from here called bisetose tubercles) and 10 short tubercles, bearing one filiform setae (from here called unisetose tubercles), distributed as follows: two transverse dorsal rows, the anterior row with one pair of tubercles (amt1) and the posterior row with two pairs of tubercles (pmt1–2) ( Fig. 5 ), one anterolateral pair (lmt) and one ventral pair (vmt1) ( Fig. 7 ); presence of one ventral bisetose tubercle (vmt2) ( Fig. 7 ), anteriorlly to the pair of unisetose tubercles. Mesothorax with one pair of annuliform spiracles above the anterolateral tubercle.

Legs ( Fig. 8 ). Partially sclerotized; coxa partially sclerotized, with trapezoidal shape, with ten filiform setae, distributed as follows: three long setae (cs1–3) in the posterior margin of the sclerotized region, one long setae (cs4) and one short seta (cms1) on the ventral inner margin, three short setae (cms2–4) in the anterior margin of the sclerotized region and two short setae (cms5–6) on the dorsal outer margin; trochanter with four filiform setae (ts1–4) ventrally; apex of femur with six filiform setae (fs1–6), the ventral seta (fs1) is the longest; tibia with seven filiform setae (tis1–7): five medially (tis1–5) and two short setae (tis6–7) at the apex. Tarsungulus elongated, almost straight, with one filiform seta (tas1) basally.

Abdomen ( Figs 5, 6 , 9 ). Segments I–VII with one pair of dorsolateral digitiform tubercles (adt1), unisetose, with filiform setae ( Figs 5 , 7 ) and 12 short tubercles, with filiform setae, distributed as follows: dorsally one anteromedially bisetose tubercle (aat1), followed by a row of two pairs of unisetose tubercles (pat1–2) ( Fig. 5 ); laterally one bisetose pair of tubercles (lat1); ventrally five bisetose tubercles, one of them medially (vat1) and the others in a posterior transverse row (vat2–3) ( Fig. 7 ). Segment VIII quadrangular, with one pair of dorsolateral digitiform tubercles (adt2), unisetose, directed posteriorly ( Figs 5 , 9 ); three bisetose dorsal tubercles with one short anterodorsal tubercle (aat2) and one pair of more developed tubercles (pat3) near the posterior margin (in these tubercles the basal seta is shorter) ( Fig. 5 ); one pair of short lateral bisetose tubercles (lat2) ( Fig. 9 ); ventral tubercles as in the previous segments ( Fig. 9 ). Segment IX ( Fig. 9 ) with 14 filiform setae, four dorsal pairs (abs1–4), near the posterior margin and three ventral pairs (vas1–3) arranged diagonally ( Fig. 9 ). Segment X not visible in dorsal view; it emerges from segment IX, forming the anal pseudopod, fusiform ( Fig. 9 ). Annuliform spiracles present in segments I–VIII, above the lateral tubercles.

Pupa (measurements in mm). Body length: 7.33 (6.17– 8.27; N = 26). Body width: 3.73 (3.13–4.38; N = 26).

Coloration. Yellow in vivo, pale yellow in AGA.

Head ( Fig. 10 ). Rounded, not visible dorsally, with three pairs of filiform setae (hs1–3) as follows: one interantennal pair on frons, near the median line (hs1) and two pairs (hs2–3) at the vertex; mouthparts developed and visible; labrum with a pair of microsetae (lms1) in the anterior angles; antennae developed, with 11 antennomeres.

Prothorax ( Figs 10, 11 ). With eight pairs of setae, four pairs anteriorly (aps1–4), two pairs medially (mps1–2) and two pairs (pps1–2) near the posterior margin.

Mesothorax and metathorax. Mesonotum and metanotum ( Fig. 11 ) with two pairs of setae (ms1–2) medially. Mesothorax with one pair of annuliform spiracles. Fore and mid-legs ( Figs 10, 11 ) with three filiform setae at the apex of femur (pfs1–3; msfs1–3); hind legs with two setae at apex of femur (mtfs1–2).

Abdomen ( Figs 10, 11 ). Segments I–VII with three pairs of setae inserted in small tubercles (abs1–3), evenly spaced, with two dorsal pairs and one lateral pair. Segment VIII with two pairs of short setae (abms1–2), thinner than those of the previous segments. Segment IX bearing one pair of urogomphi with apex directed posteriorly; base of each urogomphus with one microseta (abms3). Segments I–V with one pair of annulliform spiracles.

Remarks. The first-instar larva ( Fig. 6 ) of O. personata has differences from advanced larval instars. Beyond the size (body length: 3.62 mm, 3.24–3.99 mm, N = 7; body width: 0.76 mm, 0.72–0.89 mm, N = 7), the following differences were observed, with characteristics of second and third instars shown between parenthesis: head visible in dorsal view (not visible), pronotum with darker coloration (lighter); prosternum with one pair of median setae (two pairs); mesonotum and metanotum with one pair of egg bursters (egg burster absent), one short bisetose tubercle (met1) in the anterior dorsal row (one pair of short unisetose tubercles in the anterior dorsal row); mesosternum and metasternum with one pair of setae posterior to the bisetose tubercle (one pair of unisetose tubercles posterior to the bisetose tubercle); abdominal segments I–VII with one dorsomedially bisetose tubercle (aat1), followed by one pair of unisetose tubercles (pat1) (one dorsal anteromedially bisetose tubercle, followed by a row of two pairs of unisetose tubercles); segment VIII with one bisetose anteromedially tubercle (aat2) and two posterior unisetose tubercles (pat2) (posterior tubercles bisetose). The second larval instar of O. personata was almost identical to the third instar, with differences in the body size (length: 6.91 mm, 6.00– 7.82 mm, width: 1.70 mm, 1.60–1.80 mm; N = 2).

In general, the main differences from the first to second instar are the loss of egg bursters, replaced by two pairs of unisetose tubercles and the addition of tubercles and setae in the dorsal region of abdominal segments I–VIII.

Analyzing the immatures of O. octoguttata no differences were found in external morphology and chaetotaxy in comparison to O. personata . Only differences in size were recognized as follows (measurements in mm): egg length: 2.40 (N = 1); width: 0.72 (N = 1). First instar body length: 3.75 (3.10–5.12; N = 4); body width: 0.82 (0.69–0.95; N = 4). Second instar body length: 7.62 (N = 1); body width: 1.54 (N = 1). Third instar body length: 12.73 (12.23–13.97; N = 4); body width: 4.26 (3.85–4.51; N = 4). Pupae body length: 7.15 (6.08–8.21; N = 5), body width: 3.90 (3.54–4.31; N = 5).

Material examined. Adults (10 males, 16 females): BRAZIL, Paraná state: 3 males, 3 females, Realeza municipality -25.761349, -3.553202, 27.I.2020, Rech, T., col./ Omophoita personata, Linzmeier det. 2020; 2 males, 3 females, same data but 10.III.2020; 3 males, 2 females, same data but 13.III.2020; 1 male, 1 female, same data but 10.I.2020 / Omophoita octoguttata ; 1 male, 7 females, same data but 15.V.2019, Copini, C., col./ Omophoita octoguttata .

Immatures (17 eggs, 10 first instar larvae, 2 second instar larvae, 6 third instar larvae, 30 pupae): All immatures were obtained from adults from same locality already mentioned and reared in laboratory. Omophoita personata : 16 eggs; 6 first instar larvae; 2 second instar larvae; 3 third instar larvae; 25 pupae. Omophoita octoguttata : 1 egg; 4 first instar larvae; 3 third instar larvae; 5 pupae. All immatures were preserved inside the same container, identified as “Material voucher 001”.

Figures

Figures 1–4. Head and mouthparts of third instar larva of Omophoita personata: (1) head, frontal view; (2) mandible, ventral view; (3) maxillae and labium, ventral view; (4) epipharynx, ventral view. Scale bars: 1 = 0.3 mm; 2–4 = 0.25 mm.

Figures 5–6. Larvae of Omophoita personata: (5) third instar larva, dorsal view; (6) first instar larva, dorsal view. Scale bars: 5 = 2.25 mm; 6 = 0.75 mm.

Figures 7–9. Third instar larva of Omophoita personata: (7) head, thorax and abdomen, ventral view; (8) leg, ventral view; (9) abdominal segments VIII–X, ventral view. Scale bars: 7 = 1.2 mm; 8 = 0.45 mm; 9 = 0.5 mm.

Figures 10–11. Pupa of Omophoita personata: (10) ventral view; (11) dorsal view. Scale bars: 1.5 mm.