Phenacoccus montevidensis Pacheco da Silva & Kaydan, 2020

Pacheco Da Silva, Vitor C., Kaydan, Mehmet Bora & Basso, Cesar, 2020, Pseudococcidae (Hemiptera: Coccomorpha) in Uruguay: morphological identification and molecular characterization, with descriptions of two new species, Zootaxa 4894 (4), pp. 501-520 : 511-512

Phenacoccus montevidensis Pacheco da Silva & Kaydan , sp. n.

( Fig. 4 )

Material studied. Holotype, adult female: URUGUAY: left label: Uruguay, 142 / Montevideo / Helminthotheca echioides / Asteraceae / 18.ix.2018 / 34°53’27.4”S 56°07’32.8”W / coll. VCPS.; right label: Holotype / Phenacoccus montevidensis sp. n. / Pacheco da Silva & Kaydan. ECFA No. 142.

GenBank accession number: MW 246247 for COI and MW 251837 for 28S.

Paratypes: same data as holotype, 4 slides containing 1 adult each ♀♀, ECFA No. 142 .

Appearance in life. Body elongate, yellowish, sparsely covered with white mealy wax.

Species diagnosis. Phenacoccus montevidensis Pacheco da Silva & Kaydan sp. n. is characterized by the following combination of features: (i) circulus present; (ii) dorsal multilocular disc pores on the margins of a few abdominal segments and in the middle region of abdominal segments VII, or VI and VII; (iii) ventral multilocular pores in the abdomen, reaching to margin of body; (iv) quinquelocular pores present; and (v) some dorsal lanceolate setae each with a protrusion in the apical region.

Description. Adult female (based on holotype and 4 paratypes): body oval, 1.90–2.25 mm long, 1.12–1.40 mm wide. Eyes situated on margins, each 50.0–67.5 wide. Antenna with 9 segments, 400–445 long, with 5 fleshy setae on distalmost 3 segments, each seta 21.5–37.5 long; apical segment 57.5–65.0 long, 25.0–32.5 wide, with apical setae each 30.0–32.5 long. Clypeolabral shield 175–205 long, 160–190 wide. Labium 3-segmented, 107–145 long, 112–133 wide. Anterior spiracles each 65–75 long, 30–40 wide across atrium; posterior spiracles each 65.0–82.5 long, 42.5–50.0 wide. Circulus oval, 82.5–125.0 long, 22.5–45.0 wide. Legs well-developed; posterior leg segment lengths: coxa 165–190, trochanter + femur 262.5–300.0, tibia + tarsus 317–355, claw 30.0–32.5. Ratio of length of tibia + tarsus to trochanter + femur, 1.18–1.20:1; ratio of length of tibia to tarsus, 2.20–2.30:1; ratio of length of trochanter + femur to greatest width of femur, 3.45–3.53:1; tibia with 41–70 translucent pores. Tarsal digitules hair-like, each 30–40 long. Claw with denticle, digitules capitate, each about 30.0–32.5 long. Both pairs of ostioles present; anterior ostioles each with a total for both lips of 10–34 trilocular pores and 3–6 setae. Posterior ostioles each with a total for both lips of 18–24 trilocular pores and 2–6 setae.Anal ring about 82.5–105.0 wide, with 6 setae, each seta 100–125 long.

Dorsum. Derm membranous, with 18 pairs of cerarii around body margin, each cerarius containing 2 cerarian setae and a few auxiliary setae. Each anal lobe cerarius set on membranous cuticle and containing 2 enlarged setae each 20.0–22.5 long, and 12–20 trilocular pores. Dorsal setae lanceolate, each 3.75–20.00 long, scattered throughout dorsum, some setae with a swelling in the apical region, scattered. Trilocular pores, each 3.75–5.00 in diameter, and minute discoidal pores, each about 2.5 in diameter, scattered. Dorsal oral rim tubular ducts absent. Oral collar tubular ducts, each about 10 long and 5 wide, present in segmental clusters on margin of body and singly throughout, 1–4 on head, 48–60 on thorax and on abdominal segments as follows: segment I with 8–24, II 14–36, III 13–32, IV 19–29, V 18–42, VI 16–25, VII 22–32, VIII + IX 5–9. Multilocular disc pores, each about 7.5 in diameter, present on margins of abdominal segments, as follows: segments I–II each with 0, III 0–2, IV 1–4, V 1–3, VI 0–1, VII 0–1, VIII + IX 0.

Venter. Setae flagellate, each 12.5–147.0 long, longest setae located medially on head. Apical seta on anal lobe 120–180 long. Multilocular disc pores, each 6.2–7.5 in diameter, present on abdomen, number on each abdominal segment as follows: segments I–II each with 0, III 1–4, IV 32–37, V 32–55, VI 39–47, VII 33–48, VIII + IX 17–31. Trilocular pores and minute discoidal pores scattered. Trilocular pores, each about 3.75 in diameter, scattered throughout venter. Quinquelocular pores, each about 5 long, 112–184 on thorax and on each abdominal segment as follows: segment I with 10–34, II 22–39, III 14–32, IV 10–42, V 12–43, VI 20–38, VII 12–19, VIII + IX 1–3. Oral collar tubular ducts of 2 sizes: (i) larger ducts, each about 10.00 long and 3.75 wide, present as segmental clusters on margin of body and singly throughout; and (ii) smaller ducts, each 7.5–10.0 long and about 2.5 wide, present throughout, 4–5 on head, 39–51 on thorax and in bands across abdominal segments, as follows: segment I with 18–32, II 13–27 III 23–38, IV 73–90, V 83–133, VI 73–118, VII 61–95, VIII + IX 34–46.

Comments. Phenacoccus montevidensis sp. n. most closely resembles Ph. sisymbriifolium Granara de Willink in having: (i) circulus present, (ii) dorsal multilocular disc pores restricted to margins of abdominal segments, (iii) ventral multilocular pores on the abdomen, reaching to margin of body; and (iv) quinquelocular pores present. However, Ph. montevidensis sp. n. differs from Ph. sisymbriifolium in having dorsal multilocular disc pores in the mid-region of abdominal segments VI and VII, and some dorsal lanceolate setae each with a protrusion on the apical region. In addition, the circulus in Ph. montevidensis is oval, whereas that in Ph. sisymbriifolium is anvil-shaped. Phenacoccus montevidensis is also close to Ph. manihoti , but differs from this species in having ventral multilocular disc pores on the venter that reach the margin of the body on at least a few abdominal segments, which Ph. manihoti does not have. In addition, translucent pores are present on the hind tibiae in Ph. montevidensis whereas they are absent in Ph. manihoti .

Etymology. The species epithet montevidensis is formed from the name of the type locality, Montevideo, and the Latin suffix - ensis denoting locality.

Host plant. Helminthotheca echioides L. ( Asteraceae ).

Distribution. Uruguay, Montevideo state, Montevideo.

Molecular characterization. A BLAST hit with sequence similarity of 100% was obtained to 28S sequences assigned to Phenacoccus manihoti Matile-Ferrero , and with similarity of 93.25% to COI sequences assigned to Phenacoccus parvus Morrison (KY373176.1). Phenacoccus parvus and P. manihoti present only 0.27% dissimilarity in 28S (2/740). This high degree of similarity in 28S is interpreted as an indication that these taxa are closely related.

Figures

FIGURE 4. Adult female Phenacoccus montevidensis Pacheco da Silva & Kaydan sp. n. holotype