Paracoccus gillianae

Ellenrieder, Natalia Von & Stocks, Ian C., 2014, A new species of mealybug in the genus Paracoccus Ezzat & McConnell from North America (Insecta: Coccoidea: Pseudococcidae), Zootaxa 3873 (1), pp. 25-36 : 27-35

Paracoccus gillianae von Ellenrieder & Stocks, sp. nov.

( Figures 1–5 )

Material studied. Holotype ♀. USA. California: San Diego Co., Fallbrook, in nursery on Agave sp., T. Ellis and D. Kellum leg., 13 x 2010 [ CSCA, PDR # 1316192, specimen on the left; specimen on the right is a paratype].

Paratypes: 145 ♀, 9 ♂. MEXICO: 2 ♀, via Kansas, intercepted at Los Angeles Co., on Agave cacti, 22 x 2008, Chacon leg. [ CSCA]; 1 ♀, intercepted at San Diego, on Agave leuchajillia , 13 viii 1974, J. O. Wible Bakram leg. [ USNM]; 3 ♀, intercepted at Nogales, on Yucca , 21 ii 1952, Callaghan leg. [ USNM]. USA. CALIFORNIA: Los Angeles Co.: 2 ♀, Granara Hills, in nursery on Agave sp., I. Milled leg., 23 v 2012 [ CSCA]. Riverside Co.: 2 ♀, Perris, in nursery, on Agave sp., M. Lahti leg., 7 ii 2011 [ CSCA]; 9 ♀, 1 ♂, same but 2 iii 2011 [ CSCA]; 4 ♀, same but 16 iii 2011 [ CSCA]; 1 ♀, same but 14 vii 2011 [ CSCA]; 1 ♀, same but 22 viii 2011 [ CSCA]; 3 ♀, same but 27 x 2011 [ CSCA]; 9 ♀, same but 2 xi 2011 [ CSCA]; 1 ♀, same but 19 i 2012 [ CSCA]; 4 ♀, Romoland, in nursery on Agave sp., M. Lahti leg., 26 vi 2012 [ CSCA]; 4 ♀, Menifee, outdoors on Agave sp., M. Lahti leg., 13 iii 2012 [ CSCA]; 4 ♀, Hemet, in nursery on Agave sp., M. Lahti leg., 27 vii 2011 [ CSCA]; 3 ♀, same but 20 x 2011 [ CSCA]. San Diego Co.: 3 ♀, Fallbrook, in nursery, on Agave sp., M. Hand leg., 3 ix 2010 [ CSCA]; 8 ♀, same but T. Ellis and D. Kellum leg., 13 x 2010 [ CSCA]; 6 ♀, Escondido, in nursery, on Agave sp., C. Conway leg., 12 x 2011 [ CSCA]; 9 ♀, 3 ♂, San Diego, in nursery, on Agave sp., C. Betschart leg., 23 ix 2011 [ CSCA]; 3 ♀, same data but on ‘succulent’ [ CSCA]; 2 ♀, Vista, in nursery, on Agave sp., J. Mangen leg., 21 vi 2012 [ CSCA]; 2 ♀, 1 ♂, Rancho Santa Fe, in nursery, on Agave sp., C. Betchart leg., 5 ix 20102 [ CSCA]. Santa Barbara Co.: 6 ♀, 4 ♂, Carpinteria, in nursery on Agave sp., K. Caterino leg., 18 ix 2012 [ CSCA]. FLORIDA: Alachua Co.: 2 ♀, Hawthorne, in nursery on Agave sp., C. Zamora leg., 8 ix 2003 [ FSCA]; 2 ♀, Gainesville, in nursery on Agave sp., 6 xi 2012, C. Jones and T. Estok leg. [ FSCA]; 1 ♀, same data but 8 xi 2012 [ FSCA]; 1 ♀, same but [ CSCA]; 2 ♀, same but 30 iv 2013, C. Jones leg. [ FSCA]; 1 ♀, same but on Agave mitis , 29 xi 2012, C. Jones leg. [ CSCA]; 2 ♀, same but [ FSCA]; 2 ♀, same but on Yucca aloifolia , 29 xi 2012, C. Jones leg. [ FSCA]; 2 ♀, Alachua, in nursery on Agave sp., 30 iv 2013, C. Jones leg. [ FSCA]. Broward Co.: 2 ♀, Southwest Ranches, in nursery on Agave sp., 26 vi 2013, S. Alspach leg. [ FSCA]. Brevard Co.: 1 ♀, Palm Bay, in nursery on Agave sp., 20 xii 2013, M. Lynch. leg. [ FSCA]. Duval Co.: 2 ♀, Jacksonville, Jacksonville Zoological Gardens on Agave desmettiana , 27 ix 2012, L. Hassell leg. [ FSCA]; 3 ♀, same but on Agave sp., 17 x 2012, K. Coffey leg. [ FSCA]; 1 ♀, same but [ CSCA]; 6 ♀, same but on Agave desmettiana , 22 x 2012, L. Hassell leg. [ FSCA]; 1 ♀, same but [ CSCA]; 2 ♀, same but in nursery on Agave sp., 11 xi 2012, leg. L. Hassell [ FSCA]; 2 ♀, same but 26 xii 2012, L. Hassell leg. [ FSCA]. Escambia Co.: 2 ♀, Pensacola, in nursery on Agave sp., 3 x 2012, M. Anderson leg. [ FSCA]; 1 ♀, same but on Hesperaloe parviflora , 17 x 2012 [ CSCA]; 5 ♀, same but [ FSCA]. Miami-Dade Co.: 3 ♀, Miami, in nursery on Agave sp., H. Cruz-Escoto leg., 27 ii 2014 [ FSCA]; 1 ♀, same but on Agave angustifolia , 6 iii 2014. [ FSCA]. Orange Co.: 1 ♀, Apopka, in nursery on Agave americana, S. Stornaiuolo leg., 3 x 2002 [ FSCA]; 2 ♀, same but on Agave potatorum, B. Merritt leg., 5 v 2013 [ FSCA]; 2 ♀, same but on Agave sp., 12 ii 2014 [ FSCA].

Description. Adult female: Macroscopic appearance ( Figs 1 , 4 ). Body of live adult female grayish, with a coating of powdery white wax; 6–15 pairs of lateral filaments of white wax on margins of abdomen, with a longer pair projecting from posterior-most segment; in older adults only posterior-most pair remains visible. Color of body in alcohol pale pink-orange, turning black in 10% KOH.

Slide-mounted characters ( Fig. 2 ). Body of adult female oval, 2.3 ± 0.5 [2.2] (1.76–2.92) mm long, with maximum width of 1.3 ± 0.28 [1.2] (0.65–1.8) mm between level of posterior spiracle and base of hind coxal apodemes. Anal lobes moderately developed, each with an apical seta 186 ± 10 [177] (168–196) µm long and a well-developed anal lobe bar. Antennae each 356 ± 26 [324] (312–410) µm long, with 8 segments. Legs well developed, hind trochanter + femur 236 ± 39 [252] (178–300) µm long, hind tibia + tarsus 260 ± 45 [304] (197–326) µm long; claw well developed, 27 ± 1 [26] (26–27) µm long. Ratio of hind tibia + tarsus length to hind trochanter + femur length 1:0.92 ± 0.04 [1:0.83] (1:0.83–1:1). Ratio of hind tibia length to tarsus length 1:0.42 ± 0.03 [1:0.58] (1:0.37–1:0.58). Translucent pores present on anterior and posterior surfaces of hind coxa and with 3–14 [5–9] distally on posterior surface of hind tibia. Labium 129 ± 7 [120] (110–149) µm long (measured as l in Fig. 2 ); tentorium 145 ± 7 [135] (130–168) µm long (measured as t in Fig. 2 ); ratio of labium length to tentorium length 1:1.15 ± 0.06 [1:1.13] (1:0.8–1:1.22). Circulus present between S III and IV, 92 ± 23 [60] (60–132) µm wide, and divided by intersegmental line. Anterior and posterior ostioles moderately developed. Anal ring 88 ± 4 [74] (74–96) µm in diameter and bearing 6 setae, each 116 ± 7 [110] (101–137) µm long. Cerarii numbering 10–14 pairs [14], including 8 pairs on abdomen, 1–5 pairs on thorax [3], and 0–2 on head [1]; cerarian setae becoming more slender and cerarian trilocular pores less numerous and more loosely set progressively from anterior abdominal segments forwards to head; frontal and preocular cerarii absent. Anal lobe cerarii each containing 2 conical setae, each seta 21 ± 1 [21] (19–24) µm long, 2–4 auxiliary setae and a concentration of trilocular pores in a weakly sclerotized area. Other abdominal cerarii each containing 2 conical setae and 5–8 trilocular pores, except anteriormost abdominal cerarius rather weakly developed, with 2 or 3 small conical setae. Cerarii on thorax and head each with 1–4 [2 or 3] conical setae.

Dorsal surface with slender flagellate setae of two types: shorter setae each 12 ± 1 [13] (11–13) µm and longer setae each 21 ± 1 [21] (19–26) µm. Multilocular disc pores absent. Trilocular pores evenly distributed except in segmental folds. Discoidal pores slightly smaller than trilocular pores, scattered throughout. Oral rim tubular ducts absent from abdominal S VIII, present medially, submedially, submarginally, and/or marginally in loose rows as follows: S I 4–7 [4] (only present submarginally and marginally); S II 4–10 [6]; S III 4–8 [6]; S IV 4–8 [6]; S V 4–8 [6]; S VI 2–4 [4] (only present medially and marginally); S VII 4–7 [6]; prothorax 2–9 [6]; mesothorax 7–16 [8]; metathorax 4–16 [12]; and head 4–8 [8] (only present medially and marginally).

Ventral surface with normal flagellate setae. Cisanal setae each 32 ± 3 [31] (24–38) µm long, obanal 45± 2 [50] (41–50) µm long. Multilocular disc pores each 8 ± 1 µm [8] (8–9) in diameter, present in a single row across medial posterior edge of S IV and in double rows across medial posterior edges of S V–VIII, and 0–6 on S III [1 on one side, 3 on other], not reaching margins; also distributed across anterior submedial to submarginal areas of S V–VIII; head and thorax usually devoid of multilocular pores but occasionally with one or two near base of a coxa [one anterior to left hind coxa]. Trilocular pores evenly distributed except in segmental lines and around coxal bases. Discoidal pores same size as on dorsum, scattered. Oral rim tubular ducts present around margins of abdomen; on head and thorax, present on margins and submedial and medial areas in variable numbers: 3–6 [4] on head, 2–8 [2] on prothorax, 10–23 [12] on mesothorax, and 4–12 [12] on metathorax. Oral collar tubular ducts of 2 sizes; larger type slightly wider than a trilocular pore, and smaller type slightly narrower than a trilocular pore, both fairly numerous, intermixed, forming rows extending from margin to medially on S IV–VIII and in marginal groups on S II–VIII; some oral collar ducts also scattered medially and submedially in S II–III, with 0–6 [1–3] present near margins of S I lateral to each hind coxa, plus a few submedially in thorax; absent marginally opposite front coxa.

Adult male: Slide-mounted characters ( Fig. 3 ). Body of adult male elongate oval, 1.05 ± 0.05 (0.95–1.10) mm long, with maximum width of 0.31 ± 0.03 mm at thorax (0.27–0.36), with few setae, all hair-like; fleshy setae present only on antennae and some leg segments (always on tibiae, sometimes on femora). Antennae about as long as or slightly longer than half of total body length. Wings about 0.86 ± 0.06 as long as total body length (0.73–0.92) and 0.39 ± 0.01 (0.39–0.40) as wide as long.

Head. Width across genae 186 ± 8 (175–197) µm. Median crest weakly sclerotized, lacking setae; preoccipital ridge indistinct or absent; on each side with about 8–12 dorsal head setae, mainly between antennae, and 0–2 multilocular pores near each scape. Dorsal arm of midcranial ridge extending beyond posterior margin of dorsal eye, and ventral ridge extending from lateral arms posteriorly to just anterior to ventral simple eyes. Genae not reticulated; each with 3 or 4 genal setae. With 2 pairs of round simple eyes; dorsal eyes each placed approximately dorsad to ventral simple eyes, each 33 ± 3 (26–36) µm wide, ventral eyes 33 ± 4 (26–38) µm wide. Ocelli pronounced, situated laterally, each 14 µm wide, located between preocular and post-ocular ridges. Ocular sclerites weakly sclerotized, reticulated. Preocular ridge well developed, extending from inner margin of dorsal simple eyes antero-laterally to base of each scape and then postero-laterally to join post-ocular ridge just ventral to each ocellus. Post-ocular ridge well developed, extending from posterior to each dorsal simple eye antero-laterally past each ocellus and then fusing with the preocular ridge before extending postero-laterally to near mouth. Interocular ridge hinted at as a slightly more sclerotized bar dorsad to each ocellus. Dorsal ocular setae absent. Ventral head setae: 5–9 on each side, in an elongate group between each ocellus and ventral midcranial ridge. Preoral ridge weakly developed. Cranial apophysis not detected.

Antennae. Ten segmented and filiform; 635 ± 38 (566–684) µm, as long as 0.60 ± 0.02 (0.50–0.62) of total body length. Scape, 39 ± 3 (32–41) µm long, with 1 hair-like setae ventrally and 2 dorsally. Pedicel 60 ± 4 (55–67) µm long, with 15–20 fleshy setae, 5–7 hair-like setae. Segments III–X each about 19–29 µm wide; fs each 12–19 µm long, shorter than or about as long as width of antennal segments; lengths of segments III–X (µm): III, 85 ± 4 (79–91); IV, 64 ± 6 (57–72); V, 6 ± 7 (64–72); VI, 63 ± 6 (51–70); VII, 60 ± 5 (53–70); VIII, 65 ± 4 (60–70); IX, 58 ± 3 (51 –60); X, 73 ± 6 (63–79). Approximate number of fleshy setae (fs), hair-like setae (hs), and bristle-shaped setae (ab) on each segment: III 12–15 fs, 8–10 hs; IV 15–16 fs, 5–8 hs; V 13–16 fs, 5–6 hs; VI 12–14 fs, 3–5 hs; VII 11–13 fs, 4–6 hs; VIII 12–17 fs, 4–6 hs, 1 ab on apical third; IX 7–10 fs, 5–6 hs, 1 ab on apical third; X 10–13 fs, 4–5hs, 2 ab on apical fifth; 2 capitate setae; sensilla basiconica not detected.

Thorax. Prothorax. Pronotal ridge heavily sclerotized, pronotal sclerite represented by a small triangular sclerotization dorsolaterally, without lateral pronotal setae. Pronotum medially with 1–4 pronotal setae, 2–8 medial multilocular pores, and 4–6 discoidal pores on each side; post-tergite not detected. Pronotum laterally with 0 or 1 seta, 3–11 multilocular pores, and 2–4 discoidal pores. With 1–3 antero-spiracular dorsal setae and 1 or 2 anterospiracular dorsal multilocular pores; and with 1 or 2 antero-spiracular ventral setae and 1 antero-spiracular ventral multilocular pore. Sternum weakly sclerotized, without a median ridge and with transverse ridge well developed; with 1 or 2 prosternal setae, one multilocular pore and 1 or 2 discoidal pores on each side. Anteprosternal setae absent.

Mesothorax. Prescutum oval, sclerotized, prescutal ridge well developed, prescutal suture not developed, with 2–4 prescutal setae on each side; with a distinct sclerotized apodeme on anterior margin of each prealare. Scutum sclerotized, with about 8–10 scutal setae on each side; prealar ridge well developed. Scutellum without a scutellar ridge or foramen, with 3 or 4 scutellar setae on each side; anterior and posterior pronotal wing processes well developed. Basisternum without a median ridge, bounded anteriorly by a marginal ridge, posteriorly with strong precoxal ridges, with 5 or 6 basisternal setae on each side, mainly along medial area; lateropleurite narrow, without an extension from marginal ridge along anterior margin; furca well developed, arms divergent and extending about halfway to marginal ridge anteriorly. Mesopostnotum and pronotal apophyses well developed. Area between scutellum and mesopostnotum weakly sclerotized. Mesepisternum sclerotized, subepisternal ridge long and well developed. Postalare without setae. On each side posterior to mesospiracle 3 or 4 postmesospiracular setae, 1 or 2 multilocular pores, and 1 or 2 discoidal pores. Tegula present, with 3 or 4 tegular setae.

Metathorax. With 1 or 2 metatergal setae on each side, metapostnotal sclerite distinct. Dorsal part of metapleural ridge present, posterior part of metapleural ridge well developed; metepisternum not sclerotized and without postmetaspiracular setae; precoxal ridge well developed, extending medially; metasternal apophyses distinct. Metepimeron not sclerotized. Antemetaspiracular setae absent. A single multilocular pore posterior to each metathoracic spiracle. Dorsospiracular setae absent. Metasternum membranous, on each side 1 anterior metasternal setae, 1 anterior multilocular pore, 1 anterior discoidal pore, and 1 posterior metasternal setae.

Wings. Hyaline, 913 ± 70 (792–1,026) mµ long, 350 ± 30 (320–380) µm wide. Ratio of length to width 1:0.39 ± 0.01 (1:0.39–1:0.40) µm; ratio of total body length to wing length 1:0.86 (1:0.73–1:0.92); alar lobe well developed; each wing with 1–4 (usually 3) alar setae and 3 or 4 circular sensoria. Hamulohalteres each 72 ± 6 (60–79) µm long, with a single apical hamulus.

Legs. Metathoracic legs longest; hind femur 164 ± 11 (151–182) µm; hind tibia 220 ± 16 (194–240) µm; hind tarsus 85 ± 6 (74–91) µm; hind tarsal claw 30 ± 3 (24–34) µm. Ratio of hind femur length to hind tibia length 1:1.35 ± 0.05 (1:1.27–1:1.4); ratio of hind tibia length to hind tarsus length 1:0.39 ± 0.01 (1:0.31–1:0.41). Leg setae hair-like except for 6–8 fleshy setae on dorsal surface of all tibiae, and a variable number of fleshy setae on dorsal surface of femora: I 0–9 (0 or 1 in 5 specimens, 3–10 in 4 specimens), II 0–11 (0–2 in 5 specimens, 7–11 in 4 specimens), III 0–9 (0–2 in 5 specimens, 5–9 in 4 specimens); hair-like setae numbering: coxa I 12–16, II 13– 15, III 13; trochanter I 2 or 3, II 2–4, III 2 or 3; femur I 7–28, II 9–30, III 9–33; tibia I 23–25, II 18– 24, III 16–20; tarsus I 19–21, II 21– 25, III 20–30. Each trochanter with 3 campaniform pores arranged in a triangle medially on each side, and with strong, sclerotized Y-shaped ridges for articulation with femur. Tibiae with apical spurs: I 3, II 4 or 5, III 5 or 6; length of longest about 15 µm. Tarsi all 2 segmented, tarsal digitules capitate, claw digitules acute.

Abdomen. Segments I–VII: Small abdominal tergites usually present on mid-dorsum of S I–III (not detected in 3 specimens) and S VII. Sternites unsclerotized. Dorsum without multilocular pores. Each segment with dorsal setae numbering: I–VI 5–7, VII 2 or 3; dorsopleural setae and pores on each side: I 3 setae + 3–6 multilocular pores + 2–4 discoidal pores; II 2 setae + 2–5 multilocular pores + 1 discoidal pore; III 2 setae + 1–4 multilocular pores + 1 discoidal pore; IV 2 setae + 2–4 multilocular pores + 1 discoidal pore; V 1 or 2 setae + 2–5 multilocular pores + 1–3 discoidal pores; VI 1 or 2 setae + 2–4 multilocular pores + 1 or 2 discoidal pores; VII 3 or 4 setae + 2–6 multilocular pores + 3 or 4 discoidal pores. Ventral pleural setae on each side: I 1; II–VII 2 or 3. Ventral setae numbering: I 1, II 2, III and IV 3 or 4, V–VII 5. With a pair of indistinct ostioles laterally between segments VI and VII. Segment VIII: tergite slightly sclerotized medially, with 1 pair of ante-anal setae; sternite with a small anterior sclerotization submedially, without ventral setae; caudal extension rounded with 3 or 4 pleural setae. Glandular pouches shallow, each with 40–72 multilocular pores spreading out around pouch and 2–5 discoidal pores; each pouch with 2 long glandular pouch setae, each 289 ± 25 (264–307) µm long, and 1 or sometimes 2 additional shorter setae.

Genital segments. Penial sheath short, triangular, and blunt, 111 ± 5 (105–118) µm long, 72 ± 4 (67–76) µm wide across basal ridge, ratio of penial sheath length to width 1:0.65 ± 0.05 (1:0.59–1:0.73); anal opening not detected but probably present just posterior to tergite IX on dorsal surface. Ventrally, apex of style bluntly pointed; basal ridge well developed; lateral processes of penial sheath distinct, each with 2 or 3 short setae; 2 or 3 short setae anterior to each lateral process; 3 pairs of longer setae near posterior border. Basal rod distinct, extending anteriorly to about halfway to basal ridge. Aedeagus broad and parallel sided, smoothly rounded apically, extending beyond end of penial sheath to about halfway to tip of style, 86 ± 6 (77–94) µm long.

Molecular data. T he DNA sequences of Paracoccus gillianae specimens are available at GenBank, under the following accession numbers:

KJ830762 . Paracoccus gillianae von Ellenrieder & Stocks. USA: Florida, Duval Co., Jacksonville, Jacksonville Zoological Gardens, on Agave angustifolia, K. Coffey leg., 17 x 2012, CSCA DNA code 13M119.

KJ830763 . Paracoccus gillianae von Ellenrieder & Stocks. USA: Florida, Duval Co., Jacksonville, Jacksonville Zoological Gardens, on Agave angustifolia, K. Coffey leg., 17 x 2012, CSCA DNA code 13M120.

KJ830764 . Paracoccus gillianae von Ellenrieder & Stocks. USA: Florida, Escambia Co., Pensacola, 3601 North Davis Hwy, on Hesperaloe parviflora, J. Anderson leg., 17 x 2012, CSCA DNA code 13M125.

KJ830765 . Paracoccus gillianae von Ellenrieder & Stocks. USA: Florida, Escambia Co., Pensacola, 3601 North Davis Hwy, on Hesperaloe parviflora, J. Anderson leg., 17 x 2012, CSCA DNA code 13M126.

KJ830766 . Paracoccus gillianae von Ellenrieder & Stocks. USA: Florida, Alachua Co., Gainesville, 3701 NW 17th St., on Agave mitis, C. Jones leg., 29 xi 2012, CSCA DNA code 13M129.

KM027308 . Paracoccus gillianae von Ellenrieder & Stocks. USA: California, Riverside County, Menifee, on Agave sp., M. Lahti leg., 13 iii 2012, CSCA DNA code 12K770.

The specimens of Paracoccus gillianae sequenced from California ( KM027308 ), share 100% of the base pairs of the analyzed CO1 sequence with some specimens from Florida ( KJ830764 -65), while other specimens from Florida ( KJ830762 -63, 66) show some genetic plasticity differing by 1 base pair.

Paracoccus gillianae differs from P. marginatus , the only other Paracoccus species sequenced so-far for the CO1 gene ( Park et al., 2011), by 6% of the base pairs of the compared sequence (39 out of 610 base pairs).

Diagnosis. Adult female of Paracoccus gillianae can be differentiated ( Table 1 ) from the other three New World species recorded on Agavaceae (i.e. P. marginatus , P. re du c t u s, and P. solani ) by the presence of 8 pairs of cerarii on abdomen and 1–6 pairs on cephalothorax (8 abdominal and 8–9 cephalothoracic cerarii in P. marginatus ; cerarii absent in P. reductus , and 7 or fewer abdominal cerarii and no cephalothoracic cerarii in P. solani ). Paracoccus gillianae further differs from P. marginatus and P. reductus by the presence of oral rim ducts in rows across dorsum of thoracic and anterior abdominal segments (restricted to margins in P. marginatus and absent in P. reductus ), and from P. marginatus and P. solani by the presence of medial and submedial oral rim ducts on venter between meso- and meta-thoracic leg bases (absent in both P. marginatus and P. s ol a ni).

Adult female of P. gillianae differs from that of P. glaucus from New Zealand, also recorded from Agavaceae , in having (a) oral rim ducts on the dorsum (oral rim ducts absent from dorsum in P. glaucus ), and (b) cerarii on head, if present, not well defined, with the cerarian setae more slender and the trilocular pores less numerous and more loosely set than in abdominal cerarii, and never set on a sclerotized area (whereas P. glaucus has 1–3 welldefined pairs of cerarii on the head, each often situated on a sclerotized area).

In Williams and Granara de Willink’s (1992) key to species of Paracoccus from Central and South America, which includes all the species known from North America to-date, P. gillianae keys out to couplet 20, which leads to P. hamoni and P. mexicanus . All adult females P. gillianae differ from P. mexicanus and agree with P. hamoni in possessing ventral oral rim ducts medially in the thorax, but the presence of multilocular disc pores on the venter of S III (present in P. hamoni , absent in P. mexicanus ), is variable in P. gillianae , with about 76% (n 111) of specimens having 1–6 multilocular disc pores on venter of S III and about 24% (n 34) lacking disc-pores. Paracoccus gillianae can be separated from P. hamoni in having (a) more numerous dorsal oral rim ducts (7–16) on the mesothorax, including some marginal or submarginal ducts, whereas P. hamoni has only 1–5 ducts, all located medially and/or submedially, and (b) a shorter labium (110–149 µm, vs. 157–180 µm in P. hamoni ) and a shorter tentorium (130–168 µm, vs. 180–189 µm in P. hamoni ).

The only two Paracoccus species that have been recorded on Agavaceae for which the adult male has been described so-far are P. glaucus and P. marginatus ( Hodgson, 2012; Miller & Miller, 2002). Adult male of P. gillianae differs from P. glaucus in (character-states for P. gl a uc u s in parenthesis) (a) possessing multilocular pores near each anterior spiracle (absent), and (b) antennal segments III and IV about three times as long as wide (more than five times as long as wide), and from P. marginatus by the presence of fleshy setae on the legs (all setae on legs bristle-shaped in P. marginatus ).

Figures

FIGURE 1. Paracoccus gillianae sp. n. Macroscopic appearance of adult female and juveniles on Agave sp. leaf. Photograph: Jeff Lotz, FDACS-DPI.

FIGURE 2. Paracoccus gillianae sp. n. Holotype female, USA, California, San Diego Co., in nursery on Agave sp., deposited at CSCA. Enlargements of structures are not drawn to scale. l: measurement of labium length; t: measurement of tentorium length.

FIGURE 3. Paracoccus gillianae sp. n. Male paratype, U. S. A., California, San Diego Co., in nursery on Agave sp., deposited at CSCA. Enlargements of structures are not drawn to scale.

FIGURE 4. Coalesced mass of adult females of Paracoccus gillianae sp. n., ovisac wax, and immature stages on Agave sp. leaf. Photograph: Jeff Lotz, FDACS-DPI.

FIGURE 5. Infestation of Paracoccus gillianae sp. n. on abaxial surface of Agave sp. leaf. Photograph: Jeff Lotz, FDACS-DPI.

Tables

TABLE 1. Diagnostic characters of adult females of Paracoccus gillianae sp. n. compared to most similar species and congeners reported to feed on Agavaceae.

Source	P. gillianae P. glaucus This study Cox 1987	P. hamoni This study	P. marginatus Williams & Granara de Willink 1992; Miller & Miller 2002	P. mexicanus Ezzat & McConnell 1956 ; Williams & Cabrera de Willink 1992	P. reductus Williams & Granara de Willink 1992	P. solani Ezzat & McConnell 1956 ; Williams & Granara de Willink 1992
Hosts	Agavaceae Agavaceae & others	Cactaceae	Agavaceae & others	Crassulaceae & Fabaceae	Agavaceae & others	Agavaceae & others
Labium Length	110–149 µm?	157–180 µm	120–130 µm	?	?	140 µm
Tentorium Length	130–168 µm?	180–189 µm	120–130 µm	?	?	140 µm
Cerarii on head	absent–2, not 1–3, well well developed developed, usually on sclerotized areas	2, not well developed	3–4, well developed	3–4, not well developed	absent	absent
Cerariionthorax	1–5 absent–3	1–2	5	4–5	absent	absent
Cerarii on abdomen	8 7 or fewer	8	8	8	absent	7 or fewer
Oral rim ducts on venter between meso & metathoracic leg bases	present present	present	absent	absent	present	absent
Oral rim ducts on dorsum of mesothorax	7–16, medial, absent submedial & marginal, in rows	1–5, medial & submedial, in rows	2–3, marginal only	6–8, medial, submedial & marginal, in rows	absent	6–10, medial, submedial & marginal, in rows