Macracanthopyga verganiana Lizer y Trelles

Hodgson, Chris & Miller, Dug, 2010, A Review of the Eriococcid Genera (Hemiptera: Sternorrhyncha: Coccoidea) of South America 2459, Zootaxa 2459 (1), pp. 1-101 : 57-58

Macracanthopyga verganiana Lizer y Trelles

Macracanthopyga verganiana Lizer y Trelles, 1955: 37–38

Material examined: No collection data but slide labelled Macracanthococcus virgansi Liz. (presumably a manuscript name), sent by Lizer y Trelles, GF7 ( BME): 1/11adf in fair condition (believed to be syntype material). Also: ARGENTINA, Province of Corrientes, no date, ex Campomanesia sp. (Myrtaceae) , no coll. ( BME): 2/25adff — slide in poor condition and specimens hard to see but major characters discernable (believed to be syntype material). “These specimens are probably syntypic – Lizer y Trelles (1955) states that he sought an opinion from Dr. Ferris and so it is likely that the specimens now in the BME were those sent by Lizer y Trelles. I did check Ferris’ library for any correspondence from Lizer y Trelles, but found nothing” (personal correspondence P. J. Gullan, November 17, 2009).

Adult female ( Fig. 27 )

Unmounted material. On the branches of a species of Campomanesia (Myrtaceae) (Lizer y Trelles, 1955).

Mounted material. Length 0.43–0.80 mm, width 0.38–0.83 mm. Rounded anteriorly, bluntly pointed posteriorly; abdomen rather short, posterior 6 abdominal segments all covered dorsally with long spinose setae. With sclerotised anal lobes.

Dorsum. Derm mostly membranous, segmentation only clear in abdominal region, but some specimens with a distinct membranous line anteriorly possibly delineating posterior margin of head. Dorsal setae of 3 types: (i) fine setose setae, all short, mostly about 3–4 µm long but those on head marginally longer (up to 8 µm long); very sparse, perhaps most abundant on head; (ii) cupolate-shaped spinose setae, each about 5–12 µm tall and wide; distribution rather variable but generally with single setae laterally on abdominal segment I and on meso- and metathorax, but occasionally rather more frequent (see discussion below); also often with 1 medially on abdominal segment I; and (iii) stout, strong, elongate spinose setae, each with a very strongly sclerotised basal socket, present on posterior 6 or 7 abdominal segments, those more laterally 25–35 µm long, those medially largest, up to 65 µm long, as follows: segment II with 0 or 1 laterally; III about 8–17 large spines medially and a pair laterally; IV about 11–20 large spines medially plus a marginal pair; V about 17–21 very large spines medially and a pair laterally; VI possibly with 3 on each side and 1 medially; VII possibly with only a single spine on each side, and VIII (anal lobe) with 3 particularly stout spines (each 45–70 µm long) along dorsal posterior margin, plus other stout spines on each inner and outer margin more ventrally. Macrotubular ducts absent. Microtubular ducts about 8–10 µm long: most abundant across abdominal segments I & II, and meso- and metathorax, but also with a few in abdominal segments II and IV and also perhaps laterally in prothorax (but can be more abundant when cupolate-shaped setae more abundant — see discussion). Other pores absent. Anal lobes strongly sclerotised, each about 20 µm long, 25 µm wide; anal cleft about 25–30 µm deep; lobes with spinose setae, as described above. Median plate apparently absent. Anal ring thought to have 3 pairs of setae, each about 80–90 µm long .

Margin. Margin not demarcated apart from on abdomen, where lateral spinose setae mark margin; other marginal setae absent. Eyespots apparently absent.

Venter. Derm laterally on abdominal segments V – VII nodulose, otherwise derm membranous. Setae of 3 types: (i) setose setae, sparse, particularly on head and thorax; larger setae restricted to 1–3 pairs on each abdominal segment, range 8–27 µm, longest posteriorly; (ii) cupolate-shaped setae similar to those on dorsum, generally present laterally on abdominal segment I and metathorax, and (iii) a pair of long, finely spinose setae anterior to anal ring on abdominal segment VII, each 80–90 µm long. Macrotubular and microtubular ducts absent. Loculate pores with mainly 5 loculi: present in broad groups laterad to each spiracle, with 20–40 in each anterior group and 20–30 in each posterior group; loculate pores also present in loose groups on either side of abdominal segments II – IV: II with 2–6, III 1–4 and IV 1–3 . Cruciform pores absent. Anal lobes strongly sclerotised ventrally, with a pair of posterior suranal spinose setae, each about 55– 70 µm long .

Antennae 1 segmented, each with about 5 fleshy setae; width of segment about 8 µm. Clypeolabral shield proportionately quite large, about 105–125 µm long; labium apparently 1 segmented; number of setae unknown. Spiracles each with a very large, roundly-oval, sclerotised muscle plate, each about 28–35 µm wide; actual peritreme very narrow, about 3–10 µm wide; each with a membranous cavity laterad to peritreme, each about the same size as muscle plate. Legs entirely absent. With a large, oval concavity along margin between metathorax and abdominal segment II, approximately in position of metacoxa; each cavity about 30– 35 µm wide and 15–25 µm long. Vulva not detected.

Comment. This species was illustrated by Ferris (1957), probably from the slides cited above. The present description agrees reasonably closely but his description of the clypeolabral shield was much smaller and he did not note the microtubular ducts. His figure also showed more cupolate-shaped setae, including a group dorsad to the clypeolabral shield. Two of the specimens seen during this study had significantly more of these cupolate-shaped setae than on the other specimens but their distribution was difficult to determine. However, it was considered that the extra spines were restricted to 1 side only and none were present medially above the mouthparts. On these latter specimens, the microtubular ducts were also much more abundant on the side with the spines, extending anteriorly into the head (as shown in the small figure in Fig. 27 ).

Figures

FIGURE 27. Macracanthopyga verganiana Lizer y Trelles. Adult female; where B = dorsal microduct; L = ventral loculate pore; R = marginal spinose seta; S = nodulose derm on abdominal margin; V = antenna; X = setae on anal plates, and Z = view of specimen with more frequent cupolate-shaped (minaret) setae and dorsal microtubular ducts.