Pelionella manifecta (Borchsenius, 1949)

Tanaka, Hirotaka, 2018, First records of the genus Pelionella Kaydan, 2015 in East Asia, with description of a new species (Hemiptera, Coccomorpha, Pseudococcidae), ZooKeys 738, pp. 47-58 : 49-50

Pelionella manifecta (Borchsenius, 1949) Figure 1

Peliococcus manifectus Borchsenius, 1949: 245: Danzig, 2001: 125.

Peliococcus albertaccius Goux, 1990: 83.

Pelionella manifecta (Borchsenius, 1949); Danzig and Gavrilov-Zimin 2014: 457 (as an unavailable name); Kaydan 2015: 234.

Material studied.

All three adult females from Japan collected on Artemisia indica Willd. var. maximowiczii (Nakai) H. Hara ( Asteraceae ). Osaka-pref., Sennan City, Kansai International Airport, on: 1 adult female, 7.X.2014, coll. I. Takahashi; 1 adult female, 12.X.2014, coll. K. Fujimoto. Hyogo-pref., Kobe City, Chuo-ku, Minato-jima, Naka-machi: 1 adult female, 8.XI.2014, coll. J. Imai (NSMT-I-Ho 00082).

Description.

Slide-mounted specimens of Japanese populations, n = 3.Adult female. Body elongate oval, 1.7-3.1 mm long, 0.9-1.8 mm wide. Eyes on margins, each 31-44 μm in diameter. Antenna 9-segmented, 393-444 μm long; apical segment 58-60 μm long, 22-25 μm wide; with two apical setae each 36-45 μm long, and three fleshy setae 18-30 μm long. Labium 95-110 μm long, 80-88 μm wide. Circulus oval, 95-100 μm wide, situated just anterior to fold between abdominal segments III and IV. Legs well developed; hind legs: coxa 120-140 μm long; trochanter + femur 248-282 μm long; tibia + tarsus 285-306 μm long; claw 30-32 μm long; translucent pores absent. Ratio of lengths of tibia + tarsus to trochanter + femur 1.05-1.18:1; ratio of lengths of tibia to tarsus 2.0-2.41:1; ratio of length of trochanter + femur to greatest width of femur 3.22-4.10:1. Tarsal digitules hair-like, each 23-30 μm long. Claw digitules knobbed, each 25-29 μm long. Claw with well-developed denticle on plantar surface. Anterior ostioles each with a total for both lips of 15-25 trilocular pores and 2-5 setae; posterior ostioles each with a total for both lips of 24-37 trilocular pores and 4-7 setae. Anal ring 73-108 μm wide, bearing 6 setae, each seta 127-190 μm long.

Dorsum. Setae spine-like, each 5-15 μm long. Cerarii on margin somewhat prominent, slightly sclerotized, numbering 18 pairs; anal lobe cerarii each with 1-2 slender enlarged setae, each 10-22 μm long, and one or two spine-like auxiliary setae; other cerarii mostly each with two enlarged setae and several trilocular pores. Clusters of multilocular pores with double rings present on head and thorax and on abdominal segments as follows: I 9-12, II 12, III 14-15, IV 16-19, V 18-22, VI 10-15, VII 9-11, VIII 0; each cluster containing 1-7 (usually 2-3) multilocular pores with double rings, each pore 6.0-7.1 μm in diameter; a small oral-collar tubular duct, 0.5-1.8 μm wide; 1-5 large oral-collar tubular ducts, each 2.4-3.4 μm wide; and 1-3 minute discoidal pores, each 1.1-1.3 μm in diameter. Trilocular pores, each 3.2-3.9 μm in diameter, scattered throughout. Minute discoidal pores mainly restricted to within clusters.

Venter. Setae of two types: (i) slender hair-like setae, each 10-142 μm long, longest setae situated medially on head; and (ii) spine-like setae in submarginal areas, each 4-12 μm long. Apical setae of anal lobes 198-228 μm long. Multilocular disc pores with single ring, each 5.0-6.8 μm in diameter, present in 15-25 clusters on medial areas of abdominal segments III and IV; each cluster containing 1-5 (usually 2-3) multilocular disc pores surrounding a small oral-collar tubular duct; similar multilocular disc pores present also in single rows on other abdominal segments, as follows: V 7-8, VI 43-47, VII 62-69, VIII + IX 38-46. Multilocular pores with double rings, each 6.6-7.9 μm in diameter, restricted to submarginal areas of head, thorax, and abdomen, usually not arranged in clusters. Quinquelocular pores, each 3.2-5.6 μm in diameter, scattered medially on head, thorax, and medial area of abdominal segments. Trilocular pores, each 2.6-3.2 μm in diameter, scattered throughout. Minute discoidal pores, each 0.8-1.3 μm in diameter, few. Oral-collar tubular ducts of two sizes: small ducts restricted to within clusters; and large-sized ducts, each 2.1-2.9 μm wide, present on body margin and in single rows across posterior abdominal segments; also a few on head, thorax and abdominal segments II and III.

Distribution.

Armenia, Azerbaijan, Corsica, France, Italy, Kazakhstan, Russia (Krasnodar Territory), Sardinia, Sweden, Turkey ( Kaydan 2015), and Japan.

Discussion.

The Japanese specimens of Pelionella manifecta described here differ slightly from the Azerbaijani and French material described by Kaydan (2015) in having many more multilocular disc pores on the venter of the abdominal segments, much smaller tubular ducts and pores (Table 1) and in lacking the large oral-collar tubular ducts associated with multilocular pore clusters on venter of abdominal segments III and IV. However, these morphological differences are herein tentatively regarded as intraspecific variation, because the number of tubular ducts and multilocular pores is known to vary greatly in some mealybug species ( Cox 1983; Charles et al. 2000; Chatzidimitriou et al. 2016), considerable geographical morphological variation within P. manifecta has been also recorded ( Kaydan 2015), and hitherto, the morphological variation of P. manifecta and taxonomic significances of the ducts’ and pores’ sizes have not been sufficiently studied. This description of the Japanese population may be useful for understanding phenotypic variation in the species. Future molecular studies may help elucidate the extent of variation in P. manifecta .

In Japan, this species was collected from Kansai International Airport, one of the largest airports in the country, and from the large sea-port island of Kobe City (Minato-jima), both of which are centres of international trade. Furthermore, the species has not hitherto been recorded further east than Kazakhstan. This suggests that the species might not be truly endemic to Japan, but be a recent introduction. Studies of the detailed distribution of the species in Japan, and the current condition of the species at the sites where it was collected originally, may be important from both biological and plant-quarantine perspectives.