Megapulvinaria maxima (Green, 1904)

Wang, Fang & Feng, Ji-Nian, 2012, A review of the genus Megapulvinaria Young (Hemiptera, Coccoidea, Coccidae) from China, with a description of a new species, ZooKeys 228, pp. 59-68 : 61-63

Megapulvinaria maxima (Green, 1904) Figure 1

Pulvinaria maxima Green 1904: 206.

Pulvinaria thespesiae Green 1909: 259. Syn. by Takahashi 1935: 10.

Eriochiton formosae Takahashi 1929: 64. Syn. by Takahashi 1935: 10.

Megapulvinaria maxima (Green), Young 1982: 162.

Material examined.

5 adult females, CHINA, Yunnan, Jingdong, 18. x. 1976 on Pigeonpea ( Cajanus cajan (L.) Millsp., Leguminosae), Xiao-Ze Chen (NWAFU).

Note.

The measurements are based on all 5 specimens.

Diagnosis.

Adult female. Mounted material. Body elongate oval, about 4.2-6.2 mm long and 2.7-3.8 mm wide. Anal cleft approximately 1/7 of the body length. Stigmatic clefts deep.

Dorsum. Derm membranous. Dermal areolations well developed, each with 1 or 2 dorsal microducts. Dorsal setae conical, with a well-developed basal socket, each 8-16 µm long, scattered throughout. Dorsal simple pores each with a slightly sclerotized margin, randomly distributed. Dorsal microducts each with a very short outer ductule and a longer, fairly broad inner filamentous ductule, sparsely located in dorsal areaolations. Dorsal tubular ducts each with a short outer ductule and a fine inner ductule with a minute terminal gland, sparsely distributed. Preopercular pores absent. Anal plates together quadrate; posterior margin slightly longer than anterior margin, outer angle slightly obtuse; each plate with a large cylindrical seta in discal position, each 34-50 µm long, a large spatulate seta apically, each 52-64 µm long, and with 2 spinose and/or spatulate setae along posterior 1/3rd of inner margin, each 40-56 µm long. Ano-genital fold with 1 pair of long setae and 1 pair of short setae along anterior margin and 2 or 3 pairs lateral margin. Anal ring subcircular, with 2 or 3 rows of translucent pores and 6 anal ring setae. Eyespots present some way onto dorsum, each 80-96 µm wide.

Margin.Marginal setae of 2 types: 1) large and stout setae, each 17-38 µm long, with nearly parallel sides, and with either a truncate or a bifid apex, all with well-developed basal sockets, each socket with 1 or 2 small pores; with 96-110 setae between anterior clefts, 36-46 setae on each side between stigmatic clefts, and 84-98 setae between each posterior stigmatic cleft and anal cleft; and 2) quite broad and short setae, each 14-24 µm long, with parallel sides and a truncate, flattened apex, and with a larger basal socket about twice as broad as that of type 1), each socket with 3-8 small pores; latter type of marginal setae only distributed on anterior and posterior ends, with 16-22 setae anteriorly on head and prothorax, 5-12 setae on either side of abdomen near anal cleft. Stigmatic clefts deep; stigmatic spines bluntly spinose and mostly straight, with 4-8 spines in each anterior cleft and 5-10 in each posterior cleft; length of each 42-96 µm, with median 1-3 spines much longer than the lateral spines.

Venter. Derm membranous. Antennae 8 segmented, each 505-586 µm long; third segment longest; with 2 pairs of long setae and 1-3 pairs of short interantennal setae. Clypeolabral shield 198-232 µm long, 205-240 µm wide; labium 90-106 µm long, 113-144 µm wide. Legs well-developed, each with a tibio-tarsal articulation and articulatory sclerosis; claws with a denticle on widest part, claw digitules broad and expanded apically, tarsal digitules slender, knobbed and longer than claw digitules; trochanter+femur 239-405 µm, tibia 180-245 µm and tarsus 96-122 µm. With 2 pairs of long pregenital setae present in both segments VI & VII; submarginal setae present in a single row; other setae slender, each 4-10 µm long, quite sparsely distributed. Spiracles normal, spiracular disc-pores each with 5 loculi, present in a broad band between stigmatic cleft and each spiracle. Pregenital disc-pores each mainly with 10 loculi, present around the vulva and on posterior 4 abdominal segments. Ventral microducts scattered. Ventral tubular ducts of 3 types present: 1) a duct with a short outer ductule and a fine inner filament, with a minute terminal gland, present in a complete submarginal band; 2) a duct with outer and inner ductules both broad and with a well-developed terminal gland, present medially on head, thorax and anterior 1 or 2 abdominal segments; and 3) a duct with a moderately long outer ductule and a thin inner ductule slightly longer than outer ductule, with a flower-shaped terminal gland, present medially on posterior abdominal segments and extending and mingling with marginal band of type 1) ducts.

Distribution.

China (Guangxi, Yunnan, Taiwan), Thailand, India, Indonesia, Philippines, Sri Lanka, Vietnam, Papua New Guinea, Chuuk Islands.

Comments.

Since Green (1904) originally described Megapulvinaria maxima , it had been described and illustrated by many authors, such as Green (1904, 1909), Takahashi (1929), Tang (1991), Hodgson (1994). Our observations agree well with these in descriptions in most respects. Tang (1991) and Hodgson (1994) pointed out the presence of dorsal areolations and denticles on widest part of claws, which Green (1909) and Takahashi (1929) failed to observe respectively. The outer angles of anal plates were obtuse or broadly rounded rather than at a right-angle, as shown by Hodgson (1994). We have confirmed the occurrence of dorsal areolations and denticles, and the outer angles are slightly obtuse in our examined specimens. Moreover, Hodgson (1994) described four types of dorsal pores, but we just observed just two types.

This species is close to Megapulvinaria burkilli (Green) (data from Green, 1908), but it can be distinguished from the latter by the following features (character states of Megapulvinaria burkilli in brackets): (1) the much larger body size in comparison to the latter (4 mm long, 2 mm wide); and (2) with well-developed dermal areolations present (absent).