Megoura lathyricola Lee & Akimoto

Lee, Wonhoon, Kanbe, Takashi & Akimoto, Shin-ichi, 2014, A new species of Megoura (Hemiptera, Aphididae) from Japan, ZooKeys 417, pp. 37-44 : 39-41

Taxon classification Animalia Hemiptera Aphididae

Megoura lathyricola Lee & Akimoto sp. n. Figs 1, 2, Table 1

Holotype.

Apterous viviparous female, Coll#.120605WH26/ap.1, Muroran, Hokkaido, Japan, 05.vi.2012, leg. Wonhoon Lee, on Lathyrus japonicus subsp. japonicus.

Paratypes.

9 apterous viviparous females and 2 alate viviparous females, same data as for holotype; 5 apterous viviparous females, Coll#.120309WH16, Nagasaki, Nagasaki prefecture, Japan, 09.iii.2012, leg. Wonhoon Lee, on Lathyrus japonicus subsp. japonicus.

The type specimens, including holotype and paratypes, are deposited in the Laboratory of Systematic Entomology, Graduate School of Agriculture, Hokkaido University, Japan.

Etymology.

The specific epithet is composed of the root of the plant genus (lathyr) and the lexeme “col” that, in this case, means 'living on’.

Apterous viviparous female.

(Figs 1 A–H, 2A) Color alive: Head yellowish brown with antennae dark brown, thorax and abdomen pale green. Legs pale yellowish brown except distal 1/9 of tibiae including tarsi dark brown. SIPH dark brown. Cauda pale. Color of macerated specimens: Head yellowish brown and antennae dark brown. Rostrum pale, except the tip of URS dark brown. Thorax yellowish brown and abdomen entirely pale. Legs pale except distal 1/9 of tibiae and tarsi dark brown. SIPH dark brown and cauda pale except extreme end. Morphology: Body spindle shaped. Head: smooth on ventrum and dorsum including three pairs of acuminate setae. Antennal tubercle well developed with 3-5 setae on both side, frons U–shaped with four setae on vertex, including weakly developed median tubercle. Ant.I smooth; Ant.II granulate; Ant.III weakly imbricate with short setae, bearing 40-59 secondary rhinaria irregularly spaced; Ant.IV imbricate with 12-18 setae with no secondary rhinaria; Ant.V imbricate with 8-13 setae, primary rhinarium ciliate, longest diameter of which is shorter (0.63-0.83 times) than middle width; Ant.VI imbricate with 3-7 short setae on Ant.VIb. Rostrum attaining posterior margin of mesocoxa; mandibular laminae with 4-6 setae on each side; URS longest seta 0.78-1.00 times as long as apical primary ones. Thorax: pronotum smooth with two spinal setae and one marginal seta on anterior margin. Hind coxa weakly spinulose with 6-7 acuminate setae; hind trochanter wide at base, 1.63-1.65 times as long as apical width, bearing three setae; hind femur smooth on basal 1/17, spinulose on apical 16/17 ventrally, bearing short setae, longest seta 0.43-0.48 times as long as basal width of segment; hind tibia smooth, longest seta 0.80-1.07 times as long as middle width of segment; first segment of each tarsus smooth with three setae at apex; 2HT imbricate with 10-11 setae. Abdomen: dorsum smooth, membranous with 11-13 setae on tergite III, 0.37-0.47 times as long as basal width of hind femur. SIPH swollen, weakly spinulose except smooth base, irregularly reticulated on distal end, apex flanged. Cauda elongate, triangular, ventral spinules strong and dense, in groups of one or two; dorsal ornamentation composed of ribbed imbrication.

Alate viviparous female.

(Figs 1 I–P, 2B) Color alive: Head, antennae and thorax black, abdomen pale green. Abdomen with black patches on tergites III–VI. Legs pale yellowish brown except distal 1/2 of femora and distal 1/9 of tibiae including tarsi dark brown. SIPH dark brown. Cauda pale. Color of macerated specimens: Head, antenna, and thorax dark brown. Legs pale except dark distal 1/2 of femora, 1/9 of tibiae and tarsi. Abdomen with marginal sclerites on II–VI segments. SIPH and Cauda dusky. Wings pale with veins bordered by narrow dark pigmentation. Morphology: Antennae with 60-62 secondary rhinaria irregularly scattered on whole of Ant.III, and 20-32 secondary rhinaria scattered on whole of Ant.IV. Cauda triangular, pointed at apex. SIPH strongly imbricate. Otherwise like apterous viviparous female.

Distribution and host-plant.

So far collected and observed only on Lathyrus japonicus subsp. japonicus in Muroran, Hokkaido and Nagasaki, Japan. This plant is distributed only in seashore areas.

Biology.

This species seems to be rare. Colonies were observed on stem and young leaves of host plants. In nature it appears to be specific to Lathyrus japonicus . However a clonal lineage from Nagasaki was readily reared in the laboratory of Systematic Entomology, Hokkaido University under long day conditions by using broad bean seedlings as a host. When the clone was reared at 15 °C and 8L16D, it produced viviparae but no sexual morphs, suggesting that the Nagasaki population of this species is anholocyclic.