Rhododendraphis, Özdemir, Shalva Barjadze Işil, 2014

Özdemir, Shalva Barjadze Işil, 2014, A new genus of Macrosiphini Wilson, 1910 (1887) (Hemiptera: Aphididae) from Rhododendron in Turkey, Zootaxa 3835 (1), pp. 121-126 : 121-122

Rhododendraphis gen. n.

Type species: Rhododendraphis tuatayae sp. n.

Description. Apterous viviparous female. Body small, elliptical with 6-segmented antennae, antennae shorter than length of body. A few secondary rhinaria arranged distally on antennal segment III. Antennal segment III with imbrications on the distal 1/2 or 2/3. Processus terminalis short, length of processus terminalis/basal part of antennal segment VI is 1.45–1.65. Head with low antennal tubercles and low or absent median tubercles. Rostrum long, passes to hind coxae. Ultimate rostral segments oblong triangular with blunt apices, with 24–28 accessory hairs, ca. 2 times longer than length of second segment of hind tarsus. Legs normal, smooth. Tarsal I and II segments with spinulose imbrications, second segment of hind tarsus short (0.063–0.072 mm length) and wide (length of second segment of hind tarsus/width of second segment of hind tarsus - 3.00–3.43). First tarsal chaetotaxy: 3:3:3. Tergum dark and sclerotic with dark bands on abdominal tergites VII and VIII. Dorsum of body with reticulation pattern made by small cells. Hairs on dorsum are short with capitate apices, while on the ventral side long and pointed hairs are presented. Marginal wax gland plate absent from body. Subgenital and anal plates and cauda with spinulose imbrications. Siphunculi clavate, slightly or moderately swollen on the distal half, with scaly pattern and transverse striae before flange. Siphunculi with distinct flange. Cauda short, tongue-shaped, not constricted in the middle, with a small number of hairs on it.

Etymology. The generic name Rhododendraphis is of feminine gender and derived from the ancient Greek word “ Rhododendron ”, which is the host plant of the aphid, and “ aphis ” (= plant louse).

Diagnosis. This genus belongs to the tribe Macrosiphini Wilson, 1910 (1887) ( Hemiptera : Aphididae ). Of the Rhododendron -feeding aphids, it resembles Rostratusaphis Fang and Qiao, 2009 in the following features: (1) poorly developed antennal tubercles, (2) long rostrum, (3) high number of secondary hairs on the ultimate rostral segment, (4) spinulose hind tarsi, (5) clavate siphunculi without subapical zone of reticulation and (6) small number of caudal hairs ( Fang & Qiao 2009). However apterous viviparous females of Rhododendraphis differ from the same form of Rostratusaphis by having (1) a processus terminalis that is longer than the basal part of antennal segment VI; (2) secondary rhinaria on antennal segment III; (3) a much shorter ultimate rostral segment; (4) dorsal hairs with capitate rather than pointed; (5) no marginal wax plates on metanotum and abdominal tergites I–VI.

It also resembles Neoamphorophora , but that genus has apterae without secondary rhinaria on the antennae, tarsi without spinules, and a much shorter ultimate rostral segment with only a few accessory hairs.

Apart from Rostratusaphis , six other Rhododendron -feeding genera ( Chaetomyzus , Ericolophium , Illinoia , Indiaphis , Indomasonaphis and Vesiculaphis ) have species with spinulose second tarsal segments. Of these, only Illinoia has apterae with antennae bearing secondary rhinaria, and that is a Nearctic genus with well-developed antennal tubercles and siphunculi with a subapical zone of polygonal reticulation. Chaetomyzus and Indomasonaphis have characteristic dorsal seta-bearing processes, and Ericolophium and Indiaphis have tapering/ cylindrical siphunculi with no trace of distal swelling. Vesiculaphis has apterae with projections on the head as a ledge or lobes in front of the antennal bases.