Tuberaphis [Macrosiphini]
The genus Tuberaphis is closely allied to Cerataphis. The body of the wingless vivipara has many well-developed wax-plates arranged in a row along the whole margin other than between the antennae (Cerataphis aphids, which have wax plates between the antennae). The head is short, fused with the prothorax, with 3 prominent blunt tubercles on the front (cf. Cerataphis aphids, which do not have such tubercles). Antennal tubercles are absent, and eyes are of 3 facets (=triommatidia). The antennae are short and 5-segmented; segment III is without secondary rhinaria, and the terminal process is short. The pronotum is distinctly defined from the mesonotum. The meso- and metanota are somewhat defined and the basal abdominal segments are fused togetherAbdominal segment VIII is separate. Siphunculi are very short, represented as mere rings. The anal plate is divided, and the cauda is constricted basally. The legs are rather short, and tarsi have 2 long, somewhat knobbed hairs.
There are about 14 species of Tuberaphis in east and south-east Asia. It is thought that most species host alternate between their (often elaborately-branched) galls on Styrax, and secondary hosts in Loranthaceae or Santalaceae. Some species (e.g. Tuberaphis owadai, Tuberaphis styraci) do not host alternate, but remain on Styrax all year, producing sexuparae from the galls in July/September. As with some other Cerataphidini, the typical intracellular aphid symbionts (Buchnera) have been replaced by extracellular yeast-like symbionts. Aoki & Kurosu (2010) reviewed life cycles, gall formation and soldier behaviour.
Tuberaphis owadai (Permanent coral gall aphid) China, Vietnam
The gall of Tuberaphis owadai (see picture below) on Styrax is coral-like in appearance with rather thin gall walls. The surface is covered with fine, velvet-like hairs that catch the wax, and the entire galls are silvery gray and conspicuous (cf. the gall of Tuberaphis takenouchii which has no fine hairs, and is pale waxy green). Each gall consists of a hollow tube ramified like a tree. The inner spaces of the ‘twigs’ are united to form a single cavity. There are many ostioles on the projections, through which alates escape and soldiers crawl out from the gall. The galls are quite large measuring from 9-24 cm across, The colony sizes of the galls is estimated to be approximately 50-180 thousand individuals, of which 41-52% are soldiers. There are numerous soldiers on the surface of the galls.
The adult aptera in the gall has membranous tergites, without demarcated wax plates (wax plates are present, but indistinct). The head has a pair of spine-like hairs. The antennae are five-segmented, longer than the fore tibia, and with a few secondary rhinaria. The ultimate rostral segment is 0.100–0.108 (0.104) mm long, without secondary hairs. The siphunculi are ring like, encircled by 6-11 hairs. The anal plate is bilobed, and the cauda has 15–18 hairs. The body length of the adult Tuberaphis owadai aptera is 1.5-1.7 mm.
Image above copyright Aoki & Kurosu (2010).
The alate viviparous female (sexupara) has a pair of small, finger-like projections between the antennae on the underside of the head. The antennae are 5-segmented, 0.29–0.35 times as long as body length, and with dense spinulose imbrications on segments III–V; the terminal process is 0.14–0.22 as long as the base of the segment. Antennal segments III–V bear 8–13, 1–5, 1–5 ring-like secondary rhinaria, respectively (cf. Tuberaphis takenouchii which has more than 3 secondary rhinaria on IV and usually none on V). The rostrum is short, only reaching the fore coxae. The trochanters and femora are fused. The forewings have the media vein single branched and the two cubitals fused at base. Siphunculi on abdominal segment V are ringlike, and surrounded by 4–7 hairs. The anal plate is bilobed, and the cauda is rounded at the apex, indistinctly constricted at the base. The body length of alatae is 1.5-1.9 mm.
Tuberaphis owadai does not host alternate, but instead completes its life cycle on snowbells (Styrax tonkinensis & Styrax japonicus). It is holocyclic and alate sexuparae emerge from the galls in September. These produce the sexuales on Styrax. The species has so far been found in China (Yunnan) and Vietnam.
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Acknowledgements
We are grateful to Utako Kurosu & Shigeyuki Aoki for providing images from Aoki & Kurosu (2010) for this page.
We have used the keys and species accounts of Kurosu & Aoki (2003), Aoki & Kurosu (2010) & Jiang et al. (2012), together with those of Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors and those listed in the reference sections as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure provided by Blackman & Eastop (2006).
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References
- Aoki, S. & Kurosu, U. (2010). A review of the biology of Cerataphidini (Hemiptera, Aphididae, Hormaphidinae), focusing mainly on their life cycles, gall formation, and soldiers. Psyche 2010, Article ID 380381, 34 pp. Full text
- Blackman, R.L. & Eastop, V.F. (2006). Aphids on the world's herbaceous plants and shrubs. Vols 1 and 2. John Wiley & Sons.
- Jiang, L.-Y. et al. (2012). The hormaphidine aphid genus Tuberaphis Takahashi (Hemiptera) from China with description of a new species. Oriental Insects, 46, 3-4. Full text
- Kurosu, U. & Aoki, S. (2003). Tuberaphis owadai (Homoptera), a new aphid species forming a large gall on Styrax tonkinensis in northern Vietnam. Entomological Science 6, 89–96. Abstract
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