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Aotearoa wax-fringed sedge aphidOn this page: Identification & Distribution Other aphids on the same host
Identification & Distribution
Adult apterae of Allaphis foxtonensis are light green to light yellowish green, with mainly dusky antennae. There is extensive wax exudation laterally and ventrally, especially on the appendages and posterior. The body is elongated and somewhat flattened. Antennal tubercles are absent. The eyes are without ocular tubercles. The antennae are about 0.7 times the body length (cf. Allaphis producta, which has antennae less than 0.55 times the body length). Antennal segment antennal III bears 1-7 secondary rhinaria. The hairs on segment III are very short, only about 0.25 times the diameter of the segment, and the terminal process is about 0.8 times the base of antennal segment VI. The rostrum extends to the first pair of coxae. The abdominal dorsum has a scale-like pattern of imbrication, and bears a few small pointed hairs. The siphunculi are reduced to more-or-less round rimmed openings on each side of tergite VI. The cauda is knobbed, constricted at the middle, and with 11-14 hairs. The body length of adult Allaphis foxtonensis apterae is 2.4-2.7 mm.
Both images above copyright Stephen Thorpe under a creative common licence.
Alatae of Allaphis foxtonensis (not pictured here) have a dark head and prothorax, with a median pale yellow longitudinal streak down each of them. The abdomen is light green, with a black transverse band on each of tergites I-VII, but widest on tergites III-V. There are also black marginal sclerites on tergites I-VII, and tergite VIII is black. There is a light coating of white wax on the ventral surface. There are 12-17 variously-sized secondary rhinaria on antennal segment III.
Image above copyright Stephen Thorpe under a creative common licence.
Allaphis foxtonensis is monoecious on Carex, especially Carex ternaria. Cottier (1953) found this aphid species very common on its host, especially at the bases of the young leaves in the centres of the plants. It has a habit of holding its antennae pointing straight ahead and flat on the leaf surface when at rest. When it moves, it does so rather rapidly, leaving a deposit of honeydew. The Aotearoa wax-fringed sedge aphid was first found in New Zealand, and then (possibly) in Australia (Eastop, 1966 notes that it may not be the same species as that found in New Zealand). Allaphis foxtonensis may be endemic to this region, but Blackman in Aphids on Worlds Plants felt that the lack of related species in the southern hemisphere means it is almost certainly an introduced species, so far undescribed in its home environment. That said, if it arrived some time ago, it may have changed somewhat.
Other aphids on the same host
Allaphis foxtonensis has been recorded from 2 species of sedge (Carex gaudichaudiana, Carex ternaria). It is the only species of aphid recorded for those sedges.