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East Asian berry aphidsOn this page: Genus Matsumuraja rubifoliae
Matsumuraja aphids are distinguished by having long capitate hairs arising from tubercles, which are often extended into fingerlike processes.
There are about 14 east Asian species, with one so-far undescribed species from Australia. All but one feed on Rubus - one species is reported from Ficus rubis which Blackman suggested was probably not the true host. The only species in which the life cycle has been clarified has a sexual phase on Clethra, which indicates that Rubus may be the ancestral secondary host.
Matsumuraja rubifoliae (Asian raspberry aphid) East & South-east Asia
In Japan part of the Matsumuraja rubifoliae population passes winter in the egg stage on the primary host, Japanese clethra (Clethra barbinervis) (but see below for anholocyclic populations on Rubus). The adult fundatrices (see first picture below) can be found on the lower foliage surface from late April to early June. The fundatrix is unusually large (3-4 mm long), pale yellow, and flattened dorso-ventrally. The head bears 4 pairs of tubercles of variable length. The antennae are short but 6-segmented, with the segmental apices often blackish. The few hairs on antennal segment III are distinctly shorter than half of the basal diameter of that segment. The rostrum reaches the middle coxae, with the apical rostral segment about 1.3 times as long as the second segment of the hind tarsus. The dorsum is not sclerotic, but the pronotum is distinctly corrugated. There are long spinal and marginal projections on the mesothoracic, metathoracic and abdominal tergites and short marginal projections on each thoracic segment (the spinal projections are difficult to make out on the picture below). The siphunculi of the fundatrix are slender, never swollen. The cauda is stout, slightly constricted at base, with 8-10 hairs on each side.
The immature fundatrigeniae (see second picture below) produced by the Matsumuraja rubifoliae fundatrix are pale green and all develop to emigrant alatae. Emigrant Matsumuraja rubifoliae alatae (see third picture below) are yellow with dark head and thorax, and black dorsal and marginal patches from segments III or IV to VI. The antennae have many rhinaria on segments III-V, and a few blunt hairs on segment III which are slightly longer than half diameter of base of the segment. The apical rostral segment is about 1.4 times as long as the second segment of hind tarsus. The abdomen is without dorsal tubercles, but there are 4 short dorsal setae on each tergite. The siphunculi are black on the swollen distal part, and almost smooth. The cauda is triangular, as long as wide, bluntly pointed, and usually has 2 hairs on each side. The body length of alates from the primary host is about 2-2.2 mm.
Images above by permission, copyright Akihide Koguchi, all rights reserved.
These alatae migrate to the secondary host (Rubus spp.) where, through summer until autumn, many successive apterous generations occur on the foliage and young shoots. The apterae on Rubus (not pictured) are yellow or white. Their antennae are variable in length, sometimes much longer than half the body length, and are blackish on the distal parts of segments III-V and the base of segment VI. There is a tubercle on antennal segment I which is about 0.6 times as long as that segment. The apical rostral segment is about l.4 times as long as the second segment of the hind tarsus. The siphunculi are deep brown, sclerotized, imbricated and sometimes slightly swollen on distal part. The cauda is distinctly longer than wide, robust, with 2 pairs of setae. There is also a dwarf form of Matsumuraja rubifoliae, with small dorsal hairs and distinctly swollen siphunculi on the distal part.
In some parts of Japan Matsumuraja rubifoliae is heteroecious holocyclic with a sexual phase on Japanese clethra (Clethra barbinervis). Anholocyclic populations are also common on evergreen Rubus in Japan, and probably elsewhere. In the mountainous regions along the southern coast of the mainland of Japan, a dwarf form is very common on Rubus microphyllus in summer (see Takahashi & Sorin, 1965). Matsumuraja rubifoliae is common on shoot tips and undersides of young leaves of Rubus spp. in the southern half of Japan. This species is found in east Siberia, China, Thailand, Taiwan, Korea, and Japan.