Sitobion berkemiae

Adult apterae of Sitobion berkemiae have a deep green abdomen, a brown head and prothorax and black sclerotic siphunculi. Their antennae are black, six segmented, with a terminal process about 6.6 times as long as the base of antennal segment VI. The apical rostral segment has 4-6 accessory hairs. The dorsum is largely membranous apart from darkened postsiphuncular sclerites. The femora are greenish basally and black distally; the tibiae and tarsi are jet black. The tapering siphunculi are about 1.6 times the length of the cauda. They have a small but distinct flange, and reticulation on the distal 0.32-0.44 of their length (cf. Sitobion berchemiae in China, which have reticulation on the distal 0.25-0.33 of their siphunculi). The cauda is pale yellow-green. The body length of adult Sitobion berkemiae apterae is 1.3-1.8 mm.

Note: Sitobion berkemiae was first described as Acyrthosiphon berkemiae by Shinji (1941), then redescribed as Macrosiphum berkemiae by Miyakazi (1980), before being reassigned to Sitobion by Blackman & Eastop (1984). Sitobion berkemiae may be a synonym of the Chinese species Sitobion berchemiae Takahashi.

Image above by permission, copyright Akihide Koguchi, all rights reserved.

We can find no description of the alate vivipara of Sitobion berkemiae, but it is likely to be similarly coloured to the aptera apart from increased sclerotization on the head and thorax, and possibly black abdominal markings.

Image above by permission, copyright Akihide Koguchi, all rights reserved.

Immatures (see picture above) are coloured as the adult aptera, except that immature alatae (and probably immature apterae of instars 1-III) have only the distal part of their siphunculi dark.