Biology, images, analysis, design...
|"It has long been an axiom of mine that the little things are infinitely the most important" |
Japanese elm aphidOn this page: Identification & Distribution Biology & Ecology Other aphids on the same host
Identification & Distribution:
The winged viviparae of Tinocallis takachihoensis (see first picture below) are pale yellow-green with a shiny black head and thorax. The pattern of black markings on the wings is diagnostic. There is a black patch where the hind femur meets the hind tibia. The pronotum and mesonotum each bear a pair of dorsal processes. The pair on the pronotum are small and pale, whilst the pair on the mesonotum are large and dark. There are also two pairs of paired dorsal processes on the abdominal dorsum. The head bears no dorsal processes (cf. Tinocallis ulmiparvifoliae which has three pairs of dorsal processes on the head), and there are no brown markings on the abdominal dorsum (cf. Tinocallis platani which has extensive dark dorsal makings on the abdomen). The body length of Tinocallis takachihoensis alates is 1.8-2.0 mm.
Immature Tinocallis takachihoensis are pale yellow green with numerous tubercles topped with capitate hairs. They form large colonies with the alates on the undersides of the leaves (see second picture above). The micrographs below show (first) an alate in posterior-lateral view and (second) a dorsal close-up of the head and thorax showing the two pairs of dorsal processes.
The Japanese elm aphid feeds on elm (Ulmus spp) and some other genera in Japan, China and eastern Siberia. Tinocallis takachihoensis has also been introduced to Europe (France, Germany, England, Netherlands, Sicily, Andorra) and the USA. It now appears be established in most of these countries.
Biology & Ecology:
In Britain Tinocallis takachihoensis has been regularly found on imported Bonsai plants (Ulmus and Zelkova spp.) (Roques & Auger-Rozenberg, 2006). It was first recorded in England in 'the wild' by Döring (2007, 2008) who collected it on whych elm (Ulmus glabra) in Berkshire. Tinocallis takachihoensis has also been recorded in 2012 from Lincoln, UK by Mick Talbot.
We first confirmed the presence of Tinocallis takachihoensis in East Sussex in July 2010 on elm trees at Friston Forest, although immatures we found there in 2007 were also probably of this species.
Then in 2014 we found them in large numbers on elm in several locations in East Sussex (Middle Farm, West Dean, Ringmer) and West Sussex (Stanmer). It remains unclear how Tinocallis takachihoensis is overwintering in much of Europe, but it seems likely that they produce males and oviparae in autumn and overwinter as eggs. Patti & Barbagallo (1998) report alate males and oviparae in Sicily from mid-October. Piron (2013) suggests that with climate change in Western Europe the climate may be similar enough to Japan to enable Tinocallis takachihoensis to survive milder winters (parthenogenetically ?) even with occasional severe frosts.
There are few observations on the natural enemies of Tinocallis species. Lumbierres et al. (2005) have recorded the coccinellid Oenopia conglobata (see picture above) as a predator of Tinocallis takachihoensis in Lieida, in the Iberian Peninsula.
Other aphids on same host:
Tinocallis takachihoensis has been recorded from 4 Ulmus species (Ulmus canescens, Ulmus glabra, Ulmus ×hollandica, Ulmus japonica).
Blackman & Eastop list about 75 species of aphids as feeding on elms worldwide, and provides formal identification keys for aphids on Ulmus.