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Description. Elm leaf beetle, side view. The imago (adult beetle) is 6–8 mm in length, and ranges from yellow to green in colour, with a spot on its head, an hourglass mark and two spots on the pronotum, and a broad, dark stripe along the edge of each elytron. The larvae are usually black, occasionally black and yellow, with multiple rows of ...
Emerald Sunshine is resistant to Dutch elm disease and Elm Yellows (Phloem necrosis). Foliage of trees under assessment at the aforementioned National elm trial site at U C Davis suffered minimal damage caused by the elm leaf beetle Xanthogaleruca luteola, [3] whilst damage caused by Japanese Beetle in trials at the University of Kentucky was found to be slight, owing to the dense pubescence ...
The tree's foliage was adjudged 'resistant' to black spot by the Plant Diagnostic Clinic of the University of Missouri, [11] however it can be severely damaged by the elm leaf beetle (Xanthogaleruca luteola) in the United States [12] Several mature specimens near the Hampshire coast in England have become (2014) afflicted by Dryad's saddle ...
Dutch elm disease. Dutch elm disease (DED) is caused by a member of the sac fungi (Ascomycota) affecting elm trees, and is spread by elm bark beetles. Believed to be originally native to Asia, the disease was accidentally introduced into America, Europe, and New Zealand. In these regions it has devastated native populations of elms that did not ...
US. Ulmus ' Frontier' is an American hybrid cultivar [4], a United States National Arboretum introduction (NA 55393) derived from a crossing of the European Field Elm Ulmus minor (female parent) with the Chinese Elm Ulmus parvifolia in 1971. Released in 1990, the tree is a rare example of the hybridization of spring- and autumn-flowering elms.
Princeton elms planted in North America are highly prone to leaf damage by Japanese beetles Popillia japonica. [11] Trees grown in the UK have also proven very susceptible to damage by leaf-feeding insects, far more so than native or Asiatic elms. Henry noted that such damage was common to all American Elm Ulmus americana grown in the UK. [12]
[16] Like many of the European field elms, var. japonica retains its green foliage well into the autumn, before a late display of deep yellow. Schneider (1907) and Bean noted that the variety from western China, formerly known as U. wilsoniana, [17] has 16 to 22 pairs of leaf-veins, [18] [19] while the eastern type tree has not more than 16.
The dark green leaves are large, < 17 cm (avg. 12 cm) long by < 10 cm (avg. 7.4 cm) broad, typical of the species, turning golden yellow in autumn. In an assessment at U C Davis as part of the National Elm Trial , the tree initially grew comparatively slowly, increasing in height by 0.85 m per annum, although stem development at 2.6 cm d.b.h ...