|scientific name Scolytus schevyrewi |
common name Banded elm bark beetle.
Adults are usually found on host trees while the juveniles may be found either in the wood of the tree or in the bark (Liu & Haack 2003).
Overwintering individuals (1st generations) generally emerge from April to May (Liu & Haack 2003).
Adult S. schevyrewi are distinguishable by the presence of a black transverse band on the posterior end of the reddish-brown elytra (Liu & Haack 2003, LaBonte et. al. 2003). They are usually about 3.2 to 4.2 mm long with slightly protruding frons. A spine is usually present on the 2nd abdominal sternite and may be variable in shape and position. The spine appears mostly conical shape in lateral view and triangular in posterior view (LaBonte et. al. 2003). There are no teeth on the lateral margins of the abdominal sternites (LaBonte et. al. 2003). Larval are whitish in colour with creamy-yellow head capsules (Liu & Haack 2003).
This species of beetle overwinters as pupae or as adults hidden under bark. Upon emergence in early Spring, these individuals will mate and produce the 1st generation which emerges around July (Liu & Haack 2003). These 1st generations individuals then mate once again and produce the 2nd generation which mostly overwinters as pupae. Some of the 2nd generation beetle, however, may complete development (if conditions are favourable), emerge late in the summer and produce a 3rd generation, which will overwinter. Mating often occurs on the surface of the tree next to entry holes leading to egg galleries (Liu & Haack 2003).
These beetles feed on various species of elms. In North America, they generally attack native American Elms and Siberian Elms. Adults will target twigs while the larvae will feed on wood within a tree trunk (Liu & Haack 2003).
This beetle originated from Asia and has recently established itself in North America . They are usually found where their host plants are available (Liu & Haack 2003, LaBonte et. al. 2003).
The species S. schevyrewi is considered a tree pest in N. America because of the damage it inflicts on host trees (which are also economically important tree species) (Liu & Haack 2003). Large infections can kill a tree as larval feeding may girdle a tree. Furthermore, the banded elm bark beetle is a know vector of Dutch Elm Disease which is fatal to the trees (LaBonte et. al. 2003, Liu & Haack 2003). Since there are no natural biological controls on this beetle in N. America, control programs aimed at reducing or eradicating beetle presence are maintained in most of N. America (Liu & Haack 2003).
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