Biology Reference
In-Depth Information
lepidopteran herbivore faunas of two trees, one an oak (
Quercus cerris
) and
the second a maple (
Acer pseudoplatanus
), that had been introduced to
England in the late 1600s or early 1700s were examined byYela and Law-
ton (1997). These trees had accumulated faunas comparable to members
of the same genera that occurred at the study site and had been present
in England for thousands of years.
Acer pseudoplatanus
has a very close
native relative in
A. campestre
, which may account for the high number of
insect colonists (Frenzel et al. 2000).
Quercus cerris
belongs to the same
genus as the native
Q. robur
,a tree that harbors an abundant fauna of her-
bivorous insects. A third alien plant,
Rhododendron ponticum
, which was
introduced in 1763 and has no native congeners in England, had a lepi-
dopteran fauna much less diverse than the oak and maple aliens.
The introduction of various species of oaks (
Quercus
) to different
world regions has shown clearly how the presence and absence of close
relatives influences colonization by herbivores (Connor et al. 1980). Saw-
tooth oak (
Q. acutissima
), native to eastern Asia, has acquired a fauna of
leaf-mining insects comparable to that of native oaks since its introduc-
tion to North America in 1862.This oak, belonging to the same subgenus
as North American white oaks, has several close North American rela-
tives. Japanese blue oak (
Q. glauca
), on the other hand, lacks close sub-
generic relatives. Although it was introduced to North America in 1865,
it has accumulated few if any leaf miners. Several species of European,
North American, and Asian oaks have been introduced to Australia and
New Zealand at various times, for some species as early as 1820. Oaks are
not native to these regions, although the plant family, Fagaceae, repre-
sented by southern hemisphere beeches (
Nothofagus
spp.), is present.
Although in their native regions, oak species tend to possess 15-24 or
more species of leaf mining insects, oaks in Australia and New Zealand
were found to almost completely lack such species.
Brazilian pepper (
Schinus terebinthifolius
), a major invasive tree in
Florida, is an example of a plant lacking close relatives in North America.
Brazilian pepper was introduced to the United States in about 1840 but
was popularized as an ornamental plant in the 1920s. Surveys of the insect
fauna of Brazilian pepper revealed a fauna of 115 species in Florida (Cas-
sani 1986; Cassani et al. 1989). Of these, 46 were phytophagous species,
but none of them appeared to cause serious damage to the tree.The insect
fauna associated with the tree in Brazil is at least 200 species (Medal et al.
1999). A similar situation prevails for the Australian paperbark (
Melaleuca
quinquenervia
), another invasive alien tree in Florida. In Australia, more
than 450 species of herbivorous insects are known to feed on the species,
