ecology of phasmids - KLUEDO - Universität Kaiserslautern

Community structure & host range 21
Observed resource niches only partly represented food niches, as potential food plant families from linetransect
records (i.e. the realized niche) did not completely overlap with edible plant families from
feeding trials (i.e. the absolute food niche; Figure 2-4). The overlap between the two niche types ranged
from 0.50 to 1.00 (expressed as Sørensen index of similarity, Figure 2-4). None of the four focal
phasmid species was specialized beyond the plant family level. However, Otocrania sp. exclusively fed
on plant species of the Sapindaceae and M. diocles was clearly restricted to Araceae and Piperaceae
(Table 2-3). Generally, plant families that were recorded as preferred resources along line-transects (see
above) proved to be edible to the according phasmid species. But for the tested phasmid species the
palatability of plants was not consistent in-between the taxonomic borders of plant families (i.e., not all
confamilial plant species tested were edible, cf. Table 2-3).
The focal phasmid species had distinct diets (Table 2-3). In contrast to the plant records from linetransects
(see Table 2-2), the food niches resulting from feeding trials did not overlap (Table 2-3). Only
B. ploiaria shared one host plant family each with O. martini and Otocrania sp.. Nonetheless, plant life
form of palatable species corresponded with the preferred habitat of phasmid species. O. martini,
B. ploiaria and Otocrania sp. fed exclusively on pioneer tree species and lianas. Whereas the diet of
M. diocles, the only phasmid species with considerable occurrence in the forest understory (cf. Table 2-
1), contained herbs, shrubs and hemiepiphytes, which are characteristic elements of this habitat. None of
the four phasmid species fed neither on any of ten highly abundant tree species of BCI which
represented eight plant families, nor did they feed on any of 13 randomly selected plant species out of
12 plant families (cf. Table 2-3).