New species of arboreal predatory katydids from West Africa (Orthoptera: Tettigoniidae: Meconematinae)
Author
Naskrecki, Piotr
text
Zootaxa
2008
1732
1
28
journal article
10.5281/zenodo.181351
1f016037-2ea8-46e7-82e1-be6826ae0389
1175-5326
181351
Amyttosa
Beier 1965
Type
species:
Amytta mutillata
Karsch, 1890
: 367
.
This genus is unique among all known
Meconematinae
in the strong reduction of the ovipositor, a possible adaptation to dropping eggs to the ground, rather than their insertion in the soil, plant tissue, or bark, typical of other species of this group of katydids. The valvules of the ovipositor are poorly sclerotized and not flattened laterally, which indicates that the eggs are not inserted between the layers of the leaf epidermis, a behavior known in some
Phaneropterinae
with short ovipositors. The morphology of the egg is also unique among katydids (
Figs. 5
D–G). The egg is spherical, and not spindle shaped as in species laying eggs in the soil or plant tissues, nor is it laterally flattened as in species laying eggs in leaves. It is also unlikely that eggs of
Amyttosa
spp. are deposited in clusters on exposed surfaces, a behavior common in canopy-dwelling
Phaneropterinae
, because the morphology of the egg does not suggest a high resistance to desiccation (eggs deposited on exposed surfaces are smooth, with very thick chorionic layers that reduce the rate of water loss.) The chorion of the
Amyttosa
egg is covered with regularly distributes tubercles, and both ends of the egg carry a collar-like projections, similar, but not likely homologous to, the capitulum present in the eggs of many phasmids. This
type
of egg morphology, combined with a similar reduction of the ovipositor, also found in many Phasmodea that drop eggs to the ground, may indicate similar egg laying behavior.
Hughes and Westoby (1992)
demonstrated that phasmid eggs equipped with the capitulum have the same removal and burial rates by ants as plant seeds equipped with an elaiosome. Although at this point empirical evidence for such behavior is absent, it is possible that the morphology of eggs of
Amyttosa
has a similar function, and eggs are dispersed, and subsequently buried by ants.
Virtually nothing is known about the behavior of the previously described species of
Amyttosa
.
A. insectivora
,
the new species described below, is common in lowland and mid-elevation forests of Eastern
Ghana
, where it could be found at night on low trees and understory bushes in both primary and secondary evergreen forests. This species is predaceous and was frequently observed catching and eating small insects, primarily nymphs of
Membracidae
and
Cicadellidae
.