Amyttosa Beier 1965

Naskrecki, Piotr, 2008, New species of arboreal predatory katydids from West Africa (Orthoptera: Tettigoniidae: Meconematinae), Zootaxa 1732, pp. 1-28 : 8

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 .

Figures

FIGURE 5. A – C. Epiphallus: A. Anepitacta wrightae; B. Amyttopsis palmulicerca; C. A. bakowskii; D – G. Eggs: D & E. Amyttosa insectivora; F. Gonamytta occidentalis; G. Brachyamytta maculipes; H – I. Male pronota: H. G. occidentalis; I. Anepitacta guentheri.