A Comprehensive Key for Identification of the “Swarming Conehead” Ruspolia Differens Serville, 1838 (Orthoptera: Tettigoniidae) Occurring in the Afro-Tropical Region

This work reviewed the behavioural, morphological and molecular characteristics of the long-horned grasshopper Ruspolia differens Serville or “senene” in Swahili name (Orthoptera Tettigoniidae), as apparent in literature. On that basis, the work has generated a comprehensive key for identification of this species. As widely known, this insect native to Afro-tropical region where it is widely edible and it has a characteristic swarming behaviour that strikingly occurs during rainy season. Also, it has colour polymorphism with a total of six key sympatric colour forms, sex dimorphism with males possessing longer antennae and a unique pair of active tongue-like metathoracic flaps whereas the females have a corresponding pair of vestigial metathoracic nodules. Furthermore, the species has a pair of distinct subequal black markings on the mid and hind tibia near the knee joint and a white inter-ocular oval mark that appears like a simple eye. Its sister species which is Ruspolia nitidula Scopoli as verified by molecular phylogenetics is exclusively solitary, mostly greenish and Palearctic ranging in Asia, Europe and Northern Africa. Since swarming behaviour is a foremost diagnostic feature differentiating R. differens from other coneheads, it is worthwhile to demarcate the species with a common name “Swarming Conehead” adding to the existed names.