Geographic Distribution and Singing Activity of Pterophylla beltrani and P. robertsi (Orthoptera: Tettigoniidae), under Field Conditions

Abstract

Populations of Pterophylla beltrani and P. robertsi were studied along the Eastern Sierra Madre, in the States of Nuevo Le6n, Tamaulipas and San Luis Potosi. Thirty colonies of Pterophylla spp. were located between the Cidnega, State of Nuevo Le6n and the city of El Maiz, San Luis Potosi. Geographic distribution limits for both species are established for the first time. P. beltrani occurs from the State of Nuevo Le6n to the surroundings of Cd. Victoria and Jaumave, Tam., while P. robertsi occurs from Llera, Tam. to the city of El Maiz, San Luis Potosi. Three allopatric populations of P. robertsi previously unknown are reported in South Tamaulipas. Acoustic activity of both species is associated with factors, such as temperature, relative humidity, solar radiation, rain, wind, presence of sexually mature females or conspecific individuals, whether or not the male carries a spermatophore, predators, etc. P. beltrani suspends singing activity from 3:00 to 7:00 hours (temperature 19-210C and 70-75% relative humidity) and from 12:00 to 17:00 (temperature 330C : 40% relative humidity - at this time heat and solar radiation are most intense). P. robertsi's singing activity period is from 19:00 to 4:00, being shorter compared to P. beltrani.