Male calling, mating and oviposition in Isoperla curtata (Plecoptera: Perlodidae)

• Main Authors: José Manuel TIERNO DE FIGUEROA, Julio Miguel LUZÓN-ORTEGA, Antonino SÁNCHEZ-ORTEGA
• Format: Article
• Language: English
• Published: Institute of Entomology, Biology Centre, Czech Academy of Science 2000-10-01
• Series: European Journal of Entomology
• Subjects: isoperla curtata; reproductive biology; drumming call; mating behaviour; clutches; eggs
• Online Access: https://www.eje.cz/artkey/eje-200002-0007_Male_calling_mating_and_oviposition_in_Isoperla_curtata_Plecoptera_Perlodidae.php

The reproductive biology (drumming call, mating behaviour, fecundity and egg structure) of Isoperla curtata, an endemic species from the Southern Iberian Peninsula, is described. The male's mating call has a diphasic pattern, with a mean of 17.3 beats per call (range = 8-27; SD = 4.7) and a duration of 792.9 ms per call (range = 228-1312; SD = 307.9). This call differs from that of other species of Isoperla in having two distinct phases with different millisecond intervals, and is species-specific. Mating lasts between 131 and 3864 seconds (mean = 2180.9 s and SD = 1027.8). Since males and females mate more than once (mean number of matings per female was 1.85 and per male 2.25), the species is polyandric and polygynic. The position adopted by the male during mating is different from that described for other stonefly species. Other mating behaviours are interpreted as displacement manoeuvers, tactile stimulation and possibly sexual selection by cryptic female choice. There was a statistically significant correlation between size and the number of matings in females (r = 0.849; p = 0.016), but not in males. Each female laid between one to four egg masses composed of an average of 88.7 eggs. Maximum fecundity was 319 eggs. The mean egg volume was 80.5 × 105 µm3 which is very similar to that of other Isoperla species. An outstanding morphological characteristic of the egg is the lobed outline of the chorion cells.