Aspects of life history of the Afrotropical endangered Acisoma inflatum (Selys, 1889) (Odonata: Libellulidae) in Northeast Algeria. Issue 2 (3rd March 2020)

• Record Type: Journal Article
• Authors: Baaloudj, Affef
• Is Part Of: Annales de la Société entomologique de France. Volume 56:Issue 2(2020)
• Page Start: 180
• Page End: 188
• Publication Date: 2020-03-03
• Subjects: embryonic development -- emergence -- vertical stratification -- lifespan -- conservation; Insects -- Periodicals; Entomology -- Periodicals; 595.705
• DOI: 10.1080/00379271.2020.1754909
• Languages: English
• ISSNs: 0037-9271

Abstract

Summary: Acisoma inflatum: is a threatened dragonfly in the Mediterranean, where only a few relict populations remain. It is listed as endangered in North Africa, where no data on its biology, behaviour or ecology are available. These latter are important to understand how this species is adapted to local environmental conditions and for establishing effective conservation plans. In this study, the life history of A. inflatum is investigated in a north-east Algerian population. By combining field and laboratory investigations on embryonic development and regular collection of exuviae during the emergence season, it is revealed that the species has direct and synchronous embryonic development, with 75% of all eggs hatching after 10 days of oviposition, and a hatching period ranging from 9 to 15 days. Emergences were asynchronous with half of the larval population (EM50 ) emerging within the first 25 days of a 64-day emergence season, which matches a typical 'summer species' emergence pattern. Sex ratio at emergence was not significantly different from unity. Body size of exuviae did not show a significant pattern across the season. Exuviae males and females did not differ in their vertical stratification. Height of exuviae fixation during mergence was not random, but was rather positively correlated with support height where the relationship was logarithmic. Apparent lifespan of adults was not significantly different between sexes with a mean of 4.6 ± 2.9 days (± SD). Males and females reached their sexual maturity after two days of emergence. The information provided in this study has not been reported before and thus will be helpful in future conservation efforts.