Aspects of life history of Platycnemis subdilatata (Zygoptera: Platycnemididae) in Northeast Algeria

The determination of seasonal regulation is important to understand how species have adapted to their local environmental conditions. In this study, we investigate the life history of a North African endemic damselfly, Platycnemis subdilatata, in a northeast Algerian population. We combined field and laboratory investigations to assess the embryonic development, larval growth, emergence pattern and…

Differential larval responses of two ecologically similar insects (Odonata) to temperature and resource variation

How species respond to shifting environmental conditions is a central question in ecology, especially because ecosystems are experiencing rapidly changing climatic conditions. However, predicting the responses of species interactions and community composition to changing conditions is often difficult. We examined the effects of rearing temperature and resource level on larval survival of two ecologically similar…

Behaviour and body size: plasticity and genotypic diversity in larval Ischnura elegans as a response to predators (Odonata: Coenagrionidae)

Phenotypic plasticity represents an adaptive tool in organisms including odonates to cope with heterogeneous environmental conditions. However, while some odonate species can occupy various changing habitats, other species are adapted to a narrow range of environmental conditions. Commonly, behavioural modifications are applied to avoid detection and encounters with predators. But reduced behavioural activity results in…

Morphological differences in the ovary of Libellulidae (Odonata)

All female Odonata have been assumed to produce oocytes continuously during their mature life span. However, a recent study of ovariole orientation and development led to the suggestion that Libellulidae are divided into two groups of species, one with continuous, the other with stepwise oocyte production. To find more evidence of this division, we compared…

The life history of a temperate zone dragonfly living at the edge of its range with comments on the colonization of high latitudes by Neotropical genera of Zygoptera (Odonata)

Of the many Zygopteran genera that occur in the Neotropics, only five (Hetaerina, Archilestes, Lestes, Argia, and Ischnura) are represented north of 40°N in North America, and only three of these (Hetaerina, Archilestes, and Argia) probably had a tropical origin. In the two genera of Lestidae (Archilestes and Lestes) the life history of temperate-zone populations…

Description of the larva of Somatochlora margarita (Odonata: Corduiiidae)

The larva of Somatochlora margarita is described from a specimen reared from the egg to the final stadium. The larva, previously unknown, is morphologically similar to the larvae of S. calverti, S. filosa, S. ozarkensis, and S. provocans. Combinations of diagnostic characters are given for distinguishing these species. Growth of this species is discussed with…

Voltinism of Odonata: a review

We classified 542 records of voltinism for 275 species and subspecies of Odonata according to three variables: geographical latitude, systematic position and habitat type. We sorted records according to voltinism—categories being three or more generations per year, two generations per year, one generation per year, one generation in two years and one generation in three…

Critical species of Odonata in southern Africa

Of the 160 species in South Africa, 29 are endemic. Threats to the local odonate fauna have increased in recent years due to the growth of agriculture and impact of invasive alien trees. Currently, 13 species are red-listed as threatened. Among the activities to ameliorate threats, is a massive programme, ‘Working for Water’, to remove…

Voltinism of Calopteryx haemorrhoidalis, (Vander Linden) in the Sierra Morena Mountains, Southern Spain (Zygoptera: Calopterygidae): A preliminary study

Small sweep-net samples of larvae of Calopteryx haemorrhoidalis, obtained during five consecutive years from a permanent stream in the Sierra Morena Mountains, southern Spain, were combined according to month to infer the voltinism during the study period. Detailed records of head width, wing-sheath length and metamorphosis status for individual larvae are consistent with the population…