Using distance sampling to quantify Odonata density in tropical rainforests

Quantitative data are essential for many aspects of ecological research. Several methods exist to quantify odonate abundance, but complications may arise when abundances in different habitats need to be compared. In this study, I explored a technique that can overcome the variable detectability of odonates in habitats with different visibility. Distance sampling is briefly introduced…

Habitat associations of an Odonata community in a lower montane rainforest in Papua New Guinea

I sampled odonates in pristine lower montane rainforest in Papua New Guinea over several months, recording habitat characteristics for all encounters with adult odonates. Using ordination techniques such as cluster analysis and canonical correspondence analysis I then classified the odonate fauna into assemblages correlated with environmental factors. Within the 2.5 km2 study area I found…

The larva of Mecistogaster linearis, with notes on its abundance in lowland rainforest of Costa Rica (Odonata: Pseudostigmatidae)

The larva of Mecistogaster linearis is described and illustrated from specimens collected within or near the Río Dantas Wildlife Refuge at the north-western border of the Barbilla National Park on the Costa Rican Caribbean slope. Characters of F-0 larvae permit easy separation from Megaloprepus caerulatus, a species coexisting with M. linearis. Diagnostic characters include overall…

Abundance and vertical distribution of a bromeliad-dwelling zygopteran larva, Mecistogaster modesta, in a Costa Rican rainforest (Odonata: Pseudostigmatidae)

We compared the larval abundance of Mecistogaster modesta between bromeliads at ground level and canopy level in a primary tropical wet forest. Zygopteran abundance correlated strongly with bromeliad diameter at both levels. Although the per-bromeliad zygopteran abundance did not differ between vertical levels, M. modesta showed a strong vertical distribution in abundance owing to the…

Landscape variation in the larval density of a bromeliad-dwelling zygopteran, Mecistogaster modesta (Odonata: Pseudostigmatidae)

In the premontane rain forests of northwest Costa Rica, patches of secondary forest can contain high densities of large Vriesea spp. bromeliads. Such patches contain an average of 6,470 ± 1,080 (s.e.) larvae ha-1 of the bromeliad-dwelling pseudostigmatid, Mecistogaster modesta, ca 3 6× higher than larval densities that we previously reported for adjacent primary forest.

Territorial behaviour associated with feeding in both sexes of the tropical zygopteran, Libellago hyalina (Odonata: Chlorocyphidae)

Territorial behaviour associated with adult odonate feeding in a Bornean rain forest under-storey is described and its underlying causes are analysed. Immature males and females of all ages of Libellago hyalina defended perches along a narrow trail in kerangas forest, concentrating especially around patches of sunlight. Throughout the day there was displacement of individuals as…

A new species of Ceylonosticta Fraser, 1931 (Odonata: Zygoptera: Platystictidae) from Sri Lanka

A new species of Ceylonosticta from the wet zone of Sri Lanka is described and illustrated, namely Ceylonosticta goodalei sp. nov. (Kuruwita-Erathana foot path, Seethagangula, Adam’s Peak, Samanala Nature Reserve, Ratnapura, 6.8196°N, 80.4615°E, 1109 m asl). The species is described from male specimens only and the genital ligula is described and illustrated. Females are as…