Host-parasite interactions are an intriguing part of ecology, and understanding how hosts are able to withstand parasitic attacks, e.g. by allocating resources to immune defence, is important. Damselflies and dragonflies show a variety of parasitism patterns, but large-scale comparative immune defence studies are rare, and it is difficult to say what the interplay is between their immune defenc...

Viruses with circular ssDNA genomes that encode a replication initiator protein (Rep) are among the smallest viruses known to infect both eukaryotic and prokaryotic organisms. In the past few years an overwhelming diversity of novel circular Rep-encoding ssDNA (CRESS-DNA) viruses has been unearthed from various hosts and environmental sources. Since there is limited information regarding CRESS-...

The preceding paper of this series was pubhshed so long ago as 1907. Following Mr. E. B. WiUiamson's kind suggestion, I propose to attempt to carry on in this and in subsequent parts the faunistic survey commenced by himself. In the first place I must express my regret that he should be unable to complete the wori^ so admirably begun, and my appreciation of my own inadequacy to continue the ser...

1. Activity and microhabitat use are important factors determining species performance in habitats that differ in permanence and species composition of top predators. This study examined the relationship between the distribution across a gradient of habitat permanence and an associated transition in the composition of top predators and the behaviour of species of larval dragonflies. It also ass...

Some populations of the newt Taricha granulosa possess extremely highconcentrations of the neurotoxin tetrodotoxin (TTX). Tetrodotoxin is present in adult newts and their eggs, but has been assumed to be absent from the larval stage. We testedlarval and metamorphosed juveniles for the presence of TTX and evaluated thepalatability of these developmental stages to predatory dragonfly ...

The use of operative environmental temperature (Te) has been a major advance in the study of thermal ecology. I review the use of operative temperature in thermal biology with an emphasis on insects. Then I use data from dragonflies in Interior Alaska (Odonata: Anisoptera) to compare the efficacy of operative and ambient temperature when examining thermoregulating ability. I conclude that altho...

For dragonflies, the final exuviae are the most identifiable nymphal stage, can substitute for lethal processing of live animals, and definitively indicate life-cycle completion or reproductive success. However, dragonfly exuviae are difficult to find and identify relative to adults, and species richness in exuvial surveys is generally biased low. We tested readily acquired information in adult...

One hypothesis for the small size of insects relative to vertebrates, and the existence of giant fossil insects, is that atmospheric oxygen levels constrain insect body sizes because oxygen delivery is more challenging in larger insects. This study tested this hypothesis in dragonflies by measuring the oxygen sensitivity of flight metabolic rates and behavior during hovering for 11 species of d...