Herein I respond to a critique of my paper on wing positions in Zygoptera. The author of that critique suggested that most of the hypotheses presented in that paper were flawed and questioned some of the facts brought to bear on them. In addition, he presented his own ideas in support of hypotheses I had…
In a recent paper D.R. Paulson (2004; IJO 7: 505-515) presented five hypotheses concerning the way wings are held in the Zygoptera during perching. A critical examination suggests that most of them have substantial flaws that prevent their testing. Based on Bechly’s phylogeny (1998;
In the damselfly Calopteryx maculata, territorial males court potential mates and guard ovipositing females near the surface of the water. We conducted a survey and an experiment to determine whether there was a relationship between territoriality (site fidelity and agonistic behavior) and perch height.
Many insects including odonates thermoregulate using a combination of behavioral and physiological mechanisms. At high ambient temperature (Ta), these mechanisms include decreased heat production and increased heat loss. Heat production can be reduced by decreasing activity. Heat loss can be enhanced by perching in a shaded microhabitat where temperature is cooler than in the surrounding environment.
The behavior of Mesamphiagrion laterale (Selys, 1876) is described based upon 2430 hours of observation. A total of 2820 individuals were observed for 270 days from 2014 to 2015 using mark-recapture. Probabilities of resight, highest reproductive activity, time-perch and time of perch-temperature were statistically analyzed. Mesamphiagrion laterale is not a territorial species, the individuals perch…
In the temperate zone, male perch height of co-occurring dragonfly species (Odonata: Libellulidae) often correlates with species body size. I tested for this relationship in a guild of tropical dragonflies at a wetland at La Selva Biological Station, Heredia, Costa Rica. Males of 12 species were observed perching in January–February 2016. Mean male perch height…
Polythorid damselflies are Neotropical stream dwellers, whose behavior has rarely been recorded. Here we describe the territorial and courtship behavior of Chalcopteryx scintillans McLachlan, an Amazonian damselfly with shiny copper-colored hind wings. Territorial behavior consists of aerial contests, when males engage in threat displays and mutual pursuits in ascending and rocking flights. During courtship, males…
Behaviour of dragonflies was observed during the partial solar eclipse in Saitama, Japan, on 22 July 2009. The solar eclipse started at 09:54 h, reached its maximum magnitude of 74.9% at 11:12 h, and ended at 12:29 h. Light intensity at the peak of the eclipse was 1005 lx, a reduction by 28.2% of that…
Monitoring methods always recommend gathering data during the maximal activity of adults. Hence monitoring the threatened Lestes macrostigma requires knowledge of its activity pattern. Dragonfly “activity” is ambiguous and its intensity can be assessed in different ways, including by the threshold of response to a predator stimulus, i.e. “awareness”. We studied the daily pattern of…
Published records of Mesopodagrion are reviewed and the distributions of M. tibetanum and M. yachowensis are given. Sinocnemis henanese is considered a junior synonym of S. yangbingi. Based on morphological and behavioural characters Sinocnemis is removed from Platycnemididae and placed in Megapodagrionidae. Species of Sinocnemis show a general resemblance to species of Mesopodagrion but it…