Storm-Induced Dispersal in the Damselfly Ischnura Verticalis (Say)

1962 ◽  
Vol 68 (1) ◽  
pp. 199 ◽  
Author(s):  
Rodger Mitchell
Keyword(s):  
Ischnura Verticalis

Relationships between gregarine infection in damselflies, wetland type, and landscape characteristics

2011 ◽  
Vol 143 (5) ◽  
pp. 460-469 ◽  
Author(s):  
Julia J. Mlynarek ◽  
Daniel G. Bert ◽  
G. Haydeé Peralta-Vázquez ◽  
Joanna A. James ◽  
Mark R. Forbes
Keyword(s):  
Forest Cover ◽  
Road Density ◽  
Natural Habitats ◽  
Artificial Wetlands ◽  
Wetland Type ◽  
Landscape Characteristics ◽  
Natural Wetlands ◽  
Ischnura Verticalis ◽  
Host Parasite ◽  
Wetland Cover

AbstractAlthough human-modified landscapes are characterized by the loss of natural habitats, new habitats also can be created and exploited by many species. The importance of landscape change to invertebrate associations (particularly host-parasite associations) is understudied. Our objective was to determine whether prevalence and intensity of gregarine parasitism in the damselfly Ischnura verticalis (Say) (Odonata: Coenagrionidae) differed between 17 artificial and 7 natural wetlands in landscapes that varied in amount of forest and wetland cover and road density determined at spatial extents of 500m and 1km from each wetland. Wetlands were located in and around Ottawa, Ontario, and Gatineau, Quebec, Canada. Wetland type did not account for significant variation in principal components based on forest and wetland cover and road density at either spatial extent. Gregarine prevalence was higher in damselflies collected from natural wetlands than in those collected from artificial wetlands and was positively associated with increasing forest cover. In contrast, gregarine intensity was inversely related to road density. Our results suggest that parasitism of damselflies by gregarines is associated with wetland type and landscape characteristics, although the mechanisms producing such relationships are unknown.

Rearing of the Damsel Fly, Ischnura Verticalis Say, in the Laboratory

1942 ◽  
Vol 35 (4) ◽  
pp. 387-388 ◽  
Author(s):  
Harvey L. Sweetman ◽  
Hamilton Laudani
Keyword(s):  
Ischnura Verticalis

Diet of nymphs affects normal wing development in Ischnura verticalis (Odonata: Coenagrionidae)

2004 ◽  
Vol 136 (5) ◽  
pp. 749-751
Author(s):  
Robert L. Baker ◽  
Brian Leung ◽  
Mark R. Forbes
Keyword(s):  
Experimental Designs ◽  
Natural Food ◽  
Wing Development ◽  
Live Prey ◽  
Laboratory Conditions ◽  
Ischnura Verticalis ◽  
Critical Times

Nymphs of many species of the order Odonata are easy to maintain in the laboratory, and there are hundreds of published studies dealing with behaviour, ecology, development, taxonomy, etc. that involve maintenance of nymphs under laboratory conditions. Most of these studies call for nymphs to be fed live prey, and in some cases it is possible to collect suitable prey from the field. However, in cases in which the experimental designs call for controlled diets, or in cases in which natural food is difficult to collect, as during winter months in temperate latitudes, it is common for researchers to feed nymphs with prey cultured in the laboratory. Researchers have used a variety of different prey but Daphnia sp. is one of the most popular. We have used Daphnia sp. cultures but have encountered difficulties in rearing sufficient numbers for use in experiments involving hundreds of nymphs; also, we have had the unfortunate experience of having our cultures collapse for unknown reasons at critical times of experiments.

Food Limitation of Larval Dragonflies: A Field Test of Spacing Behaviour

1986 ◽  
Vol 43 (9) ◽  
pp. 1720-1725 ◽  
Author(s):  
Robert L. Baker
Keyword(s):  
Population Density ◽  
Field Test ◽  
Food Limitation ◽  
Population Densities ◽  
Larval Population ◽  
Southern Ontario ◽  
Growth And Survival ◽  
Gut Fullness ◽  
Dependent Growth ◽  
Ischnura Verticalis

Density-dependent growth and survival of larval odonates may result from some larvae excluding others from profitable hunting sites. This hypothesis predicts that both degree and variation in food limitation should increase with population density; it also suggests that large larvae should show less food limitation than small larvae. I tested these predictions by analyzing food limitation, determined by mass of fecal pellets, and population density of larval Ischnura verticalis and Enallagma ebrium from a pond in southern Ontario. When data from all sampling days were combined, population densities of both species were negatively correlated with gut fullness but there was no correspondence between population density and gut fullness measured at different sites on any given day. Also, there was no correlation between population density and variation in food limitation and there was no evidence that small larvae suffered a greater degree of food limitation than larger larvae. A lack of discrete and persistent prey patches and/or low larval population densities may account for the lack of evidence that larvae are excluded from patches of prey.

Estimating food availability for larval dragonflies: a cautionary note

1986 ◽  
Vol 64 (4) ◽  
pp. 1036-1038 ◽  
Author(s):  
Robert L. Baker
Keyword(s):  
Daphnia Magna ◽  
Food Availability ◽  
Food Limitation ◽  
Food Type ◽  
Cautionary Note ◽  
Fecal Pellets ◽  
Ad Libitum ◽  
Ischnura Verticalis

Fecal pellets produced by larvae of Enallagma ebrium and Ischnura verticalis given ad libitum feedings of enchytraeid worms were heavier than pellets produced by larvae given ad libitum feedings of Daphnia magna. Dependence of pellet weight on food type has marked implications for indices of food limitation for larval dragonflies.

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