T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Damselfly (Red) Xanthocnemis zealandica

Kingdom: Animalia 
Phylum:Arthropoda 
Class:Insecta 
Order:Odonata 
Family Coenagrionidae
Scientific name: Xanthocnemis zealandica
Common name: Red Damselfly, Red Coat Damselfly

The red damselfly is the most common damselfly found in a New Zealand. It is a native found through out New Zealand. They are are expert hunters - adults take small insects on the wing and their nymphs are pretty impressive aquatic predators. 
You can tell a damselfly from a dragonfly thanks to the way they hold their wings - damselflies fold them up over their body when they land while dragonflies hold them open.

Male. 

Male

A female red damselfly (heterochrome coloured, there are two versions of their colouration) - 


Female


Female.


Female Xanthocnemis zealandica carring  water mites.  See text below photo.
 

Scientists Jose Andres and Adolfo Cordero of the Universidade de Vigo, Pontevedra, Spain, took a close look at parasitism in their research “Effect of Water Mites on the Damselfly, Ceriagrion tenellum,” published in a 2002 edition of Ecological Entomology.

They pointed out:

1. "Water mite parasitism is expected to have an important effect on damselfly survivorship and reproductive success, because mites drain considerable amounts of body fluids from their hosts," they wrote in their abstract. "This study tests the effect of water mite parasitism in a marked population of the damselfly Ceriagrion tenellum during 1995 (individuals marked as mature adults) and 1996 (individuals marked as tenerals)."

2. "Almost all teneral individuals were parasitized (98%) and mites were aggregated strongly on some individuals. Parasite load increased during the season."

3. "Parasites had no effect on the probability of recapture of hosts as mature adults. The average daily survival rate of lightly- and heavily-parasitized individuals, estimated with Jolly's stochastic method, did not differ significantly."

4. "In 1995 parasites had a significant effect on host mating success. The probability of mating was about 25% lower for heavily parasitized males than for lightly parasitized males. Lightly parasitized males also mated more times than heavily parasitized males, even if heavily parasitized males lived longer. In 1996, parasitism did not have an effect on male mating success. In both years mites had no effect on female lifetime mating success."

In conclusion, they found that "water mite parasitism does not reduce damselfly survivorship, but it could reduce male mating success in some circumstances. Further long-term studies are needed, especially in populations with a lower incidence of parasitism."