Encouraging dragonflies with freshwater ponds

Dragonflies are beautiful and live amazing lives but they are in trouble worldwide. 

ZEALANDIA has several species of dragonflies and damselflies and we are playing our part to encourage them. We are currently hosting Ruary MacKenzie-Dodds and Kari de Koenigswarter, UK dragonfly ambassadors, to survey the dragonfly populations found in the sanctuary, and educate those at ZEALANDIA about dragonflies and their freshwater habitat. Ruary and Kari will also be giving a public talk on Tuesday, 18 February.

Dragonflies can spend up to four years under water before emerging and turning into the phenomenal flyers we see hurtling around us on sunny summer days, so standing fresh water is vital for them. Every little pond helps balance the enormous loss of standing waters in New Zealand. Since the arrival of humans, only 10% of original wetland remains. 

As well as being ferocious predators of mosquitoes, dragonflies are sensitive indicators of freshwater health. Under water they have an extendable jaw exactly as replicated in the film Alien! And as adults they will fight to the death to defend their territory. They are a very ancient order of insects with fossils going back 325 million years, and NZ endemic Bush Giant dragonfly is 127 million years old, much older than dinosaurs or birds. 

Ruary and Kari helped us with a survey of species at ZEALANDIA. Two damselflies were recorded: the redcoat damselfly (Xanthocnemis zealandica) and the blue damselfly (Austrolestes colensonis). Three species of dragonflies were also recorded: the beautiful Bush Giant (Uropetala carovei), the Yellow-spotted dragonfly (Procordulia grayi) and the Ranger dragonfly (Procordulia smithii).

Other species that could be in ZEALANDIA but have not yet been seen include the Lancer dragonfly (Adversaeschna brevistyla) and the Sentry dragonfly (Hemicordulia australiae). Given the right habitat long term, Ruary says it would be nice to see a couple more: the Dusk Dragonfly (Antipodochlora braueri), the Red Percher (Diplacodes bipunctata) and the Baron Dragonfly (Aeshnidae : Hemianax).

New Zealand has 14 species of dragonfly and damselfly, and if you can create a pond, you’ll be able to attract them.

Here’s what dragonflies like:

1. Plenty of sunshine on the pond
2. A pond with a shallow bit at one end, if possible
3. A water depth of a metre is plenty
4. Rainwater or stream water is best
5. Some shelter from the prevailing winds

Plants are very important, as dragonflies use them to lay eggs in, and emerge on. 

Here are the recommended types of plants:

1. Tall-stemmed plants, like rushes such as Kuawa (Schoenoplectus tabernaemontani), Oioi/jointed wire rush (Apodasmia similis), Raupo/Bull Rush (Typha orientalis), or sedges such as Isolepis prolifer and Purei (Carex secta), or small shrubs such as twigged tree daisy (Olearia virgata) and Salt marsh ribbonwood (Plagianthus divaricatus).
2. Floating plants like red pondweed (Potamogeton cheesemanii) and swamp buttercup (Ranunculus Macropus).
3. Oxygenating plants like water milfoils (Myriophyllum Triphyllum, M propinquum and M robustum) and the submerged Charophyte species (stonewort) of the genus Chara and Nitella 

Another way you can help is to share photographs of dragonflies on NZ’s i-Naturalist website. It can help with identification.

See also a brilliantly illustrated book Dragonflies and Damselflies of New Zealand by Milen Marinov and Mike Ashbee.

Photos:

Redcoat Damsefly – Photo by Ruary Mackensie Dodds

Blue Damselfly – Photo by Janice McKenna

Bush Giant – Photo by Ruary Mackensie Dodds

Yellow Spotted Dragonfly – Photo by Ruary Mackensie Dodds

Ranger Dragonfly – Photo by Ruary Mackensie Dodds