Dragonflies have been around since prehistoric times and have evolved into the most agile of aerial hunters. They only grace the healthiest of gardens as both dragonflies and the smaller damselflies are susceptible to pesticides and water contaminants. It might, therefore, come as a surprise to know that your garden could be ideal for a dragonfly or two.
I have compiled a list of interesting facts as well as a guide to help you decide if this is an adventure you would like to embark upon.
Cape Town, as with several sites around the country, used to be home to historic floodplains of which parts (Blouvlei at Century City or Isoetes Vlei in Grassy Park) still are. If you find a seep or area of the garden rarely dries up, then you might have the makings of a dragonfly pond.
What if I am a gardener but know little about dragonflies and damselflies? You do not need to know a lot about them to create a sanctuary. This article will help you with your first steps.
How do I identify dragonflies/damselflies? There are several guide books and an online identification guide here.
How many stages are there in their life cycle? Four including, 1. egg 2. Larva/Nymph (underwater), 3. Moult and 4. Dragonfly/Damselfly.
What is the difference between a Dragonfly and a Damselfly? A damselfly will close its wings when at rest, whilst a dragonfly will keep them spread. A damselfly will also have a space between the eyes that is absent in dragonflies.
What do they eat? Nymphs eat other insect larvae and adults eat a range of insects. An adult can eat between 30-100 mosquitos per day.
How long do they live? Adults will live anywhere from a month to a year, whilst nymphs will live closer to two years.
Mating can last mere seconds or in some cases the pair may stay attached as the female lays the eggs.
Attracting dragonflies to your garden
Dragonflies are hunters that will feed on mosquito, gnats, flies or midges. The best way to attract them to a garden is to provide a nursery for the nymphs as well as an attractive food source.
Some ways in which to attract breeding pairs is to:
- Provide resting areas - Dragonflies are exothermic, meaning they get their heat from the environment. Lining a pond with different coloured rocks will help them with thermoregulation.
- Exclude predators - Fish or frogs will eat dragonfly nymphs.
- Include floating plants - Water lilies minimise water evaporation from ponds and provides resting places for adults.
- Include breeding sites: An adult will deposit eggs in mud, reeds, algae (along the edges) or on wooden stumps lining a pond.
- Attract food: Adult dragonflies will feast on insects attracted by flowering flora or mosquito.
Frogs and fish are not compatible with dragonflies as they feast on the nymphs.
Things to Avoid
We set out to do the best we can when designing a biodiverse garden, but mistakes can creep in when you least expect it. A good rule of thumb is to start with the best conditions. Some things to avoid:
- Low water quality - Dragonflies are sensitive to certain compounds (e.g. heavy metals and excessive nutrients) that can be present in tap water and groundwater. The best results will be obtained by making use of rainwater.
- Pest-prone plants - Dragonflies are sensitive to pesticides, but will require plants during several stages of its life cycle. It is best to use biocontrol measures or select less pest-prone plants to surround a pond.
- Filtration - A filter will remove the nymphs and algae that you want in the pond.
Selecting plants for a waterscape
In order to create the best waterscape, one needs to know which plants will be a better fit. Some plants may take longer to establish than others, therefore, it is best to read up on wetland species before buying them. Candide makes this step easy by providing a knowledge tab dedicated to wetland species. Simply follow the link below to scroll through and select your ideal combination.
Tip | Including reeds will give nymphs a perch on which to transform into its adult shape.
Tip | Moss species such as Funaria hygrometrica and Warnstorfia fluitans have demonstrated the ability to remove heavy metals.
Tip | Plants that filter water include soft rush (Juncus effusus), water lilies and iris.
Remember to give any new projects some time to settle into place. If you have had success in your garden then why not share it with us or leave a comment if you find the advice useful.
G.B.P. Davies (2008). Dragonflies and Damselflies of South Africa. Pensoft Publishers.
Ghori, Z., Iftikhar, H., Bhatti, M.F. Nasar-um-Minullah, Sharma, I., Kazi, A.G. & Ahmad, P. (2016). Phytoextraction: The Use of Plants to Remove Heavy Metals from Soil. In P. Ahmad (Ed.), Plant Metal Interaction (385-409) Elsevier.