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www.thevillagenews.co.za
24 February 2021
MY ENVIRONMENT
Midges and ‘muggies’ – pesky little bloodsuckers By Dr Anina Lee
I
have a confession. I call myself a conservationist but there is one animal I hate. I know that every living thing is part of nature's complex interconnectedness and the delicate balance of species, so I stop short of waging outright war on them. I'm talking about certain members of the midge family – the biting midges. Biting midges are the bane of my life in summer, especially at dusk. They are like stealth bombers – you never see them approach or feel them striking until it's too late. They can get access to your skin under your clothes and in places where you never thought to smear insect repellent. It's only a day later, when you suddenly have an unexplained itch, that you realise the full horror. You absentmindedly scratch the itch – and your fate is sealed. That itch will turn into a huge red mound (a 'welt' is too polite to describe it) that will itch uncontrollably
for the next week. No amount of juice from Bulbinella, Carpobrotus (sour fig) or Cotyledon ('plakkie') will stop the agony. Even commercial antihistamine cream gives scant relief. So you see why I'm not a fan. A wide range of small flies is included in the general names midges, gnats or 'muggies'. They are all members of the order Diptera to which all flies belong. The name means two-winged. Midges are not a well-defined group – there are at least 10 families of different midges. This means that their lifestyles and biology differ considerably. Fortunately for us (and other animals), not all of them bite. Some feed on nectar or decomposing plant material, and in some species the adults do not feed at all. It's the 'vampire' midges that feed on blood that are my problem. But I'll come back to them later. Like all flies, midges have four life stages: egg, larva, pupa and adult. The larvae of most midges (except gall midges) are aquatic. The eggs are laid in or near water, and the larvae are found in the water, in the mud at the bottom of rivers, lakes or ponds, or even in very damp places. The larvae feed on detritus, diatoms and other microscopic plants and animals. Their presence in a water body usually indicates a healthy environment.
In due course, the larvae pupate, and soon the adults emerge. They can appear in such numbers that the vast swarms can be picked up on radar. I experienced such a dense swarm of muggies a few years ago near the Klein River Estuary that was closed off from the sea that year – a perfect muggie breeding spot. I could hardly breathe or see, as muggies went in my eyes, up my nose and into my mouth. It was one occasion when a Covid mask would have been welcome. Although a nuisance, these muggies are harmless and a great source of food for many other animals like dragonflies, fish, birds and frogs. If conditions are right, muggies can breed up to four times a year, providing a constant food source for animals – and irritation to people. But let's go back to the biting midges. Like some mosquitoes, female biting midges require a meal of blood before they can lay their eggs. These little bloodsuckers have extremely sharp mouthparts that cut into your skin with a scissors-like action. In close-up, you can see the whole tiny head drilling up and down as it sinks its jaws deeper and deeper into your skin until it hits blood. Then it injects saliva that contains an anti-coagulant into the wound to stop your blood clotting in its tiny mouth. The little vampire then sucks up your blood, like a smoothie
New guide for sea-goers While there is nothing quite like the thrill of encountering a whale or a pod of dolphins at sea, many sea-goers are unaware that their attempts to get close to these mammals are probably not only illegal but also potentially damaging to the animals. Now a new booklet provides legal and ethical guidance for operators of recreational vessels to help them understand the rules and how best to
handle their vessels around whales, dolphins, sharks, seals and seabirds to be found in South African waters. The booklet also serves as a useful field guide offering illustrations and detailed descriptions of some of the animals one is most likely to encounter at sea and what their common behaviours are. It is the product of a sustainable
Female biting midges are little bloodsuckers that have extremely sharp mouthparts which they use to cut into your skin with a scissors-like action. PHOTO: New York Times through a straw. It’s the saliva it injects into you that causes the severe allergic reaction and the terrible itch. The problem with biting midges is that they can carry viruses that cause severe diseases in livestock. Indeed, they don't only bite people, but sheep, cattle, antelope and horses too. African horse sickness is a highly infectious and deadly disease caused by the African horse sickness virus, which is spread by midges. It commonly
the rules but also about behaviours that could be disruptive and even damaging to marine life.
marine tourism project recently conducted in the Plettenberg Bay area by the Nature’s Valley Trust in conjunction with Nelson Mandela University (NMU) and funded by the WWF Nedbank Green Trust.
Legally, recreational vessels may not intentionally approach a whale or dolphin within 300m. If the animals approach a vessel of their own accord, the boat operator should move away slowly at a ‘no-wake’ speed.
Dr Gwenith Penry, marine mammal scientist and research associate with the Institute for Coastal and Marine Research, said the intention was to inform sea-goers, not only about
The research team also found that the approach speed influenced how the animals reacted. If operators drove at speed towards the animals, they tended to take a long, deep
affects horses, mules, and donkeys. Dogs can also become infected by eating contaminated horsemeat. Bluetongue is another serious viral infection of domestic and wild animals first identified in sheep in South Africa. It, too, is spread by biting midges. Midges, muggies, gnats – call them what you like – but the blood-sucking variety can be an irritating nuisance to humans and a serious threat to other animals.
dive or change direction or the pod might split off into smaller groups. This is highly disruptive as the animals could be socialising or heading towards a feeding ground or nursing their young. The booklet also advises anyone who comes across an entangled animal to contact the local NSRI rather than try to free it themselves. To download the guide and more information: https://www.naturesvalleytrust.co.za/resources/ marine-tourism/
