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Never trust a cute fly...

Posted by Erica McAlister on Feb 3, 2012 10:20:05 AM

So I have been travelling a fair bit recently and the only way that I could fit in writing this blog is because I have been grounded due to a blizzard in Istanbul! However, this has afforded me two days to look through some of the material from the previous collecting trips, one of which was South Africa.


The South Africa trip was a consortium from the Natural History Museum consisting of 2 Bryozoan experts, 1 Coleopterist, 1 Protist specialist and me. Beth Okamura (Team leader), Mary Spencer-Jones (mostly spends her time in waders), Peter Hammond (retired and relaxed, samples with a pipe- very dapper), Dave Bass (strange views on bird taxonomy) and I, respectively. We were based at the University of Cape Town, which offers some of the best views that a University anywhere could, under the wing of Cecile Reed, who is one of the most helpful people you could imagine. Between her and her colleagues I was told of sites, they collected some mosquitoes for me and also donated for the NHM 2 mantophasmids!!! (a lot smaller than I was expecting) which increased the collections by 20%



Dave enjoying the experience of chest waders.....


So we left at the end of a cold miserable November in the UK and arrived in glorious sunshine. Dave and I were staying in the Western Cape for the whole of the trip whilst the others were off to seek bryozoans in pastures new (or rivers and dams new). Bryozoans are tiny colonial organisms and I had only ever seen them in marine environments before. I thought that my field work was frustrating at times but I take my hat off to them as they were searching for minute colonies which may only consist of a handful of individuals to start with….


We were lodged for the majority in a fine old house that offered many advantages, not at least a swimming pool, a Braar (South African Bar-b-que) (the former was very good at catching robberflies), a good wine fridge and a very friendly dog – all of which are good after a day in the field.


Our first day of sampling was at Rondervlei Nature Reserve, which was gorgeous. I had not registered how windy it could get though which was actually a blessing on days of very intense sunshine. Rondervlei was a wonderful wetland reserve sporting a large wildfowl community and a population of hippos although we did not see them that day. But more excitingly for me, my first fly was an acrocerid!! A humpbacked fly- they are some of my favourites as they are brightly coloured, look amazing and have a fascinating life history involving firing offspring into nests. Lots of very cool asilids everywhere too. But no mosquitoes..


…in fact I did not find any for ages….


We sampled at Betty’s Bay, Raapenberg Bird Sanctuary, Western Lakes, along ditches, amongst reeds and still I did not find any mosquitoes…


However, there were other things to keep me entertained!!



A magnificent Spoonbill



And these cheeky little things....



(A bit like me...)


The first week was a hectic week of predominantly trying to find good Bryozoan sites with little joy. They are the proverbial needle in a haystack!!! There were some small successes on their side and some on mine. I spend most of the time with my head in a net which does often cause comments from anyone passing by. Luckily for me though several passes by happened to be undertaken an ecological survey and so helpfully recommended more sites, including one of their own which had mosquitoes!! I was a very excited person.


In the meantime though I set up some malaise traps at Rondevlei after a very early start due to taking a boat trip out on the wetlands in the search of Hippos. They had been reintroduced onto the reserve in 2003 and apart from one running wild after being bullied by an older male, they have been getting along fine with everyone. This is most amazing for several reasons, firstly it abuts a large housing estate, and secondly, although this is one of the most important reserves for birds in South Africa, it is located next to Zeekoevlei, which is heavily polluted!


One of my favourite localities of the trip though was De Hoop Nature Reserve, a little piece of paradise consisting of open planes, wildfowl lakes and some of the largest Dunes I have ever seen of the purest white... there was some great collecting and I caught some flies that will definitely make peoples skin crawl…or should I more accurately say make their nose dissolve


Here we have a beautiful fly, front on it looks like an inquisitive little thing (as say little – this specimen is 2cm long…..)


Gedoelstia cristata front.jpg


But this is a bot fly from the family Oestridae. It is Gedoelstia cristata which is a fairly widespread and common botfly from the afrotropical region. And it is noisy I had two of them flying straight towards me and when I caught them in the net I was most impressed. I have to say I felt a tad peculiar as well knowing these creatures were flying around as well.


Here is an abstract from ‘Parasitic diseases of wild mammals’ by William Samuel and Margo Pybus:



Sounds lovely doesn’t it! It is made more unusual as most nasal botflies directly lay their eggs into the nasal cavity. So the first instar stage uses its large mouth hooks and spines on its back to pull itself along from the eye to drop down into the nasal cavity. I have just tried looking up images for this and even for me, have decided that may be too much…..


It is generally found in large ruminants such as deer but can be problematic in sheep. It has been found in man although these cases are exceptionally rare I hasten to add. There was a case were large numbers of first instar larvae were deposited in the ear!!


I didn’t get attacked though , well not by that…there was the experience of the Cape Cobra but maybe I should leave that to peoples imagination……


All in all a very good trip. I have a mass of flies to sort, some from traps, some from me sweeping. All I need know is another life time to get through everything! Any volunteers?

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