Butterflies, Mosquitoes and Environmental ChallengesMay 31, 2013, 7:46 pm
By Dr. Rohan H. Wickramasinghe
My father started building the house in which we live in Colombo in 1957. For a decade or two after its completion, butterflies and moths were a constant presence in the garden. In the evening, they used to enter the living room and rest on the walls. They were of a variety of colours – some very beautiful. At a certain season of the year, long processions of large yellow butterflies used to fly in one direction down the road in front of the house. There are records that much larger processions of butterflies (taking over an hour to pass a given point) used to ‘migrate’ across Galle Face Green in even earlier times. Children were told that the butterflies were making their annual pilgrimage to ‘Samanala Kande’ (Sri Pada or Adam’s Peak).
We no longer see many butterflies and moths in and around our house and garden. Fragmentation of properties in the area with the loss of vegetation and vehicle exhaust emissions are partly to blame. A major factor is undoubtedly the use of various kinds of pesticides. These also decimate populations of honeybees and other pollinators, which are important for agriculture, home gardens etc.
In recent times, the agency assigned for the control of the mosquito-transmitted disease, dengue, has taken to the ‘fogging’ with pesticides of gardens and streets on receipt of residents’ arbitrary complaints of nuisance caused by mosquitoes. This is despite the fact that only a few species of mosquitoes are known to be vectors of dengue. (The ‘Report of the Inter-Agency Committee for the Control of Vector and Nuisance Mosquitos’ of January 1987 to the Central Environmental Authority of Sri Lanka noted that of the approximately 135 species described in Sri Lanka the large majority are probably not vectors of human disease.) Even more significant is the indubitable fact that ‘fogging’ does not appear to be very effective as a control measure for dengue-vector mosquitoes. One need only note that it appears to be necessary to ‘fog’ at frequent intervals in order to control mosquitoes. (The practice appears to be more effective in drastically reducing populations of butterflies, honey bees and other pollinators than of mosquitoes.)
Sri Lankans are quick to claim that they are sensitive to the wellbeing of animals. This is certainly so as regards their exemplary concern and activism in the matter of the wellbeing of stray dogs. Some may also point to the fact that we don’t buy raw meat on certain days specified by the State. On the other hand, however, others would dispute our kindliness towards animals and point, for instance, to the method of ‘hunting’ in rural and remote areas involving the procedure describe as ‘hakkapatas’. (Here an explosive contraption is mixed with food and left to blow off the jaws of any wild boar or elephant who attempts to chew on it. It is incorrect that only the ‘hunter’ is involved in this activity. His family, the trader who supplies the explosive and those who knowingly purchase the meat are also party to this.)
It is unfortunate that no serious protest has been launched to date by wildlife enthusiasts, agriculturalists etc in this country against the practice of ‘fogging’ against mosquitoes and to educate the general public about the associated adverse effects against populations of butterflies, pollinators etc. Such initiatives in educating the public are being taken in western countries. In the UK, for instance, there is an organization called ‘Butterfly Conservation’ with branches in various parts of the country. Among the activities of ‘Butterfly Conservation’ is ‘Save Our Butterflies Week’, which took place from the 18th to the 26th May 2013; happily coinciding with the season of Wesak. Details about the activities of the organization ‘Butterfly Conservation’ and ‘Save Our Butterflies Week’ may be obtained at www.butterfly-conservation.org and www.butterfly-conservation.org/SOBW. This may be helpful to any persons or groups wishing to engage in comparable activities in Sri Lanka.
A comparable non-profit organization based in the US is the Xerces Society for Invertebrate Conservation. The reach of this NGO is worldwide and it helps to protect wildlife through the conservation of invertebrates and their habitat. The Society’s website is www.xerces.org. In this, it is observed that the scope of this society’s activities includes bees, beetles, bugs, butterflies and moths, caddis flies, crustaceans, damselflies and dragonflies, flies, freshwater sponges, mayflies, molluscs, stoneflies and worms. The website also gives details of useful publications produced by it. One very recent publication is ‘Ecologically Sound Mosquito Management in Wetlands’ by C. Mazzacano and S.H.Black (2013). It can be downloaded free of charge and would make interesting reading for local government officials and university and secondary school students, in particular. The full report is 76 pages but a 4 page summary is provided. The text is divided into sections and those on ‘Impact of pesticides on non-target animals’ and ‘Integrated Pest Management Practices’ are especially interesting and valuable.
Another interesting activity which is due to be celebrated worldwide is ‘National Moth Week’ (see www.nationalmothweek.org) from the 20th to the 28th July 2013. A map is provided of locations where this will be observed around the world. Sri Lanka is already included among these locations but there is nothing to stop Sri Lankan students and wildlife enthusiasts from forming further groups to join in this international activity.
Exchange of information worldwide and collaboration between countries and groups on environmental issues are the only way out in the dire environmental straits we find ourselves in today. A spectrum of environmental concerns will be taken up at the World Environmental Education Congress 2013 (www.weec2013.org) which will be held in Marrakech, Morocco from the 9th to the 14th June 2013. This will be a major initiative with over 2800 participants from 105 countries. Being at loggerheads over unresolved environmental issues will not get anyone anywhere in the long run. It is the informed discussions which take place at initiatives such as this which offer a glimmer of hope for the future.
Last Updated Mar 27 2017 | 09:46 pm