A chronicling of long-standing carbofuran use and its menace to wildlife in Kenya - Carbofuran and Wildlife Poisoning: Global Perspectives and Forensic Approaches - page 82

effects of pesticides has included two areas, namely honeybees/pollinators and dragonfl ies as indica-
tors of aquatic habitat quality. Wild insects other than bees (e.g., hawkmoths ( Macroglossum stel-
latarum )), are now increasingly recognised as valuable pollinators and there is a movement afoot
to maintain healthy populations of a variety of pollinator species in Kenya and elsewhere (Martins
and Johnson 2009). In addition, there is growing evidence of an overlap in wild pollinators between
crops and endangered wild fl ora. Therefore, the decimation/poisoning of pollinators visiting crops
has cascade effects on plants in wild areas through loss of the specialised pollinators (Martins 2008).
Insect exposure to pesticides is not solely confi ned to agricultural regions and practices in Kenya.
The author recently investigated the harmful effects of 'pesticide fi shing' on invertebrates in Lake
Victoria, focusing on Odonata, an order which includes dragonfl ies and is a very useful indicator
of water quality (Martins 2009). Pesticide fi shing is a practice whereby a pesticide is sprayed or
granules are sprinkled onto the surface of a body of water and the fi sh that fl oat to the surface are
collected either for personal consumption or sale in the markets. Indeed, we have seen pesticides
displayed for sale in shops that carry fi shing gear and tackle and have strong anecdotal/observational
evidence that Furadan has been used for this purpose (Martins 2009). As the world's second largest
freshwater lake, Lake Victoria provides important habitat for avian species and aquatic organisms.
During this study, the author noted evident differences in the number of dragonfl y species observed
in areas that were pesticide-fi shed and those not subjected to direct application of pesticides (i.e., 1
to 2 as opposed to > 20, respectively). The use of pesticides to capture fi sh for human consumption
appears to be an increasing trend in East Africa (Martins 2009).
Studies that establish the role of selected insects in pollination and natural defence and that iden-
tify species of special interest/signifi cance are needed to further our understanding of the situation,
both in Kenya and elsewhere. Work should also be undertaken to assess the repercussions of car-
bofuran and other compounds to pollinator and natural defence species and determine which of the
compounds presently in use are of particular concern. The results of these studies would also be
highly relevant to work being undertaken on threats to insectivorous birds and mammals. Residues
of a number of compounds have been detected in fi sh in Kenya (refer to Section 3.2. and see Table
3.6), and carbofuran levels, including metabolites, in fi sh intended for human consumption, both
pre- and post-capture, should be investigated.
3.7.2 Overview of insect diversity and abundance at a mammalian carcass:
the use of insects in upcoming forensic investigations in Kenya
Insects are everywhere, and they have been called 'the little things that run the world' (Wilson
1987). Insects can offer a signifi cant amount of information about carcasses, as evidenced by the
extensive use of forensic entomology in current general forensic practice (e.g., Fernández 2010).
Insects are often the fi rst of the scavengers and decomposers to arrive at a carcass. Proper observa-
tions of insects and their behaviour (particularly abnormal behaviour and mortality in and around a
carcass) and toxicological analysis of insects recovered from the carcass and immediate vicinity can
help identify or narrow the compound(s) used. The presence of various species can also be used to
estimate time since death.
As part of our efforts to increase the uniformity and robustness of fi eld sampling procedures fol-
lowing wildlife mortality in Kenya, the author recently developed a generalised timeline of insect
activity at a 'typical' mammal carcass (see Figure 3.18), assuming that cause of death is unrelated to
poisoning. Most of the insect diversity associated with carcasses in East Africa is poorly studied and
remains to be described. As far as we know, this timeline is the fi rst of its kind in Kenya, and as such
it is still a working outline, intended as a general guideline to be further refi ned.
Flies are among the fi rst insects to arrive at a carcass, especially Lucilia species. These species
land within a few minutes to a few hours after death. Many different kinds of fl ies will visit a carcass