Environmental Engineering Reference
In-Depth Information
information that is available. A scarcity of publications regarding this topic does not mean that there
are low rates of mortality in birds poisoned by carbofuran in the agricultural fi elds of Latin America
.
Animals that die (or are dying) from an agrotoxin poison often become the quarry of carnivorous
mammals and birds of prey. Hence, whether through direct absorption, or secondary poisoning, the
effect of the agrotoxin in the agricultural landscape can spread throughout the surrounding natural
habitats. This effect is especially pronounced when populations are small and isolated (in forest
patches, for example). Latin America continues to witness increasing forest fragmentation and this
is the key driver behind the erosion of biological diversity within this part of the world (Harris 1984;
Harris and Silva-Lopes 1992; Hagan, Haegen and Mckinley 1996; Colli, Accacio, Antonini et al.
2005; Prugh, Hodges, Sinclair et al. 2008). Incidents of secondary carbofuran poisoning are well
documented in the United States and Canada, having caused substantial mortality in a diverse num-
ber of species (Eisler 1985; Mineau 1993; Mineau, Fletcher, Glaser et al. 1999, and see Chapter 8).
In Brazil, however, there is a real shortage of data concerning poisoning for the vast majority of our
fauna, regardless of the type of biocide used.
To conserve some of the natural pest control functions performed, farmers must fi nd low-impact/
sustainable methods of controlling pest biota. Otherwise, various trophic levels will suffer and this,
in turn, will threaten the survival, adaptation and reproduction of numerous species such as birds of
prey (e.g., Falconidae, Accipitridae, Strigidae, Tytonidae) and carnivorous mammals (e.g., Felidae,
Canidae, Mustelidae, Procyonidae) both of which act to control so-called 'pest species' such as
the eared-dove (
Zenaida auriculata
), the Picazuro pigeon (
Patagioenas picazuro
) and the Chopi-
blackbird (
Gnorimopsar chopi
). Usually, predatory species move along/within the agricultural
landscape matrix via the remaining uncultivated habitats. Such corridors provide a link between the
remaining (albeit impoverished) populations.
Long-term consumption of prey poisoned/contaminated with carbofuran can cause chronic poi-
soning, which can negatively affect life expectancy, growth, physiology, behaviour and reproduction
of a given species (Cox 1996). Short term, high level exposure to carbofuran will result in acute
poisoning, causing the inhibition of the enzyme acetylcholinesterase (AChE), which generally leads
to death through failure of the respiratory system (Baron 1991). The reader is referred to Chapter 2
for a detailed discussion of cholinesterase inhibition.
Carbamates tend to be extremely toxic and represent a group of insecticides commonly used in
Brazil. Compounds such as carbaryl (Sevin), aldicarb (Temik), carbofuran (Furadan) and carbo-
sulfan (Marshal) are widely used. Producers of grain such as wheat (
Triticum aestivum
), rice (
Oryza
sativa
) and corn (
Zea mays
), use systemic insecticides such as carbofuran to guarantee the integrity
of their harvests, since without pest control, their crops could be seriously compromised. The earliest
applications of carbofuran in Brazil occurred in the late 1970s (Novaretti, Lordello, Nelli et al. 1980,
Brancalion and Lordello 1981). Since the 1980s, carbofuran use has spread throughout Brazil and
Latin America and it is applied to various crops, including bananas, tomatoes, corn (maize), soya,
rice, wheat, sugarcane, cotton, peanuts, coffee and beans.
During seed treatment and post-planting treatment, liquid and granular formulations are used at
various application rates (depending on the crop/pest target). Wheat and rice are often treated with
carbofuran, carbosulfan and pyrethroids to tackle pests such as the lesser cornstalk borer (
Elasmopalpus
lignosellus
), fall armyworm (
Spodoptera frugiperda
), dark sword-grass (
Agrotis ipsilon
), spittlebugs
(
Deois fl avopicta
,
Deois incompleta
and
Zulia entreriana
), white rice tip (
Aphelenchoides besseyi
) and
various root-lesion nematodes of the genus
Pratylenchus
.
In accordance with a Brazilian Federal Decree (nº 4.074, January 2002), a systemic pesticide
should be added to a seed mix in combination with a visible dye to reduce the risk of human inges-
tion. Hence, the toxic dye Rhodamine B, which has a reddish-purple colour, has been used for
this purpose. Seeds then also become more apparent and attractive to granivorous wild birds such
as
Columbidae
and
Icterinae
. Seeds treated with carbofuran and Rhodamine B, which are not
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