Contents - Faperta

Transgenic Resistance to Insects: Interactions with Nontarget Organisms 347
No. of Spiders/plant
1.60
1.40
1.20
1.00
0.80
0.60
0.40
0.20
0.00
Bt NBt Bt NBt Bt NBt Bt NBt Bt NBt Bt NBt
UP CP UP CP UP CP
Mech 12 Mech 162 Mech 184
FIGURE 11.2 Abundance of predatory spiders and coccinellids on Bt transgenic and nontransgenic cottons
under protected and unprotected conditions in the fi eld. UP, unprotected and CP, completely protected.
(phorate and disulfoton), and untreated control (Duan et al., 2004). However, weekly sprays
of permethrin signifi cantly reduced the trap capture of ground-dwelling spiders (Araneae),
while there were no signifi cant differences in the capture of spiders between Bt and
non-Bt potato fi elds treated with Bt sprays, systemic insecticides, and untreated control.
Signifi cantly more springtails were captured in potato fi elds treated with permethrin than
in any other treatment regime.
Influence of Transgenic Crops on Activity and Abundance of Pollinators
The occurrence of the transgene product in nectar and pollen, as well as the foraging
behavior on transgenic plants, should be considered while studying the effects of transgene
or its products under laboratory and fi eld conditions (Malone and Pham-Delègue,
2001). In addition, indirect effects related to secondary changes in plant signals should also
be examined, where the aim is to assess the risk of transgene dispersal in the environment
(Pierre and Pham-Delègue, 2000). There are no signifi cant effects of Bt-transgenic crops on the
honeybee, Apis mellifera L., and bumblebees, Bombus sp. (Malone and Pham-Delègue, 2001).
Activated Bt toxin mixed with water or honey did not show any adverse effects on larvae
and adults. Arpaia (1996) supplied CryIIIB toxin in supplemental syrup to A. mellifera colonies
at two concentrations (400 and 2000 times higher than the expected protein content in
pollen from Bt-transgenic plants), and did not observe any toxic effect on the larvae. There
was no effect on pupae, indicating that transgenic crops producing CryIIIB toxin poses no
risk to the pollinators.
However, a number of studies have revealed direct toxic effects of purifi ed serine-type
protease inhibitors (PIs) on adult honeybees when fed at high concentrations under laboratory
conditions. These PI’s include BBI (Bowman-Birk inhibitor) (Pham-Delègue et al.,
2000), BPTI (basic pancreatic inhibitor) (Malone et al., 1995), Pot-I and Pot-II (Malone et al.,
1998), and SBTI (soybean trypsin inhibitor) (Malone et al., 1995; Burgess, Malone, and
Christeller, 1996; Pham-Delègue et al., 2000). In contrast, ingestion of high doses of purifi ed
Cystatin or OC-I from rice, belonging to the cystein-type inhibitors, did not cause any
effect on bee survival (Girard et al., 1998). Trypsin inhibitor and WGA do not exhibit acute