Contents - Faperta

352 Biotechnological Approaches for Pest Management and Ecological Sustainability
pyrethroid lambda-cyhalothrin (Musser and Shelton, 2003). Control of O. nubilalis,
Spodoptera frugiperda ( J.E. Smith), and H. zea by Bt sweet corn and spinosad was better than
or equal to application of lambda-cyhalothrin.
Protease Inhibitors
Pentatomids are affected adversely when fed on proteinase inhibitor contaminated prey
(Ashouri et al., 1998; Walker et al., 1998). Prey reared on transgenic oilseed rape expressing
oryzacystatin (OC-1) inhibited ladybird, H. axyridis digestive enzymes in vitro, but had
no effect in vivo. Ladybird was able to upregulate digestive proteases in response to the
inhibitor and had no adverse effects on survival and development of the coccinellid when
fed on P. xylostella larvae, which had accumulated the transgene product in the larval tissues
at levels of up to 3 ng per gut (Ferry et al., 2003). The predatory stinkbug, Podisus
maculiventris Say may suffer some indirect adverse effects as a result of foraging on prey
in crops expressing either GNA or CpTI due to prey being of inferior quality rather than
to direct toxicity of the transgene products (Bell et al., 2003). A signifi cant reduction in
growth and female adult weight was observed when P. maculiventris was provided with
tomato moth, Lacanobia oleracea (L.) larvae injected with either GNA or CpTI at 10 mg day1 .
Weight reduction was 11.3% and 16.6% in GNA-fed and CpTI-fed P. maculiventris, respectively.
The males, however, were not signifi cantly affected. The female bugs that had not
been exposed to the transgene proteins as nymphs showed no reduction in fecundity
when provided with prey injected with either GNA or CpTI at the same dose. When provided
with prey that had been reared on transgenic plants expressing either GNA or
CpTI, no effects on the survival of nymphs were observed and only small, largely nonsignifi
cant, reductions in weights were recorded throughout pre-adult development. Male
nymphs fed on prey reared on diet with GNA prolonged the pre-adult development by
0.8 days. The next generation adults showed a signifi cant reduction in egg production
when fed on GNA-fed prey.
Lectins
Two-spotted ladybirds, Adalia bipunctata L., fed for 12 days on peach potato aphid,
M. persicae colonizing transgenic potatoes expressing GNA showed a decrease in fecundity,
egg viability, and longevity (Birch et al., 1999). However, subsequent studies by Down
et al. (2000) showed that the observed effects were prey-quality mediated rather than the
direct effects of GNA. Adverse effects on ladybird reproduction caused by eating peachpotato
aphids from transgenic potatoes were reversed after switching the ladybirds to pea
aphids from nontransgenic bean plants. GNA showed high levels of toxicity to grubs of
C. septempunctata (Dhillon et al., 2008).
Interaction of Transgenic Crops with Parasitoids
The effects of transgenic crops on the parasitoids vary across crops and the cropping systems.
Some of the variation may be due to differences in pest abundance between the
transgenic and the nontransgenic crops.