First Record of Conotrachelus quadrilineatus Champion, 1904 (Coleoptera: Curculionidae: Molytinae) Damaging Beans in South America.

Common bean (Phaseolus vulgaris L.) is the most important legume used for direct human consumption in Latin America, with an increasing expansion of cultivated areas in recent years. Here, we report the first occurrence of Conotrachelus quadrilineatus Champion, 1904 (Coleoptera: Curculionidae: Molytinae) feeding on bean in South America.

Fall armyworm (Lepidoptera: Noctuidae): practical resistance of 2 Brazilian populations to Cry1A.105 + Cry2Ab and Cry1F Bt maize.

In the Americas, transgenic crops producing insecticidal proteins from Bacillus thuringiensis Berliner (Bt, Bacillales: Bacillaceae) have been used widely to manage fall armyworm (FAW, Spodoptera frugiperda [J.E. Smith]).

Bt-induced hormesis in Bt-resistant insects: Theoretical possibility or factual concern?

The biphasic dose-response of a stressor where low amounts of a toxicant may stimulate some biological processes is a recent focus of attention in insecticide ecotoxicology. Nonetheless, the importance and management consequences of this phenomenon of pesticide-induced hormesis remain largely unrecognized. Curiously, the potential induction of hormesis by insecticidal proteins such as Bacillus thuringiensis toxins (i.

Negative cross-resistance between structurally different Bacillus thuringiensis toxins may favor resistance management of soybean looper in transgenic Bt cultivars.

High adoption rates of single-gene Bacillus thuringiensis (Bt) Cry1Ac soybean impose selection pressure for resistance in the soybean looper, Chrysodeixis includens, a major defoliator in soybean and cotton crops. To anticipate and characterize resistance profiles that can evolve, soybean looper larvae collected from field crops in Brazil in 2013 were selected for resistance to Cry1Ac. Using two methods of selection viz.

Life-History Traits of Spodoptera frugiperda Populations Exposed to Low-Dose Bt Maize.

Exposure to Bacillus thuringiensis (Bt) toxins in low- and moderate-dose transgenic crops may induce sublethal effects and increase the rate of Bt resistance evolution, potentially compromising control efficacy against target pests. We tested this hypothesis using the fall armyworm Spodoptera frugiperda, a major polyphagous lepidopteran pest relatively tolerant to Bt notorious for evolving field-relevant resistance to single-gene Bt maize. Late-instar larvae were collected from Bt Cry1Ab and non-Bt maize fields in five locations in Brazil, and their offspring was compared for survival, development, and population growth in rearing environment without and with Cry1Ab throughout larval development.

Fitness costs and stability of Cry1Fa resistance in Brazilian populations of Spodoptera frugiperda.

Background: The presence of fitness costs of resistance to Bacillus thuringiensis (Bt) insecticidal proteins in insect populations may delay or even reverse the local selection of insect resistance to Bt transgenic crops, and deserves rigorous investigation. Here we assessed the fitness costs associated with Cry1Fa resistance in two strains of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), derived from field collections in different Brazilian regions and further selected in the laboratory for high levels of resistance to Cry1Fa using leaves of TC1507 corn.

Results: Fitness components were compared using paired resistant and susceptible strains with similar genetic backgrounds and F generations from reciprocal crosses, all of them reared on non-transgenic corn leaves.

Resistance to dual-gene Bt maize in Spodoptera frugiperda: selection, inheritance, and cross-resistance to other transgenic events.

Transgenic crop "pyramids" producing two or more Bacillus thuringiensis (Bt) toxins active against the same pest are used to delay evolution of resistance in insect pest populations. Laboratory and greenhouse experiments were performed with fall armyworm, Spodoptera frugiperda, to characterize resistance to Bt maize producing Cry1A.105 and Cry2Ab and test some assumptions of the "pyramid" resistance management strategy.