The fall armyworm, Spodoptera frugiperda (J. E. Smith 1797) (Lepidoptera: Noctuidae), is the most important corn pest in South America. Larvae feed mostly on leaves, but also ears when population densities are high. This pest has been historically controlled with insecticide applications, but many cases of resistance have limited their efficacy. Transgenic corn varieties expressing Bacillus thuringiensis proteins (Bt corn) have been a widely adopted alternative to insecticides and, in the past 8 yr, have been the primary technology for fall armyworm control in Brazil. Because transgenic varieties require 10–15 yr to be developed and fall armyworm has quickly evolved resistance to most commercially released Bt corn hybrids, strategies for Bt trait durability are paramount. Most of the Bt corn hybrids lost their ability to control fall armyworm in just 3 yr after their release in Brazil. Here we summarize what is known about Bt resistance in fall armyworm in Brazil, a phenomenon perhaps never seen before in any part of the world. Furthermore, we suggest that the interactions between management practices adopted (or not adopted, e.g., refuge compliance) to delay the evolution of resistance and the ecological and evolutionary characteristics of fall armyworm are driving the rapid evolution of resistance to Bt corn in Brazil. As newer products emerge in the market, careful consideration will be needed to maximize trait durability.

While much recent research has expanded our understanding of the molecular interactions between aphids and their host plants, it is lacking for the soybean aphid, Aphis glycines. Since its North American invasion, A. glycines has become one of the most damaging insect pests on this important crop. Five soybean genes for host plant resistance to A. glycines have been identified, but populations of A. glycines have already adapted to overcome these resistance genes. Understanding the molecular interactions between resistant soybean and A. glycines can provide clues to its adaptation mechanisms. Here, we used RNA-Sequencing to compare and contrast A. glycines gene expression when fed resistant (Rag1) and susceptible soybean.

Quantitative real-time polymerase chain reaction (qRT-PCR) is a common and robust tool for accurate quantification of mRNA transcripts. To normalize results, a

Aphids are one of the most important insect taxa in terms of ecology, evolutionary biology, genetics and genomics, and interactions with endosymbionts. Additionally, many aphids are serious pest species of agricultural and horticultural plants. Recent genetic and genomic research has expanded molecular resources for many aphid species, including the whole genome sequencing of the pea aphid, Acrythosiphon pisum. However, the invasive soybean aphid, Aphis glycines, lacks in any significant molecular resources. Two next-generation sequencing technologies (Roche-454 and Illumina GA-II) were used in a combined approach to develop both transcriptomic and genomic resources, including expressed genes and molecular markers. Over 278 million bp were sequenced among the two methods, resulting in 19,293 transcripts and 56,688 genomic sequences. From this data set, 635 SNPs and 1,382 microsatellite markers were identified. For each sequencing method, different soybean aphid biotypes were used which revealed potential biotype specific markers. In addition, we uncovered 39,822 bp of sequence that were related to the obligatory endosymbiont, Buchnera aphidicola, as well as sequences that suggest the presence of Hamiltonella defensa, a facultative endosymbiont. Molecular resources for an invasive, non-model aphid species were generated. Additionally, the power of next-generation sequencing to uncover endosymbionts was demonstrated. The resources presented here will complement ongoing molecular studies within the Aphididae, including the pea aphid whole genome, lead to better understanding of aphid adaptation and evolution, and help provide novel targets for soybean aphid control.