Microsatellite loci are standard genetic markers for population genetic analysis, whereas single nucleotide polymorphisms (SNPs) are more recent tools that require assessment of neutrality and appropriate use in population genetics. Twelve SNP markers were used to describe the genetic structure of Diabrotica virgifera virgifera (LeConte; Coleoptera: Chrysomelidae) in the United States of America and revealed a high mean observed heterozygosity (0.40 ± 0.059) and low global F_ST (0.029). Pairwise F_ST estimates ranged from 0.007 to 0.045, and all but 2 populations showed significant levels of genetic differentiation (P ≤ 0.008). Population parameters and conclusions based on SNP markers were analogous to that obtained by use of microsatellite markers from the identical population samples. SNP-based F_ST estimates were 3-fold higher than corresponding estimates from microsatellites, wherein lower microsatellite F_ST estimates likely resulted from an overestimate of migration rates between subpopulations due to convergence of allele size (homoplasy). No significant difference was observed in the proportion of SNP or microsatellite markers loci that were nonneutral within populations. SNP markers provided estimates of population genetic parameters consistent with those from microsatellite data, and their low back mutation rates may result in reduced propensity for error in estimation of population parameters.

Contiguous 14,535 and 14,536 nt near complete mitochondrial genome sequences respectively were obtained for Ostrinia nubilalis and Ostrinia furnicalis. Mitochondrial gene order was identical to that observed from Bombyx. Sequences comparatively showed 186 substitutions (1.3% sequence divergence), 170 CDS substitutions (131 at 3^rd codon positions), and an excess of transition mutation likely resulting by purifying selection (d_N/d_S = ω ≅ 0.15). Overall substitution rates were significantly higher at 4-fold (5.2%) compared to 2-fold degenerate codons (2.6%). These are the 3^rd and 4^th lepidopteran mitochondrial genome reference sequences in GenBank and useful for comparative mitochondrial studies.

The sweetpotato whitefly Bemisia tabaci is a highly destructive agricultural and ornamental crop pest. It damages host plants through both phloem feeding and vectoring plant pathogens. Introductions of B. tabaci are difficult to quarantine and eradicate because of its high reproductive rates, broad host plant range, and insecticide resistance. A total of 791 Gb of raw DNA sequence from whole genome shotgun sequencing, and 13 BAC pooling libraries were generated by Illumina sequencing using different combinations of mate-pair and pair-end libraries. Assembly gave a final genome with a scaffold N50 of 437 kb, and a total length of 658 Mb. Annotation of repetitive elements and coding regions resulted in 265.0 Mb TEs (40.3%) and 20 786 protein-coding genes with putative gene family expansions, respectively. Phylogenetic analysis based on orthologs across 14 arthropod taxa suggested that MED/Q is clustered into a hemipteran clade containing A. pisum and is a sister lineage to a clade containing both R. prolixus and N. lugens. Genome completeness, as estimated using the CEGMA and Benchmarking Universal Single-Copy Orthologs pipelines, reached 96% and 79%. These MED/Q genomic resources lay a foundation for future ‘pan-genomic’ comparisons of invasive vs. noninvasive, invasive vs. invasive, and native vs. exotic Bemisia, which, in return, will open up new avenues of investigation into whitefly biology, evolution, and management.

Terrestrial plants can harbor endophytic fungi that may induce changes in plant physiology that in turn affect interactions with herbivorous insects. We evaluated whether the application of entomopathogenic fungi Beauveria bassiana and Metarhizium brunneum to soybean seeds could become endophytic and affect interactions with soybean aphid (Aphis glycines Matsumura). It was found that A. glycines population sizes increased on plants with M. brunneum (strain F52) seed inoculum, but no significant effects were shown with analogous treatments with B. bassiana (strain GHA). Fungi recovered from soybean plant tissues indicate that endophytism was established, and that B. bassiana was more prevalent. Metarhizium brunneum was only recovered from stems, but B. bassiana was recovered from stems and leaves. This work confirms that some entomopathogenic fungi can be endophytic in soybean, however, some of these fungi may have a negative effect on the plants by increasing susceptibility of soybean to A. glycines. We also used DNA sequence data to identify species of Metarhizium obtained from agricultural fields in Iowa. Phylogenetic analyses, based on DNA sequence data, found that all isolates were Metarhizium robertsii, which is consistent with past studies indicating a cosmopolitan distribution and wide host range for this species. These results are important for understanding the dynamics of implementing environmentally sustainable measures for the control of pest insects.

The Asian corn borer (ACB), Ostrinia furnacalis (Guenée), is a destructive pest insect of cultivated corn crops, for which antennal-expressed receptors are important to detect olfactory cues for mate attraction and oviposition. Few olfactory related genes were reported in ACB, so we sequenced and characterized the transcriptome of male and female O. furnacalis antennae. Non-normalized male and female O. furnacalis antennal cDNA libraries were sequenced on the Illumina HiSeq 2000 and assembled into a reference transcriptome. Functional gene annotations identified putative olfactory-related genes; 56 odorant receptors (ORs), 23 odorant binding proteins (OBPs), and 10 CSPs. RNA-seq estimates of gene expression respectively showed up- and down-regulation of 79 and 30 genes in female compared to male antennae, which included up-regulation of 8 ORs and 1 PBP gene in male antennae as well as 3 ORs in female antennae. Quantitative real-time RT-PCR analyses validated strong male antennal-biased expression of OfurOR3, 4, 6, 7, 8, 11, 12, 13 and 14 transcripts, whereas OfurOR17 and 18 were specially expressed in female antennae. Sex-biases gene expression described here provides important insight in gene functionalization, and provides candidate genes putatively involved in environmental perception, host plant attraction, and mate recognition.