Spodoptera frugiperda (Smith) is a polyphagous insect of major economic impact in the Western hemisphere, and it has genetically differentiated into two strains (i.e., corn and rice) that are morphologically identical at the level of larvae and adult but differs in their wing shape and in their genetics. In 2008, corn and rice strains of this pest were identified from Tolima department in Colombia. This work continues the molecular identification of these two strains in three other regions of Colombia and three other crops (grass, sugarcane, and sweet sorghum). Our results showed that both strains are associated to the same hosts as reported in 2008. The corn strain was more abundant in corn, cotton, sorghum, sugarcane, and sweet sorghum, whereas the rice strain was more abundant in grass and rice. This host plant association reflects a population genetic differentiation in Colombia, with significant genetic differentiation between subpopulations (PhiPT) values for both markers—cytochrome oxidase I and FR (For Rice) fragment repeat—for all crops. The UPGMA (Unweighted Pair Group Method with Arithmetic Mean) dendrograms obtained with Nei genetic distances separated most of rice strain populations from the other crops, suggesting that it is genetically differentiated from the corn strain. Our results demonstrate the importance of differentiating these two strains in nature, as these two populations significantly differ in their tolerance to both insecticides and Bacillus thuringiensis endotoxins under laboratory conditions and thus transference of genes that confer resistance to any control is low.

Microbiota associated with insects play several important roles in their host, including protection against pathogens, provision of nutrition, and survival in hostile environments. The aim of this work was to identify the bacterial community found in avocado thrips from Northwestern Colombia (Antioquia department) in order to find isolates for potential biocontrol purposes. Culture-dependent methods based on 16S rRNA and gyrase B gene sequencing in 42 bacterial isolates allowed the identification of the genera Bacillus, Serratia, Moraxella, Pantoea, and Sphingomonas. Microbial diversity detected with the temperature gradient gel electrophoresis (TGGE) technique on three morphotypes of thrips, named brown (Scirtothrips hansoni), black (Frankliniella panamensis), and pale (Frankliniella sp.), showed a low bacterial community density (Shannon–Wiener index = 1480, p > 0.05) with significant differences among morphotypes (R = 0.7877, p = 0.0004). Results obtained with Illumina sequencing on the V1–V2 hypervariable region of the subunit 16S rRNA showed a predominant sequence in the brown morphotype (Scirtothrips hansoni) that belongs to the genus Wolbachia. The 16S amplicon analyses were extended to more samples and higher resolution using the V4–V5 hypervariable region. The results showed six additional bacteria phyla, confirming the previous observation for the dominant bacterial groups made in S. hansoni and the detection of the alternation of highly predominant genera among these thrips. Our results demonstrate that endosymbiont such as Wolbachia sp. are part of the microbiota of these pests, thereby indicating the possibility of employing this type of bacterium to improve the management of avocado thrips globally.

Thrips are small, cosmopolitan pests that attack a wide variety of crops, including avocado (Persea americana Mill.), where they feed on the fruit surface, hindering export quality. In Colombia, 7 thrips species have been identified in avocado where Frankliniella gardeniae (Fg) (Moulton, 1948), F. panamensis (Fp) (Hood, 1925), and Scirtothrips hansoni (Sh) (Mound and Hoddle, 2016) are the most abundant. Despite their economic importance, limited genomic and transcriptomic data are available for these pests. Here, we present the first draft genomes of these species and compare them to the reference genome of Frankliniella occidentalis. The mitochondrial genomes (mitogenomes) of the 3 species differ in size and gene order, with F. gardeniae exhibiting the largest mitochondria. Phylogenetic analysis clustered F. gardeniae and F. panamensis together and S. hansoni with S. dorsalis. Genome assembly revealed differences in genome sizes: 397 Mbp (Fp), 454 Mbp (Sh), and 601 Mbp (Fg), with F. gardeniae having the largest genome. Coverage was 118× for S. hansoni and 35× for the other 2 species. S. hansoni showed the highest sequence count and N50 values. BUSCO analysis estimated genome completeness between 96% and 97.95%. Annotated genes shared among these species included insecticide resistance and metabolism, particularly P450 and CYP family genes, as well as chemosensory genes (Ir). They are promising targets for RNA interference-based studies to enhance pest management strategies thus further studies are required in this issue.

Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) is an oligophagous pest in the Western Hemisphere and found on cultivated and wild Solanaceae species. In Colombia, the insect has diverged into four host races according to variation in female genitalia size, wing morphometrics, and haplotype. Adult insects were collected on Solanaceae species from Argentina, Brazil, Colombia, Ecuador, Honduras, and Venezuela. Sequencing of 586 bp of the mitochondrial gene Cytochrome Oxidase 1 (CO1) in 276 individuals produced 50 haplotypes. AMOVA confirmed population structuring (F_ST = 0.73, P < 0.0001). UPGMA dendrogram for F_ST paired distances indicated the Andes Mountains influenced the genetic differentiation of the pest as previously reported in Colombia. The pest might have passed through political and geographical borders by free commercialization of Solanaceae fruit from Ecuador (S. quitoense) and Honduras (S. melongena) because much genetic similarity was found between races from both countries. The Tajima test (D) indicated that populations of N. elegantalis from Brazil and Ecuador had expanded recently whereas populations from other countries were in equilibrium. Mismatch analysis showed populations of the pest expanded in Central and South America from 338,000 to 1.3 million years ago, suggesting haplotype race divergence occurred before domestication of Solanaceae plants in the Americas (10,000 years ago). The Mantel test was significant (r = 0.1943, p < 0.0001), suggesting isolation by distance, particularly in South America.