Effect of diet and density on larval immune response and larval and adult host-preference in Spodoptera littoralis

Polyphagy presents difficulties to an insect, especially in terms of host choice. The adult insect must choose from a large number of possible host plant species, something which is considered to require extensive neural capacity to process. In order to decrease the amount of information to process, it has been suggested that polyphagous insects could rely on previous larval experience to make a choice. In the polyphagous noctuid moth Spodoptera littoralis it has frequently been found that female oviposition choice is driven by ‘larval memory’, indicating that the adult chooses to oviposit upon the same host upon which it fed as a larva. However, is there a larval density effect on how the host plant is perceived, and does this effect adult behaviour? In this study the insects were reared in three different treatments: low-density (optimal), highdensity and starvation (both assumed suboptimal), on three different diets (cotton, cabbage, and maize). A development study was carried out whereby it was indeed found that lowdensity was optimal, in terms of fitness (pupal weight) and fecundity (egg load). High-density larvae were found have a higher investment in immune response, which coupled with the reduction in pupal weight and egg load, indicates that high larval density may cause a reallocation of energy and a negative effect on fitness and fecundity. Starvation was highly detrimental, having a high development time and death rate. It was found that larval density did not have an effect on larval host choice, however, it was clear that the larvae were making an experience-based choice, irrespective of density. Adult oviposition choice, however, displayed a switch from choice in adults deriving from lowdensity treatments to the supposedly random laying seen in the adults originating from the high-density treatment. Furthermore, first choice in oviposition host showed a switch between low- and high-density reared insects, with high-density adults laying eggs on a nonexperienced plant first

Data set for diet specific differential gene expression analysis in three Spodoptera moths

Examination of closely related species pairs is suggested for evolutionary comparisons of different degrees of polyphagy, which we did here with three taxa of lepidopteran herbivores,Spodopteraspp (S. littoralis,S. frugiperdamaize (C) and rice (R) strains) for a RNAseq analysis of the midguts from the 3rd instar insect larvae for differential metabolic responses after feeding on pinto bean based artificial diet vs maize leaves. Paired-end (2×100bp) Illumina HiSeq2500 sequencing resulted in a total of 24, 23, 24, and 21 million reads for the SF-C-Maize, SF-C-Pinto, SF-R-Maize, SF-R Pinto, and a total of 35 and 36 million reads for the SL-Maize and SL-Pinto samples, respectively. After quality control measures, a total of 62.2 million reads from SL and 71.7 million reads from SF were used for transcriptome assembly (TA). The resulting finalde novoreference TA (backbone) for the SF taxa contained 37,985 contigs with a N50 contig size of 1030bp and a maximum contig length of 17,093bp, while for SL, 28,329 contigs were generated with a N50 contig size of 1980bp and a maximum contig length of 18,267bp. The data presented herein contains supporting information related to our research article Roy et al. (2016) http://dx.doi.org/10.1016/j.ibmb.2016.02.00

Effective applications of genome projects: a tale of three biocontrol species

This is a presentation given the the 5th International Entomophagous Insect Conference in Kyoto, Japan, on October 18th, 2017. <div><br></div><div>Abstract:</div><div><br></div><div><p>Innovations within the realm of genetic sequencing have led to increased accessibility for biologists, both in terms of costs as well as the educational resources available, regardless of background. Our project is a prime example, comprising three different biocontrol species (parasitoid wasp <i>Trichogramma brassicae</i>, mirid bug <i>Nesidiocoris tenuis</i>, and predatory mite <i>Amblyseius swirskii</i>). The goal is to sequence, assemble, and annotate a whole genome for each species to better inform ongoing projects. With <i>T. brassicae</i>, strain-specific molecular markers would help determine if there are intraguild effects of mass releases. In the case of both <i>A. swirskii</i> and <i>N. tenuis</i>, the genome will aid trait identification for selective breeding as well as assist in phylogenetic studies by identifying molecular markers. </p><div><br></div> The applications of this project extend beyond biocontrol, and additional questions can be addressed. Did commercialization lead to genetic drift or laboratory adaptation of commercial populations? Is there an indication of less genetic variation in commercial populations compared to their native or wild counterparts? The best way to address these questions is via population genomics – comparison between populations on a genomic level. Here, we present the status of each genome and their applications, as well as the implications for future research.<br></div

Next Generation Biological Control: The Need for Integrating Genetics and Evolution

Biological control is widely successful for controlling pests, but effective biocontrol agents are now more difficult to obtain due to more restrictive international trade laws. Coupled with increasing demand, the efficacy of existing and new biocontrol agents needs to be improved with genetic and genomic approaches. Although they have been underutilised in the past, applying genetic and genomic techniques is becoming more feasible from both technological and economic perspectives. We review current methods and provide a framework for using them, incorporating evolutionary and ecological principles. First, it is necessary to identify which biocontrol trait to select and in what direction. Next, the genes or markers linked to these traits need be determined to better target their selection, followed by how to implement this information into a breeding program. Choosing a trait can be assisted by modelling to account for the proper agro-ecological context, and by knowing which traits have sufficiently high heritability values. We provide guidelines for designing genomic strategies in biocontrol programs, which depends on the organism, budget, and desired objective. Genomic approaches start with genome sequencing and assembly. We provide a guide for deciding the most successful sequencing strategy for biocontrol agents. Gene discovery involves quantitative trait loci (QTL) analyses, transcriptomic and proteomic studies, and gene editing. Improving biocontrol practices include marker-assisted selection, genomic selection and microbiome manipulation of biocontrol agents, and monitoring for genetic variation during rearing and post-release. We conclude by identifying the most promising applications of genetic and genomic methods to improve biological control efficacy

Next-generation biological control: the need for integrating genetics and genomics

Biological control is widely successful at controlling pests, but effective biocontrol agents are now more difficult to import from countries of origin due to more restrictive international trade laws (the Nagoya Protocol). Coupled with increasing demand, the efficacy of existing and new biocontrol agents needs to be improved with genetic and genomic approaches. Although they have been underutilised in the past, application of genetic and genomic techniques is becoming more feasible from both technological and economic perspectives. We review current methods and provide a framework for using them. First, it is necessary to identify which biocontrol trait to select and in what direction. Next, the genes or markers linked to these traits need be determined, including how to implement this information into a selective breeding program. Choosing a trait can be assisted by modelling to account for the proper agro‐ecological context, and by knowing which traits have sufficiently high heritability values. We provide guidelines for designing genomic strategies in biocontrol programs, which depend on the organism, budget, and desired objective. Genomic approaches start with genome sequencing and assembly. We provide a guide for deciding the most successful sequencing strategy for biocontrol agents. Gene discovery involves quantitative trait loci analyses, transcriptomic and proteomic studies, and gene editing. Improving biocontrol practices includes marker‐assisted selection, genomic selection and microbiome manipulation of biocontrol agents, and monitoring for genetic variation during rearing and post‐release. We conclude by identifying the most promising applications of genetic and genomic methods to improve biological control efficacy