Biological control—the use of organisms (e.g., nematodes, arthropods, bacteria, fungi, viruses) for the suppression of insect pest species—is a well-established, ecologically sound and economically profitable tactic for crop protection. This approach has served as a sustainable solution for many insect pest problems for over a century in North America. However, all pest management tactics have associated risks. Specifically, the ecological non-target effects of biological control have been examined in numerous systems. In contrast, the need to understand the short- and long-term evolutionary consequences of human-mediated manipulation of biological control organisms for importation, augmentation and conservation biological control has only recently been acknowledged. Particularly, population genomics presents exceptional opportunities to study adaptive evolution and invasiveness of pests and biological control organisms. Population genomics also provides insights into (1) long-term biological consequences of releases, (2) the ecological success and sustainability of this pest management tactic and (3) non-target effects on native species, populations and ecosystems. Recent advances in genomic sequencing technology and model-based statistical methods to analyze population-scale genomic data provide a much needed impetus for biological control programs to benefit by incorporating a consideration of evolutionary consequences. Here, we review current technology and methods in population genomics and their applications to biological control and include basic guidelines for biological control researchers for implementing genomic technology and statistical modeling.

Finding optimal sample sizes is critical for the accurate estimation of genetic diversity of large invasive populations. Based on previous studies, we hypothesized that a minimal sample size of 3–8 individuals is sufficient to dissect the population architecture of the harlequin lady beetle, Harmonia axyridis, a biological control agent and an invasive alien species. Here, equipped with a type IIB endonuclease restriction site-associated (2b-RAD) DNA sequencing approach, we identified 13,766 and 13,929 single nucleotide polymorphisms (SNPs), respectively, among native and invasive H. axyridis populations. With this information we simulated populations using a randomly selected 3000 SNPs and a subset of individuals. From this simulation we finally determined that six individuals is the minimum sample size required for the accurate estimation of intra- and inter-population genetic diversity within and across H. axyridis populations. Our findings provide an empirical advantage for population genomic studies of H. axyridis in particular and suggest useful tactics for similar studies on multicellular organisms in general.

Repeatability is the cornerstone of science, and it is particularly important for systematic reviews. However, little is known on how researchers’ choice of database, and search platform influence the repeatability of systematic reviews. Here, we aim to unveil how the computer environment and the location where the search was initiated from influence hit results. We present a comparative analysis of time‐synchronized searches at different institutional locations in the world and evaluate the consistency of hits obtained within each of the search terms using different search platforms. We revealed a large variation among search platforms and showed that PubMed and Scopus returned consistent results to identical search strings from different locations. Google Scholar and Web of Science's Core Collection varied substantially both in the number of returned hits and in the list of individual articles depending on the search location and computing environment. Inconsistency in Web of Science results has most likely emerged from the different licensing packages at different institutions. To maintain scientific integrity and consistency, especially in systematic reviews, action is needed from both the scientific community and scientific search platforms to increase search consistency. Researchers are encouraged to report the search location and the databases used for systematic reviews, and database providers should make search algorithms transparent and revise access rules to titles behind paywalls. Additional options for increasing the repeatability and transparency of systematic reviews are storing both search metadata and hit results in open repositories and using Application Programming Interfaces (APIs) to retrieve standardized, machine‐readable search metadata.

During the past four decades, several species of aphidophagous Coccinellidae became established in North America, including Coccinella septempunctata, Harmonia axyridis, Hippodamia variegata, and Propylea quatuordecimpunctata. After their establishment, unknown circumstances favoured a rapid increase in population densities and distribution of H. axyridis and C. septempunctata at localities hundreds and thousands of kilometers from their release sites. Propylea quatuordecimpunctata and Hippodamia variegata have spread more slowly after becoming established in northeastern North America. Comparative studies based upon allozyme variation in these four introduced species and in six native North American species of ladybird beetles revealed no significant differences in genetic diversities. Genetic variation, assessed by allelic diversity and heterozygosity, was uncorrelated with the establishment and spread of these predatory species in North America. All ladybirds studied show a remarkable degree of dispersion with little detectable population subdivision.

Many generalist predators are abundant in transgenic crops but the uptake of Bt-endotoxins could affect their role in biological control. We tested the hypothesis that small, but detectable, quantities of Cry1Ab-Bt-endotoxin would flow along the corn–slug–carabid food chain but concentrations would be small and have no effect on carabid fecundity. In addition to controlled laboratory feeding trials, it was predicted that elevated concentrations of Bt-endotoxin would be found in field-collected gut-samples of Scarites subterraneus from transgenic corn due to predation on Bt-containing prey. Despite the uptake of Bt-endotoxins by the slug Deroceras laeve, the hypothesis that movement occurred throughout the corn–slug–carabid food chain was rejected. No Bt-endotoxins were found in laboratory or field-collected Scarites. This explained the insignificant differences in egg production between carabids exposed to Bt-containing versus non-Bt-containing prey. However, laboratory and field analyses with other predators are required to identify trophic linkages through which Bt-endotoxins flow.