Population genomics in insect conservation

In our mini-review we aim to summarize the approaches routinely used in butterfly population genomics and introduce potential ways to transfer scientific knowledge into conservation action. For example, genomics can reduce the number of individuals needed to study past and present demography, or increase the possibility of using old, degraded material to compare the trends in past and present populations. Genomics enables us to quantify fine barriers to gene flow across fragmented landscapes, or to discover cryptic lineages. Further, the detection of divergent populations and parts of genomes, i.e., potential adaptative markers, might be associated with ongoing environmental pressures. Altogether, genomics provides a novel toolkit to identify small, unique populations worth conservation attention, locate source populations for assisted colonisations and reintroductions, or help to guide habitat connectivity restoration.

Population genomics has so far played a minor role in the development of insect conservation actions. By our literature search and interviews with both butterfly geneticists and practical conservationists, we identified the limitations of successfully translating knowledge gained by basic research in genomics into effective insect conservation. For example, there is a shortage of standardised methodologies that can be used in management plans, such as diagnostic kits of genome-wide genetic diversity or the detection of adaptive alleles spreading across populations. Although insect conservation practice is habitat-oriented, population genomics can aid by guiding the management of flagship and umbrella species such as butterflies, which represent important indicators of habitat health and are charismatic enough to spark interest in habitat restoration. Last, we noticed that the results of conservation practices guided by genetic data are usually reported mainly as national technical reports, preventing the wider research and conservation community from utilising their results while planning conservation practices. Moreover, studies investigating the genetic landscape before, during, and after conservation actions guided by genetics or genomics research are not yet available.

We encourage conservationists and geneticists to establish a close cooperation already in the phase of project planning, while calling for a wider and meaningful recognition by academic institutions and funding agencies to researchers taking this path. This will enhance publications of the successes and failures of applied conservation genetics in the scientific literature, and support long-term projects re-evaluating the population genetic metrics after conservation actions have been taken. Based on these, methodologies for utilising genomics in practical insect conservation can be developed.

Sucháčková Bartoňová A., Linke D., Klečková I., de Gusmão Ribeiro P., Matos Maravi P. F. (2023) Incorporating genomics into insect conservation: Butterflies as a model group. Insect Conservation and Diversity Early View : DOI: 10.1111/icad.12643

Fig. 1. Euphydryas aurinia was captive-bread and reintroduced in northern United Kingdom, where, after nine years, the success of the project was confirmed in terms of population genetic diveristy measures comparable to those of natural populations (Davis et al., 2021, Journal of Insect Conservation 25: 875-886). This is a rare example of a study that evaluated butterfly genetic diversity after a conservation action. Using genomic data, future studies might take advantage of museum samples and identify landscape genetic patterns on a fine scale, including screening for a potential selection. Only after reporting the results of conservation genetics and genomics actions, will we be able to validate the expectations of conservation genomics applied to real-word actions.

Fig. 2. Habitat of Coenonympha oeddipus (marshland in Moosbrunn, Austria, photo Kristián Grell). The enhanced protection of this butterfly species, guided by the results of a genome-wide study (Després et al., 2019, Biological Journal of the Linnean Society 126: 95–113), led to restoration of the marshes around Grenoble, France. Thus, genomic studies of umbrella species might also aid in restoring and safeguarding the habitat and other species in the ecosystems.