Determination of suitable insect part for non‐lethal DNA sampling: case study of DNA quality and regeneration capability of dragonflies

Abstract

Abstract Genetics has been widely used in insect ecology and conservation. To minimise the effect of DNA sampling on organisms as much as possible, it would be ideal to use non‐invasive or non‐lethal DNA sources. Therefore, it is also very important to determine the responses of organisms to DNA sampling. In this study, the quality and quantity of genomic DNA samples from three types of insect tissues (exuvia, mid‐legs and wings) were evaluated. As model organisms, we used two dragonfly species of different sizes (Leucorrhinia dubia, Anax imperator). We also tested the regenerative ability of dragonfly larvae as a repair mechanism after mid‐leg cut‐off, with respect to factors such as size and quantity of diet. We found that DNA of sufficient quality for analyses was obtained from all tested tissues. Nonetheless, isolates from exuviae were conclusively less useful for sequencing than those from the mid‐legs and wings. The highest quantity of DNA was obtained from the mid‐legs. The survival of larvae is not affected by removing the legs, which can usually regenerate. All the tested tissues could be a source of adequate DNA; however, we concluded that primarily the legs should be used because they provided the best DNA samples in terms of quantity and quality of DNA. Furthermore, their exploitation would not affect individuals seriously if young larvae with sufficient time (at least 6 months) for regeneration are sampled. The exuviae should be used for absolutely non‐invasive studies involving endangered or protected species.