# Comparison of the Life History and Morphological Differences in Eight Korean Tiger Beetles Reared in the Laboratory to Develop an Ex Situ Conservation Method for the Endangered Tiger Beetle

## TL;DR

This study explores how to conserve endangered Korean tiger beetles by rearing them in labs, finding that species-specific methods are crucial for success.

## Contribution

The study provides insights into species-specific rearing requirements and morphological identification traits for tiger beetle conservation.

## Key findings

- High mortality rates during pre-pupa to pupa stage suggest mass rearing is needed for population establishment.
- Reared-type adults were generally smaller than wild-type adults, indicating potential developmental differences.
- Species-specific adjustments in feeding and overwintering timing are necessary for effective ex situ conservation.

## Abstract

This study examined the ex situ conservation of eight Korean tiger beetle species through captive rearing. High mortality (37.5–80%) occurred during the transition from the pre-pupa to pupa stage, indicating that mass rearing is needed for effective population establishment. Reared-type adults were generally smaller than wild-type adults, and feeding habits, as well as the overwintering start point, varied by species. Overall, our results indicate that to develop a successful ex situ conservation method for endangered tiger beetles, it is crucial to adjust rearing methods to suit each species, rather than relying on general rearing methods. In addition, burrow entrance size was limited for species identification, while head and pronotum coloration were more useful.

Tiger beetles serve as bioindicators of ecosystem health but are under increasing threat from habitat loss and population decline. Ex situ conservation via captive breeding offers promise for species lacking viable wild populations. We evaluated laboratory rearing from egg to adult for eight Korean tiger beetle species to determine the developmental period per developmental stage, mortality rates, larval burrow entrance size, and head–pronotum morphological characteristics under controlled laboratory conditions. High mortality (37.5–80%) occurred during the transition from the pre-pupa to pupa stage, suggesting that mass larval production is needed to offset losses. Reared-type adults of most tiger beetle species tended to be smaller in body length than wild-type adults. Species-specific behaviors (e.g., feeding habits in Cephalota chiloleuca) and the overwintering times of spring–fall and summer species are different, indicating that uniform rearing protocols are suboptimal. Our findings suggest the importance of species-specific adjustment of rearing methods (feeding frequency, overwintering timing) to increase the success of ex situ conservation methods for tiger beetles. In addition, the larval burrow entrance size offered limited utility for species identification in mixed-species habitats, whereas the color of the head and pronotum was considered helpful in identifying some tiger beetle species.