Indoor Rearing Method of Diving Beetles: Cybister japonicus, Cybister tripunctatus orientalis, Cybister brevis

The aim of this study is to develop indoor-rearing methods of the diving beetles. In nature, both the adult diving beetle and its larvae are voracious aquatic predators. The larvae beetles hunt relatively bigger size of tadpoles and small fish for food source. However, due to difficulties of the food supplement for rearing diving beetles at indoor-condition further motivated us to develop new artificial food. Three separate experiments were performed. In the first experiment, adult beetles were provided with one of the several food choice treatments to self-compose their preferred foods that are affordable on the market at lower price. The second experiment was also to develop artificial diet that is possible for rearing larvae beetle under indoor condition. The larvae beetles were restricted to raw squid, artificial food source and mosquito larvae as a control at the first stadium and small fish and raw squid during second to third stadium duration. According to our result, adult beetles selected a food that made of boiled squid and dead small fish while, the young larvae consumed small fish, mosquito larvae and raw squid. Although, the larval food restriction on law squid caused noticeable decrease in survival, the result still supported the possible survival rate of keeping larvae at indoor condition. Moreover, pupation rate experiments, in which groups of larvae were placed at different mats, natural soil and fermented sawdust, showed that 80% of diving beetles pupated on the sawdust. This result indicates that female beetle preferentially selected to oviposit along soft and moist area.

물방개류 실내 사육법

점차 희소화되는 물방개류의 서식지내 복원 및 애완곤충 등 곤충산업 소재화를 목표로 실내 사육연구를 수행하였다. 물방개류는 자연상태에서 수초 줄기에 산란하는 습성을 지니고 있어 실내에서 안정적으로 대량생산을 하기 위해서는 인공산란매트 선발이 필요하며 인공산란매트는 사육상자 밑면에 깔아준 모래가 가장 좋은 것으로 나타났다. 또한 유충기(2 3령) 사육에 적합한 먹이원은 연중 안정공급시 가능한 먹이로서 날오징어를 선발하였다. 실내 사육시 개체간 공식행동이 강한 유충 사육을 위해 개체 집단사육시스템을 개발하였다. 또한 용화매트 선발 시험을 한 결과, 흙(자연매트)을 사용할 경우 표면이 쉽게 굳어 물방개유충이 파고들어가기 힘이 들어 용화율이 12~18% 저조하였고 또한 흙 관리 강도가 높았다. 그러나 발효톱밥을 용화매트로 사용할 경우 용화율 80%로 우수하여 물방개류의 용화매트로 가능함을 확인하였다.