The white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae), has been traditionally used in Korea as a medicine for preventing liver-related diseases and suppressing liver cancer. Therefore, this insect is economically important and is commercially reared and sold in Korea. Recently, P. brevitarsis was listed as a temporal food ingredient by the Korean Ministry of Food and Drug Safety. Given the increasing economic importance of this beetle, we have sought to improve rearing conditions for its commercial production. In this study, we compared the effects of two food supplements, clay and charcoal, on the growth of second instar larvae of P. brevitarsis. Clay and charcoal are generally known as good adsorbent for removal of contaminating substances in insect feed. We fed second instar P. brevitarsis larvae a commercial diet consisting of fermented sawdust with seven different combinations of clay and/or activated charcoal, and measured their effects on weight gain for approximately 17 wk until larvae pupated. We found that addition of clay at 2.5% w/w of the fermented sawdust diet had no negative effect on weight gain of second instar P. brevitarsis larvae and thus may improve the quality of P. brevitarsis as a commercial food.
IntroductionThe white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae), is distributed throughout Japan, Taiwan, Korea, China and parts of Europe (Cho, 1969). The adults are observed from late June through July in Korea (Kim et al., 2005;Zhang, 1984). These beetles are holometabolous and undergo three larval instars prior to pupation. Larvae overwinter as third instars in the soil and then pupate. In Korea, P. brevitarsis are raised commercially and used as a traditional medicine for the treatment of liver cancer (Park et al., 1994;Kang et al., 2001;Yoo et al., 2007). They were recently listed as a temporal food ingredient by Korean Ministry of Food and Drug Safety. Therefore, rearing of this beetle has gained increasing attention in Korea, and P. brevitarsis has been mass-reared for commercial purposes since the late 1990s. Thus, it is important to optimize rearing conditions for beetles to improve their commercial quality.Diet and growth conditions have been previously investigated (Kwon, 2009). In this study, we sought to characterize the effect (Table 1). These additives were suspended in an equal weight of tap water and then mixed with the basic feed as described in Table 1.