Protaetia brevitarsis seulensis (Kolbe) is widely used in Korea, as a protein-rich, alternate, functional food with pharmacological benefits. In addition to anti-oxidant properties, the larvae of P. b. seulensis also show positive effects against hepatic disorder and diabetes; therefore, P. b. seulensis larvae are being reared on a large scale in Korea. We evaluated reared larvae of P. b. seulensis from Gyeong-gi in Korea. Using 16SrRNA PCR, electro-microscopy, and bioassay techniques, we found that the larvae harbored Spo-1, a bacterium identified as the insect pathogen Serratia marcescens. Therefore, we highlight the use of this insect as an alternate food and the need for its sanitary rearing conditions, as contamination may affect public health.
IntroductionThe white-spotted flower chafer, Protaetia brevitarsis seulensis, is an insect that belongs to Coleoptera species (Coleoptera: Scarabaeidae). Its life cycle includes the embryo, larva, pupa, and imago stages, of which the larval stage is the longest, where the insect feeds and stores energy for the rest of its life cycle. In Asian countries, P. brevitarsis seulensis larvae are generally known to be pharmacologically effective and used as medicine (Suh et al., 2010). Several reports suggest that P. brevitarsis extract in Lewis' methanol has antioxidant (Suh et al., 2010), anti-hepatofibrosis, and anti-diabetic properties (Miyanoshita et al., 1996). In addition, scientific reports highlight that, based on the composition of P. brevitarsis seulensis larvae, they can be used as a functional health food. Thus, it is essential to verify that the rearing conditions for P. brevitarsis seulensis larvae are sanitary and safe for consumption as food. On the other hand, Serratia marcescens is a bacterial pathogen, found in soil (Grimont and Grimont, 2006), water (Ajithkumar, 2003;Grimont and Grimont, 2006), and plant material (Grimont and Grimont, 2006). It is also known by alternate names such as Bacillus sphingidis (White, G.F., 1923) and Bacillus asepticus (Burnside, 1928) when it does not show its characteristic red pigment but rather grows as white colonies. S. marcescens and Serratia sp. generally are known to be fatal pathogens of several insect species (Orthoptera, Coleoptera, Hymenoptera, Lepidoptera, and Diptera) once they enter the hemocoel (Tanada et al., 1993