Development and Oviposition Characteristics of Protaetia brevitarsis (Coleoptera: Cetoniidae) Fed Fermented Mulberry Sawdust

뽕나무발효톱밥 급여에 따른 흰점박이꽃무지의 발육 및 산란 특성

Abstract

This study investigated the developmental and ovipositional characteristics of Protaetia brevitarsis individuals that were fed with fermented mulberry sawdust. The developmental periods of larvae were 164.0, 73.3, and 64.8 days at 25, 28, and $30^{\circ}C$, respectively. The maximum larval weight was 2.94 g at $25^{\circ}C$, and the weight of larvae decreased as temperature increased. The average weight of female adults were 0.94, 0.51, and 0.54 g at 25, 28, and $30^{\circ}C$, respectively. The weight of male adults was higher than that of females. The addition of 10% or 30% wheat bran to the fermented mulberry sawdust increased larval weight. It was possible to sell larvae from 75 days after mass rearing, when the cumulative rate of larvae that were heavier than 2.5 g was approximately 75%. The average number of eggs per female was 83.2 at $25^{\circ}C$, and this was the highest in the 5th week. Most of the eggs (73%) were oviposited between 3 and 8 weeks after adults emergence.

뽕나무발효톱밥을 이용한 흰점박이꽃무지의 사육 가능성을 검토하기 위하여 발육 및 산란 특성을 조사하였다. 흰점박이꽃무지 유충의 발육기간은 25, 28, $30^{\circ}C$에서 각각 164.0일, 73.3일, 64.8일로 온도가 높을수록 짧아졌다. 평균 유충 최고 무게는 $25^{\circ}C$에서 2.94 g으로 가장 높았으며 온도가 높아질수록 유충 무게는 감소하는 경향이었다. 우화한 암컷 성충의 평균 무게는 25, 28, $30^{\circ}C$에서 각각 0.94 g, 0.51 g, 0.54 g이었으며 수컷 성충 무게가 암컷보다 무거웠다. 뽕나무톱밥에 밀기울을 10% 또는 30% 첨가하여 발효시킨 것이 흰점박이꽃무지 유충 발육에 양호하였다. 유충 집단 사육시 2.5 g 이상인 유충의 누적비율이 75% 정도인 사육 후 75일부터 유충 판매가 가능하였다. 흰점박이꽃무지의 평균 산란수는 83.2개이었으며, 우화 후 3~8주 사이에 전체 산란수의 73%가 산란되었고, 5주째 산란수가 가장 많았다.

Fig. 1. Body weight changes of Protaetia brevitarsis larvae fed with food fermented at different mixing rates of mulberry sawdust and wheat bran.

Fig. 2. Cumulative ratio of Protaetia brevitarsis larvae over 2.5 g among the larvae fed with fermented mulberry sawdust at 25℃.

Fig. 3. Survival ratio of Protaetia brevitarsis larvae fed with fermented mulberry sawdust at 25℃.

Fig. 4. Ovipositional pattern of Protaetia brevitarsis adult female at 25℃.

Table 1. General components (%) of the fermented mulberry sawdust used in this study

Table 2. Heavy metal contents (mg/kg) of the fermented mulberry sawdust used in this study

Table 3. Developmental periods of Protaetia brevitarsis fed with fermented mulberry sawdust at three different temperatures

Table 4. Maximum weight of the 3rd instar Protaetia brevitarsis at different temperatures

Table 5. The average adult weight of Protaetia brevitarsis at different temperatures

Table 6. Number of eggs and oviposition periods of Protaetia brevitarsis at 25℃