• International Journal of Industrial Entomology and Biomaterials
• /
• v.39 no.2
• /
• pp.60-66
• /
• 2019

This study was carried out to investigate the development and oviposition characteristics of Protaetia brevitarsis fed mulberry fermented sawdust added with mulberry cake. The results of rearing of P. brevitarsis larvae on oak fermented sawdust and mulberry fermented sawdust added with different ratio of mulberry cake, the development periods of larvae feed sawdust with mulberry cake were about 41.6~48.5 days and shortened by 117 or more than that without treatment. The development periods were shorter as the ratio of mulberry cake added increased and there was no difference according to the kind of sawdust. But the weight of the larvae raised in mulberry fermented sawdust added with mulberry cake was heavier than that of the larvae raised in oak fermented sawdust added with mulberry cake. When mass rearing P. brevitarsis larvae in oak fermented sawdust, the addition of 5% mulberry cake was appropriate. Also, the average number of laying eggs of female who fed diet with mulberry cake was 12.3% higher than that of untreated.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.44 no.2
• /
• pp.44-54
• /
• 2022

The food source of white-spotted flower chafer, Protaetia brevitarsis is important to economical performance. The P. brevitarsis larva were feed by mulberry and oak fermented sawdust. The effect of additional additives, Korean black raspberry (called bokbunja) marc and blueberry marc to fermented sawdust feed on the development and oviposition characteristics were investigated. The development periods of P. brevitarsis was decreased from 165.7 d to 40.0 d (mulberry sawdust) and 169.3 d to 39.0 d (oak sawdust), but the survival rate of larva was not affected by the addition of Korean black raspberry marc to fermented sawdust. However, blueberry marc addition to the fermented sawdust did not significant effect on the development period and survival rate of P. brevitarsis. The percentage of larva weight over 2.5 g was tend to increase by addition of Korean black raspberry marc and/or blueberry marc. The number of oviposition was also tend to increase by adding additional feed to sawdust but there was no significant different.

• Korean journal of applied entomology
• /
• v.61 no.2
• /
• pp.377-385
• /
• 2022

Most pruning branches of mulberry, Korean raspberry (bokbunja), and blueberries are discarded without use. These discarded pruning branches were utilized as feed in the investigation of the development and oviposition characteristics of Protaetia brevitarsis with a focus on breeding possibilities. It was observed that the developmental period of P. brevitarsis larvae fed with berry fermented sawdust from mulberry, bokbunja, and blueberry was shortened to 157.3 130.3 days, and 140 days, respectively, compared to 169.3 days for those fed with oak fermented sawdust. The weight and survival rate of the larvae also increased. Under all three types of fermented sawdust feed, the percentage of larvae with weight ≧ 2.5 g during the group was over 60% between 6-8 weeks after hatching; however under oak fermented sawdust feed, it was within 10%, and the percentage only increased after 10 weeks. The average number of eggs laid per female was ≧ 80, with an average oviposition period of approximately 9 weeks; however, there was no significant difference owing to the large deviation per individual. Furthermore, mixed fermented sawdust from the three berries enhanced the growth rate of larvae, and there was no difference in the number of eggs laid compared to those fed with control oak fermented sawdust. Our study demonstrates berry fermentation sawdust is just as effective as oak fermentation sawdust in the breeding of P. brevitarsis.

• Korean journal of applied entomology
• /
• v.57 no.4
• /
• pp.373-379
• /
• 2018

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.

• Korean journal of applied entomology
• /
• v.61 no.4
• /
• pp.555-562
• /
• 2022

We raised the white-spotted flower chafer, Protaetia brevitarsis seulensis, from the larvae stage using a fermented mulberry sawdust-base diet at 25℃ and 16:8 h light:dark photoperiod. First, we determined the optimal density of the neonate larvae to be introduced into a rearing box (543 × 363 × 188 mm). The survival rates of the larvae were higher than 80% at 90 days after rearing at 100-175 larval densities but reduced by more than 10% at 200 larval density. The larval weights at 100 to 150 larval densities were similar; however, the weights at 175 and 200 larval densities were lower than those at 100 larval densities, indicating that the rate of weight gain increased under lower density. Based on these results, we inferred that 100-150 larvae was the optimal density. Second, we investigated the storage conditions of the last instar larvae under low temperatures. Four weight groups (1.8-2.0, 2.0-2.3, 2.3-2.5, and 2.5 g) of larvae were stored at 4, 8, and 10℃, respectively. All the larvae at 4℃ died 70 days after storage, whereas 80% of the larvae survived at 8℃ 70 days after storage, indicating that high larval weight was associated with high survival rates. The adults that emerged from larvae with more than 2.3 g and stored for up to 50 days at 4℃ laid few eggs. However, the adults that emerged from all larval weight groups stored for 70 days at 8℃ and 10℃ laid several eggs successfully. Based on these results, we inferred that the last instar larvae with more than 2.3 g could be stored for 30-50 days at 8℃.