• Korean journal of applied entomology
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• v.57 no.4
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• pp.329-337
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• 2018

To increase the mating rate of Bombus ignitus used as insect pollinator, we investigated the sexual maturity time of B. ignitus. In investigating ovary development such as the number of eggs per ovariole and spermatheca size, the time of sexual maturity of queen was 10 days after eclosion. In case of male, the number of sperm was 246 thousand at immediately after eclosion, and was highest as 480 thousand at 9 days, and tended to show a dramatic decline at 35 days (87 thousand). The more mating time, the less the number of sperm. In consideration of number of sperms, the time of sexual maturity of male was 3-15 days after eclosion. In the sexual maturity time of queen in mating, the queen was not mated at immediately after eclosion, and showed a decrease in 20 days. In terms of the rate of mating and oviposition, the favorable time for mating of queen was 9-20 days. On the other hand, the male showed 3.3% of mating at immediately after ecolosion, showed the highest of 43.3% at 6 days after eclosion, and tended to decrease in 25 days. The sexual maturity time for mating of male was 6-20 days. In summary, our results indicate that sexual maturity time of B. ignitus in reproductive organs and mating is most favorable in 9-12 days after eclosion for queen and 6-9 days for male.

• Korean journal of applied entomology
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• v.58 no.3
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• pp.219-224
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• 2019

The super mealworm, Zophobas morio, is mainly used as food for pets, fish, reptiles, amphibians, birds, and as snacks. An experiment was conducted to investigate the effects of temperature, supplementary feeding, and spawning interval on super mealworm rearing. To efficiently rear this species, the insects were bred at a temperature of $27^{\circ}C$ or higher and reached a weight of over 0.6 g at 80 days after hatching. Supplementary feed (with high protein content: 10% of soybean meal and 10% of fish meal) enabled larvae to reach a weight of over 0.7 g at 80 days after hatching. Mass rearing of super mealworm requires increase in egg production (i.e., high yield) and uniformity of larvae. Adults were transferred to spawning bases every 5, 10, or 15 days (three treatments), which resulted in a total of 7,256, 5,439, 2,060 hatched larvae, respectively. It is possible to obtain more than 7,000 larvae by transferring the egg-laying frame to the spawning base at intervals of 5 days and with nine spawning operations; this procedure generates larvae weighing over 0.68 g each.

• Korean journal of applied entomology
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• v.58 no.1
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• pp.69-76
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• 2019

This study was evaluated to increase the production efficiency of Gryllus bimaculatus De Geer, which are recently increasing attention as industrial insects in Korea. In this study, the hatching rate and larval period were investigated along with temperature and humidity, as well as the survival rate and ovipositional temperatures along with rearing density. The optimum relative humidity for hatching was highest at 90%, which shows the hatching rate of 90%. The highest hatching rate was 98.3% at $20^{\circ}C$. The hatching period was shortest at $35^{\circ}C$ incubation, which shows 7.1 days in average. The survival rate at 3,000-20,000 individuals in the breeding container was 34-18% after rearing for 35 days. In the effect test of feeding vegetables, the survival rate was 1.8 times and the biomass weight 2.5 times higher than that of normal individuals respectively. The number of laying eggs by temperature was highest at $25^{\circ}C$, which shows 1,710 eggs after reading for 30 days.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.99-103
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• 2021

This study was conducted to investigate the hatching rate of Pochazia shantungensis according to the treatment method of machine oil and the effect on apple quality by spawning. In the effect of machine oil treatment, when 20 times of the machine oil was spread by brush, the average hatching rate was 0.57%, and the sprayed branches showed an average hatching rate of 1%. When the machine oil agent was applied 50 times, the hatching rate was about 35% to spread by brush, whereas the spray treatment showed about 77%, so there were no difference from the non-treatment considering the deviation. There was no statistically significant difference in the quality of fruit even when apple fruits were fruited in the following year in the results of spawning and non-spawning of P. shantungensis in Hongro and Fuji varieties. In addition, there was no statistical significance in the difference between branch breakage and growth caused by spawning of P. shantungensis.

• Korean journal of applied entomology
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• v.12 no.1
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• pp.1-21
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• 1973

Some experiments were conducted to investigate the effects of the chemosterilant, hempa, on the biology of the rice weevil, Sitophilus oryzae L., and the transmission of the lethal factors in the progeny. One to three days old adult males were fed on the wheat grains treated with concentrations of 0.0625, 0.125, 0.25, and $0.5\%$ of hempa water solution. The effects of the treatment on the mortality, longevity, and the performance of oviposition were examined for the Pl generation, and the hatchability and mortality in the postembryonic development were also tested in the $F_1,\;F_2,\;BC_1,\;F_3,\;and\;BC_2$ generations to analyze the inheritance of the lethal factors. The results obtained were summarized as follows. (1) The average longevity of the treated males were ranged from 26.6 to 30.4 days, and indicated no statistical differences. (2) The mortality of the treated males were ranged between $3.3\%\;and\;13.3\%$ and showed no statistical significance. (3) The overall mean number of eggs laid by a female mated to a treated male with concentrations of 0.0625, 0.125, 0.26 and $0.5\%$ were 3.78, 4.05, 3.75 and 3.61 for the respective treatments, and they were not differ significantly from those of control which were 3.60 per female per 3 day period. The unmated female laid 1.91 in the same period, and significantly differ from those in other experimental groups. (4) The overall mean hatchability of the eggs laid by the females mated with males that had been treated with various concentrations of hempa were 86.82, 64.77, 53.47, 40.33 and $24.78\%$ for the respective concentrations of 0, 0.0625, 0.125, 0.25 and $0.5\%$. The hatchability decreased with the increasing concentrations. (5) The minimum hatchabilities were obtained from the eggs laid in the period of 10-12 days after treatment, then the hatchability increased showing some recovery. The recovery seemed to be very much delayed for the males which had been treated with the greater concentrations. Such a difference in hatchability might be related with the sensitivity of the developmental stages of the sperms, and broader spectrum in the stages and severer effects seemed to be associated with the increased concentrations. (6) The overall mean of larval mortality in the $F_l$ generation were 6.55, 17.89, 27.40, 35.42 and $52.17\%$ for the respective concentrations of 0,0.0625, 0.125,0.25 and $0.5\%$. And there was a tendency to increase in the mortality with the increase of concentrations. (7) The correlation coefficients between per cent sterile eggs and larval mortality for the experimental plots of 0.125, 0.25 and $0.5\%$ treatments showed r=+0.83 and +0.85, respectively, and it seemed to be close correlation between the lethal effects on the embryonic and post-embryonic developments. (8) Since the $SC_{50}$ of the sterile eggs was $0.133\%$ and $SC_{50}$ of the larval mortality was $0.565\%$, it was considered that tile lethal factors expressed more in the egg stages than the larval stages. (9) The ratio of female to male in the $F_l$ adults showed 100 : 125, 100 : 108 and 100 : 124 for the plots of 0.125, 0.25 and $0.5\%$ treatments, respectively. And it n·as considered that the sex ratio distortions might occur with the higher concentrations. (10) When the F, males originated 1.on the eggs had been laid by p, in the period of 16-18 days after treatment, were crossed to normal females $(BC_1)$ and made sib matings $(F_2)$, the per cent sterile eggs of the $BC_1$ generation were 13.88 and $33.04\%$ , and were 31.01 and $38.73\%$ for the $F_2$generation with the plots of 0.0625 and $0.125\%$ treatment, respectively. And these seemed to be a results of the $F_1$ individuals are carrying some chromosomal aberrations (11) The larval mortality was the highest in the $F_2$ plot and followed the female backcross plot, and the least in the male backcrosses. (12) The proportions of 1st and 2nd instar larvae among the larval development at tile 17th day after oviposition were 10.98, 27.26, 32.98 and $15.73\%$ in the normal female $\times$ normal male, $F_1$ female$\times$normal male, normal $female \;\times F_1$ male and $female \;\times F_1$ male plots, respectively. It was considered that the larval development might be delayed by the treatment in the 2nd generation. (13) Per cent larval mortality and sterile eggs were greater in the $F_2$ sib mating plots $(F_3)$ than both of $F_2$ backcrosses. Therefore, it seemed that some of the recessive lethal mutations might affect in the further generations. (14) The sterility, induced by the treatment of chemosterilant, hempa, was considered as the result of the dominant lethal mutations due to chromosomal aberrations such as translocation and/or deletion. The effects of these lethal factors seemed to be inherited tip to 3rd generation after treatment.

• Korean journal of applied entomology
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• v.15 no.3 s.28
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• pp.147-151
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• 1976

Laboratory experiments were conducted to evaluate the resistance of the new rice varieties Milyang $\#$21 and $\#$23 at the seedling stage to the brown planthopper(Nilaparvata lugens), small brown planthopper(Laodelphax striatellus), white-back planthopper(Sogatella furcifera), green rorice leafhopper(Nephotettix cincticeps) and zigzag-striped leafhopper (Recilia dorsalis) The varieties Yushin and T(N)-1 were used as susceptible check and the resistant check varieties were Mudgo to brown planthopper, ASD-7 :o small brown planthopper, Colombo to white-back planthopper, IR2061 (46763) to green rice leafhopper and Vellailanalgayan to zigzag-striped leafhopper. The varieties Milyang $\#$21 and $\#$23 were moderate in plant reaction only to the green rice leafhopper and $\#$23 was moderately resistant in plant rection only to the small brown planthopper. The nymphs of plant-and leaf-hoppers were more prefered Milyang $\#$21 and $\#$23 and susceptible check-varieties were more preferred for feeding than the resistant check-varieties. The green rice leafhopper and aigzag·striped leafhopper much more prefered Milyang $\#$21 and $\#$23 for oviposition, while brown planthopper and small brown planthopper more prefered the resistant cheeks than test varieties and susceptible checks. However, there was no any steady relationship in ovipositional preference between resistant and susceptible to the hoppers. Shorter nymphal-periods and higher rate of adult emergence were observed in the test varieties and the susceptible checks compared with the resistant checks. In conclusion, the varieties Milyang $\#$21 and $\#$23 seemed to be lack of true resistance to the plant-and leaf-hoppers from the viewpoints of antibiosis and feeding preference.

• Korean journal of applied entomology
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• v.42 no.3
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• pp.217-223
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• 2003

Effects of temperature on the development and reproduction of the Luciola lateralis were investigated at various temperatures. The development time of eggs, larvae, and pupae were shorter at higher temperatures than at lower ones. The insect did not develop at 10$^{\circ}C$ and 35$^{\circ}C$. The hatchability was 61.5% at 15$^{\circ}C$, 73.9% at 20$^{\circ}C$, 93.3% at 23$^{\circ}C$, 91.8% at 25$^{\circ}C$, 74.0% at 27$^{\circ}C$, and 46.0% at 30$^{\circ}C$, indicating the best hatchability rate at the temperature condition of 23 DC. Larval periods were 341.5:t 23.2 days at 15$^{\circ}C$, 265.5${\pm}$17.5 days at 20$^{\circ}C$, and 250.9${\pm}$11.7 days at 25$^{\circ}C$. Pupal periods were 94.7${\pm}$11.5 days at 15$^{\circ}C$, 41.7${\pm}$9.1 days at 20$^{\circ}C$, and 18.5${\pm}$7A days at 25$^{\circ}C$. Emergence rate was 23.3, 89.3 and 80.7%, respectively at the above temperatures. Adult longevity of female was 18.0 days at 15$^{\circ}C$, 2004 days at 20$^{\circ}C$, 10.7 days at 25$^{\circ}C$, and 5.8 days at 30$^{\circ}C$. Mean fecundity per female was higher at 20$^{\circ}C$ compared with at other temperatures. The developmental zero point temperatures (1) and the total effect temperatures (I<) of egg, larva, pupa, and complete development were 10.6, 14.0, and l3.1$^{\circ}C$ and 214.8, 1,564.8, and 229.2 degree-days, respectively. Mean generation time in days (T) was shorter at higher temperature. Net reproductive rate per generation (Ra) was the lowest at the highest temperature as well as at the lowest, and it was 177.19 which was the highest at 23$^{\circ}C$. The intrinsic rate of natural increase (r$\sub$m/) was highest at 27$^{\circ}C$ as 0.019. As a result, optimum range of temperature for L. lateralis growth was between 20-25$^{\circ}C$.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.157-170
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• 2002

This experiment was conducted to investigate the change of egg qualify by the height of thick albumen of egg, storage temperature and storage period. The albumen index and Haugh unit were measured and compared among five different storage periods(0, 2, 4, 6, and 10 days), four different storage temperatures($15^{\circ}C$ , $20^{\circ}C$ , $25^{\circ}C$ and $30^{\circ}C$ ), and five different Parts(0, 3, 6, 9, and 12 mm) aparted from egg yolk. The albumen index and Haugh unit were as follows: the albumen index of eggs was significantly(P<0.01) different by the storage temperature and by the measuring position of thick albumen of eggs. It means that the albumen index can be differed by the measuring position of thick albumen even if eggs have a same qualify. For measuring egg qualify in this country, it should be announced that which Parts in thick albumen of eggs are measured. The albumen index of fresh eggs was 0.16. However, the index when measured at 3 hour after oviposition was lower than 0.16. Therefore, it indicates that the criterion of 0.06 lower than 0.16 is required to set for considering practical point during the marketing periods of eggs. When the criterion of albumen index puts 0.06, it is as 100%. Therefore, eggs can be kept the same quality for 6, 4 and 2 days when eggs were stored at $15^{\circ}C$ , $20^{\circ}C$ and 25 ~$30^{\circ}C$ , respectively. When the criterion of Haugh unit score puts 79 as 100%, the eggs can be maintained the quality for 6, 4, and 2 days when eggs are stored at $15^{\circ}C$ , $20^{\circ}C$ and 25~$30^{\circ}C$ , respectively. When the criterion of Haugh unit 55 as 100%, the eggs can be maintained the same quality for 10, 8 and 2 days when eggs are stored at $15^{\circ}C$ , $20^{\circ}C$ and 25~$30^{\circ}C$ , respectively. From the experimental results, it can be considered that calculathing egg quality by the height of thick albumin of eggs which was measured at the attachment Parts of thick albumin layer and yolk of eggs was most reasonable and suitable when considering the marketing periods of eggs.

• Journal of Sericultural and Entomological Science
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• v.51 no.1
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• pp.1-8
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• 2013

This study was conducted for investigation of habitat and development of indoor-rearing conditions of peacock butterfly, Inachis io (Linnaeus). Three different region, Mt. Kwangduk-san, Mt. Hae-san and Mt. Taebaek-san in Kangwon-do, was selected for investigation of domestic distribution and ecological environment of peacock butterfly. In result, there are many butterflies in the only two region, Mt. Kwangduk-san and Mt. Hae-san. On 16th April, 4 overwintered butterflies were observed in Mt. Hae-san. At the end of June and early in July, 51 individual next generation's butterflies were observed in Mt. Kwangduk-san and Mt. Hae-san. For development of indoor-rearing conditions, collected each 15 male and female peacock butterflies was reared in a room condition. Female butterflies laid eggs in the egg cluster on the underside of host-plant's leaves, Urtica angustifolia Fisch., in the ovipositioning room. We took 11 egg cluster with average $404.6{\pm}23.6$ eggs. Hatchablity of eggs was 92.3%, and the eggs hatched within $5.1{\pm}0.9$ days from the day of oviposition under high temperature, long day condition($25^{\circ}C$, 14L:10D). The larval period was $18.3{\pm}1.0$ days under high temperature, long day condition($25^{\circ}C$, 14L:10D), showing 81.0% pupal ratio. The head width of each developmental larval stage were $0.37{\pm}0.01mm$(1st instar), $0.66{\pm}0.02mm$(2nd instar), $1.07{\pm}0.05mm$(3rd instar), $1.81{\pm}0.07$(4th instar), $2.76{\pm}0.08$(5th instar). The pupal period was $8.4{\pm}0.6$ days, and the emergence rate was 87.5%.

• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.73-82
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• 1989

The development of eggs and larvae, and minute scale-like tubercles on the skin surface of the larval Acanthorthodeus asmussi from Korea were observed in the laboratory. The egg was nearly ovoid-shaped. The number of egg averaged 195 per an oviposition. The morphological character of larval development was relatively similar to those of Acheilognathus tabira tabira, A. tabira subsp. (a), A. yamatsutae, A. moriokae, A. cyanostigma and A. rhombeus. The larvae of this species had many scale-like tubercles ellipsoided in a diagonal cross section on the skin surface of the body. And also this species moved like incessant wiggly movement pattern as that of fly maggot duing the larval development. As regards the tubercles and larval movement pattern, the larvae of A. asmussi shared similar characters with those of Acheilognathus rhombeus, A. longipinnis and Pseudoperilampus typos. Hence A. asmussi may be closely related to these species. The latter three species are autumn-spawning bitterlings and the larval development always retard in a certain stage, while A. asmussi is a spring-summer spawning species and the larval development never retards. Judging from these facts, it should be considered that there are close relations in evolutionary trend between the two spawning species.