• International Journal of Industrial Entomology and Biomaterials
• /
• v.26 no.2
• /
• pp.124-130
• /
• 2013

Bumblebees are widely used to pollinate various greenhouse crops. Among the different bumblebee species, Bombus ignitus is indigenous to Korea, China, Japan and Russia. B. ignitus undergoes one generation per year, and artificial hibernation is essential for year-round rearing of the bumblebee. Keeping the queens under low-temperature conditions for several months is an effective method for terminating their diapause and promoting colony development. In the present study, we investigated how cold temperature affects the artificial hibernation of B. ignitus queens. Under chilling temperatures of $-2.5^{\circ}C$, $0^{\circ}C$, $2.5^{\circ}C$ and $5^{\circ}C$ with constant humidity >80%, the queens stored at $2.5^{\circ}C$ exhibited the highest survival rates, which were 74.0% at one month, 67.0% at two months, 60.0% at three months, 46.0% at 4 months, 33.0% at 5 months and 24.0% at 6 months. Lower survival rates were observed at $0^{\circ}C$, $5^{\circ}C$, $7.5^{\circ}C$ and $12.5^{\circ}C$. At $2.5^{\circ}C$ the colony developmental characteristics after diapause were 1.2- to 1.5-fold greater than those when queens were stored at $5^{\circ}C$. Thus, $2.5^{\circ}C$ and 70% R.H. were the most favorable chilling temperature and humidity conditions for terminating the diapause of B. ignitus queens.

• Korean journal of applied entomology
• /
• v.49 no.1
• /
• pp.17-22
• /
• 2010

Pachynematus itoi Okutani emerges three times a year, and overwinters as a pre-pupa in cocoon. First emergence of P. itoi was from 7th May to third June. Second and third emergence was from 20th June to 13th July and fourth to 25th August, respectively. Mean oviposited egg number was 59, and egg period was about 9 days. Hatching rate was >90%. Oviposited egg number was the highest in the first needle cluster of short shoot followed by second and third. P. itoi did not oviposit on single needle (long shoot) of Larix leptolepis (Sieb. et Zucc.). Larva had five instars, and larval period was about 20 days. Larva prefer needle cluster of short shoot to single needle of long shoot. Mature larva descended from host tree and pre-pupa in cocoon overwinter at topsoil.

• Journal of Sericultural and Entomological Science
• /
• v.50 no.2
• /
• pp.133-139
• /
• 2012

The Aims of this study are to investigate ecological environments and indoor-rearing conditions of Eurema hecabe for artificial rearing. Two different nesting site, a open area nearby small river(A area; Daejin-ri, Gonyang-myeon, Sachun-si, Gyoungsangnam-do) and a foot of a hill area(B area; Noryang-ri, Seolcheon-myeon, Namhae-gun, Kyoungsangnam-do), selected for investigation of ecological habitat environment, and investigated two times per month, during six month, from June to November in 2010. In result, the number of butterflies, Eurema hecabe, at the hill area(B area) was 6 times more than the open area(A area). We observed the number of eggs, larvae and puapae in the B area more times compared to those in the A area. In the B area, Lespedeza cuneata was higher preference than the other host plant, Lespedeza pilosa and Albizia julibrissin. For development of indoor-rearing conditions, common grass yellow butterfly, Eurema hecabe, was reared in a room condition. As a result of oviposition preference experiment, 100-mated-female laid significantly higher number of eggs $104.9{\pm}19.6$ on Lespedeza cuneata plant, whereas the number of eggs was $12.7{\pm}4.5$ on Cassia obtusifolia plant. Moreover, the eggs hatched within $5.1{\pm}0.9$ days from the day of oviposition and procent of egg hatchability was 53.7% on host plant. The headwidth of each developmental larval stage were $0.36{\pm}0.02$(1st), $0.61{\pm}0.02$(2nd), $0.93{\pm}0.05$(3rd), $1.46{\pm}0.08$(4th), $2.25{\pm}0.11$(5th). The larval period was $12.1{\pm}0.9$ days under high temperature, long day condition($25^{\circ}C$, 16L : 8D), showing 81.0% pupal ratio. The pupal period was $6.9{\pm}0.7$ days, and the emergence rate was 79.6%. Based on above experiment, artificial rearing system of common grass yellow butterfly, Eurema hecabe was completed in indoor condition.

• Korean journal of applied entomology
• /
• v.59 no.3
• /
• pp.243-250
• /
• 2020

Two meridic diets, N4 and N6, containing pinto bean, wheat germ, soybean, whole milk and sucrose as main nutrients were developed for rearing Spodoptera frugiperda (Noctuidae) larvae. Six larval instars were observed when neonate larvae were individually raised on these diets in small petri-dishes (ø 50 × 10 mm, 19.6 ㎤) at 25℃ and 15:9 h (light:dark) photoperiod. The average pupation rate of 97.8% on the N4 diet was significantly higher than the rate of 85.6% on N6 diet. The emergence rates were 92.0% on N4 diet and 93.5% on N6 diet, with a non-significant difference. The larval periods were 17.9 and 17.7 days for females, and 18.7 and 18.5 days for males, for N4 and N6 diets, respectively, with non-significant differences between diets and sexes. The pupal periods on both diets were identical (11.1 days for females and 12.8 days for males), despite differences between sexes. The pupal weights of both sexes on N4 diet were identical with a value of 257 mg, whereas those on N6 diet were 256 and 263 mg for females and males, respectively, with a non-significant difference. The longevity of female adults that emerged on N6 diet was 13.8 days and longer than 8.6 days on N4 diet. The pre-oviposition periods were 5.0 and 4.2 days on the N4 and N6 diets, respectively, with a non-significant difference, however, the oviposition period of 6.5 days on N6 diet was longer than the period of 3.9 days on N4 diet. The effective fecundity on N6 diet was 1,392 eggs (maximum 1,776) and was higher than that of 942 eggs (maximum 1,694) on N4 diet, with a non-significant difference. The egg hatching rates on N4 and N6 diets were 79.2 and 79.8%, and egg periods were 3.0 and 2.9 days, respectively, with non-significant differences.

• Korean journal of applied entomology
• /
• v.41 no.3
• /
• pp.211-216
• /
• 2002

The present study was aimed to examine the effect of different host plants on the biological property of cotton caterpillar, outbreak pest of cucurbit vegetables. The feeding and oviposition preferences toward cucumber and pumpkin were greater than those toward watermelon, oriental melon, and melon. The periods of egg and larva fed on oriental melon, melon, and pumpkin were longer than those on watermelon and cucumber. The longest pupal period was 10.5 days from cucumber. The hatching rate, pupation rate, emergence rate, and survival rate were observed from different host plants. The hatching rate was the highest on cucumber (87.2%) and the lowest on melon (72.8%). The pupation rate on watermelon and oriental melon (90.0% and 89.1%, respectively) was higher than that on cucumber (62.0%). The emergence rate on cucumber and pumpkin (93.5% and 92.0%, respectively) was higher than that on oriental melon (78.7%). The survival rate from hatching to emergence on watermelon (76.0%) was the highest, and the lowest on cucumber (50.0%). The adult period on melon (21.0 days) was the longest, and the shortest on cucumber (15.5 days) among 5 host plants. Average number of eggs per female on cucumber (281.8 eggs) was the highest, and the least on oriental melon (96.6 eggs). The survivorship on cucumber was the longest (30 days), and the shortest on pumpkin (17 days). The preoviposition period on oriental melon and melon (3.4 days) was longer than that on watermelon (2.1 days) and mean generation time in day (T) on melon was the longest (47.2 days) though they were not significant. The net reproductive rate per generation (R$_{o}$) on cucumber, 191.3, was the highest and the highest intrinsic rate of natural increase (r$_{m}$) was observed from cucumber as 0.127. All these results suggest that the growth ana reproduction of cotton caterpillar varies depending upon the kind of host plants. The analysis of the life table revealed that cucumber and pumpkin were the favorable host plants of cotton caterpillar.

• Korean journal of applied entomology
• /
• v.57 no.4
• /
• pp.329-337
• /
• 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
• /
• v.58 no.4
• /
• pp.381-387
• /
• 2019

From 2017 to 2019, the ovipositional and the developmental characteristics of Gampsocleis ussuriensis Adelung in the Buan area of Jeonbuk Province were examined. G. ussuriensis were mostly found in the weeded areas around the reservoir, where the adults first appeared in mid-July, showed up where by the early September, and overwintered in eggs. Nymphs appeared in early April to mid-July the next year. The nymphs hatched from early April and adults appeared after molting five times. The ovipositional period of G. ussuriensis was approximately 58 days. The total number of eggs per female was 124. The mean longevity of adults was 95.6 days for females and 84.8 days for males. Ovipositional mats were best with mixed Masato and Coco-Pitt at a ratio of 7:3. Developmental period of G. ussuriensis nymphs was 64.1 days at 24℃ and was longer than at different temperatures. The higher the temperature, the shorter the developmental period. The survival rate of nymphs was the best at 32℃ in 77.8%. The higher the density while rearing, the lower the survival rate, and the faster the development and molting velocity.

• Korean journal of applied entomology
• /
• v.49 no.4
• /
• pp.401-407
• /
• 2010

Daily predation of female/male O. sauteri during nymphal development were 4.2/3.9, 11.4/9.5, 14.3/10.8, and 14.7/12.5 at 17,22,27, and $32^{\circ}C$, respectively, and consumed 14.3/10.8 thrips, 7.5/7.2 aphids, 45.9/38.8 mites at $27^{\circ}C$, respectively. Adult females ate 42.8 thrips daily during preoviposition period and 63.2 thrips during oviposition period at $27^{\circ}C$. Predation by O. sauteri on F. occidentalis increased as the density of F. occidentalis increased. However, the rate of increase gradually lessened, resembling a Holling's type II functional response. The attack rate of adult female is higher than that of the 5th nymph. Adult female and 5th nymph of O. sauteri appeared to prefer 2nd larva of F. occidentalis.

• Korean journal of applied entomology
• /
• v.47 no.3
• /
• pp.217-226
• /
• 2008

Development of T. urticae was studied on the leaves of eggplant grown in hydroponics with potash contents of 0 mM, 2 mM, 6 mM, and 12 mM. As the levels of potash increased, that of nitrogen decreased and that of P, K, Mg increased in the plant. While contents of crude protein and fiber decreased, those of ash and sugar increased. Carbohydrate content was the highest at 2 mM. Water contents increased as those of potash increased with the exception at 0 mM. Biomass was the heaviest as 552.7 g at 6 mM and the lightest at 0 mM. Leaf thickness and the content of chlorophyll increased as the content of potash increased. Laboratory leaf disc tests provided with various potash levels revealed that feeding and oviposition preferences of T. urticae were high at 6 mM and 12 mM, respectively. Ratio of damaged leaf by naturally occurring T. urticae on eggplants of 99 days post-transplant in the greenhouse was the highest at 6 mM. Development of immature stages of T. urticae shortened as the levels of potash increased with a less tendancy in male than in female. No differences were detected in adult longevity and oviposition period but the number of eggs laid was the most as 84.7 at 6 mM and the least as 40.6 at 0 mM. There were no differences in the rate of egg hatch and the ratio of sex. $R_o,\;r_m,\;and\;{\lambda}$ were the highest at 6 mM and the lowest at 0 mM. T and Dt were the lowest at 6 mM and the highest at 0 mM. There was a descending trand of T. urticae developmet when levels of potash either gets high or low in the hydroponics.

• Korean journal of applied entomology
• /
• v.48 no.4
• /
• pp.541-546
• /
• 2009

The egg size and weight of the gray field slug, Deroceras reticulatum Muller, was $1.91{\times}2.19$ mm and 3.3 mg at $24^{\circ}C$, respectively. Its weight increased from newly laid eggs to adults for 17 weeks at four temperature regimes and was heaviest at $20^{\circ}C$, followed by 24, 16 and $28^{\circ}C$. Likewise, hatching rate of the egg batches was highest with 95% at $20^{\circ}C$, followed by 24, 16 and $28^{\circ}C$ with significant differences. The number of eggs in the batches was increased with 20 at $20^{\circ}C$ while it was only 10 at $28^{\circ}C$. The average accumulated egg-laying days was longest with 15 days at $20^{\circ}C$ while shortest with 9 days at $24^{\circ}C$. The range of egg-laying period was shortest with 84-134 days at $16^{\circ}C$ and longest at $20^{\circ}C$. Thus, the total number of eggs laid by adult D. reticulatum was highest with 217 at $20^{\circ}C$ and lowest with 105 at $16^{\circ}C$. The egg period was 12-19 days while the juvenile period and adult longevity were 51-68 days and 85-134 days, respectively. The life span of D. reticulatum from egg to adult was longest with 216 days at $20^{\circ}C$, followed by 193 days at $24^{\circ}C$, 170 days at $16^{\circ}C$ and 151 days at $28^{\circ}C$. Accordingly, the most favorable temperature for the oviposition, development and longevity of D. reticulatum is $20^{\circ}C$.