• Korean journal of applied entomology
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• v.9 no.2
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• pp.85-90
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• 1970

This study was conducted to find out the evidence of a sex attraction in the fall webworm moths, Hyphantria cunea D., in the fold conditions. The study dealt with the sex attraction between the sexes, selection of effective trap type, effect of moth age on the sex attractiveness, sex attractiveness after copulation, and the time of the sex attraction in the day, The trap was baited with a living moth in the cylindrical screened case 4cm. in long and 2.7cm in diameter. The traps were attached on the tree in a horizontal position at the height of about 3m. on the ground. A sex pheromone was evident in the female moth which attracted the male to the lure, and the modified sticky trap was most effective in this experiment. The trap consisted of a cylindrical powder milk can 11.5cm. in long and 10cm. in diameter with the entry hole 4.8cm, in diameter at both ends of the can, and the inside of can was lined with paper coated with acri-soil(sodium poliacrilate) to catch them. Males were mostly attracted to females during their first 2 days of life, and its attractiveness decreased with moth age, No males were attracted to females more than five days old, and no females lived for more than six days. After copulation, sexual attractiveness was decreased swiftly, Sexual attractiveness was found to be greatest between 4 and 6 A.M. Living females can be used as effective baits for luring the males to the fold trapt.

• Korean journal of applied entomology
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• v.18 no.1 s.38
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• pp.15-21
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• 1979

To determine the population regulation mechanism of the Green rice leafhopper (Nephotettix cincticeps Uhler), the responses of the population increase to initial densities and the effect of host conditions and temperatures during developmental period were investigated. In the out door experiment, the increasing ratio of population density of this pest was reduced as initial density increased and this density-dependent effect was differ in accordance with host condition. Host conditioning through feeding resulted in reduction in numbers of eggs produced and it seemed to be affected by some inhibiting materials secreted by the pest during feeding. though the direct effect of feeding can't be excluded. The population growth was related with population density and host stage. Thus in late planted units, the host stage was favourable to the growth of population at low initial insect density but unfavourable at relatively high initial insect density and in early planted units, vice versa. The temperature during developmental stages definitely affected the determination of sex ratio of adult population and reduced numbers of eggs produced. The most favourable temperature to the population increase was $290^{\circ}C$, and at high temperature, $33^{\circ}C$, severe reduction of fecundity was shown ana it seemed to be caused by the simple reduction in numbers of eggs produced.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.685-690
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• 2000

Caliroa carinata (Zombori) has heavily damaged the forests of Quercus mongolica in Sangju, Kyongbuk, Korea since 1996. However, information on the ecology and control of this pest was badly scarce. Thus we tried to study the ecology and chemical control of the sawfly through this study. Caliroa carinata is one generation per year. The adult sawflies emerged from June 8 to July 5 with peak at June 18. A female adult laid 11 eggs in rows on the backside of a leaf along the midribs and larger veins. Larvae have six instars, and the developmental period required to complete the larval stage was 19 days and 17 days at temperatures of $20^{\circ}C$ and $25^{\circ}C$, respectively. Each larval stage required 2-4 days to complete the development. The sawfly mostly preferred Quercus mongolica and Q. dentata, while avoiding Q. variabilis. Such insecticides as Tebufenozide, Flufenoxuron, Etofenprox, and Fenitrothion were sprayed on host plant leaves infected with test larvae in order to study the mortality. After 3 days of insecticide treatments, the mortalities were thoroughly examined. All insecticides showed higher than 95% of mortalities. Control values were also higher than 93%. The optimal season of insecticide application for pest control was estimated from late June to early July.

• Korean journal of applied entomology
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• v.33 no.2
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• pp.66-73
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• 1994

Adult emergence period, the calling behavior pattern and the mating ability of female depending on ages, 9day old male's response to sex pheromone released from each 1- to 5-day old female, and the structure and location of sex pheromone gland were obse~edin Ostrinia furnacalis. Adults usually emerged from 1 hour before to 1-2 hours after the beg~nning of scatophase under the 16L/8D photoperiod. And most active calling behavior was obserued for two hours from the 5th to 7th hours of scotophase among 2- and 3-day old females, and 3-day old male' response to 3-day old females was higher than to any other age of females during the 5th-8th hours of scotophase. Mating frequency was higher at the 4th-7th hours after the beginning of scotophase. Among 1. to Cday old females extruding sex pheromone gland, more than 65% of them successfully mated with 2- to 4-day old males. And, 2- or 3-day old females exhuding sex pheromone gland showed an abdiw. over 60%, to mate with each 1--5-day old males. Hypertrophied cell layers, presumed to be a sex pheromone gland of female adults, were located at two intersegmental membranes between the 8th & 9th, and the 9th & 10th abdominal segments.

• Korean journal of applied entomology
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• v.40 no.4
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• pp.297-300
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• 2001

Development and reproduction of the persimmon fruit moth, Stathmopoda masinissa, were investigated under different temperatures (15, 20, 25, and 3$0^{\circ}C$). It took 96.1 days to grow from egg to adult at 2$0^{\circ}C$, 43.2 days at $25^{\circ}C$, and 34.6 days at 3$0^{\circ}C$. At 15$^{\circ}C$, all tested individuals died before pupation. The developmental threshold temperatures for egg, larva, pupa, and adult were 12.2, 13.5, 13.8, and 13.4$^{\circ}C$, respectively. The total effective temperatures for egg, larva, pupa, and egg to adult were 74.0, 331.3, 160.5, and 569.9 degree days, respectively. The hatching, pupation, and emergence rates were highest at $25^{\circ}C$. The average life span of adult prior to laying eggs and the total life span of adult were 12.6 and 29.3 days at 2$0^{\circ}C$, 3.8 and 8.6 days at $25^{\circ}C$, and 2.5 and 7.0 days at 3$0^{\circ}C$, respectively. Mean generation time in days (T) was shorter at higher temperature. Net reproductive rate per generation (R$_{o}$) was lowest at 2$0^{\circ}C$. The intrinsic rate of natural increase (r$_{m}$) was highest at $25^{\circ}C$ as 0.066.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.437-442
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• 2015

This study, examined Chilocorus kuwanae for biological control of Saissetia coffeae. We measured basic developmental characteristics of C. kuwanae and its capability to prey on the second-instar larvae of S. coffeae by indoor breeding under the following conditions: $25^{\circ}C{\pm}2^{\circ}C$, humidity $70%{\pm}5%$, and day length 16L : 8D. The average daily consumption of the second-instar larvae of S. coffeae by C. kuwanae adults was approximately 77.5 larvae/day, which was significantly 2.8 and 2.9 times higher than consumption by Chrysoperla carnea and Cryptolaemus montrouzieri, respectively. During the nymphal period, C. kuwanae consumed a total of 659.0 second-instar larvae of S. coffeae. The interaction between C. kuwanae and the second-instar larvae of S. coffeae varied according to their densities, with the increase in C. kuwanae consumption rate noted to decelerate and gradually level off at the maximum, rsembling Holling's Type II functional response. Duration of egg to adult development varied from 21.1 days to nearly 27.9 days at temperatures of $25^{\circ}C{\pm}2^{\circ}C$. Hatchability, pupation rate, and adult emergence were greater than 72.3%, 77.8% and 83.3%, respectively.

• Korean journal of applied entomology
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• v.35 no.2
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• pp.164-172
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• 1996

The comparative toxicity of abamectin to the predatory mite, Amblyseius womersleyi Schicha and the spider mites, Tetranychus urticae Koch and T. kanzawai Kishida was evaluated by leaf disc method. Abamectin was much less toxic to A. womersleyi than to the spider mites. Although survival rate of adult females of A. womersleyi tended to decrease with increasing abamectin concentration, 8-78% of predators remained alive at concentrations of 0.38-6 ppm. Likewise, reproduction was significantly reduced with increasing abamectin concentration. Abamectin neither affect the hatch of A. womersleyi eggs nor the development of surviving immature predators. Survival of immature predators decreased with increasing abamectin concentration. However, 42-90% of immature predators reached adulthood at 0.38-3 ppm. Adult female predators survived on a diet of spider mites intoxicated with abamectin, although their fecundity and the sex-ratio of the progeny were significantly affected. Abamectin at selective sublethal concentrations (0.38-0.75 ppm) could he of value in adjusting predatorlprey ratios in integrated management of T. urticae and T. kanzawai.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.255-262
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• 2021

The potato tuber moth, Phthorimaea operculella (Zeller) has been known as a quarantine pest of potato. This study investigated inhibition doses of electron beam irradiation (EBM) by comparing their effects on the development and reproduction and DNA damage of the insect pest. Eggs (0-12 h old), larvae (3^rd and 5^th instar), pupae (less than 1 d old after pupation) and adults (less than 1 d old after emergence) were irradiated with increasing doses of EBM. The EBM with 150 Gy could not completely prevent the hatchability of eggs and pupation of the hatched larvae. The hatchability from the irradiated eggs were 19.3%. However, adult emergence from the irradiated eggs were completely inhibited. When 3^rd and 5^th instar larvae were irradiated at 100 Gy, the adult emergence from the irradiated larvae and the fecundity of the adults were completely inhibited. When pupae and adults were irradiated at 300 Gy and 400 Gy, respectively, the hatchability of the F₁ eggs was completely inhibited. The alkaline comet assay on the level of DNA damage by EBM in P. operculella adults indicates that the EBM increased DNA damage level in a dose-dependent manner, and the damage was repaired in a time-dependent manner. These results may recommend EBM of 150 Gy as a phytosanitary treatment for P. operculella. However further confirmative study is required for the practical application of this EBM dose for P. operculella disinfestation.

• Korean journal of applied entomology
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• v.46 no.2
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• pp.281-286
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• 2007

Two hymenopteran egg parasitoid species, Gryon japonicum (Ashmead) (Scelionidae) and Ooencyrtus nezarae Ishii (Encyrtidae), were emerged from eggs of bean bug, Riptortus clavatus Thunberg (Heteroptera: Alydidae). The former parasitoid is first recorded in Korea. Brief morphological and biological characteristics, and parasitism on R. clavatus eggs are described.

• Korean journal of applied entomology
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• v.27 no.1
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• pp.6-13
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• 1988

Studies were carried out to investigate the diapause-sensitive stage, the effect of 20-hydroxye- cdysone on diapausing pupae and the changes in pupal proteins of the fitll webworm, HYPha¬ntria cunea Drury. The stage sensitive to diapause-inducing photoperiod lies between 5th and 15th day of the larval development. And the oxygen consumption rate of diapausebound pupae decreased to a mean level of $30mu$l $O_{2}$/g/hr. The 20-hydroxyecdysone was effective in raising the respiratory acivity of 2.5% homogenate of the diapausing fall webworm pupae and in causing a normal adult development of the diapause-bound pupae. The soluble protein content rapidly declined in normally-developing pupae, but in diapause-bound pupae it was more or less static with much higher quantity. And protein bands separated from fat body of diapause¬bound pupae were different from those of nondiapausing pupae.