• Korean journal of applied entomology
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• v.36 no.1
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• pp.111-117
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• 1997

Occurrence status of Tetranychus viennensis Zacher was investigated in Kyonghuk province. Its ecological studies were carried out and chemical control efficacy against females and eggs was examined. And the results ohtained are as follows. T. viennensis occurred from mid April through mid November with the peak time in June on cherry tree. Population level of T. viennensis was varied from 0 to 160 individuals per 100 peach leaves in different peach orchards, and its occurrence rate was 35% out of 20 ochards. However no T. viennensis was observed from 25 apple orchards in 5 districts of Kyongbuk province. Overwintering stage of T. viennensis females appeared in mid October, and most of them moved into under the rough hark in early November. The overwintered adult females moved out from the rough bark to leaves in early April. Mortality during overwintering was about 55%. Under four constant temperatures of 16, 19, 22, 25$^{\circ}$C. egg periods were 14. 3, 9.2, 6.8, and 4.0 days ; larva -nymph periods were 20.2, 13.9, 8.7, and 6.6 days. Female longevity was 67. 7, 60.7, 46.4, and 34.0 days : mean tota: fecundities per female were 21.2, 44.3, 54.4, and 64.7 eggs. Some acaricides, azocyclotin, pyridaben, propargite, tehufenpyrad and fenpyroximate were highly effective against females, while hexythiazox and clofentezine showed very low control effect from 3.6 to 14.4%. Whereas, all of 7 acaricides tested highly effective against the eggs.

• Korean journal of applied entomology
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• v.32 no.1
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• pp.83-89
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• 1993

This study investigated seasonal occurrence, host preference and developmental characteristics of E. lagerstroemiae was most likely to have two generations a year with first occurrence of adults form late April to late may and second from late August to late October including 2 peaks in early May and late August, respectively. Overwintering stages were mostly eggs and larvae and its composition rate was 57.1% of eggs and 42.9% of larvae. Host plats investigated were 7 species 7 families and most preferred species were Lagerstroemia japonica and Diospyros kaki. As morphological characteristics of E. lagerstroemiae, sized of length/sidth were 0.29/0.16 mm for the egg. 0.41/0.16 mm for the first instar larva, 0.96/0.47 mm for the male adult. Number of eggs deposited per female adult was 221.9 individuals. Hatching rate at various temperatures was above 90% at below $30^{\circ}C$. Egg periods were also short\ened with increase of temperatures at below $30^{\circ}C$ but decreased to 56.3% at $35^{\circ}C$. Egg periods were also shortened with increase of temperatures at below $30^{\circ}C$. Hatching rate was not affected by photoperiods but egg periods were shortened with increase of day length.

• Korean journal of applied entomology
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• v.35 no.1
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• pp.38-44
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• 1996

These experiments were conducted to investigate the ecological characteristics of Amblyseius womersleyi Schica,which was biological agent in the integrated management of tea red spider mite, Tetranychus kanzawai Kishida.At four constant temperatures of 15, 20, 25, and 30$^{\circ}$C, the periods of A. womersleyi from egg to adult emergencewere 22.8, 9.6, 4.8, and 3.6 days, respectively. Developmental threshold and effectively cumulative degree-day from egg to adult emergence were 12.7"C and 61.4DD, respectively. Preoviposition periods of A.womersleyi were shorter than oviposition and postoviposition periods. The number of eggs laid per female was21.7, 28.1, 34.2, and 48.0 at the respective temperatures. The intrinsic rates of increase were estimated to be 0.064, 0.139, 0.349, and 0.402; the mean generation times were 36.0, 19.3, 8.6, and 7.7 days; the populationdoubling times were 10.8, 5.0, 2.0, and 1.7 days, respectively. A. womersleyi overwintered on green weeds, fallenleaves and in the soil surface as adult females. A. womersleyi gravid female consumed 3.0, 4.9, 15.7, and19.4 eggs of T. kanzawai per day at 15, 20, 25, and 30$^{\circ}$C, respectively. A. womersleyi protonymph consumed4.6 eggs, deutonymph 6.3 eggs, and female during oviposition consumed 19.4 eggs, and 6.8 eggs of T. kanzawaiduring postoviposition per day at 30$^{\circ}$C. at 30$^{\circ}$C.

• Journal of Sericultural and Entomological Science
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• v.55 no.1
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• pp.1-5
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• 2019

This study was carried out to investigate the development and oviposition characteristics of Tenodera aridifolia. The nymphs of T. aridifolia grew to adults through 6 and 7 nymphal instars. The percentage of 7 nymphal instars (7-instar type) at 25, 28, and $30^{\circ}C$ were 77.3, 76.2, and 73.5%, respectively. In the 7 instars type, total nymphal periods at 25, 28, and $30^{\circ}C$ were 71.9, 53.5, and 54.7 days, respectively. And, there was no difference in deveolpmental periods between 6- and 7-instar types at all temperatures. Egg periods were 41.3 days at $25^{\circ}C$. Adult longevity of females were 82.0 days, deposited average 3.2 oothecae at intervals of 11.7~18.7 days at $28^{\circ}C$ during her life span. The first ootheca was the largest and $40.5mm{\times}22.0mm{\times}17.3mm$ in size. The number of average eggs per oothecae was 178.6 at $28^{\circ}C$.

• Korean journal of applied entomology
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• v.40 no.3
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• pp.203-209
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• 2001

Development and reproduction of the sweetpotato whitefly, Bemisia tabaci(B biotype) were investigated under different temperatures and host plants. Developmental periods from egg to pre-adult of whiteflies measured under four constant temperatures: they were 86.2 days at $15^{\circ}C$ and 17.0 days at $30^{\circ}C$. Lower threshold temperature and total effective temperature for the development of egg and nymph, and for the complete development (egg to emergence) were $10.1,\;11.6,\;11.1^{\circ}C$ and 110.3, 204.7, 317.3 degree days, respectively. The hatching and emergence rates were 87.0% at $25^{\circ}C$ and 76.7% at $20^{\circ}C$, which were higher than the results of other temperatures. The adult longevity was 23.6 and 14.0 days at $20^{\circ}C$ and $30^{\circ}C$, respectively. The highest average fecundity per female was 103.3 at $25^{\circ}C$. But there were no significant differences among the temperatures. The highest intrinsic rate of natural increase($r_{m}$) was 0.196 at $30^{\circ}C$ and the highest net reproduction rate ($R_{o}$) was 97.33 at $25^{\circ}C$. Developmental periods from egg to pre-adult of whiteflies were 21.2 on the tomato, 28.1 on red pepper, 22.2 on eggplant and 25.5 days on poinsetia. The hatching was highest (90.3%) on red paper and emergence rate was highest (89.6%) on eggplant. The longest longevity of adult female was 26.5 days on eggplant, and the average fecundity per female was greater on tomato and eggplant than on other host plants. The intrinsic rate of natural increase($r_{m}$) was the highest on tomato as 0.165 and the net reproduction rate ($R_{o}$) was the highest on eggplant as 106.1. As a result, the optimum range of temperature for the growth of B. tabaci was between $25^{\circ}C$ and $30^{\circ}C$, and the optimum host plant were tomato and eggplant among the plants tested.

• Korean journal of applied entomology
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• v.57 no.4
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• pp.243-251
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• 2018

Eggs, immature eggs, and pupae of 8 different insects (Halyomopha halys, Riptortus pedestris, Lymantria dispar, Antheraea yamamai, Verlarifictorus spp, Antheraea pernyi, and Musca domestica) including Lycorma delicatura were used to select the alternative host for laboratory mass rearing of A. orientalis. Except L. delicatula's eggs and immature eggs of A. pernyi, other 7 tested insects were not parasitized by A. orientalis. A. pernyi was reared with oak tree leaves and its cocoons were harvested on mid-July and early October. On 4 or 5 days after emergence, only female adults showing swollen abdomen were collected and stored at $1{\sim}5^{\circ}C$. We could get 150~200 eggs per one female by dissecting the female's abdomen. For examining the possibility for laboratory mass rearing of A. orientalis with A. pernyi's immature eggs, developmental periods from egg to pupa between the two different hosts were compared. Developmental periods were 36.1 days on immature eggs of A. pernyi and 36.8 days on an original host's eggs, respectively. The number of parasitized eggs by A. orientalis' female for 24 h was 3.4 on immature eggs of A. pernyi and 4.2 on an original host's eggs, respectively. However, there were no significant statistical differences in developmental period and parasitization between the two hosts. By supplying honeyed water to newly emerged female parasitoids, it was able to maximize their longevities up to 64.3 days after emergence. Therefore, our results support potential for laboratory mass-rearing of A. orientalis using A. pernyi's immature eggs as an alternative host.

• Korean journal of applied entomology
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• v.61 no.3
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• pp.423-434
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• 2022

The two previously developed artificial diets (N4 and N6) used for rearing Spodoptera frugiperda (Noctuidae) larvae, were selected as highly-fit ones for rearing Mythimna loreyi larvae. Almost all biological characteristics were not significantly different between the colonies reared on the two diets at 25℃ and 15:9 h (light:dark) photoperiod. The developmental periods were 4.9-5.2 days for eggs, and 22.3-23.2 days for larvae. The pupal period and weight were different between the sexes in each diet colony. The pupal periods in females and males showed 12.6-12.8 days and 14.1-14.5 days, respectively. The pupal weights were ca. 345 mg for females and ca. 380 mg for males. The pupation and emergence rates were ca. 91-94%, and ca. 91-95%, respectively, without significant differences between the two colonies. The pre-oviposition and oviposition periods were 3.4 days and 4.7-4.8 days, respectively. The adult longevity was 8.2 days in females and 10.3-12.4 days in males. Total offsprings produced were found to be 724-847 larvae on an average with ca. 1,400 maximum larvae. In the life table analysis, the intrinsic rates of increases (0.1181 for N4 and 0.1253 for N6) were not significantly different between the two colonies. Individual differences in the larval instar number 5 and 6 were found within a diet colony. The ratios of 5-instar larvae were ca. 22% in N4 colony and ca. 7% in N6 colony. The larval period of 6-instar larvae was longer than that of 5-instar larvae. Width of head capsule in larvae varied from ca. 309 ㎛ for 1st instar to ca. 3,065 ㎛ for 6th instar. Body lengths measured from ca. 2.0 mm for 1st instar to ca. 29.1 mm for 6th instar. Larvae of M. loreyi and M. separata were found at the same time in a maize field during June and July, 2020.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.269-274
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• 2006

Temperature-dependent development studies of two aphid species, A. egomae and A. gossypii occurring in green perilla greenhouse were conducted at $15{\sim}35^{\circ}C$, and 16:8 (L:D h) of light period in the laboratory. The mortality of two aphid species was high in young stages (1st and 2nd). In A. egomae, the mortalitiy increased with increasing and decreasing temperature: the mortalitie at $15^{\circ}C$ and $35^{\circ}C$ were 22.3% and 15.6%, respectively. While the mortalities of A. gossypii increased with increasing temperature: the mortality at $35^{\circ}C$ was 50.0%. The developmental periods of A. egomae and A. gossypii ranged from 20.8days to 5.4days and from 22.6days to 9.1days at $15^{\circ}C$ to $30^{\circ}C$ of temperature resion, respectively, and were 7.2days and 10.7days at $35^{\circ}C$ for each species. The lower developmental threshold temperatures for total nymphs of A. egoame and A. gossypii were $9.9^{\circ}C$ and $4.9^{\circ}C$, respectively and an effective degree-days (DD) for the developmental completion of total nymph were 108.0 DD for.A. egomae and 221.2DD for A. gossypii. In green perilla greenhouse, the occurrence period of A. gossypii was earlier about 15 days than that of A. egomae. When the occurrence period of two aphid species was estimated by degree-days based on lower threshold temperatures, A. gossypii occurred earlier than A. egomae in the field. A. gossypii occurred from early April and showed dominant position to late May compared with A. egomae Whereas, A egomae started to occur from mid April and then were abundant after late May followed by abrupt population crash around late July.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.431-436
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• 2013

Ricania sp. lay eggs into the new twigs of blueberry and suck nutrients causing growth retardation and a sooty mold symptom. This study was conducted to investigate the emergence success and developmental period of overwintered eggs of Ricania sp. under the seven constant temperatures from 10 to $34^{\circ}C$ by $4^{\circ}C$ intervals (14L:10D). We also monitored the emergence time of the Ricania sp. nymph at blueberry by 3 ~ 4 day interval using a modified leaf clip cage. Development times from the overwintered egg to $1^{st}$ nymph were 107.1, 54.5, 33.9, 25.3, 25.1 and 16.7 days and the emergence successes were 23.1, 30.8, 13.8, 21.7, 11.9, and 0.6% at 14, 18, 22, 26, 30 and $34^{\circ}C$, respectively except at $10^{\circ}C$. The developmental periods were decreased with increasing temperatures. First emergence date of the nymphs in the field was between 19 and 22 May, and the average emergence success was 19.6%. The present study might be helpful to establish the management strategy of Ricania sp. based on the biological characteristic.

• Korean journal of applied entomology
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• v.13 no.2 s.19
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• pp.71-75
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• 1974

A study was conducted to investigate the relationships between the rice weevil and associated storage molds. The results are as follows; 1. All of the developmental stages of the rice weevils are carrying some storage molds in their bodies, and the order of magnitute in the number was the adult, larva and pupa. 2. The molds persist in the body of the rice weevil for 10 days who.1 they were fed on the mold free wheat, and the most persistant mold species was A. candidus. 3. When the mold free weevils were reared on the pure culture of the molds on the wheat, the number of eggs laid by the Lveevil were the greatest for A. candidus. following A. ruber, and the . least number Lvere obtained with A. niger 4. The rice weevil could complete in the pure mold culture on the wheat except for A. niger where the larvae had developed by 2nd or 3rd instars. 3. The shortest developmental periods was obtained with A. candidus and the first adult emerged in 4th week. 6. The unfavorable effects of A. niger on the development of the rice weevil might be associated with the fast growth of the mold together with some unknown effects. 7. There seems to be a protocooperative interaction between these two oraganisms having been developed through the long evolutionary course in common habitat.