• Reproductive and Developmental Biology
• /
• v.30 no.1
• /
• pp.13-19
• /
• 2006

To search of new porcine pheromonal odorants for biostimulation control system technologies to improve reproductive efficiency in livestock species, the comparative molecular field analysis (CoMFA) for binding affinity constant $(p(Od)_{50})$ between porcine odorant binding protein (pOBP) and ligands of odorant 2-(cyclohexyloxy) tetrahydrofurane derivatives as substrate molecule was conducted and discussed. In the optimized CoMFA model AIV with chirality $(C_1'(R),\;C_2(S))$ in substrate molecule and atom based fit alignment (A) of odorants, the statistical results showed the best predictability of the binding affinities $(p(Od)_{50})$ based on the LOO cross-validated value $r^2_{cv}.\;(q^2=0.886)$ and non-cross-validated conventional coefficient $(r^2_{ncv}.=0.984)$. the binding affinity constants exhibited a good correlation with steric (40.8%), electrostatic (14.6%) and hydrophobic (44.6%) factors of the substrate molecules. from the analytical results of the contour maps, which may give us some valuable informations to the modification of odorants for effective binding affinity.

• Korean journal of applied entomology
• /
• v.62 no.4
• /
• pp.277-285
• /
• 2023

The onion moth, Acrolepiopsis sapporensis, was monitored in the farms cultivating the welsh onion, Allium fistulosum, using sex pheromone from transplantation to harvest. Two occurrence peaks were observed at early June and late July after the overwintering population. However, the population sizes were varied among different years and the cultivating environments. To effectively control A. sapporensis with microbial pesticides, different Bacillus thuringiensis strains were screened to select B. thuringiensis kurstaki (BtK). To enhance the insecticidal virulence of BtK, the culture broth of Photorhabdus temperata temperata (Ptt) was added to the BtK. This mixture of two entomopathogenic bacteria was called 'BtPlus', which was superior to BtK alone in the insecticidal virulence. The enhanced virulence was explained by the immunosuppressive activity of the secondary metabolites contained in the Ptt extract. The metabolites inhibited both cellular and humoral immune responses of A. sapporensis, resulting in the enhanced virulence of BtK. These results suggest that A. sapporensis occurs in the welsh onion fields and the resulting economic damage would be effectively prevented by BtPlus application.

• Korean journal of applied entomology
• /
• v.60 no.1
• /
• pp.1-13
• /
• 2021

The concept of integrated pest management (IPM) first developed in the 1950s, and the concept of economic control via pest management was established in the 1960s. Research on IPM began in the United States and Europe, and IPM studies in Korea started with citrus insects and paddy field pests following the distribution of high-yield varieties of rice. Apple IPM in Korea began with research on pest control using chemical pesticides and pesticides resistant to insect pests, studies on the ecology of insect pests and their natural enemies, and the exploitation of sex pheromones on insect pests. Since the 1990s, IPM research and field projects have been carried out simultaneously for farming households. In the 2000s, the development of pest monitoring and forecasting models centered on mating disturbances, database programs for pests, and networks for sharing information. IPM technology has expanded via the development of unmanned forecasting systems and automation technologies in the 2010s.

• Korean journal of applied entomology
• /
• v.48 no.3
• /
• pp.295-299
• /
• 2009

Adoxophyes spp. (Lepidoptera: Tortricidae) are economically important pests of fruit trees in Asia and Europe. The geographical distribution of three Adoxophyes species, A. orana, A. honmai and A. paraorana, in Korea was surveyed using species-specific sex pheromone traps for males in 2006 and 2007. The distribution of A. orana was restricted in the midwestern area, while A. honmai was found mainly in the southern area. In contrast to these two species, A. paraorana was widely distributed. Moreover, A. paraorana coexisted with A. orana in the midwestern area, and with A. honmai in the southern area. The seasonal fluctuation of male catches was monitored with pheromone traps in 2008. In the central regions, males of A. orana and A. paraorana were captured from May to September, with peak numbers in late May, middle July, and late August. A. honmai males were trapped from late April to late September, with peak catches in middle May, late June, early August, and early September in Naju.

• Korean journal of applied entomology
• /
• v.43 no.3 s.136
• /
• pp.201-209
• /
• 2004

Overwintering ecology of the peach pyralid moth, Dichocrosis punctiferalis Guenee (Lepidoptera: Pyralidae) was studied in laboratory and in a chestnut orchard in 2001/2002 winter and 2003 spring. All twenty-four female and fourteen male moths were fruit-feeding type which were emerged from the larvae collected at the same chestnut orchard in 2003 winter. Periodical thermal treatment of overwintering larvae at $25^{\circ}C$ revealed that diapause termination of the larval population started from the end of January and was completed until April 20 in southern region of Korea. Pupation of diapause-terminated larvae started from early May and reached to $100\%$ at June 3 in chestnut orchard. Days to pupation of female larvae after diapause termination were 12.5, 8.9, and 7.5 at $20^{\circ}C,\;25^{\circ}C$, and $30^{\circ}C$, respectively. Those of male larvae were similar to those of females. Pupal periods of female were 14.7, 11.8, and 9.0 days at the three temperatures. Moths of the overwintered generation emerged from May 20 to June 28, and reached to $50\%$ emergence on June 8 to 9 under emergence cage. Attraction of the male moths of overwintered generation to sex pheromone traps showed that the date of $50\%$ catches to the traps were June 17, when data from 3 southern regions of Korea were pooled.

• Korean journal of applied entomology
• /
• v.53 no.3
• /
• pp.295-299
• /
• 2014

Seasonal occurrences of three Tortricinae species were monitored at persimmon orchard in Changwon city ($35^{\circ}$09'18.16"N $128^{\circ}$34'43.63"E), Gyeongnam, Korea, by using sex attractant traps in 2012 and 2013. The two years of monitoring revealed that Adoxophyes honmai and Homona magnanima occurred four times a year, and Neocalyptis angustilineata did three times. Peak occurrence of A. honmai was recorded in mid-May, from early to mid-July, from late July to early August, and from mid- to late September for the generation, respectively. H. magnanima population peaked during mid- to late May, mid-July, from late August to early September, and from late September to mid-October for the generation, respectively. N. angustilineata showed three clear peaks from late May to early June, in late July, and from early to mid-September for the first, second, and third generation, respectively.

• Korean journal of applied entomology
• /
• v.51 no.4
• /
• pp.383-388
• /
• 2012

This study was conducted to assess damage to the welsh onion by Acrolepiopsis sapporensis Mastumura (Lepidoptera: Acrolepiidae) during the summer season, and to estimate the economic injury level (EIL) which results, providing basic data for pest management. The adult peaks of A. sapporensis in Suwon were observed in March, April, May, and September of 2009 and 2010 through the use of pheromone traps. The feeding of A. sapporensis results in white lines on the surface, and holes within welsh onions. During the entire larval period, one larva was able to damage 1.6 leaves and punch 11.9 holes, resulting in a total damaged leaf area of $1,321.6mm^2$. Through cage experiments and larval releases, a reduction of the mean number of leaves, increased percentage of leaf damage, and reduction in gross weight and marketable weight were observed. We could obtain a regression equation that showed a clear positive correlation between pest density and percentage of damaged leaf. Using this equation, the EIL of A. sapporensis on welsh onion was calculated to one larva per 10 plants based on 7% leaf damage observed for welsh onion.

• Korean journal of applied entomology
• /
• v.60 no.4
• /
• pp.431-448
• /
• 2021

We decided the efficient application timings of organo-synthetic insecticides for controlling the first generation larvae of O. furnacalis through investigations of insect stage-specific densities, damage aspects in maize, and effects of insecticides. A waxy maize cultivar, Ilmichal, was cultivated from April 20 (sowing) to July 26 (harvest, dough stage of maize) in Suwon, 2016. The maximum and 50% cumulative catch dates of the overwintering generation adults in the sex pheromone trapping were May 29 and May 31, respectively. Most of the first generation larvae finished their occurrence till the early reproductive stage of maize. The first generation larvae fed on leaves inside the whorl leaves before tassel and stem development of maize, sequentially moved to tassel and stem, and then moved finally to stem and ear parts. In the results of insecticide applications at different dates, the 9-11 leaf stage (June 10~17) and the 6-7 leaf stage (June 3) of maize were the most efficient application timings for direct spray of Etofenprox EC to maize, and for application of Carbofuran granules onto soil surface, respectively, which resulted in suppression of tunnelling damages. The timings for the two insecticides were 12-19 days and 5 days after the adult maximum catch date, respectively. Those timings after the 50% cumulative adult catch date were advanced 2 days.

• Korean journal of applied entomology
• /
• v.62 no.4
• /
• pp.287-293
• /
• 2023

A lot of individuals of Mythimna loreyi have been attracted to the sex-pheromone traps of Spodoptera frugiperda during recent few years. However, there is no information about this pest. Thus, an efficient mass-rearing method of M. loreyi is demanded to study this pest. In this study, we compared the effects of artificial diets and rearing methods on its larval development and oviposition to suggest an efficient mass-rearing method of M. loreyi. Between S. frugipera and Agrotis ipsilon artificial diets, A. ipsilon diet showed more rapid larval development with higher survivorship, and decreased pupa weights and oviposition numbers compared to S. frugipera diet. Moreover, a grouping rearing caused more rapid larva development, decreased pupa weight and survivorship compared to an individual rearing. Therefore, for mass-rearing of M. loreyi, it is considered efficient to rear the newly emerged larvae in groups using A. ipsilon artificial diet and then rearing them individually after second or third larval stadium.

• Korean journal of applied entomology
• /
• v.61 no.2
• /
• pp.335-347
• /
• 2022

We investigated the emergence patterns of Chilo suppressalis (Lepidoptera: Crambidae) adults using sex pheromone traps in the three northeastern areas, Dandong (40°07'N 124°23'E) (Liaoning province), and Gongzhuling (43°30'N 124°49') and Longjing (42°46'N 129°26'E) (Jilin province), China, in 2020 and 2021. Two times of adult flight seasons were isolated clearly during the rice growing periods in the all areas, in which the first season from mid May to late July, and the second season from mid July to mid September were observed. The adult emergence seasons in the areas at higher latitude were later than that at lower latitude. Using the adult emergence data during the first flight seasons, the second flight seasons were estimated through insect phenology modelling, and compared with the observed data. Temperature-dependent life history models (developmental rate, development completion, survival rate, adult aging rate, total fecundity, oviposition completion, and adult survival completion) were collected or constructed for each life stage of C. suppressalis, in which the data from the four previous studies were used. Those models were combined in an insect phenology estimation software, PopModel, and operated for the observed areas. In the results, the phenology modelling operated with the models based on the data of shorter larval periods in the previous studies estimated more accurately the second flight seasons. In 2021, we investigated the change of damaged hill ratios of rice with observing the adult emergence at Dandong and Longjing, 2021. The increase periods of damaged hill ratios of rice were observed two times during the total rice cultivation season, which may be caused by different generations of C. suppressalis larvae.