Yong Jung Kwon

Metapopulation Structure and Movement of a Threatened Butterfly Parnassius bremeri (Lepidoptera: Papilionidae) in Korea

Understanding the metapopulation structure and movement of a species are required for conserving the species. In this paper, migration patterns and connectivity of patches of a threatened butterfly, Parnassius bremeri Bremer, were postulated using the mark-release-recapture (MRR) technique in a habitat located in the mid-southern region of the Korean peninsula. A total of 194 individuals were captured (137 males and 57 females) and, of them, 93 individuals (73 males and 20 females) were recaptured during the MRR experiment. The migration analysis showed 23-150% immigration and 28-53% emigration. There were high correlations between the migrating individuals and the distance between patches, but there was no correlation between migrating individuals and patch size or between migrating individuals and the number of host plants. Consequently, the migration of butterflies occurred frequently between closer patches, while patch size and quantity of the food plant had minor effects on migration behavior. Additionally, males migrated more frequently than females. Analysis of the migration patterns of P. bremeri showed that the central patch played an important role on linking patch groups and more frequent migrations were monitored between nearby patches than between the remote patches. This study suggested that active migrations take place between the neighboring multiple patches and these are accelerated if there is a stepping-stone patch between them.

Photoperiodic influence on the body mass of bumblebee, Bombus terrestris and its copulation duration

Abstract:  The body mass of Bombus terrestris individuals is an important trait for their behavioural performance and colony organization. In this study, colonies were reared under four different photoperiodic regimes, viz. 0 : 24, 8 : 16, 16 : 8 and 24 : 0 h light : darkness (L : D) at 28°C and 50% relative humidity. The changes in body mass were observed at the stages of larvae, pupae and on the day of adult eclosion. Both the wet and dry mass of sexuals gradually decreased with increasing day length. The relationship between body mass and copulation duration revealed that copulation duration was negatively correlated with male body mass, but positively with queen body mass. Higher number of matings by males resulted in significantly higher duration of copulation.

Biological Activities of Five Weed Extracts against Callosobruchus chinensis L. (Coleoptera: Bruchidae)

This study was conducted with n-hexane extracts of sensitive plant Mimosa pudica, mexican poppy Argemone mexicana, panimarich Leucus aspara, water pepper Polygonum hydropiper and shialmutra Blumea lacera weeds against pulse beetle Callosobruchus chinensis (Coleoptera: Bruchidae) for protection of mung bean Vigna radiata grains. The LC50 values of the weed extracts ranged from 4.5 to 6.4, 4.1 to 5.6 and 3.6 to 5.5 g/100 mL at 24, 48 and 72 hours of post treatment, respectively. The extracts showed 35 to 69% fecundity and 33 to 63% adult emergence inhibitory effect on the pest, and revealed 13 to 49% grain protection of mung beans. Insect mortality, fecundity and adult emergence inhibitory effects, and grain protection activity increased with increased concentration of the extracts. The shialmutra followed by water pepper extracts revealed better performances in fecundity and adult beetle emergence inhibitory effect compared to the other weeds. The findings proved that the n-hexane extracts of the five weeds are sources of botanical insecticides which may be used in the integrated management of C. chinensis.

Three Species of the Genus Neolygus Knight (Hemiptera, Miridae) New to Korea

Three species of the genus Neolygus Knight - N. hakusanensis (Yasunaga, 1991), N. roseus (Yasunaga, 1991) and N. zhugei (Yasunaga, 1991) - are recognized for the first time in Korea. An identification key to the eleven Korean Neolygus species is presented. Some illustrations of male genitalic structures are also provided.

Bionomical Characteristics of Luciola lateralis (Coleoptera: Lampyridae) in Mass Breeding

This study was performed to investigate the bionomical characteristics of Luciola lateralis in Korea. Imago`s longevity of female was and male was days at , R.H. 80%, and significant difference was not occurred in breeding density. Pre-oviposition period was a pair , two pairs , three pairs , four pairs days and pre-oviposition period was shorten in higher breeding density. The mean of laying eggs was , was not related breeding density. Daily oviposition rate was 1st day 20.8%, 2nd 17.3%, 3rd 14.3%, 4th 12.7%, 5th 7.0%, the rate was highest in 1st day and gradually reduced. Egg period was days and hatchability was . Larval instar was identified the 9th instar, the evidence was able to its skin and marking pattern. Larval period of each instar was 1st , 2nd , 3rd , 4th , 5th , 6th , 7th , 8th , 9th days. Matured 9th larva was made of cocoon during days and pre-pupal, pupal period was , days. Imago was made hard hind wing during days in cocoon and come out.

Plant material as an alternative tool for management of aphid in country bean field

Abstract The aphids Aphis craccivora Koch attack country bean Lablab purpureus L. both in its vegetative and reproductive stages and cause severe damage. To develop an integrated management of aphid powders of black pepper, chili, turmeric, and coriander; oils of mahogany, neem, and eucalyptus; aqueous extracts of neem, basil, and garlic leaves; and water were evaluated in field conditions. The treatments were applied at 7 day intervals and aphid abundance per inflorescence was counted at 24, 48, and 72 h after treatment. All the plant materials reduced aphid abundance and flower infestation, ensuring a higher yield with larger and heavier pods. The neem oil treatment had the lowest abundance of aphid and consequently produced the highest marketable and gross yields. Predatory insects were abundant in the field, but their populations were lower in the treatments than the control. An economic analysis indicated that the highest gross return, net return, adjusted net return, and benefit-cost ratio were obtained from the mahogany oil treatment. The plant materials have insecticidal potential against aphids, and the oils of mahogany and neem showed better performances.

Foraging Behavior of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) First Instar Larvae on Selected Cotton Varieties

The movement, survival, and weight gain of Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) first instar larvae were studied on CB9, CB10 and SR05 cotton varieties under field conditions. The neonate H. armigera were released on the cotton varieties at the squaring stage of the plants and, after a period of 72 hours, the survival, weight gain, and final location of the larvae were observed. While the different cotton varieties had no effect on the survival and weight gain of the larvae, the release locations on the cotton varieties had a significant influence on the larval survival and weight gain. The larvae fed small squares of the cotton varieties were significantly heavier and showed a higher mortality than the larvae fed leaflets and mature leaves. For the cotton varieties in this study, the larvae released on leaflets showed a significantly higher rate of recovery compared to the larvae released on mature leaves and squares. This study also found that that the larvae on leaflets did not move up or downward unlike the larvae on mature leaves and squares. This information on the foraging behavior of larvae on cotton varieties will assist researchers to interpret field data and thereby help with the development of pest management decisions.