Screening of Necrotizing Spiders in Korea Using Nonradioactive Sphingomyelinase Assay (I) Wandering Spiders

There are now more than 40,000 identified spider species in the world, and considered about 100 species as actually dangerous to human. Spider bites cause a range of symptoms from simple swellings to disfiguring necrotic lesions, and occasionally death. While spider bites are not a major medical problem in Korea, it would be of great value to know which species of spiders pose a threat to human health. A middle molecular weight protein, sphingomyelinase D, has been identified in the venom of the brown recluse spider and strong evidence suggests that they have a major role in spider bite necrosis. For the identification of necrotizing species, we have investigated using recently developed non‐radioactive assay of sphingomyelinase for rapidly screening the necrotizing venoms. Here, we demonstrate the fetal toxicity of total 57 species (32 genera, 9 families) of the wandering spiders among 622 identified spider species in Korea. It has been revealed that two species of the Thomisidae spider, Ozyptila nongae (0.2467) and Diaea subdola (0.2020) have the strongest sphingomyelinase activities among themselves. In addition one species of the family Pisauridae, Dolomedes sulfureus (0.2341) has also relatively higher value comparing to other wandering spiders. However comparing to that of the brown recluse spider, Loxosceles reclusa (1.814) in North America the necrotizing activities of these Korean wandering species are still very low state, so there seems to be little possibilities to create serious medical problems by the necrotizing arachnidism in Korean peninsula.     

Effect of Plant Factors, Sugar Contents, and Control Methods on the Top Borer (Scirpophaga nivella F.) Infestation in Selected Varieties of Sugarcane

Sugarcane (Saccharum officinarum L.) varieties CP‐43/33 and L‐118 susceptible, BF‐162 and SPSG‐26 resistant while CP‐72/2086 as intermediate were screened for studies on top borer, Scirpophaga nivella Fabricus (Pyralidae: Lepidoptera). Morpho‐physio chemical plant factors as well as quality of sugar were examined to elucidate the relationship between pest infestations. The observations on leaf thickness 0.735* and moisture contents 0.771* showed positive and significant correlation with the pest infestation at tillering stage. Total minerals, manganese and copper contents did not show significant correlation with the pest infestation, whereas nitrogen, potassium, calcium, magnesium and ferrous contents manifested positive and significant correlation with the pest infestation. Phosphorous, carbohydrates, fats and zinc produced significant and adverse effect on the pest infestation at tillering stage. Zinc contents with contrasting behaviors appeared to be the most important character with co‐efficient value of 0.764 followed by ferrous with positive sign. The effect of borer infestation was significantly negative on pol (sucrose), Brix contents (total soluble solids), and CCS (commercial cane sugar). The coefficient of determination value was 0.821, obtained by computing fiber content, pol, Brix and CCS factors together for multivariate regression models. Application of trash mulching at the time of sowing proved to be the most effective treatment with minimum infestation (3.91%) of borer and maximum protection level (62.87%) followed by Furadan®, removal of dead hearts + spike thrust, hand collection of egg masses, and cutting of shoots at 15 days interval.     

Screening of Necrotizing Spiders in Korea Using Nonradioactive Sphingomyelinase Assay(II) Web-building Spiders

Spider bites cause a range of symptoms from simple swellings to disfiguring necrotic lesions, and occasionally death. While spider bites are not a major medical problem in Korea, it would be of great value to know which species of spiders pose a threat to human health. A middle molecular weight protein, sphingomyelinase D, has been identified in the venom of the brown recluse spider and strong evidence suggests that they have a major role in spider bite necrosis. For the identification of necrotizing species, we have investigated using recently developed non‐radioactive assay of sphingomyelinase for rapidly screening the necrotizing venoms. Here, we demonstrate the fetal toxicity of total 65 species (24 genera, 9 families) of the web‐building spiders among 622 identified spider species in Korea. It has been revealed that four species of the orb‐weaving spider, Araneus ventricosus (family Araneidae, 0.3509), Dipoena castrata (0.2413, family Theridiidae), Argiope minuta (0.1836, family Araneidae), and Paracoelotes spinivulva (0.1760, family Amaurobiidae) have relatively strong activities among themselves. However, comparing to that of the brown recluse spider, Loxosceles recluse (1.814) in North America, the necrotizing shpingomyelinase activities of these Korean web‐building spiders are still very low. Based on our results, we may thus conclude that there would be little possibilities in South Korea to create serious medical problems caused by necrotizing arachnidism.     

Characteristics and habitats of non-native plant species in the city of Chonju,southern Korea

Investigations on non-native organisms have become an important task of modern ecology throughout the world. The major objective of this study was to identify the characteristics and habitats of non-native plant species in Korean cities in order to derive conclusions on the success of biological invaders. The city of Chonju in southwest Korea was selected as a representative investigation area. All wild-growing vascular plants were recorded in the city on a total of 106 sample plots located in representative land-use types and within various distances of the city center. Frequency, origin, life forms, and plant families of non-native species were analyzed. Additionally, the percentage of non-native species along a gradient from the city center to the outskirts was investigated. We found that most common non-native species of the flora of Chonju are: (i) native to the Northern hemisphere; (ii) belong to the annuals; (iii) belong to the plant families of the Compositae or Leguminosae; and (iv) they perform best on sites that are continuously disturbed by human impact. In conclusion, non-native species play a significant role in enhancing biological diversity in urban areas.     

First record of the family Heloridae (Hymenoptera: Proctotrupoidea) from Korea

As part of an ongoing study of the superfamily Proctotrupoidea, the family Heloridae Förster is recorded for the first time from Korea, based on the two species, Helorus anomalipes (Panzer) and H. ruficornis Förster. A species key to Korean Heloridae, diagnosis and digital images are provided.