POPULATIONS DYNAMIC AND PREFERENCE OF COLLEMBOLA ON SOIL MOLD IN A LEMBANG PINE FOREST

• Main Author: (NIM 20690013), SUHARJONO
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/11451
• Institution: Institut Teknologi Bandung

An investigation on population dynamic and preference of Collembola on soil mold was carried out in a Lembang pine forest soil. Sampling was carried out during period of six months from August 1991 to January 1992 by using soil core and was extracted by Tullgren extractor. Five species of Collembola were found from this study, i.e. Cryptopygus thermophilus was numerically abundant, Isotoma trispinata, Pseudachorutes sp., Tullbergia sp., and Folsomia onychiurina. Population densities of Collembola were maximum during the wet season and minimum during the dry season, and there was positive corelation with soil water contet except I. trispinata. Organic matter content of soil gradually decreased with increasing quantity of precipitation, pnd there was negative corelation with population density of Collembola except I. trispinata. Distribution of Collembola in the field showed an aggregated pattern, it my be caused by heterogenity of habitat condition. Degree of aggregation of Tullbergia sp. Was highest, followed by Psedachorutes sp., then. Cryptopygus thermophilus, and I. trispinata. Study preference of Collembola on soil mold based on gut content analysis. C. thermophilus prefere fed on Penicillium sp., I. trispinata and Pseudachorutes sp. prefered fed on AspergilJus sp. Life Cycle of Pseudachorutes sp. was investigated by using small plastic jars 8 cm high and 4.5 cm in diameter. A mixture of pLaster-charcoal in an 5 : 4 ratio was prepared for the rearing substrate. Cultures feed on bakery yeast were maintained at approximately 100 % relative humidity and the temperature was 19oC and in constant darkness. One generation of Pseudachorutes sp., has two ovipositions, at 8th instar and 12th instar with mean 7.6+3.2% eggs/individual and 25+2.6 eggs/individual respectively. Eggs viability was more than 90 %. Duration of first instar was longer than follow instar but after oviposition duration of each instar was equally with first instar. Incubation period of eggs between 8-15 days by mean 12 days. Longivity could reach 20th instar. It was concluded that Collembola generally took place reproduction at the wet season, and soil mater content was a significant factor. <br />