UJI TOKSISITAS INSEKTISIDA NABATI EKSTRAK DAUN PAKU RESAM (Gleichenia linearis (Burm.f.) S.W. Clarke) TERHADAP LARVA Plutella xylostella L. DIMANFAATKAN SEBAGAI SUMBER BELAJAR BIOLOGI

Tritip caterpillar (Plutella xylostella L.) are the pests that attack the most of cabbage plants. In 2008 to 2011 there was a decline in cabbage production by 28.34%, due to pests and diseases. Plant insecticides are safe way for environmentally to control these pests. The purpose of this research was to know the toxicity of plant insecticides using leaves of paku resam (Gleichenia linearis (Burm.f.) S.W. Clarke) to against Plutella xylostella L. larvae. This research was a pure experiment with a posttest group design research. The total of samples in this research were 250 larvae of Plutella xylostella L instar 3 with 4 treatments, namely the concentration of Gleichenia linearis (Burm.f.) S.W. Clarke leaf extract 5%, 10%, 15%, 20% and 1 control (0%) with 5 repetitions. The analysis result used kruscal wallis to determine the effect of Gleichenia linearis (Burm.f.) S.W. Clarke leaf extract on the mortality of Plutella xylostella L larvae, and to determine the lethal consentration of 50% (LC50) using a probit test. The results showed the effect of differences in Gleichenia linearis (Burm.f.) S.W. Clarke leaf extract on the mortality of Plutella xylostella L larvae, then the LC50-12 hours value was 11,346% -16,200%, LC50-24 hours was 1,733% -4,973%, LC50-36 hours was 0.455% -2.006 %, and LC50-48 hours are 0.127% -1.546%. From these results it can be concluded that the extract of Gleichenia linearis (Burm.f.) S.W. Clarke leaves is proven to be toxic and can be used to eradicate Plutella xylostella L. and the lowest LC50 value is the best value, 0.127% -1.546% at 48 hours