51 Flight Behavior, Development of Population and Attack of Stone Leek Leafminer Liriomyza Chinensis Kato (Diptera, Agromyzidae) towards Five Varieties of Onion (Allium cepa L.)

Stone leek leafminer Liriomyza Chinensis is an exotic pest that currently has become a major pest in onion plantings in the island of Bali. This study was conducted to determine the behavior of flight, population development and to analyze the level of attack of stone leek leafminer against five varieties of onion (Bima Brebes, Bauji, Tajuk, Probo and Bali Karet). The results showed that adult L. Chinensis has begun to invade the plant since the appearance of leaves of onion plants to the soil surface. The peak of the invasion occurs when the plant is 3 weeks after planting (WAP). While the most adult flight activity occurs at 08.00-11.00. The development of the adult population has begun to appear since 1 week and peaked at 3 WAP, then decreased to 5 WAP and rose again at 6 WAP then decreased to 8 weeks while the larval population began to monitor 3 WAP and peaked at 5 WAP and then decreased steadily to 8 WAP. The average percentage of stone leek leafminer attack against Bima Brebes varieties (12.91%), Bauji (9.68%), Tajuk (10.09%), Probo (9.96%) and Bali Karet (13.56%). Likewise, the average intensity of stone leek leafminer attack against Bima Brebes varieties (19.79%), Bauji (15.55%), Tajuk (16.80%), Probo (17.10%) and Bali Karet (20.20%). This shows that the five varieties of onion tested were susceptible to stone leek leafminer, but Bauji varieties tended to be more resistant to it.