| Liriomyza bryoniae Kaltenbach (Diptera: Agromyzidae) was defined to be supplementary quarantine pest in Jiangsu province in 2006. L. bryoniae has been found in some areas of Jiangsu especially in Suzhou, Wuxi and Nantong. The harm extent of L. bryoniae in some areas was more serious than that of L. sativae. The host plant species, population dynamics, biology and ecology were studied. The results are as follows.1. The host plant species were investigated from the year 2006 to 2007 in Jiangsu Province. There are 30 species of plants that belong to 10 families as hosts of L. bryoniae, in which Solanaceae, Composite and Laguminosae are the main families.2. L. bryoniae has 12 generations one year and overwinters by pupa in Yangzhou area. The population of L. bryoniae had two peaks in May and October, which indicated that the lower temperature availed to the development of L. bryoniae.3. The spatial distribution pattern of L. bryoniae in Yangzhou areas were determined by the methods of aggregated indices, zero frequency, Iwao's way and power law of Taylor. The results showed that the pattern of the larva was an aggregated distribution on tomato and cowpea and the aggregation indices incressed with the increase of population densities. According to the parameter of spatial distibution pattern, the theoretical sampling number was determined by the methods of KC, Iwao and power law of Taylor to improve the sampling efficiency.4. The influence of temperature on the development of L. bryoniae at 15, 20, 25, 30, 35℃were studied. The results showed that temperature was the key factor that affected the development of L. bryoniae. The shortest duration of the whole generation was 12.64 days at 35℃, while the longest duration was 48.5 days at 15℃. The development of pupa was the longest compared with egg and larva. The development threshold temperatures and the effective accumulated temperatures for egg-pupa were obtained by the methods of linear regression and optimum seeking. The results showed that the development threshold temperatures were 8.8696, 9.0979℃, respectively, and the effective accumulated temperatures were 303.0883, 298.9741 day degrees, respectively. The survival rate of egg keep high all the time, which that of larva was the second and pupa was the last.5. The host selectivity of L. bryoniae was studied indoor. The results showed that the number of feeding holes on kidney bean was 3214 entries per leaf , while there were no feeding holes on amaranth and the number of ovipositing holes on kidney bean was 406 entries per leaf, while there were no ovipositing holes on amaranth. The numbers of feeding holes on kidney bean and aubergine were 7.42, 7.99 entries per square centimeter and the numbers of ovipositing holes were 0.91, 0.89 entries per square centimeter. The results indicated that L. bryoniae prefered to feed and oviposite on vegetables of Solanaceae and Laguminosae, especially on kidney bean.6. The non-selectivity on different host plants indicated that L. bryoniae can complete the whole generation on almost hosts except on water spinach. No obvious difference of egg period exsited among different host plants. The larval period and pupal period on capsicum were different from that on other host plants. The whole generational period on tomato and greengrocery were different from that on other host plants.7. In order to evaluate interspecific interactions of L. bryoniae and L. sativae, the influence of temperature on their development, the niche breadth index and niche overlap index were estimated. The results showed that the whole generation period of L.bryoniae was shorter than L.sativae from 15 to 20℃and the whole generational period of L. sativae was shorter than L.bryoniae when temperature rose. The development threshold temperatures of L. sativae was higher than L.bryoniae, but the effective accumulated temperatures was lower than that of L. bryoniae. The population dynamics of the two Liriomyza was analyzed and the results showed that the population of L. sativae was larger than L. bryoniae and the damage extent of L. sativae was more serious than that of L.bryoniae. The niche breadth index of L.sativae was also larger than that of L. bryoniae.
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