| By field systematic investigation and, indoor trials, the characters of Chinese chestnut Canopy Arthropod Community structure and dynamics, temporal pattern, numeric dynamics of dominant pests and natural enemies in Hechuan, Chongqing were investigated using the knowledge and theory of community Ecology. The biological and ecological characters of Chestnut gall wasp (Dryocosmus Kuriphilus Yasumatsu) were also studied. The research contents and results were listed as follows:1. Composition of Canopy Arthropod Community in Chestnut OrchardCanopy arthropod community structure in chestnut orchard was studied in two seasons of 2001-2002. The result showed that species of canopy arthropod community was abundant. Total 136 species of arthropods were observed, which belong to 12 Orders, 63 Families. Among these species, there were 70 species of insect pests, 62 species of natural enemies and 4 species of neutral insects, which account for 55. 15%, 41.39%, and 2.94% , respectively. Among 62 species of natural enemies, there were 15 species of parasitoids and 42 species of predatory arthropods, which account for 75.81% and 24. 19%, respectively. Most insect pests belong to Curculionoidae (6 species), Chrysomelidae (5 species), Rutelidae (5 species), and Eucleidae (5 species), and most natural enemies belong to Coccinellidae (7 species), Salticidae(6 species), Clubionidae(6 species), Tetragnathidae (5 species), and Torymidae (5species). Species spactial structure analysis showed that the order of pest species numbers was leaf pest (57 species) >flower pest (6 species) >branch pest (4 species) >fruit pest (2 species).Based on investigation of two seasons, the name list of canopy arthropod community in chestnut orchard was established.Species composition and relative abundance of the canopy arthropod community inchestnut orchard were analyzed. The community could be divided into 3 nutrient classes, 4 guilds and 11 groups. Herbivorous nutrient class was the most dominant in individual numbers, and the relative abundance was 88. 11%. Among Herbivorous nutrient class, the relative abundance of sucking and chewing guild were 60.66% and 22.21% respectively. In sucking and chewing guilds, the relative abundances of aphid and scarab group were 40.02% and 11.56%, respectively. Relative abundance of natural enemy nutrient class was 11. 50%, and among them the relative abundance of predatory and parasitic guild were 16. 81% and 0. 32%, respectively. The relative abundance of spider group was the greatest (7.38%) among predatory guild. The relative abundance of the third nutrient class (mainly neutral insects) was only 0. 39%.During fruit storage, the relative abundance of Dichocrocis punctiferalis Guen ee was the greatest (72.59%), followed by Characama ruficrra Hampton (24. 19%). 2. Seasonal dynamics of canopy arthropod communitySeasonal dynamics of canopy community, main groups, individual numbers of main pests and natural enemies in two seasons were studied. The influential factors of their population dynamics were also analyzed. 2.1. Seasonal dynamics and influential factors2.1.1. Community and the main groupsDynamics curve of community individual numbers was two-peak pattern. The two peaks appeared in late April and middle September. So was the curve of Homoptera. The dominant species was Castanocallis castanocallis Zhang. The two peaks of curve of the dynamics of Coleopteran appeared in middle May and early September. Early and middle July was the peak period of Lepidopteran.2.1.2. Main pests and natural enemiesIndividual number of C. castanocallis Zhang had spring and autumn peaks. Variation of the individual number of Lachnus tropicalis (Van der Goot) was not quite intensive. Weevils (Macrocorynus capito (Faust) was the dominant species) mainly appeared in early April and early September. Scarabs (Anomala corpulenta Motschulsky was the dominant species) mainly appeared in early April and late May and there was a peak value during middle May. Subsequently the number descended and only Adoretus ten...
|
PDF Full Text Request