Ecology of asparagus beetle (Crioceris asparagi) (Col., Chrysomelidae) with allowance for other insect species occurring on asparagus

摘要

Asparagus beetle (Crioceris asparagi) occurring at the same field complex of an asparagus plantation in 1983, 1984, 1999 and 2000 was subjected to observations on its seasonal occurrence dynamics and harmfulness. In 1984, 1999 and 2000 - egg, larvaland adult development stages wore less numerous within the first than in the second generation of asparagus beetle, the situation in 1983, however, being reversed. Weather conditions and natural enemies have been found the most important factor affecting the occurrence of C. asparagi during all vegetation season irrespectively of the observation year. Adult beetles were always noted at the end of April during the emergence of plants and later on till the end of October. Observations of location of eggslaid by females on asparagus in the four cited years have revealed that the most attractive plant parts, comprising from 50 to 80 percent of eggs, were the "needles" and the flowers, lateral branches and main stems with shares reaching up to 25, 10 and5 percent, respectively. No significant differences in the time of occurrence of adults, egg laying and larvae development have been found between the study years. The following other phytophagous species were present abundantly: spotted asparagus beetle- C. duodecimpunctata (L.), two species of Diptera: Platyparea poeciloptera Schr. and Delia platura Meig., aphids: Brachycorynella asparagi and Aphis fabae Scop., bug - Carpocoris fuscipinus Boh. (Pentatomidae). Additionally (2000 and 2001), 11 entomophagous species of Cantharidae, Coccinelidae, Diptera, Chrysopidae and Eulopidae family and 2 saprophagous species of Diptera family were noted.