POPULATION FLUCTUATION OF Euphoria lurida (Fabricius, 1775) (COLEOPTERA-SCARABAEIDAE) IN CITRIC YARD

Abstract

The population fluctuation of Euphoria lurida was studied in a mixed citric yard, abandoned and composed by the varieties of baianinha and natal oranges, cravo and rio tangerine, tangor-sabará, and cravo lemon. Adult insects were collected using a plastic bait trap with 20% sugar-cane molasses. The collections were carried out every two weeks, when the baits were also replaced. Samples were undertaken in the period between January/94 to December/86. 716 adult insects were collected in such period and specie occurrence was verified during all months of the year. The highest population averages were observed during January, February and December, while the lowest occurrences happened in June and July. The highest population peak was observed in January, in the third year of collection. 21.4%, 28.8% and 49.8% of the adult insects were collected respectively, in the first, second and third years. An elevated food availability, caused by the high number of dropped fruits on the ground, was the main cause for the population raise observed during the last year of collection. Abandoned yards, specially those presenting a high amount of dropped fruits on the ground, propitiate the necessary conditions for the rapid population raise of the specie. Such increased population can migrate to productive citric yards causing serious damage, since they attack the flowers and lead to the fall of petals and growing fruits.