Fleabeetles, Especially Oedionychina, of a Puerto Rican Marshland in 1969-72

Abstract

Fleabeetles were observed during several years in a marshland in Playa de Salinas, on the south coast of Puerto Rico. The following plant/beetle associations were found: Verbenaceae: Clerodendrum aculeatum (L.) Schlecht.: Alagoasa (= Oedionychus) bicolor (L.) Bechyné, Omophoita cyanipennis F., Cyrsylus volkameriae (F.) Bechyné. Phyla nodiflora (L.) Greene: Omophoita cyanipennis F., Longitarsus oakleyi Blake. Borraginaceae: Heliotropium indicum L.: Omophoita albicollis F. Passifloraceae: Passiflora foetida L.: Disonycha spilotrachela Blake. In the observed conditions, A. bicolor is monophagous and sedentary, with a tendency to concentrate on particular Clerodendrum shrubs and to a more scattered distribution on the remainder of Clerodendrum. A more alert and vagile species, O. cyanipennis is biphagous and migratory between the moist Phyla fields and the drier Clerodendrum bushes. Phyla-associated O. cyanipennis roosted at night in shrubs rising above the Phyla field. Both beetles preferred C. aculeatum as food, but apparently the higher humidity requirement of O. cyanipennis limited its capability of infesting C. aculeatum. An abortive attempt of Omophoita albicollis to establish on Heliotropium indicum was recorded. Cyrsylus volkameriae, a small, monophagous Manobiine, has sedentary habits similar to those of A. bicolor. Moisture, including prolonged inundations, was the most important natural factor controlling the density and distribution of the fleabeetle demes of the site. At first the human influence was beneficial to the beetles. The cattle kept in the site ate selectively, avoiding the unpalatable Verbenacean foodplants of the beetles, and the primitive pasture management never destroyed the food plants permanently. Finally the habitat was destroyed by invading squatters, and the site is now part of the urban Playa de Salinas.