Biology and ecology of Brazilian elodea (Egeria densa) and its specific herbivore, Hydrellia sp., in Argentina

• Published in: BioControl (Dordrecht, Netherlands) Vol. 58; no. 1; pp. 133 - 147
• Main Authors: Cabrera Walsh, G, Magalí Dalto, Y, Mattioli, Federico M, Carruthers, Raymond I, Anderson, Lars W
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer-Verlag 01.02.2013; Springer Netherlands; Springer Nature B.V
• Subjects: Agriculture; Animal Biochemistry; Animal Ecology; Aquatic plants; Behavioral Sciences; Biological control; Biomedical and Life Sciences; Defoliation; Diptera; Ecology; economics; Egeria densa; Elodea; Entomology; Environmental degradation; Floating plants; Flowers & plants; Herbicides; Herbivores; Host plants; Hydrellia; Hydrocharitaceae; Hydroelectric power; Indigenous plants; indigenous species; Laboratories; leafminers; Leaves; Life Sciences; Macrophytes; Mortality; Oviposition; Plant Pathology; Plant species; rearing; Water use; weeds; Argentina; Hydrocharitaceae; Ephydridae; Biological control; Aquatic weeds
• ISSN: 1386-6141; 1573-8248
• DOI: 10.1007/s10526-012-9475-x

Egeria densa (Hydrocharitaceae) is a submerged macrophyte from South America that is a weed in several countries. It crowds out native plants and hinders water use, causing economic and environmental damage. The leafminer fly Hydrellia sp. 1 (Diptera: Ephydridae), was found feeding in E. densa throughout its Argentine distribution, and is currently the only known specialist herbivore of E. densa. It was reared in the laboratory and tested on 25 plant species. This herbivore can cause heavy defoliation in the laboratory and in the field. Hydrellia sp. 1 was found only on E. densa, but in the laboratory it also developed on two other Hydrocharitaceae species in the same family; Egeria naias, and Elodea callitrichoides. Significant oviposition and feeding were only observed on its primary natural host, and to a lesser degree on E. naias. Field studies indicate Hydrellia sp. 1 is present in the field year round, unless the host plant is prostrate for long periods, or covered by floating macrophytes. These results indicate Hydrellia sp. 1 may be a suitable biocontrol candidate for E. densa.