Roxana Mariani

Redescription of Megamelus scutellaris Berg (Hemiptera: Delphacidae), a Candidate for Biological Control of Water Hyacinth

Abstract To detect biocontrol agents of the invasive aquatic weed Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae), surveys were conducted in the basins of the Paraná and Uruguay rivers in Argentina and the basin of the Amazon river in Peru and Brazil. Among the captured delphacids, Megamelus scutellaris Berg was the most abundant. Berg originally described this species on the basis of a macropterous female. In this contribution, the macropterous and brachypterous male and the brachypterous female are described, and the holotype female is redescribed. Some biological aspects are recorded.

Diversity of planthoppers (Hemiptera: Fulgoromorpha) in rice associated with weeds in Argentina

An assemblage of Fulgoromorpha in a rice agroecosystem from La Plata city was studied for the first time in Argentina, considering those species associated with rice and the surrounding weeds, their seasonality, sex ratios and parasitoidism. Samples were obtained from 2006 to 2010 in a rice field and in the surrounding weeds. Fourteen species from three families of Fulgoromorpha were associated with rice, most of them native species. The delphacids Chionomus haywardi, Toya propinqua and Delphacodes kuscheli were the most abundant on rice. Population peaks occurred after flooding of rice and before anthesis. The native C. haywardi was more abundant in rice than in weeds, while the opposite was confirmed for T. propinqua, a well-known cosmopolitan grass specialist. The difference of abundances of D. kuscheli in rice and weeds was not significant. Our results highlight the dominance of C. haywardi during all sampling years in the rice agroecosystem as well as the role of surrounding weeds as an alternative microhabitat for planthoppers instead of rice. The strepsipteran Elenchus tenuicornis was the only recorded parasitoid and showed no preference for any of the insect hosts.

New records of forensic entomofauna in legally buried and exhumed human infants remains in Buenos Aires, Argentina

The study of carrion fauna associated with buried human corpses from a forensic perspective could provide useful information in criminal investigations. Insects and other arthropods remains sampled of 44 legally exhumed infant skeletons from La Plata (Buenos Aires, Argentina). They were identified at different taxonomic levels depending on the state of preservation. The specific diversity, abundance and frequency were analyzed and each taxon was assigned to the hypothetical colonization sequence: burial colonization, post-exhumation contamination at cemetery deposit or soil fauna. The phorid Dohrniphora sp. is mentioned for the first time in Argentina as carrion fauna of underground colonization, and the assemblage of Dohrniphora sp., Megaselia scalaris and Hydrotaea aenescens is proposed as indicator of buried cadavers. These findings provide new useful data to be applied in forensic entomology research.

First record of Cecilioides acicula (Müller, 1774) (Mollusca: Ferussaciidae), from Buenos Aires province, Argentina

Cecilioides acicula (Muller, 1774), family Ferussaciidae, is native to the Palaearctic region but has been dispersed around the word by human activity. Here, we report the presence of this introduced species in La Plata city, Buenos Aires province, Argentina. This snail is largely subterranean and frequently is found in old graves in association with skeletal remains. Our samples were collected from sediments from the Municipal Cemetery of La Plata, Buenos Aires province, Argentina.