Methyl acetate, a highly volatile floral semiochemical mediating specialized plant-beetle interactions.

Olfactory signaling is key to the reproductive biology of entomophilous palms. Both pollinating and specialized herbivorous insects are attracted to fragrance-emitting palm inflorescences that function as reliable food sources, as well as mating and oviposition sites. In the present study, we characterized the floral scent chemistry of the acuri palm (Attalea phalerata), assessing its role in the attraction of flower-visiting insects associated with this species over its natural distribution range. We sampled insects from staminate inflorescences of A. phalerata (n = 6) at four different sites in the Brazilian Atlantic Forest and Cerrado, and Colombian Amazon basin. Dynamic headspace scent samples of both pistillate and staminate inflorescences of A. phalerata (n = 3♀, 3♂) were collected and analyzed by gas chromatography-mass spectrometry. Methyl acetate, a rare floral scent compound, was identified as the almost exclusive constituent (> 99.8% relative percentage) in all the samples. Flight-interception traps baited with methyl acetate, installed in one of the sites in the Brazilian Cerrado, were attractive to beetles associated with inflorescences of A. phalerata across all four sampling sites (9 spp. in total), including the putative main pollinators (Mystrops spp., Nitidulidae; Andranthobius spp., Curculionidae) and various palm borers (Paratenthras martinsi, Cerambycidae; Parisoschoenus sp.1 and Belopoeus sp.1; Curculionidae). Methyl acetate is highly volatile and we hypothesize its efficacy relies on profuse emission by the inflorescences of A. phalerata, as specialized pollinating insects respond to high concentrations of the attractant, perhaps before odor plumes rapidly disperse. Such a strategy could prove particularly effective in dense populations of A. phalerata.

Contribution to the taxonomy of the family Membracidae Rafinesque (Hemiptera: Auchenorrhyncha) in Colombia.

The Membracidae are a relatively diverse group with nearly 400 genera and 3200 species. For Colombia 93 genera and 394 species were previously known. Study of the literature and 3744 specimens deposited in ten colections in Colombia, as well as non-systematic collections and field observations done in Colombia between 2011 and 2014, led us to record 116 genera and 474 species grouped in 9 subfamilies and 23 tribes, distributed in 24 departments. Thirteen genera were new country records. In addition, 1449 records of host plants and 262 records of associated Hymenoptera were obtained from literature, the examined collections and new, non-systematic field trips. For each genus a differential diagnosis is presented, as well as notes on biology, distribution and some taxonomic comments. Illustrated keys for the genera of Colombian Membracidae and known distributional maps are given. After examination of several Anobilia species, we propose the new combinations Stilbophora flava (Tode, 1966) n. comb., Stilbophora luteimaculata (Funkhouser, 1914) n. comb., Stilbophora sagitatta (Tode, 1966) n. comb., Stilbophora silvana (Tode, 1966) n. comb., Stilbophora tripartita (Fairmaire, 1846) n. comb., and Stilbophora variabilis (Tode, 1966) n. comb. The male of Sakakibarella sinuosa Creão-Duarte is described.