A remarkable legion of guests: Diversity and host specificity of army ant symbionts

Tropical rainforests are among the most diverse biomes on Earth. While species inventories are far from complete for any tropical rainforest, even less is known about the intricate species interactions that form the basis of these ecological communities. One fascinating but poorly studied example are the symbiotic associations between army ants and their rich assemblages of parasitic arthropod guests. Hundreds of these guests, or myrmecophiles, have been taxonomically described. However, because previous work has mainly been based on haphazard collections from disjunct populations, it remains challenging to define species boundaries. We therefore know little about the species richness, abundance and host specificity of most guests in any given population, which is crucial to understand co-evolutionary and ecological dynamics. Here, we report a quantitative community survey of myrmecophiles parasitizing the six sympatric Eciton army ant species in a Costa Rican rainforest. Combining DNA barcoding with morphological identification of over 2,000 specimens, we discovered 62 species, including 49 beetles, 11 flies, one millipede and one silverfish. At least 14 of these species were new to science. Ecological network analysis revealed a clear signal of host partitioning, and each Eciton species was host to both specialists and generalists. These varying degrees in host specificities translated into a moderate level of network specificity, highlighting the system's level of biotic pluralism in terms of biodiversity and interaction diversity. By providing vouchered DNA barcodes for army ant guest species, this study provides a baseline for future work on co-evolutionary and ecological dynamics in these species-rich host-symbiont networks across the Neotropical realm.

Remarkable sexually dimorphic features ofConiceromyia(Diptera: Phoridae): evolution in the light of phylogeny and comparative evidence about their function

Coniceromyia is a genus of 100 species of phorid flies mostly distributed in the Neotropical region. The genus is distinguishable based on several male-exclusive features in different parts of the body, many of which are unique among the Phoridae. In addition, many species of Coniceromyia have nearly identical morphology of their male copulatory apparatus (i.e. hypopygium). The co-occurrence of these unusual characteristics suggests an evolutionary correlation between them. To investigate this possible correlation and to understand other aspects of the evolution of these puzzling male-exclusive characters, we performed the first phylogenetic analysis of Coniceromyia, based on morphological and molecular data. Ancestral state reconstructions and comparative analyses then allowed us to infer the evolution of these characters and search for general evolutionary patterns and correlated histories. We demonstrate that these male-exclusive features varied from highly homoplastic to uniquely derived on the phylogenetic history of Coniceromyia. For some characters, we found evidence of a biased evolution favouring gains over losses of the feature, but no male characteristics were significantly correlated with hypopygium morphology. The evolutionary patterns of the male-exclusive features and comparative evidence with other better known groups suggest possible functions for these features related to sexual selection.

The Attractiveness of the Gravid Aedes Trap to Dengue Vectors in Fiji

The Gravid Aedes Trap (GAT) is a passive trap that relies on visual and olfactory cues to lure and capture gravid mosquitoes. The GAT was designed as a dengue vector surveillance tool for use in conditions where power sources are not readily available. Experiments were conducted over a 10-d period in Fiji to determine which species of mosquitoes the GAT would collect, how different infusion types affect the attractiveness of the trap, how long each infusion type took to begin attracting mosquitoes, and how long the infusion was attractive to container breeding Aedes mosquitoes. Infusions were created by adding 10 g of organic material to 2 liters of water. Infusions were made using chicken feed pellets, dried mango leaves (Mangifera indica), and dried lawn grasses (primarily Axonopus spp.). The GAT collected four different vectors Aedes aegypti (Linnaeus) (Diptera: Culicidae), Aedes albopictus (Skuse) (Diptera: Culicidae), Aedes polynesiensis Mark (Diptera: Culicidae), and Culex quinquefasciatus Say (Diptera: Culicidae). As observed in previous studies, using some type of organic infusion improved the attractiveness of the trap. Of the three different infusion components tested, chicken feed was most attractive followed by lawn grasses and mango leaves. All infusions performed better than plain water. Chicken feed was found to be most attractive for Ae. aegypti and Ae. albopictus during the first 6 d after placing the traps and for Cx. quinquifasciatus in days 7-9. The mango and grass infusions took longer to attract mosquitoes but were most attractive during days 7-10 for all species.

Baby Killers: Documentation and Evolution of Scuttle Fly (Diptera: Phoridae) Parasitism of Ant (Hymenoptera: Formicidae) Brood

BACKGROUND

Numerous well-documented associations occur among species of scuttle flies (Diptera: Phoridae) and ants (Hymenoptera: Formicidae), but examples of brood parasitism are rare and the mechanisms of parasitism often remain unsubstantiated.

NEW INFORMATION

We present two video-documented examples of ant brood (larvae and pupae) parasitism by scuttle flies. In footage from Estação Biológica de Boracéia in Brazil, adult females of Ceratoconus setipennis Borgmeier can be seen attacking workers of Linepithema humile (Mayr) species group while they are carrying brood, and ovipositing directly onto brood in the nest. In another remarkable example, footage from the Soltis Center, near Peñas Blancas in Costa Rica, shows adult females of an unidentified species of the Apocephalus grandipalpus Borgmeier group mounting Pheidole Westwood brood upside-down and ovipositing while the brood are being transported by workers. Analysis of evolutionary relationships (in preparation) among Apocephalus Coquillett species shows that this is a newly derived behavior within the genus, as the A. grandipalpus group arises within a group of adult ant parasitoids. In contrast, relationships of Ceratoconus Borgmeier have not been studied, and the lifestyles of the other species in the genus are largely unknown.

Revision of the New World Species of the Millipede-Parasitic Genus Myriophora Brown (Diptera: Phoridae)

The New World species of the millipede-parasitic genus Myriophora Brown are revised. Sixty-five species based on the female sex are treated, mostly from the Neotropical Region. Of these, fifty-seven are new to science: Myriophora alexandrae sp. nov., Myriophora alienipennis sp. nov., Myriophora angustifascia sp. nov., Myriophora annetteae sp. nov., Myriophora annulata sp. nov., Myriophora bicuspidis sp. nov., Myriophora bilsae sp. nov., Myriophora bimaculata sp. nov., Myriophora borealis sp. nov., Myriophora brevitarsus sp. nov., Myriophora browni sp. nov. Hash, Myriophora brunneipleuron sp. nov., Myriophora communis sp. nov., Myriophora curvata sp. nov., Myriophora curvicacumen sp. nov., Myriophora dennisoni sp. nov., Myriophora discalis sp. nov., Myriophora diversa sp. nov., Myriophora dividida sp. nov., Myriophora dolionatis sp. nov., Myriophora flavicosta sp. nov., Myriophora fuscidorsum sp. nov., Myriophora gigantea sp. nov., Myriophora gobaleti sp. nov., Myriophora harwoodi sp. nov., Myriophora hebes sp. nov., Myriophora heratyi sp. nov., Myriophora inaequalisetarum sp. nov., Myriophora infirmata sp. nov., Myriophora jeffersoni sp. nov., Myriophora kerri sp. nov., Myriophora kungae sp. nov., Myriophora longisetarum sp. nov., Myriophora luteitergum sp. nov., Myriophora magnilabellum sp. nov., Myriophora misionesensis sp. nov., Myriophora nigra sp. nov., Myriophora nigralinea sp. nov., Myriophora obscuritergum sp. nov., Myriophora pallida sp. nov., Myriophora parva sp. nov., Myriophora pectinata sp. nov., Myriophora perpendicularis sp. nov., Myriophora plana sp. nov., Myriophora porrasae sp. nov., Myriophora porrecta sp. nov., Myriophora reminatis sp. nov., Myriophora scopulata sp. nov., Myriophora simplex sp. nov., Myriophora sinesplendida sp. nov., Myriophora smithi sp. nov., Myriophora spicaphora sp. nov., Myriophora spicaticonus sp. nov., Myriophora tenuis sp. nov., Myriophora uruguaiensis sp. nov., Myriophora vancouverensis sp. nov., Myriophora wellsorum sp. nov. The first key to the species of Myriophora is provided.