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

Disney RH, Maleki-Ravasan N. The scuttle flies (Diptera: Phoridae) of Iran with the description of Mahabadphora aesthesphora as a new genus and species

Scuttle flies (Diptera: Phoridae) are mega-diverse and often synanthropic insects that play superb roles in various ecosystems. Identification of this group of insects is challenging due to their small size, morphological identification difficulties, niche diversity, and lack of taxonomic keys. To pave the way, an in-depth investigation was directed toward the scuttle flies in Iran using morphological and molecular data. A dichotomous key was also developed to identify the genus and species of the phorids reported in the country. The faunistic findings revealed the presence of about 22,000 (13,903 male and 8,097 female) phorid materials organized into 11 genera. Megaselia species (n = 13768), made up about 99% of the specimens studied. Moreover, 71 morphologically defined species belonging to nine genera were molecularly characterized using COI, 28S rRNA, and Arginine kinase datasets. Excluding four Megaselia Rondani, 1856 species, our results specified that morphologically delimited species were in agreement with the molecular analyses inferred from the COI/28S rRNA and COI/Arginine kinase sequences with genetic distances and phylogenetic trees. According to the results of the present study and previously published data, the Phoridae recorded for Iran are a total of 97 species that are ordered in 13 genera and three subfamilies, including Chonocephalinae, Metopininae and Phorinae. By comparing the known world phorid genera, a new monotypic genus of scuttle flies, Mahabadphora aesthesphora gen. nov., sp. nov., was identified based on its morphological and molecular characteristics and included in an updated key. Our results could comprehensively determine the taxonomic status of scuttle flies in Iran, scrutinize their phylogenetic structures and facilitate their identification.

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.

Millipede Defensive Compounds Are a Double-Edged Sword: Natural History of the Millipede-Parasitic Genus Myriophora Brown (Diptera: Phoridae)

Toxic defensive secretions produced by millipedes in the orders Julida, Spirobolida, Spirostreptida, and Polydesmida are highly repellent to most vertebrate and invertebrate natural enemies, but a few insects have evolved mechanisms to overcome these defenses. We demonstrate that highly specialized parasitic phorid flies in the species-rich genus Myriophora use volatile millipede defensive compounds as kairomones for host location. Of the two predominant quinone components in the defensive blend of juliform millipedes, 2-methoxy-3-methyl-1,4-benzoquinone alone was sufficient to attract adult flies of both sexes; however, a combination of 2-methoxy-3-methyl-1,4-benzoquinone and 2-methyl-1,4-benzoquinone increased attractiveness nearly threefold. We further discuss oviposition behavior, adult and larval feeding habits, life history parameters, and the potential competitive interactions between phorid flies in the genus Myriophora and other millipede-associated insects.