The scuttle flies (Diptera: Phoridae) of Iran with the description of Mahabadphora aesthesphora as a new genus and species

Abstract

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.

Fig 1. Mahabadphora aesthesphora n. gen, n. sp., male.

A, whole fly; B, frons; C, side of thorax; D, antennae, palps, and proboscis; E, abdomen; F, left face of hypopygium. The right black rectangle of each image represents a scale of 20 μm.

Fig 2. Mahabadphora aesthesphora n. gen, n. sp., male.

A, right face of hypopygium; B, front leg; C, hind femur, tibia and basitarsus; D, middle leg; E, postereior face of tip of hind tibia; F, basal third of wing. The right black rectangle of each image represents a scale of 20 μm.

Fig 3. Natural habitats for Mahabadphora aesthesphora n. gen, n. sp. in the Mahabad City.

Fig 4. Maximum likelihood tree inferred from 1200–1269 bp of the COI-28S gene sequences of 61 Megaselia species obtained in this study, along with the sequences of M. scalaris from the Genbank (KF974742-KC177721).

Only bootstrap values higher than 50% are shown on the branches. The bar indicates substitutions per site. The Drosophila melanogaster (Meigen, 1830) (KY559392-NR_133562), Glossina morsitans Westwood, 1851 (KC192971-KC177834) and Musca domestica Linnaeus, 1758 (AB479529-AJ551427) were set as outgroups.

Fig 5. Maximum likelihood tree inferred from 1200–1269 bp of the COI-28S gene sequences of 11 non-Megaselia species obtained in this study.

Only bootstrap values higher than 50% are shown on the branches. The bar indicates substitutions per site. The Drosophila melanogaster (Meigen, 1830) (KY559392 and NR_133562), Glossina morsitans Westwood, 1851 (KC192971-KC177834) and Musca domestica Linnaeus, 1758 (AB479529-AJ551427) were set as outgroups.

Fig 6. Maximum likelihood tree inferred from 1263 bp of the COI-AK gene sequences of the new genus described in this study.

Only bootstrap values higher than 50% are shown on the branches. The bar indicates substitutions per site. The Drosophila melanogaster (Meigen, 1830) (KY559392 and U26939), Glossina morsitans Westwood, 1851 (KC192971-EZ423387) and Musca domestica Linnaeus, 1758 (AB479529-JX428899) were set as outgroups.

Fig 7. Characters of adult male phorid flies used in the key.

A, Lateral view of whole fly (Megaselia scalaris); B, frontal view of head (Triphleba nudipalpis), showing bristles; C, left side of thorax (Megaselia ciliata); D, left side view of male hypopygium (Megaselia scalaris). Modified from Smith, 1986.