Efferia
Efferia is an insect genus of mainly neotropical and nearctic Diptera in the family Asilidae or robber flies. It is one of the most species-rich genera of Asilidae, with particularly high diversity in arid or semi-arid ecosystems of the New World.
Description
Small to large-sized robber flies with distinctly different shape of the posterior end of the abdomen in males versus females. Females have a short or long ovipositor that is hairless and short conical to slender wedge-shaped, its color is usually glossy black. Males have a "helicopter tail" with glossy black claspers that are covered in hairs, forming part of a complex genital structure that is clearly larger than the abdominal segments and is oriented diagonally to vertically upwards relative to the main body axis.Abdominal coloration is usually greyish to brownish in females, versus more contrasting with silvery and/or black segments or patches in males. In both sexes the tip of the genitalia usually extends past the wing tips. Wings are clear or uniformly tinted, with tints varying from transparent brown to dark black. Venation includes a recurrent vein on R1, narrow cell r4, R4 extending roughly parallel to R5 or converging moderately with R5 towards the wing tip.
Biology
As is typical for robber flies, adult Efferia are ambush predators, taking off from a resting position on the ground or on a branch to intercept other flying insects in mid-air. Prey are taken from a wide variety of insect orders: Robert Lavigne's Predator-Prey Database for the family Asilidae has 918 records for Efferia species feeding frequently on Diptera, Homoptera, Hymenoptera, Heteroptera, Coleoptera, Lepidoptera, Orthoptera, as well as a few reports of prey species belonging to Neuroptera, Odonata, Ephemeroptera - and even one record for Araneae. Other asilids are frequently preyed upon, and cannibalism is common as well.Efferia species of deserts and grasslands can occur in high abundance, at times even exceeding one individual per square foot. They tend to perch close to the ground and often remain quite immobile - sometimes until they are about to get stepped on. Spotting them is often a matter of first hearing the typically short evasive flight, before seeing where one landed. This is especially true for the males, which emit a characteristic pulsing buzz during the few seconds in flight; this sound tends to be loud and noticeably higher pitched than that of a flying female.
Taxonomy
This is an as yet provisional list of 241 recognized species, combined from 235 entries for accepted species of Efferia in GBIF plus 6 species only listed as valid in other recent sourcesEfferia abdominalis Efferia aestuans Efferia affinis Efferia albibarbis Efferia albispinosa Efferia albiventris no corresponding record found in GBIFEfferia alia Scarbrough & Perez-Gelabert, 2009Efferia amarynceus Efferia amazonica Efferia amphissa Efferia anacapai Efferia anomala Efferia antiochi Efferia anza Efferia apache Efferia aper Efferia apicalis Efferia argentifascia Enderlein, 1914Efferia argentifrons Efferia argyrosoma Efferia arida Efferia armata Efferia aurimystacea Efferia auripila Efferia aurivestitus Efferia azteci Efferia badiapex Efferia barbiellinii Efferia bardyllus Efferia basingeri Efferia basini Efferia bastardi Efferia beameri Wilcox, 1966Efferia belfragei Efferia bellardii Scarbrough, 2008Efferia benedicti Efferia bexarensis Efferia bicaudata Efferia bicolor Efferia bilineatus Efferia bimaculata Efferia bromleyi Efferia brunnescens Efferia bryanti Efferia bullata Scarbrough & Perez-Gelabert, 2009 Efferia cabeza Efferia calienta Efferia californica Efferia camposiana Efferia cana Efferia candida Efferia canella Efferia carbonaria Scarbrough, 2012Efferia carinata Efferia caudex synonym: Efferia invaria Efferia caymanensis Scarbrough, 1988Efferia cazieri Efferia cellatus Efferia cerdai Tomasovic, 2002Efferia chapadensis Efferia cingulata Efferia clavata Scarbrough & Perez-Gelabert, 2009Efferia clementei Efferia cockerellorum Efferia commiles Efferia completa Efferia concinnata Efferia coquilletti Efferia costalis Efferia coulei Efferia cressoni Efferia cubensis Efferia cuervana Efferia currani Efferia davisi Efferia demifasciata Efferia deserti Efferia dilecta Efferia dubia Efferia duncani Efferia ehrenbergi Efferia eraxoides Efferia eurylaris Efferia exacta Scarbrough & Perez-Gelabert, 2009Efferia eximia Efferia femorata Efferia fisheri Scarbrough, 2012Efferia flavida Efferia flavofasciata Efferia forbesi Efferia fortis synonym: Efferia rufitibia Efferia frewingi Efferia fulvibarbis synonym: Efferia pachychaeta Efferia fusca Efferia fuscanipennis Efferia fuscipennis Efferia garciai Lamas, 1971Efferia gila Efferia gossei Efferia grandis Efferia haitensis Efferia halli Efferia haloesa Efferia halterata Enderlein, 1914Efferia harveyi Efferia helenae Efferia heteropterus Efferia hinei Scarbrough, 2008Efferia hubbelli Efferia hyalipennis Efferia imbuda Efferia imperialis Efferia incisura Scarbrough & Perez-Gelabert, 2009Efferia incognita Efferia inflata Efferia insula Scarbrough, 2008Efferia intermedius Lamas, 1971Efferia jubata Efferia kansensis Efferia kelloggi Efferia knowltoni Efferia kondratieffi Efferia labidophora Efferia lades Efferia lasciva Efferia latiforceps Efferia latruncula Efferia lesbius Lamas, 1971Efferia leucocoma Efferia loewi Efferia luna Efferia macrolabis Efferia macroxipha Efferia macularis Efferia marginata Efferia mediana Efferia mellina Efferia mesquite Efferia mexicana Efferia minor Efferia monki Efferia montensis Scarbrough & Perez-Gelabert, 2009Efferia mortensoni Efferia murina Efferia mygidon Efferia nemoralis Efferia neoinflata Efferia neosimilis Efferia nigerina Efferia nigripes Efferia nigritarsis Efferia obscura Efferia okanagana Cannings, 2011 no corresponding record found in GBIFEfferia ordwayae Efferia pallidula Efferia parkeri Efferia parva Efferia parvula Efferia patagoniensis Efferia pavida Efferia peralta Efferia pernicis Efferia picea Scarbrough & Perez-Gelabert, 2009Efferia pictipennis Efferia pilosa Efferia pilosula Efferia pina Efferia pinali Efferia plena Efferia poecilolampra Efferia pogonias Efferia portoricensis Efferia prairiensis Efferia prattii Efferia producta Efferia prolifica Efferia propinqua Efferia pulchripes Efferia pumila Efferia pyrrhogona Efferia quadrimaculata Efferia rapax Efferia remus Tomasovic, 2002Efferia rubidiventris Efferia rufina Efferia rufipes Efferia rufithorax Efferia sagax Efferia satyrus Lamas, 1971Efferia schadei Efferia senilis Efferia serrula Scarbrough & Perez-Gelabert, 2009Efferia setigera Efferia sicyon Efferia similis Efferia singularis Efferia sinuosa Scarbrough & Perez-Gelabert, 2009Efferia slossonae Efferia snowi Efferia sonorensis Forbes, 1987Efferia speciosa considered synonym of Eccritosia rubriventris in GBIFEfferia spiniventris Efferia spinula Scarbrough & Perez-Gelabert, 2009Efferia splendens Efferia staminea Efferia stigmosa Efferia stimicon Efferia stylata synonym: Efferia tortola Efferia subappendiculata Efferia subarida Efferia subchalybea Efferia subcuprea Efferia subpilosa Efferia suspiciosa Scarbrough & Perez-Gelabert, 2009Efferia tabescens Efferia tagax Efferia tapeats Scarbrough, 2012Efferia texana Efferia titan Efferia tolandi Efferia tricella Efferia triton Efferia truncata Efferia tuberculata Efferia tucsoni Efferia utahensis Efferia varipes Efferia vauriei Efferia velox Efferia vertebrata Efferia vinalensis Efferia wilcoxi Efferia willistoni considered homotypic synonym of Neomochtherus willistoni in GBIFEfferia woodleyi Scarbrough & Perez-Gelabert, 2009Efferia yermo Efferia yuma Efferia zetterstedti- ''Efferia zonata''