Wingless Insects Research Articles

Molecular systematics and biogeography of an Australian soil‐burrowing cockroach with polymorphic males, Geoscapheus dilatatus (Blattodea: Blaberidae)

AbstractAn iconic group of arid‐adapted insects is the Australian soil‐burrowing cockroaches (Blaberidae: Geoscapheinae), large, wingless insects that evolved burrowing behaviour and associated forms in parallel from wood feeding ancestors in the subfamily Panesthiinae. A particularly problematic taxon within the Geoscapheinae is Geoscapheus dilatatus (Saussure, 1864), which might represent a species complex and whose delimitation has been complicated for decades by the species harbouring polymorphic males. Males can be divided into two main morphs: individuals possessing horn‐like protrusions on the anterior margin of the pronotum (‘tuberculate’) and those without these characters (‘non‐tuberculate’). A less common, third form consists of individuals that possess tubercles but are far larger than other tuberculate males and occur solely to the north of the species' distribution (‘atypical’ tuberculates). Here, we make use of whole mitochondrial genomes and nuclear ribosomal RNA data from individuals across the range of G. dilatatus to conduct the first phylogenetic analysis of this species to date. We recover all tuberculate males (including atypical forms) as monophyletic and the derived form of G. dilatatus, having evolved only once in this species, whereas non‐tuberculate forms are paraphyletic. Fossil‐calibrated molecular clock analysis revealed that the divergence between these two forms occurred during the late Miocene approximately 6.7 Mya, concurrent with an expansion of the continent's drier biomes. Environmental niche modelling suggests that tuberculate male forms are more climatically tolerant than their more restricted non‐tuberculate counterparts, and both forms' predicted fundamental niches are strongly limited by rainfall. Three species delimitation analyses implemented here failed to consistently delimit G. dilatatus beyond a single species. Ultimately, population genetic approaches paired with additional sampling will be necessary to determine these findings more concretely, but at present, we do not consider the results presented here sufficient to delimit G. dilatatus based on morphological differences found in the species' polymorphic males alone.

Spotlight on the invasion of a carabid beetle on an oceanic island over a 105-year period

The flightless beetle Merizodus soledadinus, native to the Falkland Islands and southern South America, was introduced to the sub-Antarctic Kerguelen Islands in the early Twentieth Century. Using available literature data, in addition to collecting more than 2000 new survey (presence/absence) records of M. soledadinus over the 1991–2018 period, we confirmed the best estimate of the introduction date of M. soledadinus to the archipelago, and tracked subsequent changes in its abundance and geographical distribution. The range expansion of this flightless insect was initially slow, but has accelerated over the past 2 decades, in parallel with increased local abundance. Human activities may have facilitated further local colonization by M. soledadinus, which is now widespread in the eastern part of the archipelago. This predatory insect is a major threat to the native invertebrate fauna, in particular to the endemic wingless flies Anatalanta aptera and Calycopteryx moseleyi which can be locally eliminated by the beetle. Our distribution data also suggest an accelerating role of climate change in the range expansion of M. soledadinus, with populations now thriving in low altitude habitats. Considering that no control measures, let alone eradication, are practicable, it is essential to limit any further local range expansion of this aggressively invasive insect through human assistance. This study confirms the crucial importance of long term biosurveillance for the detection and monitoring of non-native species and the timely implementation of control measures.

A Review of the Phenotypic Traits Associated with Insect Dispersal Polymorphism, and Experimental Designs for Sorting out Resident and Disperser Phenotypes.

Dispersal represents a key life-history trait with several implications for the fitness of organisms, population dynamics and resilience, local adaptation, meta-population dynamics, range shifting, and biological invasions. Plastic and evolutionary changes of dispersal traits have been intensively studied over the past decades in entomology, in particular in wing-dimorphic insects for which literature reviews are available. Importantly, dispersal polymorphism also exists in wing-monomorphic and wingless insects, and except for butterflies, fewer syntheses are available. In this perspective, by integrating the very latest research in the fast moving field of insect dispersal ecology, this review article provides an overview of our current knowledge of dispersal polymorphism in insects. In a first part, some of the most often used experimental methodologies for the separation of dispersers and residents in wing-monomorphic and wingless insects are presented. Then, the existing knowledge on the morphological and life-history trait differences between resident and disperser phenotypes is synthetized. In a last part, the effects of range expansion on dispersal traits and performance is examined, in particular for insects from range edges and invasion fronts. Finally, some research perspectives are proposed in the last part of the review.

A Systematic Review and Meta-Analysis of the Bed Bug Infestation (Cimex lectularius) as a Public Health Insect in Iran (1995 – 2019)

Background: The common bed bug (Cimex lectularius) is a small hematophagous and wingless insect of the order of Hemiptera and the Cimex genus. This insect is mainly nocturnal and feeds specifically on humans. Objectives: This systematic review reflects the distribution of the bed bug and this is a hypothesis about the relationship between the mean of humidity and temperature with the bed bug infestation that the meta-analysis evaluates. Data Sources: Various electronic databases were investigated for choosing reliable research by suitable keywords during 1995 to 2019. Relevant studies were accepted regarding to the inclusion criteria. Cochrane Q and I2 statistics were used to evaluate heterogeneity and inconsistency. Small study effects were assessed by Egger’s regression test. Statistical analysis was performed using STATA12 software. Results: Four researches were entered in this review based on inclusion criteria. According to previous studies, the prevalence of bed bug infestation was reported to be from 2.8% to 90.1% in Iran. Despite of an extensive range of insect infestation, only the reports of the bed bug distribution were published in the Kohgiluye-and-Buyer Ahmad, Esfahan and Mazandaran provinces. The weighted mean of prevalence of common bed bug infestation was obtained using random effects method. The summary estimate of the prevalence was 0.28 [95% CI: (-0.01 - 0.71)]. Conclusions: The current study showed that the prevalence of the common bed bug is mainly focused on the southern, south-western and northern provinces of Iran. Moreover, the bed bug can be called a neglected urban pest, which needs further investigation to know its distribution in the country.

Transcriptome Surveys in Silverfish Suggest a Multistep Origin of the Insect Odorant Receptor Gene Family

The insect odorant receptor (Or) gene family is among the largest multigene families in insect genomes, but its evolutionary origin and mode of expansion is still a matter of debate. We performed transcriptomic surveys of two wingless insect species, the silverfish Lepisma saccharina and Tricholepidion gertschi, and identified multiple Or gene family members in both species. A phylogenetic analysis suggests that the silverfish Ors do not fall into the clade comprised of more derived flying insect ligand-binding Ors, but, along with bristletail, firebrat and some mayfly Ors, are consistently resolved as a distinct set of genes that may constitute an evolutionary intermediate between gustatory receptors and the more derived Ors of flying insects. We propose to consider these “primitive Ors” separately from higher insect Ors until their cellular expression patterns and function are resolved and suggest a multistep evolutionary scenario ultimately leading to the highly sensitive, rapidly evolving and physiologically diverse Or gene family observed in higher insects.

A survey of basal insects (Microcoryphia and Zygentoma) from subterranean environments of Iran, with description of three new species.

A survey of wingless insects belonging to the orders Microcoryphia (=Archaeognatha) and Zygentoma (=Thysanura s. str.) has been performed in subterranean habitats of central Iran. As a result, several new species have been discovered. In this work, three new species are described: a new species of bristletail of the family Machilidae, Haslundiellairanicasp. n., a new silverfish of the family Lepismatidae, Ctenolepismasubterraneumsp. n., and a new Nicoletiidae, Lepidospora (Brinckina) momtazianasp. n. These new taxa are compared with related species in their respective genera and keys for their identification are provided: one for all known species of Haslundiella and one for all basal insects of subterranean environments of Iran which includes those previously reported. Moreover, the previously published keys of Iranian Ctenolepisma and the subgenus Brinckina are modified to include the new species. Three additional species of Lepismatidae are reported in this work: Neoasterolepìsma palmonii and Ctenolepismatargionii are newly recorded from Iran and both species, together with Acrotelsacollaris, are cited for the first time in the subterranean habitats. This survey progresses the knowledge on the biodiversity of these insects in Iran.

Isolation, identification, and time course of human DNA typing from bed bugs, Cimex lectularius

Bed bugs (Cimex lectularius L.) are ectoparasitic wingless insects that feed on the blood of mammals, typically in residential settings. The objectives of this study were to establish a time-course of human DNA quantitation from bed bugs and to generate human DNA profile(s) of a host and/or multiple hosts from a bed bug that fed on human blood. Female human genomic DNA concentrations ranged from 18.370 to 0.195ng/bed bug at 0–108h post blood meal (PBM), male human genomic DNA concentrations ranged from 5.4 to 0.105ng/bed bug at 0–108h PBM, and pooled human female and male blood ranged from 5.49 to 0.135ng/bed bug at 0–96h PBM. Human autosomal STR complete profiles were obtained until 72h PBM for female, male, and pooled human blood. These results reveal that identification of multiple human hosts is possible from a single bed bug. However, the ratio of each contributor may be variable depending on the amount of blood ingested from each individual and the time difference of blood consumed from each subject. Average peak heights for three STR markers of low (D3S1358), medium (D13S317), and high molecular weight (D2S1338), were also compared over time. Peak heights were consistently higher for the low molecular weight marker over all time intervals. These data suggest that some markers can be successfully recovered more than three days PBM. Hence, bed bugs can serve as physical evidence in temporal and spatial predictions to match suspects and/or victims to specific locations in criminal investigations.

The origin of the odorant receptor gene family in insects.

The origin of the insect odorant receptor (OR) gene family has been hypothesized to have coincided with the evolution of terrestriality in insects. Missbach et al. (2014) suggested that ORs instead evolved with an ancestral OR co-receptor (Orco) after the origin of terrestriality and the OR/Orco system is an adaptation to winged flight in insects. We investigated genomes of the Collembola, Diplura, Archaeognatha, Zygentoma, Odonata, and Ephemeroptera, and find ORs present in all insect genomes but absent from lineages predating the evolution of insects. Orco is absent only in the ancestrally wingless insect lineage Archaeognatha. Our new genome sequence of the zygentoman firebrat Thermobia domestica reveals a full OR/Orco system. We conclude that ORs evolved before winged flight, perhaps as an adaptation to terrestriality, representing a key evolutionary novelty in the ancestor of all insects, and hence a molecular synapomorphy for the Class Insecta.

CRISPR/Cas9-based heritable targeted mutagenesis in Thermobia domestica: A genetic tool in an apterygote development model of wing evolution

Despite previous developmental studies on basally branching wingless insects and crustaceans, the evolutionary origin of insect wings remains controversial. Knowledge regarding genetic regulation of tissues hypothesized to have given rise to wings would help to elucidate how ancestral development changed to allow the evolution of true wings. However, genetic tools available for basally branching wingless species are limited. The firebrat Thermobia domestica is an apterygote species, phylogenetically related to winged insects. T. domestica presents a suitable morphology to investigate the origin of wings, as it forms the tergal paranotum, from which wings are hypothesized to have originated. Here we report the first successful CRISPR/Cas9-based germline genome editing in T. domestica. We provide a technological platform to understand the development of tissues hypothesized to have given rise to wings in an insect with a pre-wing evolution body plan.

Bed Bugs

Bed bugs are blood sucking arthropod parasites and are found in tropical and temperate regions. They are small oval-shaped flat reddish brown wingless insects. They possess a segmented abdomen and exhibit ant-like movement. They mate by traumatic insemination. Bed bugs have adapted to the human environment. They get distributed from human travel. They bite human hosts and suck the blood. They feed during night times without being noticed. Bite of bed bugs result in cutaneous and systemic reactions. They are not known to transmit or spread diseases. Antihistaminics control urticarial itchy lesions. Improved cleanliness will help in the control of beg infestations.

A century and a half of research on the evolution of insect flight

The gill and paranotal lobe theories of insect wing evolution were both proposed in the 1870s. For most of the 20th century, the paranotal lobe theory was more widely accepted, probably due to the fundamentally terrestrial tracheal respiratory system; in the 1970s, some researchers advocated for an elaborated gill (“pleural appendage”) theory. Lacking transition fossils, neither theory could be definitively rejected.Winged insects are abundant in the fossil record from the mid-Carboniferous, but insect fossils are vanishingly rare earlier, and all earlier fossils are from primitively wingless insects. The enigmatic, isolated mandibles of Rhyniognatha (early Devonian) hint that pterygotes may have been present much earlier, but the question remains open.In the late 20th century, researchers used models to study the interaction of body and protowing size on solar warming and gliding abilities, and stability and glide effectiveness of many tiny adjustable winglets versus a single, large pair of immobile winglets. Living stoneflies inspired the surface-skimming theory, which provides a mechanism to bridge between aquatic gills and flapping wings. The serendipitously discovered phenomenon of directed aerial descent suggests a likely route to the early origin of insect flight. It provides a biomechanically feasible sequence from guided falls to fully-powered flight.

First Report of Chewing LiceHeterodoxus spiniger(Enderlein, 1909) andTrichodectes canis(De Geer, 1778) on Domestic Dogs at Tabasco, Mexico

Abstract. Lice are small wingless insects in the order Phthiraptera. Historically, the chewing louse Heterodoxus spiniger (Enderlein) was described from marsupials to the domestic dog (Canis lupus familiaris L.). Clinical manifestations of infestations by chewing lice are characterized by intense irritation and inflammation of the skin. We found six of 337 domiciled dogs from Tabasco State, Southeastern Mexico infested by chewing lice. Dogs were systematically examined, and ectoparasites were removed using a fine-toothed comb. Lice were deposited on a white sheet of paper and placed into plastic containers. The dog houses sampled were typically small and built of cement, and most inhabitants lived in vulnerable conditions. This is the first record of H. spiniger and the dog biting louse, Trichodectes canis (De Geer), infesting domestic dogs in Mexico. H. spiniger was present in the six dogs infested by lice, and T. canis co-infested one of them. Therefore, six infested dogs (100%) were positive for H. spi...

First report of Rickettsia raoultii and R. slovaca in Melophagus ovinus, the sheep ked.

Background Melophagus ovinus (Diptera: Hippoboscidae), a hematophagous ectoparasite, is mainly found in Europe, Northwestern Africa, and Asia. This wingless fly infests sheep, rabbits, and red foxes, and causes inflammation, wool loss and skin damage. Furthermore, this parasite has been shown to transmit diseases, and plays a role as a vector. Herein, we investigated the presence of various Rickettsia species in M. ovinus.MethodsIn this study, a total of 95 sheep keds were collected in Kuqa County and Alaer City southern region of Xinjiang Uygur Autonomous Region, northwestern China. First, collected sheep keds were identified on the species level using morphological keys and molecular methods based on a fragment of the 18S ribosomal DNA gene (18S rDNA). Thereafter, to assess the presence of rickettsial DNA in sheep keds, the DNA of individual samples was screened by PCR based on six Rickettsia-specific gene fragments originating from six genes: the 17-kilodalton antigen gene (17-kDa), 16S rRNA gene (rrs), surface cell antigen 4 gene (sca4), citrate synthase gene (gltA), and outer membrane protein A and B genes (ompA and ompB). The amplified products were confirmed by sequencing and BLAST analysis (https://blast.ncbi.nlm.nih.gov/Blast.cgi?PROGRAM=blastn&PAGE_TYPE=BlastSearch&LINK_LOC=blasthome).ResultsAccording to its morphology and results of molecular analysis, the species was identified as Melophagus ovinus, with 100% identity to M. ovinus from St. Kilda, Australia (FN666411). DNA of Rickettsia spp. were found in 12 M. ovinus samples (12.63%, 12/95). Rickettsia raoultii and R. slovaca were confirmed based on phylogenetic analysis, although the genetic markers of these two rickettsial agents amplified in this study showed molecular diversity.ConclusionsThis is the first report of R. raoultii and R. slovaca DNA in M. ovinus. Rickettsia slovaca was found for the first time around the Taklimakan Desert located in China. This finding extends the geographical range of spotted fever group rickettsiae. Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1885-7) contains supplementary material, which is available to authorized users.

Strategies used by two apterous strains of the pea aphid Acyrthosiphon pisum for passive dispersal.

ABSTRACTWingless forms of aphids are relatively sedentary, and have a limited ability to migrate or disperse. However, they can drop off hosts or walk away if disturbed, or their food quality or quantity become deteriorated. Earlier, we found that the pea aphid, Acyrthosiphon pisum (Harris, 1776), could use differed strategies to escape danger and locate new host plants. To determine the mechanisms behind the different strategies, we undertook a series of studies including the aphids' host location, energy reserves under starvation, glycogenesis, sugar assimilation, olfactory and probing behaviors. We found that in our controlled laboratory conditions, one strain (local laboratory strain) moved longer distances and dispersed wider ranges, and correspondingly these aphids assimilated more sugars, synthesized more glycogen, and moved faster than another strain (collected from Gansu Province, northwestern China). However, the latter strain could locate the host faster, probed leaves more frequently, and identified plant leaves more accurately than the former strain after they were starved. Our results explained how flightless or wingless insects adapt to fit biotic and abiotic challenges in the complex processes of natural selection.

Parthenogenesis in Hexapoda: Entognatha and non-holometabolous insects

In hexapods, unlike the majority of animals, development without fertilization is a common phenomenon. They evolved a striking diversity of unisexual reproductive types that include a variety of modes starting from spontaneous parthenogenesis in females to the production of impaternate males with different variants in between. Many reports about parthenogenetic species have accumulated over time. Here, we present a review of various parthenogenetic hexapod groups with a particular focus on their chromosome systems and ploidy level. We show that conclusions about the reproductive mode often lack solid evidence and sometimes inefficiently demonstrate how parthenogenesis is maintained in corresponding groups. In this review, basal hexapods (Protura, Collembola, Diplura), primarily wingless insect groups (‘Apterygota’) and non-holometabolous insects are listed with references to a variety of their unisexual reproductive modes.

The thorax of the cave cricket Troglophilus neglectus: anatomical adaptations in an ancient wingless insect lineage (Orthoptera: Rhaphidophoridae).

BackgroundSecondary winglessness is a common phenomenon found among neopteran insects. With an estimated age of at least 140 million years, the cave crickets (Rhaphidophoridae) form the oldest exclusively wingless lineage within the long-horned grasshoppers (Ensifera). With respect to their morphology, cave crickets are generally considered to represent a `primitive’ group of Ensifera, for which no apomorphic character has been reported so far.ResultsWe present the first detailed investigation and description of the thoracic skeletal and muscular anatomy of the East Mediterranean cave cricket Troglophilus neglectus (Ensifera: Rhaphidophoridae). T. neglectus possesses sternopleural muscles that are not yet reported from other neopteran insects. Cave crickets in general exhibit some unique features with respect to their thoracic skeletal anatomy: an externally reduced prospinasternum, a narrow median sclerite situated between the meso- and metathorax, a star-shaped prospina, and a triramous metafurca. The thoracic muscle equipment of T. neglectus compared to that of the bush cricket Conocephalus maculatus (Ensifera: Tettigoniidae) and the house cricket Acheta domesticus (Ensifera: Gryllidae) reveals a number of potentially synapomorphic characters between these lineages.ConclusionsBased on the observed morphology we favor a closer relationship of Rhaphidophoridae to Tettigoniidae rather than to Gryllidae. In addition, the comparison of the thoracic morphology of T. neglectus to that of other wingless Polyneoptera allows reliable conclusions about anatomical adaptations correlated with secondary winglessness. The anatomy in apterous Ensifera, viz. the reduction of discrete direct and indirect flight muscles as well as the strengthening of specific leg muscles, largely resembles the condition found in wingless stick insects (Euphasmatodea), but is strikingly different from that of other related wingless insects, e.g. heel walkers (Mantophasmatodea), ice crawlers (Grylloblattodea), and certain grasshoppers (Caelifera). The composition of direct flight muscles largely follows similar patterns in winged respectively wingless species within major polyneopteran lineages, but it is highly heterogeneous between those lineages.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0612-5) contains supplementary material, which is available to authorized users.

Taxonomist's Nightmare … Evolutionist's Delight : An Integrative Approach Resolves Species Limits in Jumping Bristletails Despite Widespread Hybridization and Parthenogenesis.

Accurate species delimitation is fundamental to biology. Traditionally, species were delimited based on morphological characters, sometimes leading to taxonomic uncertainty in morphologically conserved taxa. Recently, multiple taxonomically challenging cases have benefited from integrative taxonomy—an approach that highlights congruence among different disciplines and invokes evolutionary explanations for incongruence, acknowledging that different methods can mirror different stages of the speciation continuum. Here, we used a cohesive protocol for integrative taxonomy to revise species limits in 20 nominal species and 4 morphospecies of an ancestrally wingless insect group, the jumping bristletail genus Machilis from the European Eastern Alps. Even though morphologically conserved, several small-scale endemic species have been described from the Eastern Alps based on variation in hypodermal pigmentation patterns—a highly questionable character. As valuable as these endemics are for conservation, they have never been verified by alternative methods. Using traditional morphometrics, mitochondrial DNA, ribosomal DNA, and amplified fragment-length polymorphism markers, we identify six nominal species as taxonomic junior synonyms (Machilis alpicola Janetschek, 1953 syn. n. under M. vagans Wygodzinsky, 1941; M. ladensis Janetschek, 1950 syn. n., M. robusta Wygodzinsky, 1941 syn. n., and M. vicina Wygodzinsky, 1941 syn. n. under M. inermis Wygodzinsky, 1941; M. aleamaculata Wygodzinsky, 1941 syn. n. under M. montana Wygodzinsky, 1941; M. pulchra Janetschek, 1950 syn. n. under M. helleri Verhoeff, 1910) and describe two new species (Machilis cryptoglacialis sp. n. and Machilis albida sp. n.), one uncovered from morphological crypsis and one never sampled before. Building on numerous cases of incongruence among data sources, we further shed light on complex evolutionary histories including hybrid speciation, historical and recent hybridization, and ongoing speciation. We hypothesize that an inherent affinity to hybridization, combined with parallel switches to parthenogenesis and repeated postglacial colonization events may have boosted endemicity in Eastern Alpine Machilis. We thus emphasize the importance of integrative taxonomy for rigorous species delimitation and its implication for evolutionary research and conservation in taxonomically challenging taxa.

The Bacteriome of Bat Flies (Nycteribiidae) from the Malagasy Region: a Community Shaped by Host Ecology, Bacterial Transmission Mode, and Host-Vector Specificity.

The Nycteribiidae are obligate blood-sucking Diptera (Hippoboscoidea) flies that parasitize bats. Depending on species, these wingless flies exhibit either high specialism or generalism toward their hosts, which may in turn have important consequences in terms of their associated microbial community structure. Bats have been hypothesized to be reservoirs of numerous infectious agents, some of which have recently emerged in human populations. Thus, bat flies may be important in the epidemiology and transmission of some of these bat-borne infectious diseases, acting either directly as arthropod vectors or indirectly by shaping pathogen communities among bat populations. In addition, bat flies commonly have associations with heritable bacterial endosymbionts that inhabit insect cells and depend on maternal transmission through egg cytoplasm to ensure their transmission. Some of these heritable bacteria are likely obligate mutualists required to support bat fly development, but others are facultative symbionts with unknown effects. Here, we present bacterial community profiles that were obtained from seven bat fly species, representing five genera, parasitizing bats from the Malagasy region. The observed bacterial diversity includes Rickettsia, Wolbachia, and several Arsenophonus-like organisms, as well as other members of the Enterobacteriales and a widespread association of Bartonella bacteria from bat flies of all five genera. Using the well-described host specificity of these flies and data on community structure from selected bacterial taxa with either vertical or horizontal transmission, we show that host/vector specificity and transmission mode are important drivers of bacterial community structure.

Structural mouthpart interaction evolved already in the earliest lineages of insects.

In butterflies, bees, flies and true bugs specific mouthparts are in close contact or even fused to enable piercing, sucking or sponging of particular food sources. The common phenomenon behind these mouthpart types is a complex composed of several consecutive mouthparts which structurally interact during food uptake. The single mouthparts are thus only functional in conjunction with other adjacent mouthparts, which is fundamentally different to biting-chewing. It is, however, unclear when structural mouthpart interaction (SMI) evolved since this principle obviously occurred multiple times independently in several extant and extinct winged insect groups. Here, we report a new type of SMI in two of the earliest wingless hexapod lineages--Diplura and Collembola. We found that the mandible and maxilla interact with each other via an articulatory stud at the dorsal side of the maxillary stipes, and they are furthermore supported by structures of the hypopharynx and head capsule. These interactions are crucial stabilizing elements during food uptake. The presence of SMI in these ancestrally wingless insects, and its absence in those crustacean groups probably ancestral to insects, indicates that SMI is a groundplan apomorphy of insects. Our results thus contradict the currently established view of insect mouthpart evolution that biting-chewing mouthparts without any form of SMI are the ancestral configuration. Furthermore, SMIs occur in the earliest insects in a high anatomical variety. SMIs in stemgroup representatives of insects may have triggered efficient exploitation and fast adaptation to new terrestrial food sources much earlier than previously supposed.

A Survey on Fauna of Fleas (Order: Siphonaptera) of Cow and Sheep in Southern Khorasan-e-Razavi Province, Iran

Background:: Fleas are wingless insects belonging to the Siphonaptera order (named because of their siphon-like mouthparts). Objectives:: The aim of this study was to evaluate the abundance and fauna of the fleas that are the carrier pathogen in the South of Khorasan-e-Razavi province. Materials and Methods:: In this cross-sectional study, for catch the fleas of cow and sheep were used 3 methods such as: light trap, sticky trap, and human bite. Results:: A total number of 580 fleas from Gonabad and Bajestan cities were collected that all species were Pulex iritans. Thirty five percent fleas were collected from cow and 65% from sheep. Conclusions:: Considering that fleas are carrier pathogens and tend to feed on human blood, which is offered periodically at different seasons, barn spraying with appropriate insecticide was performed.