Contribution to the Cimicidae (Hemiptera: Heteroptera) fauna from Argentina: biology and geographical distribution.

The bed bug family Cimicidae (Hemiptera: Heteroptera) constitutes a group of specialized haematophagous ectoparasitic insects with about 110 species worldwide and 13 species in the Neotropics. Here we provide biological and faunistic observations for 4 out of the 8 species recorded in Argentina. Propicimex tucmatiani (Wygodzinsky, 1951) was recorded for the first time in the Province of Santa Fe and we provide the first barcode sequence for this species. Acanthocrios furnarii (Cordero & Vogelsang, 1928), a mainly ornithophilic species, has been found in a human apartment in Buenos Aires and was probably attacking humans. Bertilia valdiviana (Philippi, 1865) had been reported in 1950 in the Province of Ro Negro, we discuss its potential habitat and host association after visiting the only location where this species had been recorded so far in Argentina. Moreover, we provide some natural history data, i.e. developmental stages, sex ratio and feeding habit of the parrot parasite Cyanolicimex patagonicus Carpintero, Di Iorio, Masello & Turienzo, 2010 from a colony in El Condor (Province of Ro Negro).

First detection of Bartonella spp. in bat bugs Cimex pipistrelli (Hemiptera: Cimicidae), Central Europe.

Bats are an important reservoir for many viral pathogens in humans. However, their role in the transmission of bacterial pathogens is neglected, as is that of their ectoparasites. This study focuses on the molecular detection of Bartonella spp. in bat bugs Cimex pipistrelli using partial sequences of gltA (citrate synthase), ssrA (transfer messenger RNA, tmRNA), and the 16S-23S rDNA internal transcribed spacer (ITS) region as targets. Bartonella DNA was detected in 2/112 (1.79% prevalence) samples from bat bugs. Due to the fact that bat bugs can sporadically bite humans, more extensive surveillance and vector competence studies are needed to ascertain zoonotic risk of bat-associated Bartonella spp.

Behaviour, feeding and cytogenetic features of the wingless blood-sucking ectoparasite Cyanolicimex patagonicus (Heteroptera: Cimicidae).

Cyanolicimex (Haematosiphoninae) includes a single species, C. patagonicus, which is found in the largest known colony of its avian host Cyanoliseus patagonus (Psittacidae) located in Patagonia (Argentina). Relationships between Cyanolicimex and other genera of Haematosiphoninae are still unclear because this genus shares some characters with other South American genera and possesses some similarities with Hesperocimex from the Neoarctic region. The aim of the present study was to provide additional data of C. patagonicus so as to better understand its relationships with other South American species. We examined some biological features of C. patagonicus in the field and we performed a cytogenetic analysis. We observed in the field that C. patagonicus does not live inside the hollow nests of Cyanoliseus patagonus. The cytogenetic analysis showed that the male karyotype is 2n= 31= 28A+X1X2Y and revealed an achiasmate male meiosis and of the collochore type. Our results together with available cytogenetic data in other cimicids, allow proposing the possible chromosomal rearrangements involved in the chromosomal evolution of C. patagonicus and also contribute to better understand the evolutionary divergence at the chromosomal level within Haematosiphoninae. Based on the whole evidence, we propose to place in four groups the species of Haematosiphoninae cytogenetically hitherto studied.

Morphology of the Eggs of Ornithocoris pallidus (Hemiptera, Cimicidae, Haematosiphoninae).

Morphology of cimicid eggs are scarce, and this is the first record for the genus Ornithocoris Pinto, 1927 (Hemiptera: Cimicidae), using scanning electron microscopy (SEM). This genus comprises two species: Ornithocoris toledoi Pinto, 1927 (Hemiptera: Cimicidae) and Ornithocoris pallidus (Usinger, 1959). The eggs of O. pallidus are ellipsoid, and an evident 'lateral flattening', which may give clear asymmetry from the longitudinal axis. The exochorion of the body of the egg and operculum of O. pallidus present spherical or polygonal structures in relief, and pseudomicropyles on the border of the operculum, both differing from Cimex lectularius. The internal face of the operculum is smooth and the border also presented three layers. It was not possible to observe micropyles in the egg of O. pallidus. Bed bugs have a great psychological impact on people, and some people can develop a more or less severe allergic reaction against the bite. Successful control of bed bugs needs serious organization. Studies on egg morphology will add more information to assist in taxonomy studies of O. pallidus and can serve as a basis for control studies because eggs are resistant to insecticides.

Wolbachia: A tool for livestock ectoparasite control.

Ectoparasites and livestock-associated insects are a major concern throughout the world because of their economic and welfare impacts. Effective control is challenging and relies mainly on the use of chemical insecticides and acaricides. Wolbachia, an arthropod and nematode-infecting, maternally-transmitted endosymbiont is currently of widespread interest for use in novel strategies for the control of a range of arthropod-vectored human diseases and plant pests but to date has received only limited consideration for use in the control of diseases of veterinary concern. Here, we review the currently available information on Wolbachia in veterinary ectoparasites and disease vectors, consider the feasibility for use of Wolbachia in the control of livestock pests and diseases and highlight critical issues which need further investigation.

Bedbugs Evolved before Their Bat Hosts and Did Not Co-speciate with Ancient Humans.

All 100+ bedbug species (Cimicidae) are obligate blood-sucking parasites [1, 2]. In general, blood sucking (hematophagy) is thought to have evolved in generalist feeders adventitiously taking blood meals [3, 4], but those cimicid taxa currently considered ancestral are putative host specialists [1, 5]. Bats are believed to be the ancestral hosts of cimicids [1], but a cimicid fossil [6] predates the oldest known bat fossil [7] by >30 million years (Ma). The bedbugs that parasitize humans [1, 8] are host generalists, so their evolution from specialist ancestors is incompatible with the "resource efficiency" hypothesis and only partially consistent with the "oscillation" hypothesis [9-16]. Because quantifying host shift frequencies of hematophagous specialists and generalists may help to predict host associations when vertebrate ranges expand by climate change [17], livestock, and pet trade in general and because of the previously proposed role of human pre-history in parasite speciation [18-20], we constructed a fossil-dated, molecular phylogeny of the Cimicidae. This phylogeny places ancestral Cimicidae to 115 mya as hematophagous specialists with lineages that later frequently populated bat and bird lineages. We also found that the clades, including the two major current urban pests, Cimex lectularius and C. hemipterus, separated 47 mya, rejecting the notion that the evolutionary trajectories of Homo caused their divergence [18-21]. VIDEO ABSTRACT.

Occurrences of Ornithocoris toledoi (Cimicidae) on a free-range chicken farm in the state of Rio de Janeiro, Brazil.

Ornithocoris toledoi is a hematophagous insect that parasites birds, particularly, galliformes. Although the occurrence of this arthropod is relatively low in Brazil, this is an important ectoparasite associated with backyarding poultry. The objective of this study was to report the occurrence of O. toledoi in a free-range chicken farm in the state of Rio de Janeiro, Brazil, including aspects of its taxonomic identification, biology and epidemiology.

Parasites favour intermediate nestling mass and brood size in cliff swallows.

A challenge of life-history theory is to explain why animal body size does not continue to increase, given various advantages of larger size. In birds, body size of nestlings and the number of nestlings produced (brood size) have occasionally been shown to be constrained by higher predation on larger nestlings and those from larger broods. Parasites also are known to have strong effects on life-history traits in birds, but whether parasitism can be a driver for stabilizing selection on nestling body size or brood size is unknown. We studied patterns of first-year survival in cliff swallows (Petrochelidon pyrrhonota) in western Nebraska in relation to brood size and nestling body mass in nests under natural conditions and in those in which hematophagous ectoparasites had been removed by fumigation. Birds from parasitized nests showed highest first-year survival at the most common, intermediate brood-size and nestling-mass categories, but cliff swallows from nonparasitized nests had highest survival at the heaviest nestling masses and no relationship with brood size. A survival analysis suggested stabilizing selection on brood size and nestling mass in the presence (but not in the absence) of parasites. Parasites apparently favour intermediate offspring size and number in cliff swallows and produce the observed distributions of these traits, although the mechanisms are unclear. Our results emphasize the importance of parasites in life-history evolution.

DNA of free-living bodonids (Euglenozoa: Kinetoplastea) in bat ectoparasites: potential relevance to the evolution of parasitic trypanosomatids.

Kinetoplastids are flagellated protozoa, including principally free-living bodonids and exclusively parasitic trypanosomatids. In the most species-rich genus, Trypanosoma, more than thirty species were found to infect bats worldwide. Bat trypanosomes are also known to have played a significant role in the evolution of T. cruzi, a species with high veterinary medical significance. Although preliminary data attested the occurrence of bat trypanosomes in Hungary, these were never sought for with molecular methods. Therefore, amplification of an approx. 900-bp fragment of the 18S rRNA gene of kinetoplastids was attempted from 307 ixodid and 299 argasid ticks collected from bats, and from 207 cimicid bugs collected from or near bats in Hungary and Romania. Three samples, one per each bat ectoparasite group, were PCR positive. Sequencing revealed the presence of DNA from free-living bodonids (Bodo saltans and neobodonids), but no trypanosomes were detected. The most likely source of bodonid DNA detected here in engorged bat ectoparasites is the blood of their bat hosts. However, how bodonids were acquired by bats, can only be speculated. Bats are known to drink from freshwater bodies, i.e. the natural habitats of B. saltans and related species, allowing bats to ingest bodonids. Consequently, these results suggest that at least the DNA of bodonids might pass through the alimentary mucosa of bats into their circulation. The above findings highlight the importance of studying bats and other mammals for the occurrence of bodonids in their blood and excreta, with potential relevance to the evolution of free-living kinetoplastids towards parasitism.

No Detectable Insecticide Resistance in Swallow Bugs (Hemiptera: Cimicidae) Following Long-Term Exposure to Naled (Dibrom 8).

The swallow bug, Oeciacus vicarius Horvath, is a hematophagous ectoparasite of the cliff swallow, Petrochelidon pyrrhonota Vieillot, and is closely related to bed bugs (Cimex spp.). Evolution of insecticide resistance has been documented for bed bugs but not studied in Oeciacus. For periods of 17 and 32 yr, two cliff swallow colonies in western Nebraska were treated during the summer breeding season using the organophosphate insecticide Dibrom. Despite continual treatments, O. vicarius has been observed frequently within these colonies. We evaluated the efficacy of Dibrom 8 on O. vicarius during the 2016 season at two treated colonies and four that had never experienced treatment. Dibrom 8 was found to be effective in 100% of trials, with immobilization within minutes and death within 72 h, for individuals from all colonies. In control treatments (water), individuals collected from treated colonies exhibited greater survival than individuals from untreated colonies, and those from active colonies (bugs fed) had greater survival than those from inactive colonies (bugs unfed). A residual effect was observed in both lab and field trials: 100% mortality occurred in the lab after exposure to filter paper substrates treated both 5 and 10 d earlier, and in the field, nests treated once early in the season had O. vicarius counts 43 d later that were <1% of those from untreated nests within the same colony. We hypothesize that the lack of resistance results from the limited potential for resistance allele fixation due to outbreeding and frequent immigration of insecticide-naïve individuals.

An annotated catalog of the Iranian Cimicidae and Largidae (Hemiptera: Heteroptera) and in memoriam Carl Walter Schaefer (1934-2015).

The Iranian fauna of the Cimicidae and Largidae (Hemiptera: Heteroptera) is summarized in this paper. In total, 2 species from 2 genera of Cimicidae and single species of Largidae are listed.

Predation by ants controls swallow bug (Hemiptera: Cimicidae: Oeciacus vicarius) infestations.

The swallow bug (Oeciacus vicarius) is the only known vector for Buggy Creek virus (BCRV), an alphavirus that circulates in cliff swallows (Petrochelidon pyrrhonota) and house sparrows (Passer domesticus) in North America. We discovered ants (Crematogaster lineolata and Formica spp.) preying on swallow bugs at cliff swallow colonies in western Nebraska, U.S.A. Ants reduced the numbers of visible bugs on active swallow nests by 74-90%, relative to nests in the same colony without ants. Ant predation on bugs had no effect on the reproductive success of cliff swallows inhabiting the nests where ants foraged. Ants represent an effective and presumably benign way of controlling swallow bugs at nests in some colonies. They may constitute an alternative to insecticide use at sites where ecologists wish to remove the effects of swallow bugs on cliff swallows or house sparrows. By reducing bug numbers, ant presence may also lessen BCRV transmission at the spatial foci (bird colony sites) where epizootics occur. The effect of ants on swallow bugs should be accounted for in studying variation among sites in vector abundance.

Costs and benefits of late nesting in cliff swallows.

Many organisms of temperate latitudes exhibit declines in reproductive success as the breeding season advances. Experiments can delay the onset of reproduction for early breeders to investigate the consequences of late nesting, but it is rarely possible to observe a distinct second round of nesting in species that normally nest only once. The colonial cliff swallow (Petrochelidon pyrrhonota) is a migratory songbird that has a relatively short breeding season in the western Great Plains, USA, with birds rarely nesting late in the summer. Previous work suggested that ectoparasitism is a primary reason why reproductive success in this species declines over the summer. At colony sites where nests were fumigated to remove ectoparasitic swallow bugs (Oeciacus vicarius), cliff swallows frequently undertook a distinct round of late nesting after previously fledging young that year. Mark-recapture revealed that late-nesting pairs at these colonies produced fewer offspring that survived to the next breeding season, and that survival of late-nesting adults was lower during the next year, relative to pairs nesting earlier in the season. These reproductive costs applied in the absence of ectoparasites and likely reflect other environmental costs of late nesting such as seasonal declines in food availability or a delayed start of fall migration. Despite the costs, the estimated fitness for perennial early-and-late nesters in the absence of ectoparasites was equivalent to that of birds that nested only early in the season. The collective disadvantages of late nesting likely constrain most cliff swallows to raising a single brood in the middle latitudes of North America.

Heterochromatin characterization and ribosomal gene location in two monotypic genera of bloodsucker bugs (Cimicidae, Heteroptera) with holokinetic chromosomes and achiasmatic male meiosis.

Members of the family Cimicidae (Heteroptera: Cimicomorpha) are temporary bloodsuckers on birds and bats as primary hosts and humans as secondary hosts. Acanthocrios furnarii (2n=12=10+XY, male) and Psitticimex uritui (2n=31=28+X1X2Y, male) are two monotypic genera of the subfamily Haematosiphoninae, which have achiasmatic male meiosis of collochore type. Here, we examined chromatin organization and constitution of cimicid holokinetic chromosomes by determining the amount, composition and distribution of constitutive heterochromatin, and number and location of nucleolus organizer regions (NORs) in both species. Results showed that these two bloodsucker bugs possess high heterochromatin content and have an achiasmatic male meiosis, in which three regions can be differentiated in each autosomal bivalent: (i) terminal heterochromatic regions in repulsion; (ii) a central region, where the homologous chromosomes are located parallel but without contact between them; and (iii) small areas within the central region, where collochores are detected. Acanthocrios furnarii presented a single NOR on an autosomal pair, whereas P. uritui presented two NORs, one on an autosomal pair and the other on a sex chromosome. All NORs were found to be associated with CMA3 bright bands, indicating that the whole rDNA repeating unit is rich in G+C base pairs. Based on the variations in the diploid autosomal number, the presence of simple and multiple sex chromosome systems, and the number and location of 18S rDNA loci in the two Cimicidae species studied, we might infer that rDNA clusters and genome are highly dynamic among the representatives of this family.

Dispersing hemipteran vectors have reduced arbovirus prevalence.

A challenge in managing vector-borne zoonotic diseases in human and wildlife populations is predicting where epidemics or epizootics are likely to occur, and this requires knowing in part the likelihood of infected insect vectors dispersing pathogens from existing infection foci to novel areas. We measured prevalence of an arbovirus, Buggy Creek virus, in dispersing and resident individuals of its exclusive vector, the ectoparasitic swallow bug (Oeciacus vicarius), that occupies cliff swallow (Petrochelidon pyrrhonota) colonies in western Nebraska. Bugs colonizing new colony sites and immigrating into established colonies by clinging to the swallows' legs and feet had significantly lower virus prevalence than bugs in established colonies and those that were clustering in established colonies before dispersing. The reduced likelihood of infected bugs dispersing to new colony sites indicates that even heavily infected sites may not always export virus to nearby foci at a high rate. Infected arthropods should not be assumed to exhibit the same dispersal or movement behaviour as uninfected individuals, and these differences in dispersal should perhaps be considered in the epidemiology of vector-borne pathogens such as arboviruses.

Horizontal transfer of diatomaceous earth and botanical insecticides in the common bed bug, Cimex lectularius L.; hemiptera: cimicidae.

BACKGROUND: Horizontal transfer of insecticide occurs when insects contact or ingest an insecticide, return to an aggregation or a nest, and transfer the insecticide to other conspecific insects through contact. This phenomenon has been reported in a number of insects including social insects, however it has not been reported in bed bugs. Since horizontal transfer can facilitate the spread of insecticide into hard to reach spaces, it could contribute greatly to the management of these public health pests. METHODOLOGY/RESULTS: To demonstrate horizontal transfer of diatomaceous earth and botanical insecticides in C. lectularius, an exposed (donor) bed bug, following a 10-minute acquisition period, was placed with unexposed (recipient) bed bugs. Mortality data clearly demonstrates that diatomaceous earth (DE 51) was actively transferred from a single exposed bug to unexposed bugs in a concentration dependent manner. LC50 values varied from 24.4 mg at 48 h to 5.1 mg at 216 h when a single exposed bed bug was placed with 5 unexposed bed bugs. LT50 values also exhibited a concentration response. LT50 values varied from 1.8 days to 8.4 days when a 'donor' bug exposed to 20 and 5 mg of dust respectively was placed with 5 'recipient' bugs. Dust was also actively transferred from adult bed bugs to the nymphs. In addition we observed horizontal transfer of botanical insecticides including neem, ryania, and rotenone to varying degrees. CONCLUSION/SIGNIFICANCE: Our data clearly demonstrate horizontal transfer of diatomaceous earth and botanical insecticides in the common bed bug, C. lectularius. Use of a fluorescent dust provided visual confirmation that contaminated bed bugs transfer dust to untreated bed bugs in harborage. This result is important because bedbugs live in hard-to-reach places and interaction between conspecifics can be exploited for delivery and dissemination of management products directed at this public health pest.

Rusingeria nom. nov, a new substitute name for Usingeria Coetzee & Segerman, 1992 (Hemiptera: Heteroptera: Cimicidae).

Rusingeria nom. nov. is established as a new substitute name for Usingeria Coetzee & Segerman, 1992 (Hemiptera: Heteroptera: Cimicidae), which is junior homonym of Usingeria Schouteden, 1952 (Hemiptera: Heteroptera: Aradidae). The following new combination is proposed: Rusingeria transvaalensis (Coetzee & Segerman, 1992), comb. nov., for Usingeria transvaalensis Coetzee & Segerman, 1992.

New family host and records of Acanthocrios furnarii (Cordero & Vogelsang, 1928) (Hemiptera: Cimicidae) from Argentina, and implications in the transmission mechanism of cimicid bugs among birds' nests.

Acanthocrios furnarii (Cordero & Vogelsang, 1928) [Hemiptera: Cimicidae: Haematosiphoninae] is an ectoparasite on avian hosts from Argentina and Uruguay. It has been mostly found in mud nests of Furnarius rufus (Gmelin, 1788) [Aves: Furnariidae], but its true hosts are some of the inquiline birds that use F. rufus nests. These inquiline hosts belong to the families Emberizidae, Hirundinidae, Icteridae, Passeridae, and Troglodytidae. Outside F. rufus mud nests, A. furnarii has been found in nests of other Furnariidae, Hirundinidae, and Passeridae. The present work adds the first nonpasserine host (Falconidae) of A. furnarii, together with new records in La Pampa, Argentina. The transmission mechanism of A. furnarii, together with all other cimicid bugs from Argentina and adjacent countries, is increased considering this new host; and we also take into account the birds that nidificate in nest boxes, the cavity-nesting birds in trees and earth, and the inquiline birds in stick nests of Furnariidae and Psittacidae.

Isolation and characterization of twelve polymorphic microsatellite Loci for the cocoa mirid bug Sahlbergella singularis.

Mirids are the primary pests affecting cocoa production in Africa, but no genetic studies have been conducted on these insects. Here we report the isolation and characterization of 12 polymorphic microsatellite loci for Sahlbergella singularis. A microsatellite-enriched genomic DNA library was developed and screened to identify marker loci. Twelve polymorphic loci were identified by screening 28 individuals collected from one presumed population in cocoa plantations in Southern Cameroon. The number of alleles ranged from 5 to 25, whereas the observed and the expected heterozygosities ranged from 0.179 to 0.786 and from 0.671 to 0.946, respectively. Tests showed significant deviations from HW equilibrium for four loci, but no linkage disequilibrium was detected at any of the loci. No cross-species amplification was observed in two other mirid pests in Africa.