Reduviid Bug Research Articles

Biology, morphometrics and mating behaviour of reduviid predator, Rhynocoris marginatus (Fab.)

A biology study of Rhynocoris marginatus revealed that eggs of this species had a length of 2.65mm and breadth of 0.72mm, incubated for 8.07 days with an average 89% hatching rate. Average durations of first to fifth nymphal instars were 9.3, 9.5, 8.25, 11.4 and 19.45 days, respectively. The size of nymphs increased with successive nymphal instars with the first instar of 2.02 mm in length and the fifth instar being 9.4 mm in length. The average nymphal developmental period was 57.9±2.5 days. Female adults were easily distinguishable due to their broader size measuring a length of 15.2 mm and abdominal width of 5.92 mm, while male adults measured 12.3 mm in length and 4.2 mm in abdominal width. The sex ratio was female-biased (0.89:1). Pre-oviposition, oviposition and post-oviposition period lasted for 12.9, 44.6 and 5.6 days, respectively. Fecundity was 279±48.2 with an average of 45.5 eggs per batch. Female adults survived (63.1 days) more than males (42.1 days). Total generation time was found longer in females (129.3 days) than in males (108.8 days). Keywords: Reduviid bug, Morphometrics, Rhynocoris marginatus

The importance of estimating the burden of disease from foodborne transmission of Trypanosoma cruzi.

Chagas disease (ChD), caused by infection with the flagellated protozoan, Trypanosoma cruzi, has a complicated transmission cycle with many infection routes. These include vector-borne (via the triatomine (reduviid bug) vector defecating into a skin abrasion, usually following a blood meal), transplacental transmission, blood transfusion, organ transplant, laboratory accident, and foodborne transmission. Foodborne transmission may occur due to ingestion of meat or blood from infected animals or from ingestion of other foods (often fruit juice) contaminated by infected vectors or secretions from reservoir hosts. Despite the high disease burden associated with ChD, it was omitted from the original World Health Organization estimates of foodborne disease burden that were published in 2015. As these estimates are currently being updated, this review presents arguments for including ChD in new estimates of the global burden of foodborne disease. Preliminary calculations suggest a burden of at least 137,000 Disability Adjusted Life Years, but this does not take into account the greater symptom severity associated with foodborne transmission. Thus, we also provide information regarding the greater health burden in endemic areas associated with foodborne infection compared with vector-borne infection, with higher mortality and more severe symptoms. We therefore suggest that it is insufficient to use source attribution alone to determine the foodborne proportion of current burden estimates, as this may underestimate the higher disability and mortality associated with the foodborne infection route.

The inquilines (Microtermes obesi), termitophile associates, and natural enemies of the subterranean termite, Odontotermes horni (Wasmann)

The inquilines, termitophile associates, and natural enemies of subterranean nest-building termite Odontotermes horni were investigated at the GKVK, Bengaluru, India. The results showed that the subterranean termites Microtermes obesi and Dicuspiditermes sp were observed as inquilines. A simple royal chamber with a royal pair of M. obesi, scattered fungus combs and egg depository cavities was observed in the nesting area of O. horni. Mites, Lasioseis spp., and unidentified phorid flies were collected as termitophile associates. The ants, Leptogenys processionalis, Camponotus compressus, C. sericeus, reduviid bug, Anacanthaspis pedestris, carabid beetles, Ompra pilosa, common frog, Bufo melanastictus as predators.

Predatory potential of reduviid bug, Rhynocoris marginatus (Fab.) against fruit borers of tomato

Predatory potential of reduviid bug, Rhynocoris marginatus (Fab.) against fruit borers of tomato

First report of Scipinia horrida (Stål) (Heteroptera: Reduviidae) from Assam, with comments on related genus Irantha Stål

Presence of reduviid bugs Scipinia horrida (Stål, 1861) and Irantha sp., belonging to the family Reduviidae and subfamily Harpactorinae, is reported here for the first time from Guwahati, Assam. We provide images and comparative comments on these two bugs.

Debris-carrying behaviour of bark lice immatures preserved in 100 million years old amber

Camouflage strategies, including several types of concealments, are known for several insect groups today, such as immatures of some species within reduviid bugs (Hemiptera), lace wings (Neuroptera), caddisflies (Trichoptera) and bark lice (Psocodea). However, camouflage has only rarely been reported in the fossil record. Here we report findings of four bark lice preserved in 100 Million year old amber from Myanmar, which represent the first fossil evidence for masking behaviour in Cretaceous representatives of Psocodea. All four of these, probably not conspecific, and immature bark lice carry sand granules and organic material atop their back, which probably resulted in camouflaging them against the background (e.g. bark) to avoid detection by predators. We briefly summarise concepts of camouflage and examples of decoration behaviour within insects, as well as possible “receiver” (i.e. predators) of the camouflage of the herein described bark lice. The exact phylogenetic position of the specimens remains unclear, due to the scarce fossil record of Cretaceous immatures of Psocodea, as well as extant immatures. This demonstrates the importance of findings as reported here, as a wide knowledge of morphology and development of a certain group is crucial to get an insight into their evolution and reconstructing environments in deep time.

Epidemiology of Trypanosomiasis in Wildlife-Implications for Humans at the Wildlife Interface in Africa.

While both human and animal trypanosomiasis continue to present as major human and animal public health constraints globally, detailed analyses of trypanosome wildlife reservoir hosts remain sparse. African animal trypanosomiasis (AAT) affects both livestock and wildlife carrying a significant risk of spillover and cross-transmission of species and strains between populations. Increased human activity together with pressure on land resources is increasing wildlife–livestock–human infections. Increasing proximity between human settlements and grazing lands to wildlife reserves and game parks only serves to exacerbate zoonotic risk. Communities living and maintaining livestock on the fringes of wildlife-rich ecosystems require to have in place methods of vector control for prevention of AAT transmission and for the treatment of their livestock. Major Trypanosoma spp. include Trypanosoma brucei rhodesiense, Trypanosoma brucei gambiense, and Trypanosoma cruzi, pathogenic for humans, and Trypanosoma vivax, Trypanosoma congolense, Trypanosoma evansi, Trypanosoma brucei brucei, Trypanosoma dionisii, Trypanosoma thomasbancrofti, Trypanosma elephantis, Trypanosoma vegrandis, Trypanosoma copemani, Trypanosoma irwini, Trypanosoma copemani, Trypanosoma gilletti, Trypanosoma theileri, Trypanosoma godfreyi, Trypansoma simiae, and Trypanosoma (Megatrypanum) pestanai. Wildlife hosts for the trypansomatidae include subfamilies of Bovinae, Suidae, Pantherinae, Equidae, Alcephinae, Cercopithecinae, Crocodilinae, Pteropodidae, Peramelidae, Sigmodontidae, and Meliphagidae. Wildlife species are generally considered tolerant to trypanosome infection following centuries of coexistence of vectors and wildlife hosts. Tolerance is influenced by age, sex, species, and physiological condition and parasite challenge. Cyclic transmission through Glossina species occurs for T. congolense, T. simiae, T. vivax, T. brucei, and T. b. rhodesiense, T. b. gambiense, and within Reduviid bugs for T. cruzi. T. evansi is mechanically transmitted, and T. vixax is also commonly transmitted by biting flies including tsetse. Wildlife animal species serve as long-term reservoirs of infection, but the delicate acquired balance between trypanotolerance and trypanosome challenge can be disrupted by an increase in challenge and/or the introduction of new more virulent species into the ecosystem. There is a need to protect wildlife, animal, and human populations from the infectious consequences of encroachment to preserve and protect these populations. In this review, we explore the ecology and epidemiology of Trypanosoma spp. in wildlife.

Analysis and solutions of generalized Chagas vectors re-infestation model of fractional order type

• A generalized Chagas vectors re-infestation model of fractional order type is proposed. • Our model considers insecticide treatment as continuous spraying where the spraying rate depends on the rate of detection of infestation and time lag between detection and application of insecticide. • Existence and uniqueness results of solutions are proven. • We prove local and global stability of the proposed model and obtain conditions for unique endemic equilibrium. • The effects of the fractional order and key parameters on the proposed model are examined from the numerical analysis results. • Based on the results obtained, we provide some recommendations useful to better understand and reduce the re-infestation of Chagas disease. Trypanosoma cruzi is the parasite that causes Chagas disease in which Triatomine bugs, a type of reduviid bug, are the carrier. Insecticide spraying is one of the most common measures to reduce triatomine infestation. In this paper, we propose a generalized Chagas vectors re-infestation model of fractional order type. This fractional model has been developed to study insecticide-based strategies for controlling vectors of Chagas disease. Our model considers insecticide treatment as continuous spraying where the spraying rate depends on the rate of detection of infestation and time lag between detection and application of insecticide. We incorporate two spraying rates, r (triatomines detection and only infected housing units are treated with deltamethrin insecticide) and r o (other insects detection and treatment is applied to all units). Existence and uniqueness results of solutions are proven. We prove local and global stability of the proposed model and obtain conditions for unique endemic equilibrium. Our numerical results exposed the intrinsic properties of the model using fractional derivative . Based on our results, triatomines infestation cannot be eradicated when there is migration from the sylvatic areas, control strategies aimed at reducing infestation from the sylvatic areas are highly recommended.

The Tryp and the Pendulum.

The Brazilian microbiologist, Carlos Chagas, made the discovery of trypanosomes in the gut of reduviid bugs in 1908. He named them Trypanosoma cruzi in honor of his mentor, Oswaldo Cruz, and subsequently established their etiologic role in a new infectious disease to be called Chagas disease. Over more than a century, study of this complex disease has led to widely differing conceptualizations of the pathogenesis and immunopathogenesis that has led to equally differing paradigms for clinical management in terms of the role of antiparasitic drugs and vaccines.

Glossary

Glossary

Toxoplasma gondii in small exotic felids from zoos in Europe and the Middle East: serological prevalence and risk factors

BackgroundToxoplasma gondii infections and cases of clinical toxoplasmosis have been recorded in zoo animals. Wild felids in human care can serve as definitive hosts that shed oocysts, but also as intermediate hosts for the parasite. Some felid species, such as the Pallas’s cat (Otocolobus manul) or sand cat (Felis margarita), may suffer from clinically apparent toxoplasmosis. In the present study, our main aim was to assess risk factors for T. gondii infections in small exotic felids.MethodsA seroepidemiological study was conducted using the reduviid bug Dipetalogaster maxima for blood sample collection, a method previously evaluated on domestic cats. A total of 336 samples from 17 felid species were collected in 51 institutions, 48 of which were within Europe and the remaining three in the Middle East (United Arabic Emirates and Qatar). These samples were analyzed for T. gondii antibodies by immunoblotting and an immunofluorescent antibody test. Potential risk factors in zoos for seropositivity regarding T. gondii among members of the European Association of Zoos and Aquaria (EAZA) were evaluated using a questionnaire and individual data from the Zoological Information Management System (ZIMS).ResultsThe sampled felids showed an overall seroprevalence for T. gondii of 63%. The risk factor study including data of 311 small exotic cats of 10 species resulted in a final generalized linear mixed model comprised of five variables: the likelihood of seropositivity increased statistically significantly with “Age”, while feeding “Cattle: frozen” relative to “Cattle: fresh”, “Outdoor housing fenced in on all sides”, “Mesh size 2–5 cm” relative to “Mesh size > 5 cm” and “Wearing gloves: yes” had statistically significant protective effects.ConclusionsWild felids, including endangered species, kept in human care in European and Middle Eastern institutions, are widely exposed to T. gondii. Risk factor analysis revealed that feeding previously frozen tissues, keeping animals in enclosures that are fenced on all sides using fences with small mesh sizes, and wearing gloves when working inside enclosures seem to be the most relevant protective measures to prevent T. gondii infections in these animals.

Tri-trophic interaction of different diet fed Corcyra cephalonica (Stainton) on feeding efficiency of reduviid predator, Sycanus collaris (Fab.) under laboratory condition

Sycanus collaris Fabricius (Hemiptera: Reduviidae) are voracious and polyphagous reduviid predators of economically important insect pests of agriculture and forest. Only limited work has been done in case of S. collaris , but life history of these predators on Corcyra cephalonica Stainton were documented. The present study was carried out at the Bio-control laboratory, Department of Entomology, College of Agriculture, IGKV, Raipur (C.G.), during February to May, 2018 with an aim to assess influence of various diets fed C. cephalonica larvae on feeding efficiency of reduviid predator, S. collaris , which are responsible for preference and non-preference of reduviid bugs for mass rearing in laboratory conditions. For this experiment, ten freshly hatched first instar S. collaris nymphs were placed in Petri-dish, replicated thrice and larvae of C. cephalonica reared on twelve different diets were provided throughout their life cycle and the feeding efficiency was recorded. Results indicated that feeding efficiency of S. collaris was found to be maximum (183.31) in T1 (Rice), whereas it was found to be minimum (91.33) in T9 (Maize + Groundnut) reared larvae of C. cephalonica .

Bee pollen addition in zebrafish diets and its effect on immune response and microbiota

A 47-y-old man was bitten by a reduviid bug from the Zelus Fabricius, 1803 genus, which was hidden inside a rubber-coated boot. The bite caused immediate and sharp pain, followed by local edema and constant pruritus for 15 d. Pain and fever within the first 24 h were managed with analgesics as needed, and resolution was complete and without sequelae after 21 d.

Biodiversity analysis of natural arthropods enemies in vineyard agroecosystems in La Rioja, Spain

Major knowledge gaps exist regarding effects of landscape-level agroecosystem composition on the presence of natural enemies of agricultural pests. The objective of this study was to evaluate the influence of landscape mosaic characteristics on the diversity of predators and parasitoids of a viticultural landscape in La Rioja, Spain. Five habitats were evaluated: Mediterranean forest, Mediterranean scrub, olive groves, natural grassland, and vineyards. In all, we collected 28,640 arthropods, representing 10 orders: Araneae, Coleoptera, Dermaptera, Diptera, Hemiptera, Hymenoptera, Mantodea, Neuroptera, Solifugae, and Thysanoptera. The grassland habitat presented the highest arthropod abundances. Carabid beetles showed preferences for Mediterranean forest and scrub, whereas reduviid bugs showed preferences for natural grassland. Landscape heterogeneity and connectivity with natural elements in the study area turn out to be effective in conservation of diversity of natural enemies of viticulture.

Second-Best Is Better Than Nothing: Cockroaches as a Viable Food Source for the Kissing Bug Triatoma recurva (Hemiptera: Reduviidae).

Kissing bugs in the genus Triatoma are obligate blood feeders that feed mainly on vertebrate blood and have lost the predatory lifestyle found in other reduviid bugs. They occasionally also feed on the hemolymph of arthropods, especially during the first and second instar stages. The largest kissing bug species in the United States, Triatoma recurva (Stål) (Hemiptera: Reduviidae), is poorly known and was chosen to investigate its ability to feed and develop on a diet of cockroach hemolymph. Molting from first instar individuals to second instars readily occurred at approximately the same rate reported for the species feeding on mammalian blood. Subsequent instars also fed on and survived on cockroach hemolymph with some individuals maturing to adults. In the larger instars, development time and survival rates were reduced relative to the results reported in the literature for mammalian-blood-fed individuals. Two other species of kissing bugs, Triatoma protracta (Uhler) and T. rubida (Uhler) failed to survive on cockroach hemolymph with most individuals failing to molt from the first instar stage. Although T. recurva does not thrive on a diet limited to hemolymph of cockroaches, it appears to be an unusual species in which cockroaches might be a primary source of nutrition for smaller individuals and are a viable exclusive source of nutrition for all immatures. At a minimum during times of limited availability of vertebrate blood sources, the presence of cockroaches enhances survival opportunities. Efforts to control populations of this kissing bug species likely will be improved with additional control of cockroach populations in the environment.

Identification and characterization of the causative triatomine bugs of anaphylactic shock in Zhanjiang, China

BackgroundTwo health concerns primarily related to triatomine bugs are transmission of Trypanosoma cruzi through infective feces, and allergic reactions induced by triatomine bites. In the Southwestern United States, reduviid bugs bites commonly cause insect allergy. In South China, four cases of anaphylactic shock have been reported after this bite exposure. To further classify the species of these bugs and confirm the sensitization of the triatomine saliva, we caught triatomine bugs from the region where the bites occurred and performed phylogenetic and immunohistochemical (IHC) analysis.MethodsTriatomine bugs were collected in Donghai Island of Zhanjiang City in South China. The genomic DNA was extracted from three legs of the bugs. The fragments of mitochondrial 16S rRNA, cytochrome c oxidase subunit I (COI) gene and nuclear ribosomal 18S and 28S rRNA genes were obtained by PCR and sequenced. A phylogenetic tree was constructed based on the sequence of 16S rRNA gene using a maximum likelihood method with MEGA 7.0 software. Trypanosomal specific fragments and vertebrate COI genes were amplified from the fecal DNA to detect the infection of trypanosomes and analyze the blood feeding patterns, respectively. Paraffin-embedded sections were then prepared from adult triatomines and sent for IHC staining.ResultsWe collected two adult triatomine bugs in Donghai Island. Morphological and molecular analyses indicated that the triatomines were Triatoma rubrofasciata. No fragments of T. cruzi or other trypanosomes were detected from the fecal DNA. Mitochondrial gene segments of Homo sapiens and Mus musculus were successfully amplified. The allergens which induced specific IgE antibodies in human serum were localized in the triatomine saliva by IHC assay.ConclusionsThe two triatomine bugs from Donghai Island were T. rubrofasciata. They had bitten humans and mice. Their saliva should contain the allergens related to the allergic symptoms and even anaphylactic shock of exposed residents. Great consideration should be given to this triatomine bugs due to their considerable distribution and potential threat to public health in South China.

Preliminary results from a survey of lava tube caves in the southwest region of the Ka’ū district of the Big Island, Hawai’i

The discovery of troglobionts in lava tube caves on the Hawaiian Islands archipelago altered our understanding of how species may evolve and permanently inhabit subterranean environments. To date, 74 troglobionts are reported from the islands with 44 known from the youngest (Big Island). Previous lava tube cave surveys on the Big Island have focused on the wetter, eastern side of the island and in lava tubes at higher elevations. Along with members of Cave Conservancy of Hawai’i, we surveyed 24 lava tube sections on the drier, western side of the Big Island, primarily in Hawaiian Ocean View Estates in the Ka’ū District. Surveys occurred during late November and early December of 2015–2017. Species present in each cave were documented by observation and limited collections of specimens for identification purposes. Significant species were discovered in these caves, representing new locations for rare and limited species previously documented from different regions on the island, and/or new, undescribed species from significant lineages that are federally listed on other islands. The most significant species observed included a reduviid thread-legged bug (Nesidiolestes sp.), a terrestrial amphipod (Spelaeorchestia sp.), a microvellid (Cavaticovelia sp.), and a new cave-adapted planthopper (Oliarus sp.). While identification of the collected specimens is ongoing, documenting these significant species from lava tube caves in Ka’ū District illustrates the need for continued bioinventory work in this area.

<b>A record after 52 years, and additional description of the emesine assassin bug <I>Emesopsis nubila</I> (Hemiptera: Reduviidae: Emesinae) from western India</b>

A small reduviid bug Emesopsis nubila Uhler, 1893 is reported from Maharashtra State, India, for the first time. Digital illustrations of important morphological characters, including male genitalia and female terminalia, are provided in the additional description.

Chagas Disease Recommendations for Solid-Organ Transplant Recipients and Donors.

Chagas Disease Recommendations for Solid-Organ Transplant Recipients and Donors.

Evolution, Systematics, and Biogeography of the Triatominae, Vectors of Chagas Disease.

In this chapter, we review and update current knowledge about the evolution, systematics, and biogeography of the Triatominae (Hemiptera: Reduviidae)-true bugs that feed primarily on vertebrate blood. In the Americas, triatomines are the vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Despite declining incidence and prevalence, Chagas disease is still a major public health concern in Latin America. Triatomines occur also in the Old World, where vector-borne T. cruzi transmission has not been recorded. Triatomines evolved from predatory reduviid bugs, most likely in the New World, and diversified extensively across the Americas (including the Caribbean) and in parts of Asia and Oceania. Here, we first discuss our current understanding of how, how many times, and when the blood-feeding habit might have evolved among the Reduviidae. Then we present a summary of recent advances in the systematics of this diverse group of insects, with an emphasis on the contribution of molecular tools to the clarification of taxonomic controversies. Finally, and in the light of both up-to-date phylogenetic hypotheses and a thorough review of distribution records, we propose a global synthesis of the biogeography of the Triatominae. Over 130 triatomine species contribute to maintaining T. cruzi transmission among mammals (sometimes including humans) in almost every terrestrial ecoregion of the Americas. This means that Chagas disease will never be eradicated and underscores the fact that effective disease prevention will perforce require stronger, long-term vector control-surveillance systems.