Reduviidae Research Articles

The first report of an assassin bug of the genus Ademula McAtee & Malloch (Reduviidae: Emesinae) from India and its rediscovery from Sri Lanka

The first report of an assassin bug of the genus Ademula McAtee & Malloch (Reduviidae: Emesinae) from India and its rediscovery from Sri Lanka

A new apterous species of the genus Ploiaria (Hemiptera: Heteroptera: Reduviidae) from Maharashtra, India

A new species of thread-legged assassin bugs, Ploiaria enigmatica sp. nov. (Hemiptera: Heteroptera: Reduviidae: Emesinae: Leistarchini), is described from Western Ghats of Maharashtra, India. The new species has an interesting set of characters not found in any Indomalayan members of the genus Ploiaria Scopoli, 1786, and it appears to be morphologically similar to some Afrotropical congeners.

Performance of Artificial Diets for Zelus renardii (Hemiptera: Reduviidae) Rearing.

Mass production is a prerequisite for using natural enemies in integrated pest management and organic farming. Natural enemies in agroecosystems include predators that prey on insects, which they can subdue while maintaining adequate pest population densities. The Leafhopper Assassin Bug (LAB), Zelus renardii, can be a natural enemy in agroecosystems, selecting its prey for size and mobility. Some of LAB's prey include Philaenus spumarius (L.), Bactrocera oleae (Rossi), Drosophila suzukii (Matsumura), and Macrohomotoma gladiata Kuwayama, suggesting this reduviid for biocontrol agent in various contexts. We reared LABs for two subsequent broods offering living prey and artificial diets. Our data show that the rearing of Z. renardii is feasible with oligidic, meridic, and holidic artificial formulations. Four artificial diets allowed the complete post-embryonic development of LABs in captivity for two successive generations. The accumulated degree-days (ADDs) accurately predict the growth of LABs based on heat accumulation, estimating that up to three generations could grow per year in captivity at the experimented T°C.

A revised classification of the assassin bugs (Hemiptera: Heteroptera: Reduviidae) based on combined analysis of phylogenomic and morphological data

AbstractAssassin bugs (Hemiptera: Reduviidae Latreille) comprise not only one of the largest radiations of predatory animals (22 subfamilies; >6,800 spp.) but also include the medically important kissing bugs (Triatominae Jeannel). Reduviidae are morphologically diverse, engage in an astounding array of predatory strategies and have evolved some of the most unique anti‐predator and stealth techniques in the animal kingdom. While significant progress has been made to reveal the evolutionary history of assassin bugs and revise their taxonomy, the non‐monophyly of the second largest assassin bug subfamily, Reduviinae Latreille, remains to be addressed. Leveraging phylogenomic data (2,291 loci) and 112 morphological characters, we performed the first data‐ and taxon‐rich (195 reduvioid taxa) combined phylogenetic analysis across Reduvioidea and reconstructed morphological diagnostic features for major lineages. We corroborated the rampant polyphyly of Reduviinae that demands substantial revisions to the subfamilial and tribal classification of assassin bugs. Our new classification for Reduviidae reduces the number of subfamilies to 19 and recognizes 40 tribes. We describe three new subfamilies to accommodate distantly related taxa previously classified as Reduviinae (Heteropinae subfam. nov., Nanokeralinae subfam. nov., and Pasirinae subfam. nov.). Triatominae sensu nov. are expanded to include closely related predatory reduviine genera. Cetherinae Jeannel, Chryxinae Champion, Pseudocetherinae Villiers, Salyavatinae Amyot & Serville and Sphaeridopinae Amyot & Serville are treated as junior synonyms of Reduviinae sensu nov. Epiroderinae Distant are synonymized with Phimophorinae Handlirsch sensu nov. and Bactrodini Stål stat. nov. are reclassified as a tribe of Harpactorinae Amyot & Serville. Psophidinae Distant is treated as a valid subfamily. This new classification represents a robust framework for future taxonomic and evolutionary research on assassin bugs.Zoobank Registration: http://zoobank.org/urn:lsid:zoobank.org:pub:2310C9AA-0D53-4EF6-9E75-C2B3A98CE096

Combined effects of the assassin bug alloeocranum biannulipes mont. And sign. (hemiptera: reduviidae) and botanical powders in the control of the stored yam chips beetle, dinoderus porcellus lesne (coleoptera : bostrichidae)

Background Dinoderus porcellus Lesne (Coleoptera: Bostrichidae) is the main pest of stored dried yam chips that causes significant losses in a few months. The assassin bug, Alloeocranum biannulipes (Montrouzier & Signoret) (Hemiptera: Reduviidae) and the Khaya senegalensis (Desv.) A. Juss. (Meliaceae), Blighia sapida K. Koenig (Sapindaceae) and Bridelia ferruginea Benth. (Euphorbiaceae) leaf powders have proven to be efficient in the control of this pest. Methods This study aims to evaluate the compatibility of the leaf powders of these medicinal plants and the predator A. biannulipes in the integrated management of D. porcellus under laboratory and farm conditions. Various leaf powders were tested at a concentration of 6% (w/w) with or without the predator. Yam chips mixed with leaf powder from each species served as negative and those mixed with a synthetic insecticide as positive controls. Results The results revealed that no combination of leaf powders and predators could induce complete mortality of D. porcellus like the synthetic insecticide. No significant difference in terms of the survival of A. biannulipes exposed to botanical powders was observed compared to the positive control. Under farm conditions, B. ferruginea leaf powder showed a sub-lethal effect on the predator A. biannulipes and no impact on the abundance of D. porcellus. However, the survival of D. porcellus was significantly reduced by the combination of K. senegalensis leaf powder and A. biannulipes, which did not allow the reproduction of the predator. Conclusions We recommend the combination of K. senegalensis leaf powder and A. biannulipes for the short-term conservation of yam chips as part of an augmentative biological control program. For long-term conservation, we suggest the use of a combination of B. sapida leaf powder with the predator A. biannulipes because it presented a reduced population of D. porcellus after 8 weeks of storage and offspring of A. biannulipes.

Discovery in leaf litter: uncovering the systematics of Porcelloderes (Heteroptera: Reduviidae: Phimophorinae)

Abstract The subfamily Phimophorinae includes ~113 species of cryptic assassin bugs found in the Neotropics and Paleotropics. Presumably due to its small size, cryptic coloration, and occurrence in the remote Eastern Arc Mountains (EAM), Porcelloderes impenetrabilis Rédei, 2012 (Heteroptera: Reduviidae: Phimophorinae), was only recently described as the first representative of this subfamily from mainland Africa. Previous morphology-based phylogenetic research on Phimophorinae (then known as Physoderinae or Epiroderinae) recovered Porcelloderes as sister taxon to the remaining epiroderine-lineage of Phimophorinae. Recent fieldwork in Tanzania has resulted in 241 additional specimens of Porcelloderes from 3 EAM) ranges. We used molecular and morphological analyses for these 241 specimens to (i) determine their species identity, (ii) test the phylogenetic position of Porcelloderes within Phimophorinae, and (iii) determine if divergence within Porcelloderes coincides with periods of climate-driven forest fragmentation in the EAM. Specimens from the Kimboza and Nguru Mountains likely represent P. impenetrabilis, but we here describe Porcelloderes harles, n. sp., from the Udzungwa Mountains. Our molecular phylogeny shows Porcelloderes nested within the epiroderine-lineage of Phimophorinae and as sister taxon to a Madagascar clade. We estimate that the epiroderine-lineage diverged from other Phimophorinae ~44 MYA. The divergence estimates for the 2 Porcelloderes species is ~15 MYA, consistent with proposed dates for other EAM assassin bugs and a period of forest fragmentation.

First record of Canthesancus gulo Stal, 1863 (Reduviidae, Stenopodainae) from Maharashtra, India

The brownish castaneous spot assassin bug Canthesancus gulo Stal, 1863 is reported from Maharashtra for the first time, as the first species of this genus in the Maharashtra state. The diagnostic characters, colour images, and current geographical distribution of species are given.

Structure and bioactivity of an insecticidal trans-defensin from assassin bug venom

Disulfide-rich peptides such as defensins play diverse roles in immunity and ion channel modulation, as well as constituting the bioactive components of many animal venoms. We investigated the structure and bioactivity of U-RDTX-Pp19, a peptide previously discovered in venom of the assassin bug Pristhesancus plagipennis. Recombinant Pp19 (rPp19) was found to possess insecticidal activity when injected into Drosophila melanogaster. A bioinformatic search revealed that domains homologous to Pp19 are produced by assassin bugs and diverse other arthropods. rPp19 co-eluted with native Pp19 isolated from P.plagipennis, which we found is more abundant in hemolymph than venom. We solved the three-dimensional structure of rPp19 using 2D 1H NMR spectroscopy, finding that it adopts a disulfide-stabilized structure highly similar to known trans-defensins, with the same cystine connectivity as human α-defensin (I-VI, II-IV, and III-V). The structure of Pp19 is unique among reported structures of arthropod peptides.

New species and reclassification of the fossil assassin bug Koenigsbergia (Hemiptera: Reduviidae: Phimophorinae)

The assassin bug genus Koenigsbergia Popov, 2003 is currently monotypic and represented by a female holotype from Baltic Amber (~33.9–55.8 MYA). The genus was originally described within Phymatinae (Phymatine Complex or phymatine clade). However, our literature review reveals that the amber fossil likely belongs to the subfamily Phimophorinae, which is distantly related to the phymatine clade. The recent acquisition of one male and one nymph of Koenigsbergia provides the opportunity to reevaluate the systematic placement of this genus. We here examine the new fossils, concluding that the adult male represents an undescribed species, and describe it as Koenigsbergia explicativa, new species. Our morphological comparison between Phimophorinae, Phymatinae, and Koenigsbergia (macro imagining, scanning electron microscopy) shows that the fossil genus shares notable similarities with Phimophorus Bergroth, 1886 and Mendanocoris Miller, 1956. We therefore formally transfer the fossil genus to Phimophorinae.

Zelus longipes (Linnaeus, 1767) (Hemiptera: Reduviidae: Harpactorinae) as a predator of Apis mellifera L., 1758 (Hymenoptera: Apidae) in Brazil

Zelus longipes (Linnaeus 1767) is an insect known as an assassin bug (Reduviidae) member of the subfamily Harpactorinae. Its distribution includes southern North America, Central America, and South America (except Chile), and especially in agroecosystems in Brazil. Z. longipes has been considered a potential biocontrol agent, as it prefers the caterpillars of Spodoptera frugiperda (Smith, 1797), which is a pest moth of corn fields. This article aims to describe the predatism of Z. longipes on the prey Apis mellifera L., 1758 (Hymenoptera: Apidae) in Terminalia mantaly Perrier (Combretaceae). During the collection of flies with an entomological net in the urban area of the Federal University of Goiás, in November 2017, the stink bug of the species Z. longipes was collected carrying in its trunk a specimen of A. mellifera in an almond tree known as the Madagascar almond tree of the species T. mantaly, also called Sete Copas.

Phylogeographic Pattern of the Assassin Bug Sycanus bifidus Inferred from Mitochondrial Genomes and Nuclear Genes.

The assassin bug Sycanus bifidus has a wide distribution across southern China. This study explored its distribution and evolution by analyzing mitochondrial and nuclear ribosomal RNA genes, revealing how Pleistocene climate and geological changes shaped its phylogeography. We identified two main clades, A and B, that diverged in the Middle Pleistocene. Hainan Island's populations form a unique group within Clade A, suggesting that the Qiongzhou Strait served as a dispersal corridor during glaciation. Rising sea levels likely separated the Hainan population afterward. Ecological niche modeling showed that both populations have been viable since the last interglacial period, with demographic analyses indicating possible expansions during the Middle and Late Pleistocene, driven by favorable climates. This study highlights the significant effects of Pleistocene sea-level and climatic changes on the distribution and evolution of S. bifidus in China.

Phimophorus chiodii sp. nov., first representative of a cryptic assassin bug subfamily from Dominican amber (Reduviidae: Phimophorinae) as revealed with traditional light microscopy and computed micro-tomographic reconstruction

Phimophorus chiodii sp. nov., first representative of a cryptic assassin bug subfamily from Dominican amber (Reduviidae: Phimophorinae) as revealed with traditional light microscopy and computed micro-tomographic reconstruction

Occurrence of Stenopoda spinulosa Giacchi, 1969 (Hemiptera, Reduviidae, Stenopodainae) in Brazil

The Reduviidae family is economically important, as many species are used in the biological control of agricultural pests. Many species in the Stenopodainae subfamily are endemic to tropical forests, and some smear their front paws with sticky plant-derived resin to help capture prey. The genus Stenopoda Laporte, 1833, has 14 species in Brazil. Stenopoda spinulosa Giacchi, 1969 (Reduviidae: Stenopodainae) has so far only been reported for the State of Rio Grande do Sul. They have wings that serve to protect the second pair of membranous wings and the body against crushing shocks. They are characterized by rigidity close to the notch of the wing and, at the same time, by the membranous region at the tip of the wing in the distal region. Their bite can cause edema, allergies, pain, and inflammation. To collect insects, a sweeping net or entomological net was used in shrubs and grasses. The objective of this study is to report the first occurrence of S. spinulosa in the State of Goiás, Brazil.

Social wasps (Vespidae: Polistinae) harvesting food bodies of Cecropia Loefl. (Urticaceae) in Central Amazon

Social wasps are among the most curious non-ant insects known to harvest food bodies of Cecropia Loefl. The aim of this note is to describe for the first time: (1) interactions between wasp species which harvest food bodies; (2) interactions of these wasps with other insects associated to Cecropia (ants, assassin bugs); (3) the use of a food resource different from müllerian bodies; and (4) wasp species whose association with Cecropia was unknown until now. All records were made in Manaus region and in Uatumã Sustainable Development Reserve (Amazonas State, Brazil), with the aid of a digital camera. The wasp and ant species involved were captured for later identification. The recorded wasp species were: Charterginus xanthura Saussure, 1854, Protopolybia chartergoides Gribodo, 1891, Protopolybia minutissima Spinola, 1851, and Synoeca virginea Fabricius, 1804 (Hymenoptera: Vespidae). The findings corroborate the importance of food bodies not only for Azteca Forel, 1878 ants, but also for other social insects.

First report of the predatory potential and functional response of the red flower assassin bug Rhynocoris segmentarius (Germar), a natural enemy of Spodoptera frugiperda (J.E. Smith)

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is currently the most devastating invasive arthropod pest of maize in sub-Saharan Africa. Following its first report in Ghana in 2016, control has been reliant mainly on synthetic chemicals. However, biocontrol has been an effective, sustainable, cheaper, and environmentally friendly option for FAW management. We tested the potential of the red flower assassin bug, Rhynocoris segmentarius (Germar) (Hemiptera: Reduviidae) as a natural enemy candidate for augmentative biocontrol of FAW in Ghana by assessing its predatory rate and functional response under laboratory conditions in Ghana. The feeding responses of the five nymphal instars and adults (female and male) of R. segmentarius were tested against three larvae ages of FAW: (i) < 1 day old or newly emerged (NE), (ii) 2 days old, and (iii) 6 days old, at six different prey densities: 5, 15, 25, 30, 35, and 40, respectively. All life-stages of R. segmentarius successfully attacked, killed, and fed on the larvae of S. frugiperda, and exhibited a Type II functional response. However, the first and second nymphal stages of R. segmentarius did not successfully attack or kill six-day-old FAW larvae. Females had a significantly higher attack rate (7.79 ± 1.01) and the shortest handling time (1.17 x 10–1) than all life-stages. Our results suggest that R. segmentarius is a potential candidate for augmentative biocontrol of S. frugiperda.

Integument morphology of assassin bugs of the genus Platymeris

The study of the integument or external integument of insects that have the most pronounced diversity of forms and functions among other invertebrates, allows to use them successfully in materials science, nanotechnology and other areas. Common in captivity, primarily due to their aesthetic appearance, assassin bugs of the genus Platymeris (Pl. biguttatus; Pl. rhadamanthus) are of particular interest since they are characterized by significant morphological features of different parts of the exoskeleton. In addition to the common chitinous covers, they have a rostrum, that differs from the general structure of the cuticle and has specific characteristics. In this regard, we set out to study the morphological features of the microstructure of various parts of the integument of assassin bugs of the genus Platymeris. To study the integument, histological preparations were made using an adapted technique. Based on the data received we can point out significant variability in the organization of the integument depending on the location and function performed. The least variety of structure was observed in the protocuticle, which is probably due to its more ancient origin and the fact that it determines the shape of a specific section of the insect. Despite the fact that it takes a long time and significant changes in the microstructure to identify them, in the studied bugs areas (rostrum) that differed from the typical organization of the protocuticle were discovered.

Female mate choice is affected by male condition but not female condition in an assassin bug

Abstract Sexual selection theory predicts that females prefer males in good condition because mating with them provides more resources such as sperm, ejaculates and nuptial gifts. The female's condition also affects her mating decisions, and condition‐dependent mate choice may allow her to gain more resources from a mate in the context of fluctuating resource availability. We here investigated how female mating decisions and their fitness consequences varied in the assassin bug Amphibolus venator when the conditions of potential mates and/or the females differed (good or poor condition). Females in both good and poor conditions preferred males in good condition, and females that mated with males in good condition produced more eggs with higher hatch rates. This increase in fitness may be attributed to the males in good condition transferring more ejaculate to the females. In contrast, female mate preference, fecundity and hatch rates were not affected by their own condition. This suggests that females do not choose mates according to their own condition in A. venator. However, the females in good condition laid larger eggs than females in poor condition, implying that females in good condition may invest more per egg to improve their reproductive success. To understand the evolution of female mate choice, it is necessary to investigate the effects of the condition of both sexes on female mating decision and their fitness. In A. venator, male condition may affect mate choice more than female condition.

Life Cycle and Morphometric Analysis of Yellow Assassin Bug Cosmolestes Pecticeps Stal (Hemiptera: Reduviidae) Feed on Elaeidobius Kamerunicus Faust (Coleoptera: Curculionidae)

Elaeidobius kamerunicus is an important insect in oil palm ecosystems, as it is the primary pollinator of oil palm flowers. Oil palm is an economically important crop, and its cultivation requires the successful pollination of its flowers to ensure high yields. Without the pollination services of insects such as E. kamerunicus, oil palm production would be significantly reduced. Additionally, E. kamerunicus is known as a food source for the yellow assassin bug Cosmolestes pecticeps. Understanding the interactions between E. kamerunicus and predators such as the yellow assassin bug is crucial for the sustainable management of oil palm ecosystems. This study aims to provide preliminary data on the yellow assassin bug’s life cycle and feeding habits, focusing on its prey, E. kamerunicus, and morphometric analysis. We found that E. kamerunicus is a common prey of the yellow assassin bug, and its feeding habits significantly impact the ecology of its inhabited areas. Our study provides valuable insights which could be useful for future research in the field. Understanding the interactions between the yellow assassin bug and E. kamerunicus in oil palm ecosystems is important to manage and maintain their ecological balance effectively in supporting sustainable agriculture.

ANTI-APOSTATIC FEEDING BEHAVIOR IN TWO SPECIES OF ASSASSIN BUG, THE WHITE-SPOTTED ASSASSIN BUG PLATYMERIS BIGUTTATUS AND RED-SPOTTED ASSASSIN BUG PLATYMERIS RHADAMANTHUS (HEMIPTERA: REDUVIIDAE)

Abstract Predator-prey relationships are a driving force when examining community ecology. One question in predator-prey interactions is how a predator may respond to novel prey phenotypes, a form of frequency dependent prey selection. A predator may selectively target or avoid the novel prey, a behavior referred to as anti-apostatic or apostatic selection respectively. We examined apostatic prey selection by observing feeding behavior in two species of assassin bugs (Hemiptera: Reduviidae), the white-spotted assassin bug (Platymeris biguttatus) and the red-spotted assassin bug (Platymeris rhadamanthus) which were fed unmodified and modified (novel) phenotypes of Turkistan cockroaches, Blatta lateralis (Blattodea: Blattidae). The two species of assassin bugs represent either generalist (P. biguttatus) or specific feeders (P. rhadamanthus). We hypothesized that the generalist feeder would engage in anti-apostatic feeding while the specific feeder would engage in apostatic feeding. Our results indicated that there was no difference in feeding behavior between the two species, however an overall trend of apostatic feeding was observed in response to two of the four novel prey phenotypes. Factors beyond prey phenotype may also be influencing feeding choice in these insects. While the two predator species did not exhibit different feeding behaviors, the observation of apostatic feeding in this genus suggest an overall trend of utilizing specific prey images in feeding.

Maintaining understory vegetation in oil palm plantations supports higher assassin bug numbers

Abstract The expansion of oil palm agriculture across Southeast Asia has caused significant biodiversity losses, with the reduction in habitat heterogeneity that accompanies the conversion of forest to oil palm being a major contributing factor. However, owing to their long commercial lifespan, oil palm plantations can support relatively high levels of vegetation complexity compared to annual crops. There is therefore potential for the implementation of management strategies to increase vegetation complexity and associated within‐plantation habitat heterogeneity, enhancing species richness and associated ecosystem functioning within productive oil palm landscapes. This study focusses on two species of asassin bugs Cosmolestes picticeps and Sycanus dichotomus, which are important agents of pest control within oil palm systems. Using a Before‐After Control‐Impact experimental manipulation in Sumatra, Indonesia, we tested the effect of three alternative herbicide spraying regimes and associated vegetation complexity treatments on assassin bug numbers. Our treatments encompass a range of current understory vegetation management practices used in oil palm plantations and include removing vegetation only in areas key to harvesting (“Normal”), removing all understory vegetation (“Reduced”), and allowing native vegetation to regrow naturally (“Enhanced”). We assessed both the long‐term (18 months) and short‐term (within 2 weeks) effects of our treatments following herbicide spraying. Pre‐treatment, we found high numbers of assassin bugs of both species in all plots. Long‐term post‐treatment, the abundance of both C. picticeps and S. dichotomus declined in reduced understory plots, although this decline was only significant for C. picticeps (98%). In contrast, there were no significant differences in the post‐treatment abundance of either species in the short‐term. These results suggest that the long‐term decline in assassin bug abundance was likely to be caused by loss of vegetation, rather than any immediate effects of the herbicide spraying. Our findings have clear management implications as they demonstrate that maintaining vegetation in oil palm understories can benefit an important pest control agent.