Malaise Trap Samples Research Articles

Synchronised monitoring of plant and insect diversity: a case study using automated Malaise traps and DNA-based methods.

The occurrence and distribution of insects and their possible associations with plant species are largely unknown in Germany and baseline data to monitor future trends are urgently needed. Using newly-designed automated Malaise trap multi-samplers, the occurrence of insect species and their potential associations with plants was monitored synchronously at two contrasting field sites in Germany: an urban botanical garden and a forest research station. Taxa were identified by metabarcoding of the insects and the plant traces present in the preservative ethanol of the Malaise trap samples. For comparison, a botanical survey was conducted in the vicinity of the traps. Across both sites, we identified a total of 1290 exact sequence variants (ESVs) assigned to Insecta, of which 205 are known to be pollinators. In the botanical garden, we detected the occurrence of 128 plant taxa, of which 41 also had one of their known insect pollinator species detected. Insect species richness was highest in May, mainly attributed to an increase in Diptera. These results present a case study of the applicability of automated sampling and DNA-based methods to monitor the timings of flowering and corresponding activity of plant-visiting insects.

Unveiling South African insect diversity: DNA barcoding’s contribution to biodiversity data

Insects are one of the most species-rich groups on Earth. They comprise much of animal diversity and play vital roles in ecosystems, including pollination, pest control, and decomposition. However, only a fraction of this diversity has been formally described. South Africa is recognised as one of the most biologically diverse countries globally, with an estimated 44 000 insect species. Many crops rely on insect pollinators, including canola, apples, oranges, and sunflowers. A shortage of wild pollinators currently threatens crop yields, yet our knowledge of insect diversity within South Africa is sparse. There are few taxonomic specialists relative to South Africa’s biodiversity, and the methods used for insect identification can be time-consuming and expensive. DNA barcoding provides an important research tool to accelerate insect biodiversity research. In this review, we queried the public DNA barcoding BOLD (Barcode of Life Data System) database for records of “Insecta” within South Africa, and 416 211 published records assigned to 28 239 unique BINs (Barcode Index Numbers) were returned. We identified five taxonomic orders with more BINs than known species in southern Africa (Hymenoptera, Diptera, Thysanoptera, Plecoptera, and Strepsiptera). Most of the barcoded records were derived from Malaise trap sampling in Gauteng, Mpumalanga and Limpopo, while the rest of South Africa remains poorly sampled. We suggest that there is a need for a comprehensive national sampling effort alongside increased investment in taxonomic expertise to generate critical baseline data on insect biodiversity before species are lost to extinction.

Combining environmental DNA and remote sensing for efficient, fine-scale mapping of arthropod biodiversity.

Arthropods contribute importantly to ecosystem functioning but remain understudied. This undermines the validity of conservation decisions. Modern methods are now making arthropods easier to study, since arthropods can be mass-trapped, mass-identified, and semi-mass-quantified into 'many-row (observation), many-column (species)' datasets, with homogeneous error, high resolution, and copious environmental-covariate information. These 'novel community datasets' let us efficiently generate information on arthropod species distributions, conservation values, uncertainty, and the magnitude and direction of human impacts. We use a DNA-based method (barcode mapping) to produce an arthropod-community dataset from 121 Malaise-trap samples, and combine it with 29 remote-imagery layers using a deep neural net in a joint species distribution model. With this approach, we generate distribution maps for 76 arthropod species across a 225 km2 temperate-zone forested landscape. We combine the maps to visualize the fine-scale spatial distributions of species richness, community composition, and site irreplaceability. Old-growth forests show distinct community composition and higher species richness, and stream courses have the highest site-irreplaceability values. With this 'sideways biodiversity modelling' method, we demonstrate the feasibility of biodiversity mapping at sufficient spatial resolution to inform local management choices, while also being efficient enough to scale up to thousands of square kilometres. This article is part of the theme issue 'Towards a toolkit for global insect biodiversity monitoring'.

Effectiveness of Malaise trap and sweep net sampling in sawfly research (Hymenoptera: Symphyta)

Malaise traps and sweep nets are commonly used to study sawfly faunas, seasonality and communities. Here we analyse a large dataset obtained with these methods in Slovakia and Hungary over the last two and a half decades. The dataset included collections from twenty-one sites, each covering the entire growing season, eleven of which were obtained with the Malaise trap and ten with the sweep net. We conclude that both methods are suitable for faunistic studies of sawflies (Hymenoptera, Symphyta), although they may lead to certain biased results for some Symphyta groups. Special attention should be paid to Siricidae, Orussidae, Xiphidriidae and Cimbicidae, which were only weakly recorded with both methods. Argidae, Blennocampinae, Dolerinae and Tenthredininae were underrepresented in the Malaise trap samples and Allantinae in the sweep net samples. Both methods gave equally good results in measuring species richness in an one-year study. Ideally, they should be used together as they complement each other well. The net method has a great advantage in determining the exact population density. In contrast, the Malaise trap collections were often heavily dominated by only a few species, with males being preferentially trapped. Use of Malasie trap should be preferred for the study of seasonal flight activity.

Black gold rush - Evaluating the efficiency of the Fractionator in separating Hymenoptera families in a meadow ecosystem over a two week period.

In the face of insect decline, monitoring projects are launched widely to assess trends of insect populations. Collecting over long time periods results in large numbers of samples with thousands of individuals that are often just stored in freezers waiting to be further processed. As the time-consuming process of sorting and identifying specimens prevents taxonomists from working on mass samples, important information on species composition remains unknown and taxonomically neglected species remain undiagnosed. Size fractioning of bulk samples can improve sample handling and, thus, can help to overcome the taxonomic impediment. In this paper, we evaluate the efficiency of the fractionator in separating Hymenoptera families from a Malaise trap sample of a meadow ecosystem over a two week interval to make them available for further morphological identification. The fractionator system by Buffington and Gates (2008) was used to separate the sample in two size classes - a large (macro) and a small (micro) fraction - and Hymenoptera specimens were then counted and identified on family level. In total, 2,449 Hymenoptera specimens were found in the macro fraction and 3,016 in the micro fraction (5,465 specimens in total). For 24 out of 34 Hymenoptera families (71%), separation was significant. This study illustrates the efficiency of the fractionator and its potential to improve workflows dealing with specimen-rich Malaise trap samples.

Xylota norma sp. nov., a second hoverfly species (Diptera: Syrphidae) in its genus for Tasmania and for Australia

This work describes a new and distinctive species of hoverfly, Xylota norma sp. nov., discovered in Malaise trap samples collected from the Tarkine rainforests of northwest Tasmania during the austral summer of 2021-22. To date, the species is only known from the type series of six specimens. It is only the second species in its genus known from Australia – the other species, Xylota flavitarsis, is widespread along the eastern seaboard of Australia and throughout Tasmania.

FAVIS: Fast and versatile protocol for non-destructive metabarcoding of bulk insect samples.

Insects are diverse and sustain essential ecosystem functions, yet remain understudied. Recent reports about declines in insect abundance and diversity have highlighted a pressing need for comprehensive large-scale monitoring. Metabarcoding (high-throughput bulk sequencing of marker gene amplicons) offers a cost-effective and relatively fast method for characterizing insect community samples. However, the methodology applied varies greatly among studies, thus complicating the design of large-scale and repeatable monitoring schemes. Here we describe a non-destructive metabarcoding protocol that is optimized for high-throughput processing of Malaise trap samples and other bulk insect samples. The protocol details the process from obtaining bulk samples up to submitting libraries for sequencing. It is divided into four sections: 1) Laboratory workspace preparation; 2) Sample processing-decanting ethanol, measuring the wet-weight biomass and the concentration of the preservative ethanol, performing non-destructive lysis and preserving the insect material for future work; 3) DNA extraction and purification; and 4) Library preparation and sequencing. The protocol relies on readily available reagents and materials. For steps that require expensive infrastructure, such as the DNA purification robots, we suggest alternative low-cost solutions. The use of this protocol yields a comprehensive assessment of the number of species present in a given sample, their relative read abundances and the overall insect biomass. To date, we have successfully applied the protocol to more than 7000 Malaise trap samples obtained from Sweden and Madagascar. We demonstrate the data yield from the protocol using a small subset of these samples.

Insects benefit from agri-environmental schemes aiming at grassland extensification

One key target of agri-environmental schemes (AES) is maintaining biodiversity. However, if and how insect biomass and diversity benefit from grassland AES is not well known. Using Malaise trap samples from 72 grassland sites in four grassland dominated regions in Southern Germany, we investigated the effect of 1) local grassland AES (three levels: control, farm-wide, site-specific), and 2) an index of land use extensification (LEI, calculated for each site) on insect biomass and species richness of all insects, of five insect orders including all species (Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera), and two pollinator groups (Syrphidae, Apiformes). Moreover, the effect of grassland AES in the surrounding landscape was quantified. Insect samples were subjected to metabarcoding to create DNA barcode sequences which were then compared with reference libraries (BOLD; NCBI) and additionally classified using the Ribosomal Database Project (RDP) classifier. Resulting taxonomies were combined into a consensus taxonomy table and the potential minimum number of species per sample was estimated. Statistical analyses were carried out using Generalized linear mixed models and Bayesian inference. Our results indicated that species richness of many insect groups benefited from AES. As predicted by the regression model, presence of site-specific grassland AES increased the species richness of all insects (∼8%), Hymenoptera (∼27%), Lepidoptera (∼35%) and Syrphidae (∼26%). While Apiformes benefited most, we found an average increase of species richness in the presence of farm-wide AES by ∼82% and even more with site-specific AES ∼120%. We found that an increasing LEI, and thus more extensive management, positively affected insect diversity in grassland habitats. No effect of local AES and LEI on insect biomass was found. Moreover, the amount of grassland AES in the landscape was less important for insect diversity. We conclude that many grassland insects (especially pollinators) benefit from extensive management. However, we showed that the studied AES variants comprise variable management intensities hampering general AES recommendations for promoting insects. AES programs should, therefore, specifically reward extensification measures that were shown to benefit insect diversity. The integration of the land use extensification index (LEI) as a tool in the AES framework seems a promising approach to preserve and promote of insect diversity.

Differentiating the effects of organic management, pesticide reduction, and landscape diversification for arthropod conservation in viticulture

Biodiversity loss is a main challenge for agricultural sustainability. Major drivers include local management and landscape simplification. Therefore, conservation measures aim to increase organic agriculture, reduce pesticide use, and increase the proportion of semi-natural habitats (SNH). Yet, it is important to understand the effects of such measures. We investigate how arthropod biomass, taxa richness, and community composition in Malaise trap samples are affected by organic management, pesticide use, and SNH in the landscape. The 32 studied vineyards were chosen in a crossed design of management (organic vs. conventional) and pesticide use (regular vs. reduced) along a gradient of landscape composition. Pesticide reduction by 55% was obtained by including half of the vineyards with fungus-resistant grape (FRG) varieties. Malaise trap samples were weighed and arthropods identified using metabarcoding. Surprisingly, biomass was almost one-third higher in conventionally managed vineyards compared to organic ones. Taxa richness increased by more than one third when the proportion of SNH in a radius of 1,000 m in the surrounding landscape increased from zero to 50%. Diptera richness tended to be 4% higher in conventionally managed vineyards and the richness of Hymenoptera was 9% higher in FRG varieties. Community composition changed with the proportion of SNH and differed between organic and conventional management. Overall, organic viticulture was not effective to enhance the arthropod community, which was dominated by flying insects in our study. Agricultural policies should therefore rather preserve and promote SNH in the surrounding in order to promote arthropod biodiversity in viticultural landscapes.

Using DNA metabarcoding to assess insect diversity in citrus orchards.

DNA metabarcoding is rapidly emerging as a cost-effective approach for large-scale biodiversity assessment and pest monitoring. The current study employed metabarcoding to assess insect diversity in citrus orchards in Ganzhou City, Jiangxi, China in both 2018 and 2019. Insects were sampled using Malaise traps deployed in three citrus orchards producing a total of 43 pooled monthly samples. The Malaise trap samples were sequenced following DNA metabarcoding workflow. Generated sequences were curated and analyzed using two cloud databases and analytical platforms, the barcode of life data system (BOLD) and multiplex barcode research and visualization environment (mBRAVE). These platforms assigned the sequences to 2,141 barcode index numbers (BINs), a species proxy. Most (63%) of the BINs were shared among the three sampling sites while BIN sharing between any two sites did not exceed 71%. Shannon diversity index (H') showed a similar pattern of BIN assortment at the three sampling sites. Beta diversity analysis by Jaccard similarity coefficient (J) and Bray-Curtis distance matrix (BC) revealed a high level of BIN similarity among the three sites (J = 0.67-0.68; BC = 0.19-0.20). Comparison of BIN records against all those on BOLD made it possible to identify 40% of the BINs to a species, 57% to a genus, 97% to a family and 99% to an order. BINs which received a species match on BOLD were placed in one of four categories based on this assignment: pest, parasitoid, predator, or pollinator. As this study provides the first baseline data on insect biodiversity in Chinese citrus plantations, it is a valuable resource for research in a broad range of areas such as pest management and monitoring beneficial insects in citrus gardens.

Depicting environmental gradients from Malaise trap samples: Is ethanol‐basedDNAmetabarcoding enough?

AbstractDNA metabarcoding is revolutionising biodiversity research, as it offers researchers a holistic taxonomic approach across lineages. Many studies are dedicated to testing its application and optimising workflows. One topic of discussion is the nature of samples used for sequencing and comparing taxonomic results.However, in ecological and environmental studies, where scientists always work with subsets of species, it may be less important whether different methods provide different subsets but more important if ecological and environmental information is conserved equally.Numerous studies have successfully applied destructive and non‐destructive metabarcoding approaches to evaluate patterns in biodiversity and in this respect, we aim to determine for the very first time whether environmental information is also conserved in the preservative ethanol of terrestrial arthropod bulk samples.To test this, we applied DNA metabarcoding on tissue DNA and on ethanol‐based DNA of the same Malaise trap samples. The arthropod material was collected with eight traps located in three different habitats: forest, meadow, and riparian.We identified more than 3000 operational taxonomic units and demonstrate that ethanol‐based DNA sequencing did not provide information on ecological gradients, except for the case of seasonal patterns, which was well conserved for some taxa.The conserved seasonality is an interesting starting point for further investigations. Until future research has provided more successful results, we recommend researchers dealing with terrestrial ecosystems to be careful when using ethanol DNA.

Comparison of destructive and nondestructive DNA extraction methods for the metabarcoding of arthropod bulk samples.

DNA metabarcoding is routinely used for biodiversity assessment, in particular targeting highly diverse groups for which limited taxonomic expertise is available. Various protocols are currently in use, although standardization is key to its application in large-scale monitoring. DNA metabarcoding of arthropod bulk samples can be conducted either destructively from sample tissue, or nondestructively from sample fixative or lysis buffer. Nondestructive methods are highly desirable for the preservation of sample integrity but have yet to be experimentally evaluated in detail. Here, we compare diversity estimates from 14 size-sorted Malaise trap samples processed consecutively with three nondestructive approaches (one using fixative ethanol and two using lysis buffers) and one destructive approach (using homogenized tissue). Extraction from commercial lysis buffer yielded comparable species richness and high overlap in species composition to the ground tissue extracts. A significantly divergent community was detected from preservative ethanol-based DNA extraction. No consistent trend in species richness was found with increasing incubation time in lysis buffer. These results indicate that nondestructive DNA extraction from incubation in lysis buffer could provide a comparable alternative to destructive approaches with the added advantage of preserving the specimens for postmetabarcoding taxonomic work but at a higher cost per sample.

The potential of metabarcoding plant components of Malaise trap samples to enhance knowledge of plant-insect interactions

The worldwide rapid declines in insect and plant abundance and diversity that have occurred in the past decades have gained public attention and demand for political actions to counteract these declines are growing. Rapid large-scale biomonitoring can aid in observing these changes and provide information for decisions for land management and species protection. Malaise traps have long been used for insect sampling and when insects are captured in these traps, they carry traces of plants they have visited on the body surface or as digested food material in the gut contents. Metabarcoding offers a promising method for identifying these plant traces, providing insight into the plants with which insects are directly interacting at a given time. To test the efficacy of DNA metabarcoding with these sample types, 79 samples from 21 sites across Germany were analysed with the ITS2 barcode. This study, to our knowledge, is the first examination of metabarcoding plant DNA traces from Malaise trap samples. Here, we report on the feasibility of sequencing these sample types, analysis of the resulting taxa, the usage of cultivated plants by insects near nature conservancy areas and the detection of rare and neophyte species. Due to the frequency of contamination and false positive reads, isolation and PCR negative controls should be used in every reaction. Metabarcoding has advantages in efficiency and resolution over microscopic identification of pollen and is the only possible identification method for the other plant traces from Malaise traps and could provide a broad utility for future studies of plant-insect interactions.

Climate-induced forest dieback drives compositional changes in insect communities that are more pronounced for rare species

Species richness, abundance and biomass of insects have recently undergone marked declines in Europe. We metabarcoded 211 Malaise-trap samples to investigate whether drought-induced forest dieback and subsequent salvage logging had an impact on ca. 3000 species of flying insects in silver fir Pyrenean forests. While forest dieback had no measurable impact on species richness, there were significant changes in community composition that were consistent with those observed during natural forest succession. Importantly, most observed changes were driven by rare species. Variation was explained primarily by canopy openness at the local scale, and the tree-related microhabitat diversity and deadwood amount at landscape scales. The levels of salvage logging in our study did not explain compositional changes. We conclude that forest dieback drives changes in species assemblages that mimic natural forest succession, and markedly increases the risk of catastrophic loss of rare species through homogenization of environmental conditions.

DiversityScanner: Robotic handling of small invertebrates with machine learning methods.

Invertebrate biodiversity remains poorly understood although it comprises much of the terrestrial animal biomass, most species and supplies many ecosystem services. The main obstacle is specimen-rich samples obtained with quantitative sampling techniques (e.g., Malaise trapping). Traditional sorting requires manual handling, while molecular techniques based on metabarcoding lose the association between individual specimens and sequences and thus struggle with obtaining precise abundance information. Here we present a sorting robot that prepares specimens from bulk samples for barcoding. It detects, images and measures individual specimens from a sample and then moves them into the wells of a 96-well microplate. We show that the images can be used to train convolutional neural networks (CNNs) that are capable of assigning the specimens to 14 insect taxa (usually families) that are particularly common in Malaise trap samples. The average assignment precision for all taxa is 91.4% (75%-100%). This ability of the robot to identify common taxa then allows for taxon-specific subsampling, because the robot can be instructed to only pick a prespecified number of specimens for abundant taxa. To obtain biomass information, the images are also used to measure specimen length and estimate body volume. We outline how the DiversityScanner can be a key component for tackling and monitoring invertebrate diversity by combining molecular and morphological tools: the images generated by the robot become training images for machine learning once they are labelled with taxonomic information from DNA barcodes. We suggest that a combination of automation, machine learning and DNA barcoding has the potential to tackle invertebrate diversity at an unprecedented scale.

Pooling size sorted Malaise trap fractions to maximize taxon recovery with metabarcoding.

BackgroundSmall and rare specimens can remain undetected when metabarcoding is applied on bulk samples with a high specimen size heterogeneity. This is especially critical for Malaise trap samples, where most of the biodiversity is contributed by small taxa with low biomass. The separation of samples in different size fractions for downstream analysis is one possibility to increase detection of small and rare taxa. However, experiments systematically testing different size sorting approaches and subsequent proportional pooling of fractions are lacking, but would provide important information for the optimization of metabarcoding protocols. We set out to find a size sorting strategy for Malaise trap samples that maximizes taxonomic recovery but remains scalable and time efficient.MethodsThree Malaise trap samples were sorted into four size classes using dry sieving. Each fraction was homogenized and lysed. The corresponding lysates were pooled to simulate unsorted samples. Pooling was additionally conducted in equal proportions and in four different proportions enriching the small size fraction of samples. DNA from the individual size classes as well as the pooled fractions was extracted and metabarcoded using the FwhF2 and Fol-degen-rev primer set. Additionally, alternative wet sieving strategies were explored.ResultsThe small size fractions harboured the highest diversity and were best represented when pooling in favour of small specimens. Metabarcoding of unsorted samples decreases taxon recovery compared to size sorted samples. A size separation into only two fractions (below 4 mm and above) can double taxon recovery compared to not size sorting. However, increasing the sequencing depth 3- to 4-fold can also increase taxon recovery to levels comparable with size sorting, but remains biased towards biomass rich taxa in the sample.ConclusionWe demonstrate that size fractionation of Malaise trap bulk samples can increase taxon recovery. While results show distinct patterns, the lack of statistical support due to the limited number of samples processed is a limitation. Due to increased speed and lower risk of cross-contamination as well as specimen damage we recommend wet sieving and proportional pooling of the lysates in favour of the small size fraction (80–90% volume). However, for large-scale projects with time constraints, increasing sequencing depth is an alternative solution.

Wet grinding of invertebrate bulk samples – a scalable and cost-efficient protocol for metabarcoding and metagenomics

Most metabarcoding protocols for invertebrate bulk samples start with sample homogenisation, followed by DNA extraction, amplification of a specific marker region, and sequencing. Many of the above-mentioned laboratory steps have been verified thoroughly and best practice strategies exist, yet, no clear recommendation for the basis of almost all metabarcoding studies exists: the homogenisation of samples itself. Two different categories of devices are typically used for homogenisation: bead mills or blenders. Both have upsides and downsides. Bead mills rely on single-use plastics and therefore produce a lot of waste and are expensive. In addition to that, processing times can go up to 30 minutes making them unsuitable for large-scale studies. Blenders can handle larger sample volumes in a shorter time, and be cleaned – yet suffer from an increased risk of cross-contamination. We aimed to develop a fast, robust, cheap, and reliable sample homogenisation protocol that overcomes limitations of both approaches, i.e. does not produce difficult to discard waste and avoid single-use plastics while reducing overall costs. We tested the performance of the new protocol using six size-sorted Malaise trap samples and six unsorted stream macroinvertebrate kick-net samples. We used 14 replicates per sample and included many negative controls at different steps of the protocol to quantify the impacts of i) insufficient homogenisation and ii) cross-contamination. Our results show that 3-min homogenisation is sufficient to recover about 80% of OTUs per sample in each replicate and that a non-hazardous DIY cleaning solution provides an effective and efficient way of cleaning. The improvements of the protocol in terms of speed, ease of handling, an overall reduction of costs as well as the documented reliability and robustness make it an important candidate for sample homogenisation after sampling in particular for large-scale and regulatory metabarcoding but also metagenomics biodiversity assessments and monitoring.

Aleiodes (Hymenoptera, Braconidae, Rogadinae) diversity in Washington U.S.A. including three new species.

Aleiodes Wesmael is a large cosmopolitan genus of endoparasitoid wasps that is evidently especially speciose in the Western Hemisphere based on numbers of described species. As with most diverse insect groups, relatively little is known about Aleiodes species diversity and biology. Here I summarize what is known about Aleiodes diversity in Washington State and contiguous Inland Northwest states and province, and I report three new species recently collected by malaise trap sampling for Aleiodes in Okanogan County, WA: Aleiodes khalafi, Aleiodes okanoganensis, and Aleiodes quasiburrus. Given the number of new species (three) and first records of previously described species (two) in Washington elucidated by this study, there is evidently much work to do to reach a fair estimate of Aleiodes species diversity in the Inland Pacific Northwest.

Cooking small and large portions of “biodiversity‐soup”: Miniaturized DNA metabarcoding PCRs perform as good as large‐volume PCRs

AbstractDNA metabarcoding is a powerful tool to assess arthropod diversity in environmental bulk samples such as Malaise trap, pitfall trap, or hand net samples. While comparative performance tests for different extraction protocols, primers, and Taq polymerases have been made, the effect of different PCR volumes on bulk sample metabarcoding performance is less explored. Although using small PCR volumes reduces overall costs, they may lead to decreased taxon recovery or higher replicate variability due to increased pipetting imprecision, PCR stochasticity (PCR drift), or inhibition when using high amounts of template community DNA. We here performed a simple DNA metabarcoding experiment to test if species detection and the consistency of technical replicates decrease with decreasing PCR volume in standard reaction tubes. We used a mock community sample consisting of different amounts of DNA from 35 arthropod species, and a Malaise trap sample composed of many thousand insect specimens. PCR volumes tested were 5, 10, 15, 20, 25, and 50 µl. Both samples were replicated 14 times in the first PCR step with two technical replicates each in the second PCR step. Our data show that small PCR volumes did neither have systematically lower species detection or richness values, nor lower consistency between PCR replicates. We therefore recommend low volumes primarily depending on handling constraints. Further, we emphasize the importance of sequencing depth for taxon recovery.

Two new species of Abelocephala (Heteroptera: Reduviidae) from Taiwan

The millipede assassin bug genus Abelocephala Maldonado, 1996 (Heteroptera: Reduviidae: Ectrichodiinae: Abelocephalini) is currently comprised of seven Oriental species. Two macropterous males, representing two new species, were recently collected from Taiwan in Malaise trap samples: A. baliensis sp. nov. and A. yilanensis sp. nov. Habitus and structural images are provided for each new species. A revised diagnosis of Abelocephala and an updated identification key to all species of the genus are given.