This post turned out to be a bit of a mess and much longer than I originally intended as I gradually unearthed more and more information about the bugs, I may return to clarify and elaborate more on certain things in the future, especially the bit on Toxocamptellus.

1. Introduction

Vesbius Stål, 1865 is a genus of relatively small Harpactorines (Reduviidae: Harpactorinae) distributed in the Indomalayan realm. One particular species, Vesbius purpureus (Thunberg, 1783), is widespread throughout the region. It often inhabits urban habitats, a trait which may have contributed to its range. The 15 Vesbius species that have been described more or less all have red bodies and mostly black heads and legs. This aposematic motif is adopted by some Harpactorines in other genera which inhabit the same region, causing many of them to have been misidentified as Vesbius on iNaturalist. This post seeks to clarify the generic position of these bugs, and also to act as a reference for my own future identifications.

2. TLDR - What is NOT Vesbius

A concise (although somewhat lacking) diagnosis of Vesbius can be found here provided by W. L. Distant. Notably:

Distinguished by the structure of the head, the postocular region being nearly three times longer than the anteocular area, the eyes are inserted near the apex of the head.

(shown in image below)

This head structure is not found in any of the other genera which may resemble Vesbius superficially. This characteristic can also be observed in nymphs.

3. Further elaboration on the non-Vesbius genera

More information for differentiating between the aforementioned species not belonging to Vesbius.

3.1 "Sphedanolestes"

In 1874, in an attempt to provide better taxonomic treatment for Sphedanolestes Stål, 1866, the entomologist Carl Stål assigned a number of subgenera to the growing genus. This consisted of:

1. Aulacosphodrus (later raised to genus) - Afrotropical species with long postocular regions
2. Graptosphodrus - New Guinea "Sphedanolestes"
3. Haemactus
4. Lissonyctus
5. Sphedanolestes - What I interpret Stål to have considered the "typical" Sphedanolestes, based on resemblance to the East Asian Sphedanolestes impressicollis Stål, 1866 (type of genus)
6. Sphactes

These classifications were discontinued and are not used today, but they still give us an idea into the species that superficially resemble Vesbius.

He keyed the subgenera here along with the Sphedanolestes species described at the time. The dichotomous key is presented in an unsual way by today's standards and is a little hard to follow, so I've converted it into this flow chart:

The species that resemble Vesbius, based on my interpretation, belong to what Stål considered Lissonyctes and Haemactus. Here is what Sphedanolestes politus (type of Lissonyctes) looks like: http://www2.nrm.se/en/het_nrm/p/sphedanolestes_politus.html . Its similarity to Vesbius purpureus is noted in its original description available here ("Vesbio purpureo haud dissimilis" → "Not unalike Vesbius purpureus"). This makes the subgenus a good fit for Harpactorines similar to the smaller of the two Sphedanolestes featured in the first image.

Stål used pronotum colouration to separate these two subgenera (along with others) from the "typical" Sphedanolestes (b, bb), and the angles of the posterior pronotal lobe to separate them from each other (i, ii). Interestingly, he notes that the first (visible) rostral segment of Haemactes widens posteriorly. This character, combined with the unusually robust body shape and S. trichrous being observed to be stenophagous on Crematogaster ants (pers. comms with @psophis_zelun), suggests that species described under this subgenus might not belong to Sphedanolestes at all.

3.2 Toxocamptellus

Toxocamptellus Breddin, 1900 is perhaps the most poorly documented genus featured in this post, and was first described by Breddin in 1900 here, with minimalistic drawing of the head and pronotum available here (Fig 11). Notably, it is the most robust of the bunch, and a characteristic to distinguish it from the other species/genera featured in this post would be to compare the length of the head and posterior pronotal lobe (length of head < length of posterior pronotal lobe).

Bonus: Toxocamptellus misidentified as Vesbius purpureus on flickr - https://www.flickr.com/photos/61827574@N03/49854803707

1. Introduction

Acanthaspis is a genus (Reduviidae: Reduviinae) of assassin bugs found in Africa and parts of Asia. The most recent large publication concerning the oriental species deals with species found in China. You can read more about the genus there.

Currently there are three Acanthaspis species known from Singapore on the Biodiversity of Singapore website: Acanthaspis inermis Stål, 1870, Acanthaspis nr. quadriannulata, and Acanthaspis signifera Stål, 1863. This species is not an Acanthaspis species, but most likely a female Psophis species. Here are some comments I have on the former two:

2. Acanthaspis inermis

A. inermis was described by Stål from the Philippines. Images of the type can be found here. Another image can be found on the Heteroptera Species Pages, which was collected from Zamboanga, Mindanao. With that in mind, here are some other iNaturalist observations I think may be A. inermis:
https://www.inaturalist.org/observations/209125303
https://www.inaturalist.org/observations/209127898
https://www.inaturalist.org/observations/115355948
https://www.inaturalist.org/observations/115555711

Besides the BoS website, more pictures of the “A. inermis” from Singapore can be found in iNaturalist:
https://www.inaturalist.org/observations/195675300
https://www.inaturalist.org/observations/101995084
https://www.inaturalist.org/observations/216458610
I’ve noticed some consistent differences between the Singaporean and Filipino individuals, which I attempt to illustrate by comparing observation 115555711 by hrc_habitat21 and 216458610 by moniquecordeiro. These include:

1. Scapus dark brown basal half + pale yellow apical half (S1) vs pale yellow throughout with small dark brown annulation(s) (P1)
2. Anterior pronotal lobe more or less uniformly dark brown (S2) vs with clear pale yellow elevated regions (P2)
3. Outer membrane cell without pale spot (S3) vs with a pale spot basally (P3)

These differences can also be observed in all the other links I posted. Acanthaspis species can vary in colour intraspecifically, some documented examples include Acanthaspis siva Distant, 1904 (posterior pronotum and legs), Acanthaspis cincticrus Stål, 1859 (mostly posterior pronotal lobe), and Acanthaspis quinquespinosa (Fabricius, 1781) (posterior pronotal lobe). Despite that, I still think these differences are enough to suggest the species in Singapore isn’t A. inermis, especially character 3.

The species from Singapore is more comparable to Acanthaspis laoensis Distant, 1919, although there are still come differences like A. laoensis having a uniformly black scape and also generally more colour on the anterior pronotal lobe (example).

3. Acanthaspis quadriannulata

This species from Singapore with four large round spots on the posterior pronotum, spinose humeral angles, and an elongate head is often labelled as A. quadriannulata:
https://www.inaturalist.org/observations/195669936
https://www.inaturalist.org/observations/203333735
https://www.inaturalist.org/observations/214311169

The characters I mentioned make it visually similar to Acanthaspis collaris Hsiao, 1976, which received an updated description in the Chinese Acanthaspis revision. On page 20 you can find remarks comparing it to A. quadriannulata and Acanthaspis flavovaria (Hahn, 1834). In particular I would like to highlight this statement:

A. collaris is also similar to A. flavovaria in body plan, however, it can be distinguished from the latter in each femur with two annulations and tibiae are bicolourous (vs. each femur with one annulation on subapical portion and tibiae are unicolourous in A. flavovaria).

The leg colouration (femora and tibia with two annulations) on A. collaris is similar to that of A. quadriannulata. The Singapore species, on the other hand, only has one subapical yellow annulation on the femora and unicolorous tibiae, making it much closer to A. flavovaria. Acanthaspis flavovaria was first described from Java, so the species identity may apply to these individuals, which look very much like the species from Singapore:
https://www.inaturalist.org/observations/131289359
https://www.inaturalist.org/observations/142052493

1. Introduction

During the latter half of 2023, I became increasingly active on iNat, spending a considerable amount of time identifying assassin bugs (family Reduviidae) in east Asia, most of which belong to the subfamily Harpactorinae.
I've decided that it might be good to note down some of my thoughts (about Reduviidae) in the form of iNat journals, primarily so that I don't lose track of them, but also to showcase the basis of my ID framework and thought process so that anyone can challenge them when I mess up (I'm not an expert). I'll try to keep the language used simple, andnpretty much all the body parts I'll refer to can be found in this key for assassin bug subfamilies on page 6.

2. Reduviidae photo identification

Species level identifications can be extremely difficult from photos, but generally, I find most observations can at least be identified to genus based on these important identfiying features (refer to the images in the key if unfamiliar with terminology):

1. Antennal shape and segments
2. Head dorsal features (spines at base of antenna, presence of ocelli, relative lengths of anteocular and postocular regions, etc)
3. Rostrum structure and relative lengths of segments (can forget about it if no lateral/ventral shots)
4. Pronotum dorsal features (spines, relative lengths of lobes, etc)
5. Scutellum shape and presence of spines
6. Legs - Femora and tibiae (especially front pair)
7. Connexival segments (how drawn out they are/presence of spines or other protrusions)
8. Hemelytra - generally how much the wings exceed the abdominal margin

Usually these should be checked first before relying on colouration. This is not to say that the other features are not diagnostically important, just that they aren't usually (clearly) visible in photographs.

3. Amendments to identified Reduviidae in Singapore

Since I'm from Singapore, I thought it'd be fitting to write about the identification of two Reduviids on the "Biodiversity of Singapore" website as the primary subject for my first journal post. They are Campsolomus nr. sp. "1" and Graptoclopius nr. sp. "1". The former is generally more concerning as it has caused a chain of misidentifications, as it resulted in the genus Campsolomus being added to iNaturalist for the wrong reasons.

In this post, the "first rostral segment" refers to the first visible labial segment (L2) and the "second rostral segment" refers to L3.

3.1 "Campsolomus" nr. sp. "1" → Rhynocoris aulicus Stål, 1866

Some examples of "Campsolomus" on iNaturalist:
https://www.inaturalist.org/observations/39205450
https://www.inaturalist.org/observations/8051023

I don't think this is Campsolomus, but instead, Rhynocoris aulicus, a species described from penninsular Malaysia. Dorsal and ventral views of its type image are published by the Swedish Museum of Natural HIstory. It's good to note that this species basically looks like a yellow version of Rhynocoris fuscipes, a relatively widespread and well-documented species in Asia.

The species description is given by the entomologist Carl Stål in 1866, a rough translation is as follows:

R. aulicus Stål --- (Body) Croceus, sprasely with gray pubescence. Two large spots on the upper part of the head, one on the front, the other behind the middle, the antennae, the two apical segments of the rostrum, a transverse impression on the thorax, a basal spot on the scutellum, some small lateral spots on the thorax, transverse lines on the lateral sides of the ventre, the apical part of the femur, the base and apices of the tibiae, and the tarsi black. Clavus, corium internally and membrane black-violaceous. Ventrally, before the black lines, decorated with whitish spots. Male. Length 14mm, width 3.5mm.
From: Malacca.
The anteocular part of the head is somewhat shorter than the postocular part. The first rostral segment is much shorter than the second, and a little longer than the anteocular part of the head. Scapus subequal to head + half the length of the thorax. Anterior pronotral lobe posteriorly obsoletely and obtusely bituberculate, posterior lobe with posterior corners slightly prominent. The scutellum apically slightly foliaceous. Hemelytra exceeding apex of abdomen. Legs long, not nodulose.

Now, it's important to note that the BoS website isn't necessarily wrong, as "nr." indicates a degree of uncertainty about the genus. The misidentifications are mainly a result of the genus Campsolomus being added to the site and applied without independent verification of the genus diagnosis from the ID-er.

3.1.1 So what is a Campsolomus anyway?

Campsolomus Stål, 1870 is also a reduviid genus, and its type species is Campsolomus strumulosus Stål, 1870, described from the Philippines. Sadly, there are no observations of it on iNaturalist (yet), but fortunately its type images are also available online. At first glance, structurally, the genus actually resembles Rhynocoris aulicus quite a bit. Separating them requires checking the original genus description (little work has been done on it since its inception), once again given by Stål in 1870. It is available here.

A rough translation is as follows:

The body is very oblong. The head is slightly shorter than the thorax, unarmed, postocular part longer than the anteocular part, gradually tapering towards the posterior when seen on the side, anteocular part not elevated. Ocellar tubercule distinctly elevated. Antennal segment 1 about 1.5 times the length of head. First and second rostral segments equal in length. Thorax distinctly constricted, with anterior corners drawn up into sharp conical tubercles. The impression of the anterior pronotal lobe does not extend to the tip. Posterior pronotal lobe twice as long as the anterior lobe, the lateral corners obtuse, rounded, very slightly prominent, with the rear and lateral-posterior margins totally conjoinedly reflexed, the latter depressed, obtusely rounded. Scutellum triangular, with a very distinct trivial sulcus. Hemelytra somewhat exceeding the distal end of the abdomen. Mesosternum deprived of an anterior tubercle. Abdomen somewhat wider than hemelytra, rounded on both sides. The legs are of moderate size, unarmed, anterior femora a little thicker than posterior. Tarsi of moderate size. Toothed claws.

From here, by comparing this description with the specimen on the BoS website, we can see that the first rostral segment in the Singapore species is shorter and very much not equal to the second. Additionally, the lateral to lateral-posterior margins of the posterior pronotum in the SG species does not match the profile of Campsolomus, along with some other differences.

3.2 "Graptoclopius" nr. sp. "1" → Hagia sp.

The genus tentatively identified as "Graptoclopius" on BoS belongs to the genus Hagia Stål, 1863. The original description is available here for reference, but generally Hagia are a bunch of elongated red and black bugs where the posterior-lateral edge of the pronotum is almost parallel to the longitudinal axis, which clearly contrasts things like Rhynocoris and many other robust Harpactorines where the corresponding portion curves inwards towards the scutellum. It's hard to give a species level identification, as species delineations in Hagia are weak, mostly due to being extremely dated. The specimen on BoS more or less fits both the description of Hagia punctoria Stål, 1863 and Hagia sarawakensis Miller, 1941.

3.2.1 So what is a Graptoclopius anyway?

The type species of Graptoclopius is Graptoclopius helluo Stål, 1863, described from New Guinea. You notice that the species name preceeds the genus name, and that's because Stål initially described it as Reduvius helluo, the type image of which can be found here. The original genus description of Graptoclopius by Stål can be found here, and is translated roughly as follows:

The scutellum is very elevated. Head a little shorter than thorax; the first rostral segment somewhat shorter than the second, the anterior of the posterior pronotal lobe and the anterior pronotal lobe conjointly longitudinally impressed, the region posterior to the impression somewhat convexly elevated, the posterior edges of the latter neither raised nor reflected, the posterior margin straight; abdomen slightly expanded; the legs are long, thick, the tibia, especially in females, thickened before the middle.

This description is actually quite applicable for Hagia too, except that in Hagia, the first rostral segment is longer than the second. From comparing the type specimen of G. helluo with Hagia, I think another distinguishing character would be the high pilosity on the legs of Graptoclopius.

Here are some observations on iNaturalist which are likely G. helluo, for a better idea of what a member of the genus looks like:
https://www.inaturalist.org/observations/176023730
https://www.inaturalist.org/observations/181960968
https://www.inaturalist.org/observations/177679070