Old Hobby Hemiblabera tenebricosa/brunneri = Hemiblabera roseni

Welcome back to another episode of what I'm gonna start calling: "Old Hobby Stock Roach IDs Were Made Waaaay Too Hastily and We're All Paying For it Now"! 🙃😂

Well, turns out the old hobby stock of Hemiblabera "tenebricosa" (sometimes erroneously labeled as "H.brunneri" in Europe) is in fact, not tenebricosa, and is likely H.roseni... And the US hobby JUST got some real H.tenebricosa into culture for the first time in decades. 😄

First off, let's start with what REAL H.tenebricosa look like. H.tenebricosa's type locality is in the Dominican Republic, however populations have long been documented in the FL Keys as well (though it seems their range there has shrunk in recent decades). They are one of the largest of the described Hemiblabera, and max out at around 32mms in length for males, 46mm for females. They are also fairly colorful, with red abdominal spotting/striping on adults, males especially. Below are pictures of the Holotype male from the Dominican Republic, as well as a pair of live individuals recently collected by friends of mine from FL.

Holotype H.tenebricosa male ©CSF 

Female (top) & male (bottom) tenebricosa from Monroe County, FL ©Junkai Wang

Adult female H.tenebricosa "Monroe County" (bits of a H.roseni "Cuba" female visible in some pics) ©Alan Jeon

Adult male H.tenebricosa "Monroe County" ©Alan Jeon

Now onto the old hobby stock of Hemiblabera "tenebricosa". The only locality data we have for this stock is "Cuba", which is interesting because no described Hemiblabera have formally been documented from Cuba. This stock has also long been mislabeled as H.brunneri in European collections, however that species is WAY smaller, more colorful, and seemingly restricted to Puerto Rico and the Virgin Islands. So they're not brunneri.

Now, morphologically this species is very close to tenebricosa, so that previous ID is understandable. However, they are significantly larger than true H.tenebricosa, maxing out at around 40mm for males, 53mm for females. They also have different, duller coloration, and differ in some morphological features as well (they're more granulated in texture, have a slightly different tegmina shape, etc.). So, they're not actually H.tenebricosa either.

Now, I went through and found the descriptions or at least images of the holotypes of every Hemiblabera species, and I'm pretty confident I've found the correct ID for this old hobby stock; Hemiblabera roseni! 😁 They match the old hobby stock almost perfectly, from the granulated/tubercle covered exoskeleton, tegmina shape, and the coloration. 

One inconsistency is that the known range for roseni is in the Bahamas, however Cuba is very close to the Bahamas, so it seems likely their range would naturally extend there as well.

The other, bigger issue is size; the largest recorded roseni female is only 41mms long, so a similar size to true tenebricosa, not quite as large as the hobby stock Hemiblabera, which can max out at 53mm. However, this could merely be due to the hobby stock being from Cuba, rather than the type locality of the Bahamas. Perhaps this species evolved to be larger on Cuba as a result of it being a much larger island in general, probably with more food availability than much of the Bahamas.

None of the other described Hemiblabera spp. match the hobby stock much at all in description, H.roseni seems to be the closest possible match.

Here's the original description for H.roseni, (translated from German):

"Dorsum shagreened, d. H. covered with small warts of various sizes and densities. Head completely covered by pronotum. Interocular distance scarcely noticeably narrower than the distance between the ocellar spots. Interocular area maroon, demarcated below by a tan transverse band which is widest in the middle and connects the two antennal bases. The two ocellar spots are joined by a chestnut-brown transverse band that bulges downwards and becomes a little more indistinct in the middle. Eyes yellowish grey, curved. The third segment of the antennae about twice shorter than the first. Pronotum roughly semicircular, slightly projecting at anterior end; the posterior edge truncated transversely, slightly concave; the latero-caudal corners drawn backwards and noticeably overhanging the middle of the posterior border of the pronotum (Fig. 1). The edge of the pronotum has a fine hem all around, which becomes more indistinct at the posterior edge; laterally above the sides of the head, the rim is slightly bent upwards, but finely grooved transversely in the vicinity of the latero-caudal corners. Disc of the pronotum with indistinct lyre-shaped markings composed of impressions and smooth, non-chagrined stripes. ground color of the pronotum black-brown, with a yellow marginal band along the anterior margin; the marginal fascia is widest laterally over the sides of the head, gradually narrowing further caudally, then disappearing near the latero-caudal corners. Underside of the pronotum yellowish, with stiff, protruding hairs above the head.

Elytra black-brown, lighter in the marginal field; they are abbreviated and generally in the form of a parallelogram (Fig. 1). The sutural margins overlap slightly and are about the same length as the costal margins. The distal margins oblique, sigmoidal: the disto-sutural corners obtuse, rounded. Hind wings rudimentary. Upper abdomen blackish-brown with reddish-brown transverse striations: one reddish-brown stripe along proximal edge of each segment; the first abdominal segments have incomplete transverse stripes, d. H. these lack the middle part and only consist of 2 separate side parts. The latero-caudal corners of the tergites moderately protruded backwards, pointed. Last tergite transversal, with slightly rounded distal margin, shallowly incised in the middle; the distal part of the tergite slightly curved upwards. Cerci broad, flattened, not reaching the distal border of the last tergite. abdomen underside smooth, not shagreened; coloring similar to that of the upper side, only lighter. The last sternite is large, symmetrical, with shallow indentations on each side near Cerci. Legs brown, caudal metatarsi a little shorter than other tarsal segments combined. Pulvilles present, Arolian absent. 

Body length - 41 mm; prontum length - 14 mm; the greatest prouotum width - 22.5 mm; elytra length - 12 mm; the greatest width of the elytra - 14 mm. Times unknown. Type: Bahamas, 1908, coll. N. Rosén. In the Museum of the Entomology Department of the Zoological Institute of Lund University.

In addition to the type, there is another example: Female, Bahamas, 108, coll. N. Rosén. This female was probably caught with the type; it is smaller than the type specimen and the corresponding body measurements are as follows: body length - 34.5 mm; pronotum length - 12.5 mm; the greatest width of the pronotum - 20 mm; elytra length - 10 mm; the greatest width of the elytra - 12.5 mm.

The new species can be distinguished from the other Hemiblabera species as follows: H.granulata Saussure. and H.capucina Saussure. are much smaller and with lateral elytra not in contact above the dorsum; H.brunneri (Sauss) has trigonal elytra and their inner margin is at most half as long as the costal margin; H.pabulator Rhen & Heb. differs in the different coloration and shape of the pronotum (the latero-caudal corners do not reach further back than the middle of the posterior border of the pronotum); in H.tenebricosa Rehn & Heb. the latero-caudal corners of the pronotum also do not extend posteriorly than the middle of its posterior margin, and the disto-sutural corners of the elytra are square (obtuse in roseni).

The new species is the closest to H.tenebricosa, and at a cursory glance one might assume that one is dealing with this species. But the above differences seem to justify the creation of the new species. Rehn & Hebard (1927: 273) also reported a female of H.tenebricosa from the Bahama Islands, although this species is only endemic to the Dominican Republic. The authors mentioned wanting to explain this find with introduction, but one cannot simply dismiss the suspicion that in this case it might not be a question of tenebricosa, but of the roseni described here. I name the new species after the collector, Dr. N. Rosen".

Line drawing of the H.roseni holotype

Male H.roseni "Cuba"

Female H.roseni "Cuba"

H.roseni "Cuba" VS H.tenebricosa "Monroe County" males ©Alan Jeon

H.roseni "Cuba" VS H.tenebricosa "Monroe County" females ©Alan Jeon

H.roseni "Cuba" female abdomen ©Alan Jeon

H.tenebricosa "Monroe County" female abdomen ©Alan Jeon

True H.brunneri for comparison, just 'cause. Adult male (L) and nymph (R) ©Wenhua Lu

So quite obviously, there's a significant difference between the old hobby stock of "H.tenebricosa" and true H.tenebricosa, as we can see here. And based on the description of H.roseni, that seems to be the most probable ID for the old hobby stock (and obviously, H.brunneri belongs nowhere in this equation).

As a result of these findings, the proper course of action for hobbyists right now IMO would be to relabel all old hobby stock of Hemiblabera "tenebricosa" (sometimes erroneously labeled "H.brunneri" in Europe) to Hemiblabera roseni "Cuba" (the locality technically being optional). You can throw a cf. before the species name if you want, I won't judge.

While the name Hemiblabera tenebricosa should only be used for the obviously true H.tenebricosa from Florida that have just now entered the hobby and aren't cultured by more than half a dozen people at the time of writing this.

And the name Hemiblabera brunneri should not be used for anything in the hobby, because true H.brunneri are not in culture yet, period.

Well, that does it for today's roach taxonomy ranting. 😂 Thanks for reading, hope everyone enjoyed, stay safe, and I'll see you all next time! 😉