Thoughts on identifying Lacessititermes from Hospitalitermes
Introduction: (for anyone who happened to stumble across this)
Lacessititermes and Hospitalitermes are both open foraging lichen/microbe harvesting termites of the subfamily Nasutitermitinae, mainly found in Southeast Asia. The main characteristic which is used to distinguish the two is the presence of a notch on the molar plate of the worker. In conjunction with Longipeditermes (and apparently Ceylonitermes) these four genera can be separated from the other Nasutitermitinae of the region by the elongated soldier antennae segments. Longipeditermes, can further be distinguished by the very elongated 3rd antennal segment (Gathorne-Hardy, 2001).
Of course, worker mandible morphology is not applicable to most iNat observations, and furthermore, aside from the general consensus that Hospitalitermes and Lacessititermes are apparently very similar, to the point where separation aside from worker mandibles is ambiguous, there does seem to consistent trends evident in the literature and iNaturalist or other online observations.
This is a relatively brief and informal piece on my personal thoughts and opinions regarding the identification of these two genera.
Information on their distinction mentioned in the literature:
| Lacessititermes | Hospitalitermes | Reference |
|---|---|---|
| 3rd antennae shorter/subequal to 4th | "Third antennae segment very long much longer than fourth" | (Sornnuwat et al., 2004) |
| "Soldiers generally with distinct color forms" | (Sornnuwat et al., 2004) | |
| 2 worker castes | 3 worker castes | (Miura & Matsumoto, 1998a; Miura & Matsumoto, 1998b) | Arboreal carton nest | Cavity nest | Various; see below |
Additionally, perhaps the most noteworthy distinction across the literature, Lacessititermes is consistently reported to construct suspended arboreal carton nests (Gathorne-Hardy, 2001; Kalshoven, 1958; Syaukani, 2010; Syaukani, 2008). In comparison, Hospitalitermes seem to be cavity nesters, usually building their nests within cavities in trees, typically around the base, and lining their nest with a characteristic dark loose fecal material (Collins, 1979; Kalshoven, 1958; Miura & Matsumoto, 1997; Miura & Matsumoto, 1998a; Poovoli et al., 2014; Syaukani, 2010; Syaukani, 2014; Syaukani et al., 2016).
Observations (and Notes) on Observations (and Notes)
In general, termites suffer from a lack of pronounced morphological characteristic, high degrees of interspecific and intraspecific variation, and generally being small, cryptic and fragile (harder to preserve). However, I've come to view that above all, what probably hinders their ID the most is simply the fact that they are understudied. In addition to the lack of accessible material (literature, data, images) for ID, at least, in a centralized location (i.e compare to Antwebs, Antwiki and Antmaps for Formicidae), there is very few material to start off with.
Hospitalitermes and Lacessititermes seem to suffer from this greatly despite their less cryptic biology and how often they are posted onto iNat in comparison to other termites. They probably compose most of the South East Asian Nasutitermitinae observations on this site. Most of the literature on the two are quite old, as most were described in the early part of the 20th century and are succeeded in ID material by a few select keys (not all of which I've been able to access) . This is especially true for Lacessititermes. (see: Krishna et al., 2013)
Lacessititermes
Hence, the most significant material for ID I've found for Lacessititermes are images of the types (I believe, mostly syntypes) for L. albipes, L. cuphus, L. filicornis, L. lacessitus and L. sordidus hosted on the Muséum National d'Histoire Naturelle (MNHN) website. Which keep getting taken down it seems (though I'm unsure of the reason).
Link to google drive folder of the images: https://drive.google.com/drive/folders/13boQ4WKSao9BTLM7FcmwLvproAgnTRxN?usp=sharing
What is particularly interesting in my opinion is that the soldiers of these Lacessititermes, are all very small in comparison to the workers, about half their length. In comparison, Hospitalitermes soldiers generally seem to be equal in size, if perhaps, a bit smaller than the major workers.
These small Lacessititermes match some of the observations on iNaturalist.
e.g:
https://www.inaturalist.org/observations/42228662 (L. cf. cuphus)
https://www.inaturalist.org/observations/160002539
https://www.inaturalist.org/observations/35350023
https://www.inaturalist.org/observations/101302362
Still, I'm unsure about how ubiquitous this trend is, as I've never seen the size of the soldiers brought up as a diagnostic characteristic in the literature. Other observations of "heavily sclerotized Lacessititermes" are more ambiguous on the size difference, but admittedly, these observations usually do not show the workers (in any good detail at least). All Lacessititermes I've IDed prior to the posting of this journal, have been based only the presence of a carton nest, with the exception of "Lacessititermes sp. A"
Lacessititermes sp. A (or "Quah's Lacessititermes" as I refer to it in communication), is in contrast, not heavily sclerotized, does not have minute soldiers, typically has multicolored heads, and relatively short limbs and antennae segments in comparison with other Lacessititermes (and Hospitalitermes). I've wondered if it's a single species, or a Lacessititermes sp. for that matter. All documentations with location data, as I'm aware, are from the Malay peninsula.
- It is represented by "Lacessititermes sp. A" on the Biodiversity of Singapore website.
- Documented by an individual (Quah) from Malaysia as "Lacessititermes sp."
The following observations:
37836262,
37971919,
37630445
92651800- And possibly Lacessititermes ASA110 from Dr. R. Scheffrahn's termite gallery.
Nests of Lacessititermes
- https://www.inaturalist.org/observations/66313158
- https://www.inaturalist.org/observations/101302362
- https://www.inaturalist.org/observations/2434883
- https://www.inaturalist.org/observations/35522089
- https://www.inaturalist.org/observations/143542345
- https://www.inaturalist.org/observations/141611331
- https://www.inaturalist.org/observations/153299323
- https://www.inaturalist.org/observations/189516035
- https://www.inaturalist.org/observations/146876168
- https://www.inaturalist.org/observations/35522091 ?
- https://www.inaturalist.org/observations/12628123 ?
Hospitalitermes
Compared to Lacessititermes, Hospitalitermes are not as understudied and the literature less incomplete, though I've not had much better luck accessing it. Of the information I've come across, my general impression is that most Hospitalitermes species resemble closely to one another and fall broadly into two groups. However both groups seem to be more common, widespread and more speciose than Lacessititermes. Therefor, the vast majority of this site's processional termite observations are likely Hospitalitermes.
As a result, the following are foremost, personal opinions informed by observations on the site, with little to do with the literature.
"Typical" Hospitalitermes:
The "typical" looking Hospitalitermes sp.; heavily sclerotized; sclerites usually completely black (not very colourful) but abdomenal sclerites are often lighter in colour; at most, a beige colour, sometimes also with a mottled appearance, usually more typical to the soldiers. Soldier abdomen is notably more often flat in comparison to other group. Antennae usually more elongated compared to other group; soldiers with elongated to very elongated antennae segments, workers' usually somewhat elongated. Limbs usually more elongated in proportion to body compared to the other group. The limbs are noticeably much more elongated in soldiers relative to the workers, especially the tibias and hind tibia. No observations in South East Asian Mainland for the most part (not north of the Malay peninsula), but present in the Philippines.
Possible species:
H. hospitalis, H. medioflavus(?), H nigriantennalis*, H. seikii, H. umbrinus(?), H. krishnai,
H. nigriantennalis Soldiers with distinctive multicoloured heads; easily separated from all other Hospitalitermes (Syaukani et al., 2016).
Examples: (most of the observations on this site comprise of this group, however, I will be mostly posting obs with nests, since these are almost certainly positive)
H. nigriantennalis
- https://www.inaturalist.org/observations/42192679
- https://www.inaturalist.org/observations/188624591
- https://www.inaturalist.org/observations/36129521 (nest of H. nigriantennalis)
H. hospitalis
Hospitalitermes
Abnormally beige specimens. Probably Hospitalitermes; pronounced trimorphic worker caste.
Typical Hospitalitermes nest.
An example of the many "Typical Hospitalitermes" with unfortunately, no nest to go with, on iNaturalist, Songkhla, Thailand. On the Malay Peninsula.
"Brown" Hospitalitermes:
Heavily sclerotized; sclerites black or brown, with shades of red, brown or orange (usually generally colourful). Soldiers not particularly different in colour or pattern from workers. Members of this group typically have shorter antennae and limbs compared to "Typical Hospitalitermes"; antennae segments in soldiers vary from somewhat elongated to elongated, worker antennae usually not particularly elongated, generally shorter legs compared to the other group, the soldiers with only somewhat longer legs than the workers.
Observations of this group are within the range of "typical Hospitalitermes" in Indonesia+Malaysia, but also extend into China and far East India. India has no recorded Lacessititermes species, but it does have a plethora of Hospitalitermes species. Ergo, this group likely is Hospitalitermes.
Species described from India and Thailand:
H. atamarensis, H. jepsoni, H. birmanicus, H. blairi, H. brevirostratus, H. madrasi, H. bicolor (Ahmad, 1965; Mithan Lal Roonwal & Om Bahadur Chhotani, 1997, pp. xx + 801).
Examples:
India; East: (No Lacessititermes)
- https://www.inaturalist.org/observations/26730881
- https://www.inaturalist.org/observations/191449226
- https://www.inaturalist.org/observations/19587197
China; Yunnan: ( Lacessititermes present)
- https://www.inaturalist.org/observations/134450934
- https://www.inaturalist.org/observations/141988227
- https://www.inaturalist.org/observations/183764337
Thailand (Lacessititermes present)
- https://www.inaturalist.org/observations/98015977 (H. cf. jepsoni)
- https://www.inaturalist.org/observations/108358600 (H. cf. bicolor, with possible nest as indicated by dark substrate)
- https://www.inaturalist.org/observations/103416114 (Showcasing very pronounced trimorphic worker caste)
Malaysia and Indonesia (Lacessititermes present)
- https://www.inaturalist.org/observations/141976419 (showcasing dark material typical to nest)
- https://www.inaturalist.org/observations/2477914 (with nest)
Usefulness of aforementioned characteristics
[added 11/Jan/2024]
Revisiting the characteristics outlined in the table above:
Color forms:
I have no idea what "soldiers generally with distinct color forms" is supposed to mean exactly. Presumably, it is noting that Lacessititermes soldiers vary in colour (as seen in Quah's Lacessititermes and L. cf. cuphus). However, most of the Lacessititermes observations, show soldiers with consistent colour between one another, and a minority of Hospitalitermes and cf. Hospitalitermes observations also have colour variation within soldiers (i.e H. nigriantennalis, H. cf. jepsoni). Evidently, color variation is not a particularly useful differentiator and was probably not intended to be.
Antennae segments:
The characteristic noted regarding antennae segment lengths also appears to be inconsistent for Hospitalitermes but not Lacessititermes. All of the MNHN specimens and "Quah's Lacessititermes" confirm to the description given, but not all Hospitalitermes have a 3rd segment greatly elongated compared to the 4th. Typically in Hospitalitermes the 3rd segment seems to be about equal in length or slightly longer; fourth segment about 3/4ths the length of the 3rd segment, regardless of the actual degree of elongation of the antennae segments, and so do not map consistently onto either group. For example, in H. umbrinus, a "typical Hospitalitermes", the 3rd and 4th are about the same length despite this sp. having very elongated antennae segments.
Worker dimorphism vs worker trimorphism:
Among the Lacessititermes observations, only 101302362 shows workers with a nest. It is difficult to determine whether these are multiple castes or a single caste. For "Quah's Lacessititermes", only Quah's documentation features separate worker castes; the other documentation feature only a single worker specimen at most.
The observations of 35350023, L. cf. cuphus and 160002539 also features workers. For the L. cf. cuphus observation, there is clearly a minor worker, but I'm unsure of the second one.
The majority of the remaining observations on iNaturalist (= cf. Hospitalitermes & Hospitalitermes) feature at least two worker castes, but no more than three distinct sizes. It is probable that in some species, there is a much less pronounced caste distinction compared to others; specifically between the major and median worker caste, as shown in this H. nigriantennalis observation and this cf. Hospitalitermes observation from Yunnan, China.
Overall, worker dimorphism vs trimorphism seems to be the most promising morphological diagnostic excluding mandible dentation, but it still suffers from a lack of data and therefor the assumption that it is diagnostically significant. Ironically, also the only characteristic listed here that is unpublished.
References
Ahmad, M. (1965). Termites (Isoptera) of Thailand. Bulletin of the AMNH ; v. 131, article 1. Bulletin of the American Museum of Natural History, 131(1), 1–114.
Collins, N. M. (1979). Observations on the foraging activity of Hospitalitermes umbrinus (Haviland), (Isoptera: Termitidae) in the Gunong Mulu National Park, Sarawak. Ecological Entomology, 4(3), 231–238. https://doi.org/10.1111/j.1365-2311.1979.tb00580.x
Gathorne-Hardy, F. J. (2001). A review of the South-East Asian Nasutitermitinae (Isoptera: Termidae), with descriptions of one new genus and a new species and including a key to the genera. Journal of Natural History, 35(10), 1485–1506. https://doi.org/10.1080/002229301317067647
Kalshoven, L. G. E. (1958). Observations on the black termites,Hospitalitermes Spp., of Java and Sumatra. Insectes Sociaux, 5(1), 9–30. https://doi.org/10.1007/bf02222427
Krishna, K., Grimaldi, D. A., Krishna, V., & Engel, M. S. (2013). Treatise on the Isoptera of the World. Bulletin of the American Museum of Natural History, 377(7), 1–200. https://doi.org/10.1206/377.1
Mithan Lal Roonwal, & Om Bahadur Chhotani. (1997). The Fauna of India and the Adjacent Countries: Family termitidae (pp. xx + 801). Calcutta: Zoological Survey of India,.
Miura, T., & Matsumoto, T. (1997). Diet and nest material of the processional termite Hospitalitermes, and cohabitation of Termes (Isoptera, Termitidae) on Borneo Island. Insectes Sociaux, 44(3), 267–275. https://doi.org/10.1007/s000400050047
Miura, T., & Matsumoto, T. (1998a). Foraging organization of the open-air processional lichenfeeding termite Hospitalitermes (Isoptera, Termitidae) in Borneo. Insectes Sociaux, 45(1), 17–32. https://doi.org/10.1007/s000400050065
Miura, T., & Matsumoto, T. (1998b). Open-Air Litter Foraging in the Nasute Termite Longipeditermes longipes (Isoptera: Termitidae). Journal of Insect Behavior, 11(2), 179–189. https://doi.org/10.1023/a:1021039722402
Poovoli, A., Keloth, R., Chenthamarakshan, B., Chandrashekaramenon, R., & Nivedita, S. (2013). First record of the Srilankan Processional Termite, Hospitalitermes monoceros (Konig) (Termitidae: Nasutitermitinae) from India. HALTERES, 4, 48–52.
Poovoli, A., Keloth, R., & Chenthamarakshen, B. (2014). Foraging activity of Hospitalitermes monoceros (König) (Termitidae: Isoptera) in Western Ghats, India . Journal of Entomology and Zoology Studies, 2(2), 138–143.
Sornnuwat, Y., Vongkaluang, C., & Takematsu, Y. (2004). A Systematic Key to Termites of Thailand. Kasetsart Journal. Natural Sciences, 38(3), 349–368.
Syaukani. (2010). Lacessititermes yamanei and Hospitalitermes seikii two new species of open-air processional termites from West Sumatra, Indonesia. Malayan Nature Journal, 62(4), 349–358.
Syaukani, S. (2008). A new species of Lacessititermes (Isoptera, Termitidae, Nasutitermitinae) from the Mentawai Islands, Indonesia. Sociobiology, 52(3), 459–469. A new species of Lacessititermes (Isoptera, Termitidae, Nasutitermitinae) from the Mentawai Islands, Indonesia
Syaukani, S. (2014). BIOSYSTEMATICS OF HOSPITALITERMES HOSPITALIS HOLMGREN (ISOPTERA) FROM BORNEO. Proceedings of the Annual International Conference, Syiah Kuala University - Life Sciences & Engineering Chapter, 4(2), 133–137.
Syaukani, S., Thompson, G. J., Zettel, H., & Pribadi, T. (2016). A new species of open-air processional column termite, Hospitalitermes nigriantennalis sp. n. (Termitidae), from Borneo. ZooKeys, 554, 27–36. https://doi.org/10.3897/zookeys.554.6306
Syaukani, S., Thompson, G., & Yamane, S. (2011). Hospitalitermes krishnai, a new nasute termite (Nasutitermitinae, Termitidae, Isoptera), from southern Sumatra, Indonesia. ZooKeys, 148, 161–169. https://doi.org/10.3897/zookeys.148.1768
