Niche Differentiation between Two Sympatric Cubitermes Species (Isoptera, Termitidae, Cubitermitinae) Revealed by Stable C and N Isotopes

Abstract

Many African termite species are true soil-feeders: how can they coexist, sometimes with high densities? How do they separate their trophic niches? Preliminary results suggest that two coexisting Cubitermes species forage in different soil layers, and stable C and N isotopes show that they feed on different organic material. Cubitermes aff. ugandensis forages near the soil surface whereas C. aff. sankurensis forages in deeper layers; however, unexpectedly, the former shows a higher δ15N than the latter, highlighting, for the first time, a trophic niche differentiation between two sympatric true soil feeders bearing different enteric valve patterns.

Use of the proteomic tool MALDI-TOF MS in termite identification

“…Most probable explication is the morphological misidentifications that we made due to close anatomical similarities among species from Reticulitermes and Trinervitermes genera 33 , 34 . On the other hand, this discrepancy between our morphological and molecular identification would be due to the updating of the systematics of the termites with a change in the name of the genus as in the case of the genus Cubitermes changed to Nitiditermes 35 , 36 or by the lack of reference sequence of some species in the GenBank database, as in the case of the species M. ivorensis and P. holmgreni , which is one of the limitations of the molecular method 21 .…”

Cubitermitinae

“…In some places, as near Kampala, Uganda [21], or near Bossembélé, Central Africa [20], two species of formerly Cubitermes (now one of Isognathotermes and one of Nitiditermes) coexist at high densities, suggesting that their diets are sufficiently different as to provide an adequate niche separation. In both cases, the two species have different enteric valves, which may be linked with their diets [12].…”

Soil organic matter is essential for colony growth in subterranean termites

“…Second, all of these studies measured N 2 fixation rates in very short intervals (hours or days), which could not be correlated with colony growth over time. Third, 15 N 2 isotope studies run the risk of a number of potential errors: fractionation due to tissue-level degradation 27 , contamination of enriched 15 N 2 sources 28 , pressure-related nitrogen solubilization in tissues, or even a reflection of prior trophic-level feeding 29 , 32 . Finally, atmospheric N 2 fixation has a high energetic cost: roughly 20 ATP are hydrolyzed to release 1 N from N 2 33 .…”