Morphology of the alate and worker mandibles of the soil-feeding nasute termites (Isoptera, Termitidae, Nasutitermitinae) from the neotropical region

Abstract

ABSTRACT. The morphology of the mandibles of the alates and workers of theThe mandibular morphology is highly adaptive to the soil diet, in a similar way either in the soil-feeding nasutes as in other soil-feeding termites. The function of the molar tooth in the soil-feeding termites is discussed, and new characteristics of the molar regions are presented.

Morphology of the worker digestive tube of the soil-feeding nasute termites (Isoptera, Termitidae, Nasutitermitinae ) from the neotropical region

“…from the Neotropical Region, and Eutermellus, Afrosubulitermes and Verrucositermes, from the Ethiopian Region, all have in common the following set of characteristics: weak or incomplete gizzard armature; absence of rT'ixed segment; Malpighian tubules attached to the mesenteron, at the level of the mesenteron-proctodeal junction inside the mesenteric arch, and being dilated into a small ampul, or not dilated, near the insertion point; mesenteron with or without a small lump for the insertion of the Malpighian tubules; first proctodeal segment tubular, a little shorter or a little longer than the mesenteron; enteric valve well armed, with sclerotisations and developed spines, or weakly armed, and with bilateral ( only Eutermellus ) or trilateral symmetry; paunch with a large and more or less J-shaped anterior part, separated from a smaller and tubular posterior part by a constriction inside the mesenteric arch; colon long and tubular. The workers of the genera grouped under this pattern of digestive tube have mandibles with complete marginal dentition and no reduced teeth ( Fontes, 1985 ), what suggests a close phylogenetic relationship of these genera.…”

“…The specimens studied in this paper are listed in Fontes (1985). Concerning the 6 genera with dimorphic worker caste ( Fontes, I.e ), only the more frequent worker type was studieo; the gut, as visible through the body wall of undissected specimens, seems to be identical in both worker types.…”

“…The workers of the three genera grouped here have mandibles with incomplete marginal dentition ( Fontes, 1985), like the Neotropical genus Cyranotermes, with a different gut pattern (gut pattern 4).…”

“…46); Malpighian tubules dilated along their promixal course over the mesenteric part of the mixed segment and attached to the mesenteron, a short distance from the mesenteron-proctodeal junction of the promixal end of the mixed segment; enteric valve well armed and with trilateral symmetry; posterior part of the paunch more' volumino'l1s than the anterior part; colon long, dilated te the proximal 2/3. Angularitermes workers have mandibles with complete marginal dentition and two vestigial teeth (Fontes, 1985). This genus is exceptional among the 14 genera of soil-feeding nasutes from both the Neotropical and Ethiopian Regions by its distinctive pallerns of worker gut and worker mandibles.…”

“…This paper is the fourth one of a series on the taxonomy of the 8 genera of soil-feeding nasutes from the Neotropical Region (Fontes, 1979;1982: 1985, a group which was previously known virtually only from the original descriptions of the taxa. The gut anatomy provided a large collection of characteristics, indispensable for the definition of most of these genera.…”