Neotermes Jouteli Research Articles

A Comparison of Morphology among Four Termite Species with Different Moisture Requirements.

The thicknesses of the cuticle and rectal pads, and the spiracle morphology were compared for four termite species from different habitats, including one drywood termite, Cryptotermes brevis Walker, one “wetwood” termite, Cryptotermes cavifrons Banks, one subterranean termite, Coptotermes formosanus Shiraki, and one dampwood termite, Neotermes jouteli (Banks). Cuticle thicknesses were significantly different among all four termite species. Neotermes jouteli had the thickest cuticle, while Co. formosanus had the thinnest. The cuticle of C. brevis was thicker than that of C. cavifrons and Co. formosanus, which may reflect a comparably greater need to prevent water loss in drier habitats for C. brevis. Rectal pad widths were significantly different among all four termite species, except those of C. brevis with N. jouteli. The rectal pads of N. jouteli and C. brevis were thicker than those of C. cavifrons and Co. formosanus, and the rectal pads of C. cavifrons were thicker than those of Co. formosanus in turn. Larger rectal pads likely account for the water conservation mechanism of producing dry, pelleted frass in the kalotermitids (N. jouteli, C. brevis, and C. cavifrons). Morphological observations of the spiracles showed the presence of protuberances (atrial arms) in the three kalotermitids. The function of this protuberance is unclear, but it may serve as a sac-like structure, aiding in gas exchange, or a moisture trap aiding in the prevention of water loss through evaporation.

Survival of Termites (Isoptera) Exposed to Various Levels of Relative Humidity (RH) and Water Availability, and Their RH Preferences

Abstract Termites (Isoptera) are widely believed to be one of the most desiccation-prone insects. They must combat desiccation by locating and efficiently conserving water resources. Termites have evolved morphological, physiological, and behavioral characteristics that aid in the tolerance of desiccation. In 3 studies using 4 termite species, water loss tolerance and relative humidity (RH) preferences of termites exposed to 5 different RH, as well as the use of different water sources, were examined. Our results showed that Coptotermes formosanus Shiraki (Rhinotermitidae) preferred and survived better at high RH and with readily available water sources. Neotermes jouteli (Banks in Banks and Snyder) (Kalotermitidae) also preferred a high RH, but was more capable of tolerating lower RH and a lack of free water than C. formosanus. Cryptotermes brevis Walker (Kalotermitidae) and Cryptotermes cavifrons Banks (Kalotermitidae) did not exhibit greater survival in a certain RH nor when exposed to various sources ...

Molecular Evidence for the Polyphyly of Macrotrichomonas (Parabasalia: Cristamonadea) and a Proposal for Macrotrichomonoides n. gen.

Macrotrichomonas (Cristamonadea: Parabasalia) is an anaerobic, amitochondriate flagellate symbiont of termite hindguts. It is noteworthy for being large but not structurally complex compared with other large parabasalians, and for retaining a structure similar in appearance to the undulating membrane (UM) of small flagellates closely related to cristamonads, e.g. Tritrichomonas. Here, we have characterised the SSU rDNA from two species described as Macrotrichomonas: M. restis Kirby 1942 from Neotermes jouteli and M. lighti Connell 1932 from Paraneotermes simplicicornis. These species do not form a clade: M. lighti branches with previously characterised Macrotrichomonas sequences from Glyptotermes, while M. restis branches with the genus Metadevescovina. We examined the M. restis UM by light microscopy, scanning electron microscopy, and transmission electron microscopy, and we find common characteristics with the proximal portion of the robust recurrent flagellum of devescovinids. Altogether, we show the genus Macrotrichomonas to be polyphyletic and propose transferring M. restis to a new genus, Macrotrichomonoides. We also hypothesise that the macrotrichomonad body plan represents the ancestral state of cristamonads, from which other major forms evolved.

Phylogeny and Ultrastructure of Oxymonas jouteli, a Rostellum-free Species, and Opisthomitus longiflagellatus sp. nov., Oxymonadid Flagellates from the Gut of Neotermes jouteli

The biodiversity of oxymonadid flagellates in termite hindguts is not fully explored. Many species have been differentiated only by morphological features, and small-celled species have been overlooked or ignored. Our analysis of the dry wood termite Neotermes jouteli by light and electron microscopy revealed the presence of two distinct morphotypes of oxymonads. The larger one matched the morphology of Oxymonas jouteli, the only oxymonad species described from this termite. Although it generally lacks the typical anterior rostellum of the genus Oxymonas, its SSU rRNA gene sequence clusters among other members of this genus, including novel phylotypes that we obtained from Incisitermes tabogae. The second morphotype was a tiny oxymonad that showed the typical traits of the genus Opisthomitus, including a pointed anterior prolongation (lappet). However, the four equal flagella were much longer than those of Opisthomitus avicularis from Kalotermes flavicollis, the only species of the genus and so far described only by light microscopy. We provide a detailed description of Opisthomitus longiflagellatus sp. nov. and demonstrate that despite ultrastructural similarities to members of the Polymastigidae, its SSU rRNA gene sequences form a separate family-level lineage with a slight affinity to the Pyrsonymphidae.

Morphology and Molecular Phylogeny of Staurojoenina mulleri sp. nov. (Trichonymphida, Parabasalia) from the Hindgut of the Kalotermitid Neotermes jouteli

Staurojoenina is a large and structurally complex genus of hypermastigont parabasalians found in the hindgut of lower termites. Although several species of Staurojoenina have been described worldwide, all Staurojoenina observed to date in different species of North American termites have been treated as the same species, S. assimilis. Here, we characterize Staurojoenina from the North American termite Neotermes jouteli using light microscopy, scanning electron microscopy, and phylogenetic analysis of small subunit ribosomal RNA, and compare it with S. assimilis from its type host, Incisitermes minor. The basic morphological characteristics of the N. jouteli symbiont, including its abundant bacterial epibionts, are similar as far as they may be compared with existing data from S. assimilis, although not consistently identical. In contrast, we find that they are extremely distantly related at the molecular level, sharing a pairwise similarity of SSU rRNA genes comparable to that seen between different genera or even families of other parabasalians. Based on their evolutionary distance and habitat in different termite genera, we consider the N. jouteli Staurojoenina to be distinct from S. assimilis, and describe a new species, Staurojoenina mulleri, in honor of the pioneering parabasalian researcher, Miklos Muller.

Poikilolaimus floridensis n. sp. (Rhabditida: Rhabditidae) associated with termites (Kalotermitidae)

AbstractA survey of termite-associated nematodes was done in southern Florida to compare the diversity of such associations with other latitudes in the Neotropics. Six species (15 colonies) of termites (Isoptera) were collected from the field and eight species (15 colonies) from laboratory populations were examined for nematode associates. All six field-collected termite species, Cryptotermes cavifrons, Incisitermes snyderi, Neotermes jouteli, N. castaneus, Prorhinotermes simplex and Reticulitermes flavipes, representing two families (Kalotermitidae and, for the latter two species, Rhinotermitidae), were associated with nematodes. Nematodes were also isolated from laboratory populations of I. snyderi and Coptotermes formosanus. In total, seven putative species of nematodes were discerned using molecular bar-coding and culturing (when successful) including four rhabditids, one diplogastrid, Rhabditis rainai and a nematode that we are describing herein as Poikilolaimus floridensis n. sp. This nematode was isolated as dauer juveniles in the foregut of N. jouteli, N. castaneus and I. snyderi. It was recovered from workers, a soldier and an alate, suggesting internal phoresy. It is characterised by six triangular cuticular flaps covering the stomatal opening, simple tube-like stomatal structure, i.e., absence of teeth and glottoid apparatus, cuticularised and refractile secretory-excretory pore, conical male tail lacking 'bursa' or spike, short and conical female tail and didelphic female reproductive system. Poikilolaimus floridensis n. sp. is morphologically characteristic and does not easily fit the current genus definition of Poikilolaimus which is redefined herein. Molecular phylogenetic analysis based on near full length SSU ribosomal DNA sequence showed that the new species occupies a basal position in the genus.

Redescriptions of the Dampwood Termites <I>Neotermes jouteli</I> and <I>N. luykxi</I> (Isoptera: Kalotermitidae) from Florida, Cuba, Bahamas, and Turks and Caicos Islands

Two species of dampwood termites, Neotermes jouteli (Banks) and N. luykxi Nickle & Collins, are redescribed based on the imago and the small and large soldier caste. Morphological characters are reported to separate the above castes of these two species. N. jouteli occurs in southeastern Florida, the central Bahamas, Cuba, and Mexico. N. luykxi is endemic to southeastern Florida, the Bahamas, and Turks and Caicos Islands, but is apparently absent from Cuba. A key to the Neotermes found sympatrically with N. luykxi is given.

Yeasts associated with termites: a phenotypic and genotypic characterization and use of coevolution for dating evolutionary radiations in asco- and basidiomycetes

Thirtynine yeast isolates or dimorphic fungi were obtained from the hindgut of the lower termites Mastotermis darwiniensis (Mastotermitidae), Zootermopsis angusticollis, Z. nevadensis (Hodotermitidae), Neotermes jouteli (Kalotermitidae), Reticulitermes santonensis, Heterotermes indicola (Rhinotermitidae) and the roach Cryptocercus punctulatus. Using RAPD-PCR the 39 yeast isolates were assigned to 13 different species. Commonly yeast species were specific to the termite species isolates from. There were only two yeast species which were found in different species of lower termites. Based on phenotypic characters Debaryomyces hansenii showed a high score in four species. The qualitative and quantitative yeast cell wall monosaccharide composition, the ubiquinone system, partial sequencing of 18S ribosomal DNA (bases 1273 to 948; numbering according to the gene of Saccharomyces cerevisiae), and the ultrastructure of septal pores indicate that 11 yeast species belong to the Endomycetales. Although ascospores were lacking, two of these species were identified to belong to the genus Debaryomyces. One remaining yeast isolate was identified as a Sporothrix anamorph representative for the filamentous Ascomycetes (Ophiostomataceae s. str.); the second species showed affinities to the Basidiomycetes in particular to the genus Trichosporon. Comparing an additional 18S rDNA fragment (bases 595 to 993) and RAPD-PCR data using different species type strains of the genus Sporothrix, the filamentous ascomycete was genotypically identified as Sporothrix albicans. Sporothrix. albicans, although phylogenetically closely related to S. schenckii var. schenckii and Ophiostoma stenoceras remains genotypically distinct. An emended species description of S. albicans is presented. Evidence is provided that the yeasts isolated from the hindgut can be considered symbionts.

Evaluation of a Novel, Hand-Held, Acoustic Emissions Detector To Monitor Termites (Isoptera: Kalotermitidae, Rhinotermitidae) in Wood

A hand-held, battery-powered acoustic emissions (AE) detector designed to locate and monitor wood-feeding insects was evaluated for its ability to detect termites in wood. It was possible to detect 20 Coptotermes formosanus Shiraki, Incisitermes snyderi (Light), and Neotermes jouteli (Banks) pseudergates in small wooden blocks 100% of the time during an experimental 5-min interval. If undisturbed, 20 Reticulitermes flavipes (Kollar) pseudergates could be detected at a 98% frequency. AE production was governed largely by termite species and density. In detection tests along longitudinally oriented wood grain, termites could be detected up to 80 cm from the AE sensor, although detection at progressively shorter distances from termites was increasingly more likely. Detection of termites in wood in a tangential orientation (against grain) was unlikely beyond 8 cm. Although counts were high (up to 299 per min), there was a poor relationship between I. snyderi numbers and AE event counts in naturally infested logs. The only termite behavior observed to elicit detection by the AE units was wood feeding. Most ambient noises were not registered by the detector. It was concluded that this device offers a reliable method for localized, nondestructive detection of termites in wood.

Degeneration of the compound eye of the termite Neotermes jouteli (Isoptera) in darkness during the phase of reproduction

Long-term light deprivation of the royal pair of Neotermes jouteli during the phase of reproduction leads to a dramatic change in the organization within the compound eye. In a swarming alate, investigated with scanning and transmission electron microscopy, the eye consists of about 200 ommatidia. No differences between male and female eyes are observed. Each ommatidium is composed of a biconvex cornea, a cone of the eucone type, and a rhabdom which is located directly beneath the Semper cells. The rhabdom consists of eight rhabdomeres which are fused along the ommatidial axis. In the central part of the compound eye the rhabdom measures roughly 20 μm in length. Concealed life of the imagines causes a dismantling of the cone and the rhabdom until complete destruction. This is accompanied by an increase in the number of pigment granules and a decrease in the number of mitochondria.

Laboratory Comparisons of Sulfuryl Fluoride Toxicity and Mean Time of Mortality Among Ten Termite Species (Isoptera: Hodotermitidae, Kalotermitidae, Rhinotermitidae)

Ten termite species representing three families [ Zootermopsis angusticollis (Hagen), Hodotermitidae; Cryptotermes cavifrons Banks, Incisitermes minor (Hagen), Incisitermes snyderi (Light), Neotermes jouteli (Banks), Kalotermes approximatus Snyder, Kalotermitidae; Coptotermes formosanus Shiraki, Reticulitermes tibialis Banks, Reticulitermes flavipes (Kollar), and Prorhinotermes simplex (Hagen), Rhinotermitidae] were fumigated with sulfuryl fluoride for 22 h in the laboratory. R. flavipes and R. tibialis were most sensitive (LAD30 = 13.42 and 14.52 mg-h/liter, respectively), and I. minor was least sensitive (LAD50 = 30.36 mg-h/liter). Greatest and least postfumigation grand mean time of mortality (±SEM) was 3.11 ± 0.04 and 1.58 ± 0.05 d for R. tibialis and I. snyderi , respectively. Z. angusticollis had a uniquely steep probit-mortality slope.

Caste determination inNeotermes jouteli (Banks)

Studies of the mechanism of caste determination in termites were carried out on the southern Florida Kalotermitid,Neotermes jouteli (Banks). It was found that pseudergates of this species can respond to isolation by rapid and extensive production of supplementary reproductives (SRs). Similarly, soldier production was found in groups from which this caste was removed.