Flavicollis Fabr Research Articles

THE COMPETENCE OF KALOTERMES FLAVICOLLIS FABR. (ISOPTERA) PSEUDERGATES TO DIFFERENTIATE INTO SOLDIERS

SUMMARY Previous investigations carried out in our laboratory on Kalotermes flavicollis Fabr. had shown that the royal pair exerts a stimulatory action on pseudergate differentiation into soldiers, while the latter have an inhibitory influence on it (SPRINGHETTI, 1969). The present experiments have shown that the pseudergate moulting interval is of fairly variable duration, from 18 to 140 days, with a mean of about 70 days. Its average duration, however, is the same both in specimens differentiating into soldiers and in those undergoing a larval moult. Pseudergates display a rather short competence period for differentiation into soldiers during the second half of the moulting interval: possibly between the 45th and 60th day. Pseudergates are responsive only during their competence period, to the antagonistic stimuli exerted by the royals and soldiers respectively. The absence of soldiers prior to the 40th day does not elicit the differentiation of new soldiers (even in the presence of the reproductives);...

Caste and Population Specificity of Termite Cuticule Hydrocarbons

The composition of hydrocarbons from the termites Reticulitermes lucifugus Rossi and Kalotermes flavicollis Fabr. belonging to different castes and populations was determined using GC and mass spectrometry. The role of cuticular hydrocarbons in olfactory recognition of termite caste and population status was demonstrated.

Antimicrobial activity of certain essential oils against hindgut symbionts of the drywood termite Kalotermes flavicollis Fabr. and prevalent fungi on termite‐infested wood

Abstract: When the kalotermitid Kalotermes flavicollis Fabr. pseudergates exposed to Casuarina wood wafers treated separately with different concentrations (5, 15 and 30 μl/2 g wood wafer) of the essential oils, their spirochaete and flagellate populations abnormally reduced in numbers and vigour. The lophomonadids Joenia sp. and Mesojoenia sp. were the most adversely affected flagellates followed by the polymastigid Foaina sp. and the trichomonadid Tricercomitus sp. The Taxodium distichum essential oil evidently appeared to have the greatest adverse effect on the flagellates (95–100% decline in numbers within 2–4 days) followed by the Eucalyptus citriodora (89–100%) and the Cupressus sempervirens oils (31–100%). While with the hindgut spirochaetes, the adverse effect seemed to be reversed where the E. citriodora essential oil had the greatest effect (54–100%) followed by C. sempervirens (46–100%) and T. distichum (8–100%) oils. Moreover, the essential oils were assayed for their antifungal activity, at 15, 20, 25, 30, and 50 μl/1 ml acetone/15 ml Czapek‐Dox medium, against isolates of four woodrotting fungi associated with Casuarina timber, Aspergillus sp., Penicillium sp., Fusarium sp. and Mucor sp. by a method based on inhibition of the fungus growth on agar plates. E. citriodora exhibited the most potent fungicidal activity against the tested four fungi, followed by T. distichum oil. While the C. sempervirens essential oil appeared to have the least significant antifungal property.

Histopathology of termite Kalotermes Flavicollis Fabr. Infected with a nuclear Polyhedrosis virus

The pathology of the nuclear polyhedrosis virus from Spodoptera littoralis against Kalotermes flavicollis was confirmed under light microscope. Sections of infected termites showed a comprehensive viral infection. Nuclei of cells of the foregut, cardiac valve, pyloric valve, hindgut, gut musculature, fat body, nerve tissue, muscle, oviduct, pedicel of the ovariole, calyx, accessory glands, wing buds in termite reproductive nymphs, and to a lesser degree, the tracheal matrix, malpighian tubules and hypodermis, were susceptible to the virus. Infection to midgut was generally limited. However, when the termites were heavily infected, the midgut epithelial cells sloughed off into the lumen, and became hypertrophied and granular.

Patterns of activity of nucleolar organizer regions during spermatogenesis and oogenesis in Kalotermes flavicollis Fabr. (Insecta: Isoptera) analyzed by silver staining

The distribution and the behaviour of the nucleolus organizer regions (NORs) were analysed during the spermatogenesis and oogenesis of K. flavicollis with the silver staining method. The Ag-stainability of the NORs increases in growing spermatocytes up to pachytene and is absent during the remainder of the meiotic prophase. During female meiosis the nucleolar material undergoes a more complex transformation. It is active until pachytene; in early diplotene the mass of silver stainable material progressively increases as an effect of rDNA amplification. By the end of meiotic prophase the nucleolar strands disappear and a large nucleolus is rebuilt in the mature oocyte.

Trail pheromone of Kalotermes flavicollis

The trail pheromone of the termiteKalotermes flavicollis Fabr. has been isolated with the aid of column, liquid, and gas chromatography. Four of its components have been identified by PMR and chromato-mass spectrometry: nonan-l-ol, decan-l-ol, undecan-l-ol, and dodecan-l-ol, which are present in the natural trail pheromone in a ratio of 1:2:4:4. This has been confirmed by comparison with standard substances by means of gas chromatography and biotesting.

Note on tryptophan metabolism via kynurenine inKalotermes flavicollisFabr. (Isoptera: Kalotermitidae)

Abstract In Kalotermes flavicollis Fabr. (Isoptera, Kalotermitidae) the tryptophan metabolites were determined by paper chromatography. The metabolites, present in varying amounts in all the castes and stages studied, seem to be synthetized by Kalotermes flavicollis itself and not by symbionts in the insect intestine. The differences in the quantities of the metabolites among the groups do not seem to be correlated with the castes and stages. The results are discussed in relation to the synthesis of ommochromes.

Group effects in the differentiation of the soldiers ofKalotermes flavicollis Fabr. (Isoptera)

The differentiation of pseudergates into soldiers was investigated in soldierless experimental groups formed by a royal pair of supplementary reproductives and by different numbers of pseudergates in a range from 2 to 25.

ZUR LABORATORIUMSPRÜFUNG VON TEXTILIEN AUF TERMITENFESTIGKEIT MIT KALOTERMES FLAVICOLLIS FABR

Für die Prüfung von Textilien auf Termitenfestigkeit hat sich seit langer Zeit die Trocken‐holztermite Kalo***termes flavicollis Fabr. hervorragend bewährt. Durch neue radiobiologische und verhaltensphysiologische Untersuchungen wird die vorgeschlagene Prüfmethodik biologisch begründet und im einzelnen näher erläutert.SummaryLABORATORY EXPERIMENTS ON THE RESISTANCE OF VARIOUS MATERIALS, ESPECIALLY TEXTILES, TO KALOTERMES FLAVICOLLIS FABR.Experiments were made over a period of two years on the resistance of various materials, especially textiles, to termites. The dry wood termite, Kalotermes flavicollis Fabr. was used as a test animal, as this insect is resistant to environmental conditions and it readily attacks hard materials. Quantitative radio‐biological investigations showed that fifth‐instar larvae and “Pseudergates”, which both feed actively, are good test animals. After moulting, larvae do not feed for 4 days. It is advisable therefore to use large batches (30 larvae in each) to ensure that some are trying to feed at any time. Experiments should last 21 days at least. The method used in testing the effects of K. flavicollis on textiles, and the way the insect is acclimatised, are described. A useful new technique for these tests consists of pulling the textile into the metal frame of a projector‐slide. Termites can gnaw through materials otherwise resistant when they are covered by a thin perforated film of termite‐proof material. If the perforations are of the same diameter as the termite's head they serve as innate releasing mechanisms for “food‐tunnel gnawing”. This method should only be used in special cases, e.g. testing for repellency, surface hardness, etc.