Kalotermes Flavicollis Research Articles

Localization of silver positive structures in mitotic and meiotic chromosomes ofKalotermes flavicollis(Fabr.) (Isoptera Kalotermitidae)

Application of the silver staining technique to mitotic and meiotic chromosome preparations of Kalotermes flavicollis have shown: (1) four pairs of mitotic chromosomes have nucleolus organizer regions located near the centromere regions; (2) that in suitable preparations core-like structures are visible in mitotic chromosomes; (3) the sex determining mechanism.

Oogenesis in immature stages and sterile castes ofKalotermes flavicollis(Fabr.) (Isoptera Kalotermitidae)

Ovaries of winged and dewinged imagos, 2nd instar nymphs, pseudergates, presoldiers and soldiers of Kalotermes flavicollis were investigated. During the normal developmental cycle, after the imaginai moult, the ovary starts to produce eggs as a result of the activation of oogenic processes. In pseudergates, presoldiers and soldiers oogenesis is blocked at the first previtellogenic stage and the oocytes undergo degeneration. In nymphs a block is also observed, but it happens at the second previtellogenic stage and without any hint of oocyte degeneration. The evidence suggests that in pseudergates, presoldiers and soldiers, the oogenesis block is related to a lack of differentiation of follicular cells which may be one of the main targets for control factors.

Arthropod fauna and main insect pests of plane trees in Israel

Fifty-four insect and four mite species are included in a list of the entomofauna of plane trees in Israel. Only two species are monophagous:Phyllonorycter platani (Stgr.) (Lepidoptera: Gracillariidae) andEdwardsiana iranicola Zachv. (Heteroptera: Cicadellidae). Four species are noxious:P. platani, the main insect pest of the plane trees in Israel;Zeuzera pyrina L. (Lepidoptera: Cossidae);Kalotermes flavicollis F. (Isoptera: Kalotermitidae); andE. iranicola. Of much lesser importance areTargionia vitis Sign. (Homoptera: Diaspididae),Heliothrips haemorrhoidalis Bche. andRetithrips syriacus May. (Thysanoptera: Thripidae). About half of the listed species are natural enemies and many are parasites ofP. platani. Details are given on the noxious species, together with recommendations for prevention and control.

Oogenesis inKalotermes flavicollis(Fabr.) (Isoptera, Kalotermitidae) III. Choriogenesis and corpus luteum formation in female supplementary reproductives

Abstract Follicular cell ultrastructure during chorion and corpus luteum formation was studied in supplementary reproductives of the termite Kalotermes flavicollis. During choriogenesis the follicular epithelium is formed by large flattened cells joined together by specialized junctions. Follicular cells have an extended rough endoplasmic reticulum (RER) with cisternae parallel to the cell long axis and many Golgi complexes surrounded by secretion vesicles moving towards the egg surface. At the end of choriogenesis the follicular cells move away from the just completed chorion and show few RER cisternae and scarce Golgi apparati. When the egg is ejected from the ovariole, the empty ovarian follicle collapses; the irregularly shaped follicular cells, now exhibiting in their cytoplasm small autophagic vacuoles and polymembranous structures, form the initial corpus luteum. This undergoes a further shrinking, becoming an ovoidal mass (the advanced corpus luteum) formed by irregularly shaped follicular cells c...

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.

Digging behaviour and royal pair's influence inkalotermes flavicollis(Isoptera, kalotermitidae)

Abstract Groups of Kalotermes flavicollis were removed from their wild nest and colony in order to study the digging of their new shelter in an agar/sawdust mixture. On the first day the insects dug numerous tunnels, some of which (usually the shortest) were soon abandoned. Digging continued with great regularity and finally the nests consisted mainly of tunnels with few branches and communication passages. Some tunnels were filled with sawdust taken from other parts of the nest. There was a correlation between the total length of dug tunnels and that of filled ones. The presence of the royal pair stimulated insect activity. In the presence of royals, insects dug larger nests made of tunnels that had more branches.

Infection of Termites by Spodoptera littoralis Nuclear Polyhedrosis Virus

A nuclear polyhedrosis virus isolated from the Egyptian cotton leafworm, Spodoptera littoralis, was found to infect termite castes of Kalotermes flavicollis. Laboratory studies indicated that no specific trend toward mortality responses among the different individuals of termites was noted. All test castes of termites, young, middle-sized, old and reproductive nymphs, and soldiers, were quite equal in their response to the virus infection, regardless of whether the virus concentration was high or low; a concentration of 6.4 × 108 polyhedra/ml, killed only 64% of the treated individuals, while the dosage of 6.4 × 107 polyhedra/ml produced over 90% mortality. Also, the same trend of response was recorded with the survivors which received challenge doses of NPV suspension each 9 or 10 days. On the other hand, these results revealed that if the NPV is used to control termites, periodic applications would be more efficacious than one treatment. Virus symptoms were recorded in all affected insects.

Changes in the cuticle, ovaries and colleterial glands during the pseudergate and neotenic molt in Kalotermes flavicollis (FABR.) (Isoptera : Kalotermitidae)

Through a particular molt, the pseudergates of the lower dry-wood termite Kalotermes flavicollis (Isoptera : Kalotermitidae) can develop into neotenic replacement sexuals. With electron microscopy, we have studied the development of the cuticle and the reproductive organs (ovaries, colleterial glands) during a neotenic molt and compared with those during a molt of pseudergate. Our work confirms Lüscher's results, indicating that the neotonic molt is shorter than the pseudergate molt (6 days vs 7 days). However, apolysis, digestion of endocuticle, and formation of epi- and procuticle are synchronous in the 2 types of molts. In the pseudergates, the ovaries are in previtellogenesis; the colleterial glands show neither secretory units, nor cuticular lining of the glandular lumen. During the pseudergate molt, the ovaries and the colleterial glands do not undergo cytological modifications. During the neotenic molt, vitellogenesis occurs slowly in the ovaries, whereas the colleterial glands develop very rapidly and are functional when ecdysis occurs; the secretory units are differentiated and the cuticle of the glandular lumen is secreted as early as the second day after the beginning of the molt. Therefore, the colleterial glands appear to be a very good marker for the anticipated sexual maturation of the neotenics and seem appropriate for in vitro study of the hormonal regulation of the neotenic differentiation.

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.

Endocrine Activity retained in Diapause Insect Larvae

DIAPAUSE is a state of arrested development which synchronises insect activity cycles with seasons when food resources are available. Facultative diapause occurs in response to environmental cues such as photoperiod and temperature which influence the endocrine system before the unfavourable conditions arrive1,2. We have now obtained evidence that the currently accepted theory of humoral regulation of larval diapause should be revised. Past research on the pupal diapause of Saturniid moths led to the widely accepted conclusion that larval and pupal diapause result from a failure of the neurosecretory cells of the brain or the corpora cardiaca to release the brain (prothoracotropic) hormone which is required to stimulate the prothoracic glands to secrete the moulting hormone, ecdysone3–5. The arrest of growth and moulting and the initiation of diapause have therefore been attributed to the absence of this brain hormone from the haemolymph6. Available evidence linking larval diapause with an inactive endocrine system has, however, remained inconclusive7–10. Our data indicate that, on the contrary, mature diapause larvae of the southwestern corn borer, Diatraea grandiosella Dyar, must retain a functional endocrine system since they undergo stationary ecdyses during diapause. The ability of diapause larvae to undergo stationary ecdyses remains consistent with the concept of diapause as a state of arrested development because the stationary ecdyses do not affect the developmental stage11. (Luscher used the term stationary ecdysis to describe the ecdysis of the pseudergate larvae of the termite, Kalotermes flavicollis, when no progressive development occurs.) We now have evidence to implicate juvenile hormone (JH) in the regulation of this larval diapause.

Über Zwischenformen bei der Kastenbildung von Kalotermesflavicollis (F.) und Heterotermes indicola (Wasm.) (Kalotermitidae, Rhinotermitidae)1

AbstractOn the occurrence of intercastes in Kalotermes flavicollis (F.) und Heterotermes indicola (Wasm.) (Kalotermitidae, Rhinotermitidae). The occurrence of intercastes in the both termite species is described. In both cases the intercastes (pseudoimagines) showed well developed dark complex eyes but only small wing pads.

Protection of wood particle board against termites

Particle boards are of increasing economic importance. Without special treatment they are destroyed by termites. Deterioration of unprotected material as well as possibilities and present knowledge of preservation against termite attack are briefly described. Recent laboratory experiments with particle board treated to make it resistant to humidity and basidiomycete fungi showed that only one organic preservative out of four protected the boards also against termite attack; one of two water-soluble preservatives gave promising results. Heterotermes indicola (Wasmann) from India proved to be more aggressive and resistant to the preservatives than Coptotermes amanii (Sjostedt) from Kenya and Nasutitermes nigriceps (Haldemann) from Guatemala. Kalotermes flavicollis (Fabr.) from Italy was also very tolerant to the fungicidal preservatives. Further development of treatments of particle board against termites is required.

Innervation de type neurosécréteur dans la glande sternale de Kalotermes flavicollis (Isoptera). Étude ultrastructurale

The sternal gland of Kalotermes flavicollis secretes a trail pheromone dissolved in a lipid substance. The gland appears as an epidermal thickening in the anterior part of the fifth abdominal sternite. Two types of cells may be recognized: glandular cells with many lipidic droplets and columnar cells with a brush border beneath the cuticle. There are also about thirty campaniform sensilla. An ultrastructural study discloses nervous efferent fibres in the anterior part of the sternal gland. These fibres are easily distinguished from the sensory fibres by the following features: glial cells, which surround the axon before reaching the gland, end in the connective layer, and naked axons run between the gland cells to the base of the brush border. In the axoplasm there are electrondense granules (probably neurosecretory), 900 to 1500 Å in diameter. Both at the level of the connective layer and in the gland near the columnar cells, ‘synaptoid vesicles’ are aggregated close to the axon membrane in ‘synaptoid areas’ where the neurotransmitter may be released. Such a ‘neurosecretomotor junction’ probably plays a rôle in the control of secretion. It is tentatively suggested that efferent nerve fibres influence the release of pheromene. Then the pheromone is mixed with the continuously produced lipid component before being laid down on the ground.

Effect of Synthetic ‘Queen Substance’ (9-oxodec-trans-2-enoic acid) on Ovary Development of the House-fly, Musca domestica L.

RECENT investigations1 have shown that when ‘queen substance’ (9-oxodec-trans-2-enoic acid) is distributed throughout the colony of honey bees, it partially inhibits the development of ovaries in workers and influences their behaviour by inhibiting queen-cell construction. Similar effects of crude extracts of queen honey bees have been demonstrated on other groups of social insects, for example, Formica fusca L.2 and Kalotermes flavicollis F.3 This non-specificity for orders of social insects suggests that ‘queen substance’ might have similar inhibitory effects on ovary development even of non-social insects. This hypothesis was tested by examining the effect of synthetic ‘queen substance’ on ovary development in the house-fly, Musca domestica L.

Untersuchungen über die Bedeutung der Corpora allata für die Differenzierung der Kasten bei der Termite Kalotermes flavicollis F.

The role of the corpora allata in caste differentiation has been studied in the termite Kalotermes flavicollis by transplanting corpora allata of differnt donors into pseudergates in normal and in orphaned colonies. When corpora allata from primary and secondary reproductives, from nymphs just before the alate moult, and from soldiers were implanted, a great number of the hosts differentiated into pre-soldiers. Transplants from pseudergates and last-stage nymphs which were not preparing for a moult, had no such effect, but those of pseudergates seemed to stimulate the production of supplementary reproductives. The absence of the reproductives or of their pheromones had an accelerating effect upon pre-soldier differentiation. In some cases intercasts between pre-soldiers and supplementary reproductives were produced. Their occurrence can be explained by an induction of a supplementary reproductive moult at a time when pre-soldier differentiation was already in progress. Intercastes between pre-soldiers and pseudergates have been produced experimentally by injecting ecdyson 10 days after the implantation of corpora allata from reproductives. Thus in soldier differentiation the moult is induced normally only some time after the onset of differentiation. Ligation experiments showed that the remarkable volume increase of the corpora allata before a supplementary reproductive moult has nothing to do with differentiation, but occurs in connexion with the production of gonadotropic hormone which in females stimulates growth of the oocytes. All transplanted corpora allata with the exception of those of last-stage nymphs, had an inhibiting effect upon the pigmentation of eyes in supplementary reproductives. This typically juvenile effect was especially significant after transplanting corpora allata from pseudergates. The corpora allata seem to produce two different hormones, which have different effects in caste differentiation. The juvenile hormone probably increases the competence for supplementary reproductive differentiation. The gonadotropic hormone on the other hand initiates pre-soldier differentiation.

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.