Die embryonalentwicklung des kopfes und prothorax von Carausius morosus br. (Insecta,Phasmida)

The development of the head — especially of the head structures which show traces of a metameric origin — is described. These structures confirm that the head of Carausius consists of an acron and six segments. The development of the thorax and legs confirm Weber's subcoxal theory.     

Complete and incomplete extra DNA reduplication during spermatogenesis of Carausius morosus Br. (Insecta,Phasmida)

In one individual of the triploid hybrid Aloe “Sherman Hoyt” (2n=21) a large supernumerary segment on the end of the long arm of an L₂ chromosome was shown to be a reversed duplication formed by the distal breakage of a U-type chromatid bridge at anaphase I in the tetraploid parent. The segment misdivides and is partially or wholly lost during mitotic anaphase at a constant rate. Sectors of tissue lacking the segment do not become established, indicating that its loss is lethal to the daughter cell line after a few mitotic divisions. This constant rate of breakage combined with the elimination of deficient cell lines results in a system which is stable overall.     

Central projections of a homoeotic regenerate, antennapedia, in a stick insect, Carausius morosus (Phasmida)

Homoeotic appendages provide a system for the analysis of neural path-finding in which the appendage is mismatched with its segmented ganglion. Central projections of sensory neurons from homoeotic antennapedia regenerates induced by antennal amputation in the stick insect, Carausius morosus, are described. The majority of afferent axons project to the olfactory lobe as in the normal antennal nerve, but they do not give rise to compact glomeruli. Nor does the form of the projection resemble that of leg sensory nerves in thoracic ganglia. The projection of antennapedia regenerate neurons in Carausius resembles the antennapedia mutant of Drosophila except that some primary afferents bypass the olfactory lobe and take several courses through the brain, sometimes reaching distant contralateral areas. It appears that these wandering fibers, having bypassed the olfactory lobe, tend to follow established tracts and to arborize or to deviate at circumscribed synaptic areas. The behavioral evidence for sensory input from antennapedia regenerates is equivocal.     

DNA reduplication during meiotic prophase in the oocytes of Carausius morosus Br. (Insecta,Cheleutoptera)

Cytological investigations combined with cytophotometric DNA determinations on Feulgen stained squash preparations of ovarioles from third and fourth instar nymphs of Carausius morosus revealed that during meiotic prophase a largely despiralized stage follows pachytene and that in this stage an extra reduplication of the nuclear DNA takes place (pachyreduplication phase). Meiotic prophase then proceeds with tetrapachytene, a pachytene-like stage with twice the amount of DNA as compared to oocyte nuclei in earlier meiotic stages, and with more than half the somatic number of elements, being probably autobivalents.Supported by Deutsche Forschungsgemeinschaft.     

Influence of aminergic and peptidergic substances on heart beat frequency in the stick insect Carausius morosus (Insecta,Phasmatodea)

The dorsal heart of the Indian stick insect, Carausius morosus, is responsible for the anterograde flow of hemolymph to the aorta and into the body cavity. The contraction frequency of the insect heart is known to be influenced by several substances of neural source. Here, a semi‐exposed heart assay was employed to study the effect of an aminergic substance (octopamine) and three neuropeptides (C. morosus hypertrehalosemic hormone [Carmo‐HrTH], crustacean cardioactive peptide [CCAP], and proctolin) on heart contraction. The contraction frequency was measured as beats per minute in adults ligated between the head and the prothorax. All three investigated neuropeptides had a stimulatory effect on heart contraction that lasted approximately 6 min, after which the normal heart beat rate was restored. Proctolin and CCAP stimulated the rate of heart beat also in unligated stick insects, whereas Carmo‐HrTH was active only in ligated insects. The latter could suggest that when the stick insect is not ligated, a competing substance may be released from the head of C. morosus; the competing substance is, apparently, not physiologically active but it binds or blocks access to the receptor of Carmo‐HrTH‐II, thereby rendering the HrTH peptide “not active.” In ligated stick insects, 6.7 × 10^?8 M Carmo‐HrTH‐II significantly increased the heart beat rate; higher doses resulted in no further increase, suggesting the saturation of the HrTH receptor. Octopamine inhibited the rate at which the heart contracted in a dose‐dependent manner; inhibition was achieved with 10^?4 M of octopamine.     

Microtubules in the epidermal cells of Carausius morosus (Br.). Their pattern and relation to pigment migration

The existence of one or several systems of microtubules, consisting of a central bundle that branches off towards the basal and distal ends of epidermal cells of Carausius morosus has been shown by indirect immuno-fluorescence microscopy using monospecific anti-tubulin. The pattern of microtubules coincides with the position of the ommochrome granules and their migration path during physiological colour change. The ommochrome granules stick to isolated bundles of microtubules. Small bundles of microtubules extend almost perpendicularly towards the apical cell membrane where they are attached. Distally they are covered by pore channels within the cuticle. Parallel to the basal cell membrane and in close contact with it, there are very small bundles of microtubules. These findings strongly support the idea that during physiological colour change the ommochrome granules migrate along a firmly fixed system of microtubules.     

Intervention possible d'un facteur cephalique dans la regeneration des pattes chez les embryons du Phasme,Carausius morosus Br. (Phasmida : Lonchodidae)

Suppressions of endocrine cephalic areas (which contain the presumptive endocrine glands) were performed on young (stage IV₃-V₁) or differentiated (stages VI₈, or VII₁) embryos of Carausius morosus Br.(Phasmida : Lonchodidae). In all these operated embryos (= cephaloprives), amputation of a thoracic leg during the second cuticle formation (stage VI₈), or even after this event (stage VII₁), prevented regeneration. On the other hand, regenerative abilities were preserved when the amputation of the leg was made on embryos deprived of abdominal segments, with similar conditions as for cephaloprives. Consequently, operative shock did not modify regenerative abilities. Because very similar ecdysteroid levels were assayed both in cephaloprives and normal eggs, interference of a possible cephalic factor (perhaps neurosecretion) in the regeneration of the embryonic leg could be envisaged.     

The eggs of leaf insects (Insecta: Phasmida)

The morphology of seventeen samples of phylliine egg is described and figured, and an attempt is made to relate these egg forms to the alleged identity of the adult insects.     

The capitulum of phasmid eggs (Insecta: Phasmida)

The term capitulum is defined and a survey of the known eggs of the Phasmida is made to show the occurrence of this structure. Its value as a taxonomic criterion is considered.     

Immunohistological studies on the distribution of yolk proteins in the stick insect (Carausius morosus)

The path of yolk proteins through stick insect embryos at two developmental levels was studied immunologically. In 18-day-old embryos, all the blastema takes up the yolk proteins directly. In 30-day-old embryos, two transport systems are developed: embryonic contraction moves the yolk particles throughout the embryonic cavities, and amoeboid cells complete the yolk transport to its destination.     

Oscillations of force in the standing legs of a walking insect (Carausius morosus)

In the experiments presented here adult stick insects (Carausius morosus) walk on a treadwheel with various legs standing on platforms fixed relative to the body of the insect. These standing legs produce large forees directed towards the rear which are modulated in the rhythm of the walking legs. Neighbouring legs which both stand on a platform often oscillate in phase. Possible reasons for the occurrence of the force oscillations are discussed.Supported by DFG (Cr 58/1)     

The maturation divisions of the parthenogenetic stick insect Carausius morosus Br. (Orthoptera,Phasmidae)

The meiotic stages in the maturation of the egg of the parthenogenetic stick insect Carausius morosus Br. is described. The meiosis consists of two equational divisions and parthenogenesis is thus apomictic. The first prometaphase is formed between 5.8–5.5 days before oviposition; the first metaphase lasts until oviposition; the meiosis ends between 14 and 24 hours after oviposition. An extra chromosome doubling occurs before first anaphase, causing the first metaphase chromosomes to resemble bivalents and requiring that meiosis consists of two divisions instead of one. A terminal affinity between the daughter chromosomes influences chromosome movement during first and second metaphase and anaphase. The first and second polar bodies degenerate. The first polar body divides amitotically during pycnosis. Meiosis takes place ventrally in the egg, the germ anlage development dorsally. The pronucleus divides mitotically in the ventral part of the egg during its migration from ventral to dorsal, enabling blastoderm development to take place both ventrally and dorsally.