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Foraging honeybees (Apis mellifera) are well known to fly straight from the hive, their primary hub, to distal goals as well as between familiar feeding sites. More recently, it was shown that a distal feeding site may be used as a secondary hub. If not fully satiated, the foraging bee may decide to depart the first feeding site in a new compass direction straight to one of many other feeding sites (inter-patch foraging). Using a recently developed recording method, we discovered that the chosen departure direction at a secondary hub can be guided exclusively by either celestial or terrestrial compass cues. Given our data, we draw two theoretical inferences. First, the bees must be capable of learning and remembering multiple, spatially distinct, navigation vectors between the hive and among multiple feeding sites. Second, this documented and useful representation of multiple navigation vectors between multiple, identified target locations logically implies composite place-vector mapping, stored in long-term memory.

Upon leaving the nest for the first time, honeybees employ a tripartite orientation/exploration system to gain the requisite knowledge to return to their hive after foraging. Focal exploration comes first- the departing bee turns around to face the return target and oscillates in a lateral flight pattern of increasing amplitude and distance. Thereafter, for the peripheral exploration, the forward flying bee circles the return-goal area with expanding and alternating clockwise and counterclockwise arcs. After this two- part proximal exploration follows distal exploration, the bee flies straight towards her potential distal goal. For the return path, supported by the preceding exploratory learning, the return navigational performance is expected to reflect the three exploratory parts in reverse order. Previously only two performance parts have been experimentally identified: focal navigation and distal navigation. Here we discovered peripheral navigation as being distinct from focal and distal navigation. Like focal navigation, yet unlike distal navigation, peripheral navigation is invariably triggered by local place recognition. Whereas focal navigation (orientation) is close to unidirectional, peripheral navigation makes use of multiple goal-vector knowledge. We term the area in question the Peripheral Correction Area because within it peripheral navigation is triggered, which in turn is capable of correcting errors that accumulated during a preceding distal dead-reckoning based flight.

For honeybees, Apis mellifera, the hive has been well known to function as a primary decision-making hub, a place from which foragers decide among various directions, distances, and times of day to forage efficiently. Whether foraging honeybees can make similarly complex navigational decisions from locations away from the hive is unknown. To examine whether or not such secondary decision-making hubs exist, we trained bees to forage at four different locations. Specifically, we trained honeybees to first forage to a distal site "CT" 100 m away from the hive; if food was present, they fed and then chose to go home. If food was not present, the honeybees were trained to forage to three auxiliary sites, each at a different time of the day: A in the morning, B at noon, and C in the afternoon. The foragers learned to check site CT for food first and then efficiently depart to the correct location based upon the time of day if there was no food at site CT. Thus, the honeybees were able to cognitively map motivation, time, and five different locations (Hive, CT, A, B, and C) in two spatial dimensions; these are the contents of the cognitive map used by the honeybees here. While at site CT, we verified that the honeybees could choose between 4 different directions (to A, B, C, and the Hive) and thus label it as a secondary decision-making hub. The observed decision making uncovered here is inferred to constitute genuine logical operations, involving a branched structure, based upon the premises of motivational state, and spatiotemporal knowledge.

Milkweed bugs (Oncopeltus fasciatus, Lygaeidae) groom the distal segment of each antenna between the tibial combs of both forelegs. Variable numbers of grooming strokes compose a grooming bout. A total of 112 spontaneous grooming bouts, comprising all developmental stages, were videotaped, the angular movements of the forelegs were digitized, and the outcomes computer-analyzed. Individual strokes of forelegs were measured by their angular amplitude and mean angular elevation. These two measures are randomly combined in the first instar and then differentiate during ontogeny into two distinct types: small amplitude strokes of high average elevation and large amplitude strokes of lower average elevation. The sequencing of small and large strokes within bouts is largely (97%) random in all developmental stages. The outcome of the analysis fits the general empirical rule that premature action patterns are more random than mature ones. Some traits do not follow this rule and are persistently highly random. It is suggested that excessive randomness in premature behavior is due to genetic underdetermination, and that incorporation of non-genetic information helps to specify the less random mature behavior. Developmentally persistent behavioral randomness is explained by the behavioral-entropy principle: traits in behavior vary randomly unless randomness is selected against.

Some of the foraging of the arboreal Australian weaver ant Oecophylla smaragdina takes place on the ground. Odor trails and compass orientation are used to return to the trunk of their nesting tree. Field experiments established directional responses to light and the natural magnetic field. The precision of the light compass orientation is much greater than that of the magnetic compass orientation: the respective average wrapped-around standard deviations (WSD) of directional choices towards home are WSD = ± 48° and WSD = ± 105°.

Zusammenfassung 1. Als Detektoren werden distinkte Elementarstrukturen in Auslose-mechanismen bezeichnet, die auf bestimmte Komplexmerkmale von Reizmustern ansprechen. 2. Weit verbreitet bei Insekten ist ein Dunkelzentrum-Detektor, in welchem der Ausgang eines den Lichtreiz negativ beantwortenden rezeptiven Zentralfeldes mit dem Ausgang eines den Lichtreiz positiv beantwortenden Umfeldes konvergiert. 3. Der Dunkelzentrum-Detektor lost Zulaufen oder Zufliegen auf schwarze Figuren aus. 4. Drei Regeln uber den Auslosewert von Schlusselmerkmalen dunkler Figuren finden in der funktionellen Struktur des Dunkelzentrum-Detektors ihre kausale Erklarung: 1. Der Auslosewert ist am hochsten bei einer bestimmten Grose der Dunkelfigur. 2. Der Auslosewert wachst mit dem Simultankontrast zwischen Figur und Umgebung. 3. Bei Figuren von uberoptimaler Grose haben die Randzonen den grosten Auslosewert. 5. Musterdetektoren sind bis jetzt weniger scharf definierbar, aber ebenfalls weit verbreitet. Sie sprechen auf Hell-Dunkelgrenzlinien bestimmter Raumordnung an. 6. Bei Apiden dominiert bei der Blutensuche der Musterdetektor und bei der Nestsuche der Dunkelzentrum-Detektor. Summary 1. Detectors are defined as unitary functional structures within releasing mechanisms, being sensitive to complex characters of sign stimuli. 2. Many insects are equipped with a detector for dark centres, having two converging receptive fields, a central one being inhibited, and a peripheral one being stimulated by light. 3. The detector for dark centres releases movements towards black figures. 4. Three rules, concerning the releasing power of sign stimuli, can be explained causally by the functional structure of the detector for dark centres: 1. The releasing power is maximal, if the black figure has a definite size. 2. The releasing power is growing with the contrast between figure and background. 3. The peripheral zone of oversized figures releases more approaches than the centre. 5. The widespread detector for visual patterns is less clearly defined. It is sensitive to dark edges against white background in definite spatial arrangements. 6. In honey-bees and bumble-bees searching for food the detector for visual patterns is dominating, when searching for the nest entrance, however, the detector for dark centres.

A sample of compound eyes from 15 species of female pollen foraging bees (apiform Apoidea) was morphometrically analyzed. These species were chosen for size differences, different social organization, and a wide geographic and taxonomic distribution (Apidae, Megachilidae, Andrenidae, Halictidae). The results demonstrate the following characteristics for the typical compound eye in female foraging bees: (1) the vertical diameter of the eye is about twice the horizontal diameter; (2) the eyes of diurnal foragers scale isometrically with body size; (3) the eyes of three species of nocturnal foragers have about 1.8 times the surface area as compared to diurnal foragers of matching size; (4) the number of ommatidia per eye range from about 1000 in Perdita minima to about 16 000 in Xylocopa latipes; and (5) the corresponding mean interommatidial angles range from 4.7 to 1.2 degrees . Body size, rather than species-specific ecological adaptation, is the major (97%) determinant of the number of ommatidia per eye in diurnal, as well as nocturnal foragers. The number of ommatidia per eye, and hence the visual resolution, is proportional to the square root of both body size and eye size across all species studied. The eye parameter (the product of the mean interommatidial angle and the mean lens diameter) increases slightly with decreasing body size. All this is taken as evidence that the features of the bees' visual macro-niche remained largely constant over the roughly 130 million years of their macro-evolution.

The hippocampus, one of the most studied regions of the mammalian forebrain, plays some well-established roles in topographic navigation. For two decades, one widely accepted explanation for the observed impairment of hippocampectomized rats in spatial navigation has been an inability to form place representations. In this report, we present a direct experimental evidence that animals with hippocampal lesions can learn to recognize places using the constellation of distinct landmarks. The extrahippocampal implementation of all three basic constituents of topographic orientation — guidance, vector navigation, and place recognition — shows that the hippocampus, and its place cells, serve a much more specialized cognitive function than previously thought. We propose that this function includes multi-place and multi-vector topographic integration.

Food-seaching workers of eastern yellow jackets, Vespula maculifrons, are attracted by the natural odors of a wide variety of succulent fruits; particularly effective was pear. The only part of a fruit that repelled was the leathery epicarp of oranges. After rewarding with sugar water, odors of six fruits, including the pulpy mesocarp of oranges and, in addition, the leaves of catmint Nepeta cataria, all become highly attractive. To learn the distinctive odors of any one of three fruits (pear, apple, quince), nondiscrimination training with a rewarded fruit was sufficient for the subsequent olfactory preference of the training fruit over the control fruit. In the other cases [banana, hawthorn (Crataegus crus-galli), grape] simultaneous discrimination training with a rewarded and an unrewarded fruit was necessary and effective for obtaining differential responses to the odors of the training fruits. As far as current evidence goes, olfactory learning plays similar roles in the fruit foraging of this wasp and in the nectar foraging of the honey bee (Apis mellifera).

Mice (Mus musculus) that shuttle between their nest and an outside goal use different navigation mechanisms, depending on their distance from the nest. This was studied by rotating directional cues and the mice relative to one another. Close to home (20-50 cm) mice choose path integration and orientation by beacon, while farther away from the nest distal landmark orientation becomes more important. The larger the beacon is at the home site, the greater is the distance over which it is used as a directional cue. As mice head towards their nest, they demonstrate a tendency to home by means of distal landmarks at large distances, and by means of path integration or guided beacon integration at smaller distances. This space related sequence in the use of orientation mechanisms is the reverse from the temporal sequence (stages) of learning mechanisms employed when first learning to navigate home (Alyan and Jander, 1994).

Exploration is a locomotor and scanning behavior accompanied by the acquisition of information that can be used for topographic orientation and homing. Our experiments demonstrate that the exploring house mouse ( Mus musculus ) learns the use of distal landmarks for short-range homing. However, mice that had no exploratory experience at all also learned how to use distal landmarks for homing while shuttling between two goals. In addition, exploration-based knowledge in itself appears to be weak or provisional. Whereas one straight line path integration is strong enough to override orientation by distal landmarks based on 1 day of exploration, prolonged straight line shuttling results in navigation by distal landmarks that is strong enough to override path integration based on prolonged straight line shuttling. We conclude that exploratory behavior by itself is sufficient, but not necessary, for learning the use of distal landmarks for navigation within the home range.

Abstract. Female house mice readily learn to retrieve their pups 50 cm from the centre of an open arena and take them to their nest outside the arena's periphery. Experimental manipulation to reveal the spatial-orientation constituents of this behaviour disclosed thus submechanisms. Guided orientation, the direct response to objects. Path integration, the continuous monitoring of spatial displacements combined with computation of the locomotor vector to the starting point of the path. Landmark navigation, the movement by means of distal visual cues toward a goal not directly perceived. Learning to home passes through three stages. First, the exploring mouse is directly guided to objects of interest. Second, the homing mouse adds path integration; that is, it keeps a running, integrated spatial record derived from locomotion. Finally (circumstances permitting) the homing mouse links path integration with spatial references to distal visual landmarks. Sparse comparative evidence from other species of rodents suggests that such a system of short-range topographical orientation is universal among rodents.

Investigations made into the cognitive decision making of honeybees (Apis mellifera) traveling from one flower patch to another flower patch (interpatch foraging) are few. To facilitate such research, we present methods to artificially emulate interpatch foraging and quantify the immediate decision making of honeybees (within 50 cm) choosing to fly an interpatch path. These “Interpatch Methods” are validated, applied, and shown to produce novel information for the field of honeybee spatial cognition. Generally, we demonstrate that a single foraging cohort of honeybees is shown to be capable of making decisions based upon different sets of learned cues, in the exact same context. Specifically, both terminal beacon orientation cues and compass navigation cues can guide the cognitive decision making of interpatch foraging honeybees; our bees chose both cues equally. Finally, the theoretical importance of decision making for interpatch paths is compared with the other foraging paths (outward and homing) with respect to the information available to recruited foragers and scout foragers. We conclude that the ability to analyze interpatch foraging is critical for a more complete understanding of honeybee foraging cognition and that our methods are capable of providing that understanding.

Publisher Summary This chapter focuses on the magnetic field sensitivity in insects. Experimental evidence for magnetic field sensitivity has been reported in insects belonging to various orders, including Isoptera, Diptera, Coleoptera, Hymenoptera, and Lepidoptera. There is evidence that a few insect species obtain directional information from geomagnetic fields for compass orientation. Two alternative properties of the local geomagnetic vector could serve this purpose. Magnetic compass orientation can be useful for insects in the context of home range (topographic) orientation and during long-distance migration, especially in the absence of visual compass cues. Both honey bees building combs in darkness and blind termites building oriented mounds appear to use magnetoreception for aligning their structures. On the other hand, it is difficult to imagine how an insect could make adaptive use of sensing the absolute strength of the local geomagnetic field. In flight, the honeybee, Apis mellifera, also uses a magnetic compass in home range orientation. Foraging bees approaching the vicinity of their “target” learn the precise location of resources with respect to surrounding landmarks so they can return to the same place in the future. The most popular hypothesis assumes fast “snapshot”–—like recall of near-target constellations of landmarks. The returning bee finds the target location by matching the current perception of landmarks with the “snapshot memories” of them. While learning the spatial relations of landmarks, bees face in a preferred compass direction, using directional light and the geomagnetic field.

Ants (Formicidae) perform two distinct search behaviors for resources: on the ground they use irregular, almost random alternating looping, and on branches and leaves they resort to outline-tracing (arboreal systematic search), whereby the individual systematically turns to one side at bifurcations and to the opposite side when turning about at end points. Experiments with searching Formica pallidefulva and Crematogaster cerasion artificial stick mazes under seminatural conditions demonstrated that bifurcations and end points only trigger turn decisions, whereas an intrinsic mechanism specifies the handedness of such turns. Arboreal homing differs from arboreal searching by a much stronger tendency to rectify paths by counterturning. The theory is advanced that searching on branches by outline-tracing is evolutionarily derived from ranging search by superposing a sustained intrinsic turn bias and by suppressing random turns.

Previous studies have explored two-dimensional path integration in rodents by recording responses to passive rotation on a horizontal plane. This study adds the element of passive rotation in a vertical plane, necessitating the mouse to integrate positional information from three dimensions. Mice were trained to climb a wire mesh joining two horizontal planes. The whole arena was rotated 90 degrees while the mouse was vertically oriented as it moved between planes. Rotation was conducted both clockwise and counter-clockwise, controls being provided by rotation of the arena while the mouse was in its nest-box. All 16 mice tested altered their direction of travel subsequent to rotation in the vertical plane, compensating with a change in their path on the following horizontal plane.

Fall migratory monarch butterflies, tested for their directional responses to magnetic cues under three conditions, amagnetic, normal, and reversed magnetic fields, showed three distinct patterns. In the absence of a magnetic field, monarchs lacked directionality as a group. In the normal magnetic field, monarchs oriented to the southwest with a group pattern typical for migrants. When the horizontal component of the magnetic field was reversed, the butterflies oriented to the northeast. In contrast, nonmigratory monarchs lacked directionality in the normal magnetic field. The results are a direct demonstration of magnetic compass orientation in migratory insects.

Locomotion on complex substrata can be expressed in a plane by two geometric components of body movement: linear locomotion and rotational locomotion. This study examined pure rotation by analysing the geometry of leg movements and stepping patterns during the courtship turns of male Blattella germanica . Strict rotation or translation by an insect requires that each side of the body cover equal distance with respect to the substrate. There are three mechanisms by which the legs can maintain this equality: frequency of stepping, magnitude of the leg arcs relative to the body and the degree to which legs flex and extend during locomotion. During the courtship behaviour of Blattella germanica selected males executed turns involving body rotation along with leg movements in which the legs on the outside of the turn swung through greater average arcs than those on the inside of the turn. This difference should have resulted in a translation component. However, legs on the inside of the turn compensated by flexion and extension movements which were greater than those of opposing legs. The net effect was that both sides of the body covered equal average ground. These cockroaches used a wide variety of stepping combinations to effect rotation. The frequency of these combinations was compared to an expected frequency distribution of stepping combinations and further to an expected frequency of these stepping combinations used for straight walking. These comparisons demonstrated a similarity between interleg coordination during straight walking and that during turning in place.

Leg movements of Camponotus americanus workers during straight swimming and turning are described herein. Thrust is generated through the different speeds and drag control between power v. return strokes in the forelegs. During the power stroke, femur, tibia and tarsus are straightened and thereby increase resistance; they bend backward during the return stroke. These thrusting legs move in a vertical plane which is similar to their position during walking. The backward stretching mesothoracic and metathoracic legs act, in conjunction with the gaster, as a rudder. Swimming in ants can be derived from walking; the major transformation being a suppression of the rhythmic movements of the middle and hind legs.

Three modes of self cleaning occur in insects: nibbling by the maxillae, scraping one structure by another in one direction only, and rubbing back and forth while the respective parts are in continuous contact. This paper describes a comprehensive and comparative account of this behaviour in bees, with special reference to the cleaning of or by the forelegs. Bees, like all Hymenoptera, clean various parts of the head, including the mouthparts and the antennae, with the forelegs. Lower Hymenoptera scrape each antenna with either foreleg; in the species of Aculeata that possess the antenna cleaner (strigil) on the foreleg, only the ipsilateral leg is used. The thoracic dorsum of most bees, as in many sphecoid wasps, is scraped in a forward direction by the middle leg; Triepeolus spp., however, use the hind leg, and the Anthophorinae the foreleg. Some beetles and lacewings clean their forelegs in the mouthparts by nibbling and scraping. Most higher Hymenoptera as a rule scrape the foreleg between the ipsilateral maxilla and the labium; bees, however, clamp the foreleg between the flexed ipsilateral middle leg and then scrape it. An evolution of this behaviour is postulated via several intermediate forms derived from original stepping movements. Halictidae and Andrenidae clamp the foreleg for scraping underneath the middle tibia, whereas all other bees nearly always clamp it underneath the middle basitarsus. Very similar movements are used in various species for transferring pollen, oil, or nest materials from the foreleg to the middle leg. It is argued that the original way of pollen carrying in bees must have been by filling the crop through direct eating or by scraping pollen off the foreleg between the ipsilateral maxilla and the labium. The latter movement is widespread among bees and is homologous to the normal foreleg cleaning in the mouthparts of most other Hymenoptera. The efficiency of this behaviour is enhanced in many lower bees by a comb on the galea, which is the homologue of a similar structure widespread among aculeate wasps. In higher bees, Apidae and Anthophoridae, the galeal comb is replaced by an equifunctional stipes comb. Many bees have neither of these types of maxillary combs.

1. Once in several days large numbers ofHospitalitermes sharpi, like other species of this oriental genus, leave their nests for a foraging trip to replenish food stores. Foraging columns are continuous, well ordered files of marching termites, up to 300 meters long and sometimes longer, stretching without interruption all the way from the nest to the grazing area on living tree bark. Topography permitting, the foraging columns follow pre-existing guide-lines, the crest-lines on the tops of sticks, roots and other elongate objects (=crest-line trailing). On vertical substrate, like cliffs or standing tree trunks, they either proceed horizontally or vertically. During any such foraging period each individual soldier and worker leaves the nest only once. 2. Homebound traffic inHospitalitermes marching columns occupies the central lanes, outbound traffic the lateral lanes. Soldiers lead the advancing column, trail the retreating column and stand on either side of every column, facing away from the column's edge. 3. The odor trails laid down by the foraging columns are bidirectional, i.e. homebound and outbound direction are indistinguishable for the termites. Misdirected homing termites restore their correct orientation after series of head-on collisions with correctly oriented companions. 4. No outside directional stimuli, in particular the directions of light and gravity, are used byHospitalitermes to make up for the directional ambivalence of the odor trail. 5. The orientation mechanism underlying crest-line trailing, the predominant type of orientation prior to the formation of an odor trail (=primary orientation), is a geoklinotaxis: the advancing termites on a crest-line, say the top of a horizontal stick, oscillate to the sides, turning back up-slope after reaching a particular angle of downward inclination. In 50% of the cases measured withHospitalitermes umbrinus, this angle is 12–13° or less from horizontal. 6. InHospitalitermes rufus, H. sharpi, andMacrotermes carbonarius, the orientation angle between the slope direction upward or downward and the direction of walking (=angle of geomenotaxis) decreases with increasing slope inclination. InMacrotermes carbonarius body weight is one factor mediating gravity perception. 7. The orientation strategy and marching column organization of the orientalHospitalitermes-species bear some striking resemblances to those of some neotropicalEciton-species (=army ants).

Binary choice tests revealed under field conditions of the humid tropics that well established odor trails ofOecophylla smaragdina gradually fade away over a period of three days.

Despite the immense body of literature concerning animal orientation, little previ­ ous effort has been made to prepare a comprehensive discussion and unified theory of orientation ecology, the subdiscipline at the interface between ecology and ethology. Much of the existing orientation literature is widely dispersed, found partially in explicit studies on orientation and partially in countless publications about life histories. In this review, in order to organize this hidden scientific treasure and to facilitate access to it, the concept of orientation ecology is defined, then the subdiscipline is naturally divided into six categories. Finally, within these categories, predictive generalizations or rules, based on induction, deduction, and intuition are formulated. All these rules and principles are preceded by consecutive bold numbers in square brackets to facilitate recognition.

Alle folgenden Angaben beziehen sich auf Formica rufa L., die Rote Waldameise, und sind nur unter Vorbehalt auf andere Insektenarten ubertragbar.

1. Bei der Grundorientierung der Insekten lassen sieh bis jetzt vier verschiedene Gruppen von Schaltvorgangen scharf gegeneinander abgrenzen: Beim An- und Abschalten wechselt das Insekt zwischen dem orientierten und dem nicht orientierten Zustand. Bei den Taxiswechseln wird zwischen Grundrichtungen gewechselt. Dieser Wechsel geschieht entweder durch Vorzeichenumkehr der Drehreaktion (Reversion) oder durch Ersatz eines Richtmechanismus durch einen anderen (Substitution). Beim Umproportionieren wird zwischen positiver und negativer Lichtstarkenabhangigkeit der Reaktionsstarke gewechselt. Beim Ubertragungswechsel steuert ein Richtmechanismus nacheinander verschiedene Koordinationsmechanismen. 2. Fur Cloeon-Larven gilt bei der optischen Richtungsorientierung im dreidimensionalen Raum das Prinzip des kleinsten Drehweges: Um die Korperachse, die in der Reizrichtung liegen soll, gibt es keine Drehreaktionen; um die beiden anderen Achsen rotiert sich die Larve bei Fehlorientierung um den jeweils kleineren Winkel. 3. Bis jetzt kennt man vier Grundrichtungen der Orientierung zu Lichtquellen: Auf das Licht zu (positive Phototaxis), vom Licht weg (negative Phototaxis) und mit dem Rucken oder Bauch quer zum Licht (transversale Phototaxis). 4. Vier Grundrichtungen relativ zur Schwingungsrichtung linear polarisierten Lichtes sind bei den Insekten die Regel. Nach der Art der Schaltvorgange lassen sich zwei dieser Grundrichtungen (parallel und quer) dem orthogonalen Richtsystem und zwei (45° links und rechts) dem diagonalen Richtsystem zuordnen. Innerhalb der Systeme wird durch Reversion geschaltet, zwischen ihnen durch Substitution. 5. Bei der Richtungsorientierung mit Hilfe linear polarisierten Lichtes, der Oscillotaxis, bei der Phototaxis und bei der Geotaxis ist die Funktion zwischen der Reizrichtung und der Starke der Drehreaktion sinusahnlich (=Sinusregel). 6. Die Phototropotaxis last sich in eine Archi, Pro- und Metaphototaxis untergliedern, je nachdem die Starke der Drehreaktion durch Bewertung im Zentralnervensystem nur von der Lichtintensitat, der Lichtintensitat und der Lichtrichtung oder nur von der Lichtrichtung abhangt. 7. Eine Prophototaxis ist typisch fur die Myriopoden, Apterygoten und die Polyneopteren; die Metaphototaxis dagegen ist bei den Palaeopteren, Paraneopteren und Oligoneopteren (=Holometabolen) die Regel. 8. Es gibt Insekten mit Progeotaxis und solche mit Metageotaxis wie z. B. die Wanze Mesocerus marginatus. Beim ersten Geotaxistyp andern sich die Orientierungswinkel mit der Hangneigung, beim zweiten nicht. 9. Es wird wahrscheinlich gemacht, das sich die Richtungsmechanismen der Insekten mit entwickelter Prophototaxis aus sinusbewertenden, addierenden, subtrahierenden und dividierenden nervosen Instanzen zusammensetzen. 10. Eine Reihe von Eigenschaften der Oscillotaxis konnen befriedigend kausal erklart werden, wenn angenommen wird, das jeweils die Ausgangsdaten von zwei 90° zueinander stehenden Analysatoren voneinander subtrahiert werden. 11. Bei Insekten mit Prophototaxis und Progeotaxis variiert, soweit gepruft, der Menotaxiswinkel mit der Reizstarke. Es ist daher sehr wahrscheinlich, das es bei Insekten mit Prophototaxis keine zeitkompensierte Sonnen- und Mondorientierung (=Astrotaxis) gibt.

Der Schwanzeltanz der Bienen wird um so langsamer, je weiter das Ziel entfernt ist. Mit Hilfe von Zeitlupenaufnahmen sollte geklart werden, welches Element des Tanzes die beste Beziehung zur Entfernung zeigt.

1. Innerhalb der Uberfamilie der Bienen (Apoidea) gibt es zwei Typen der Geotaxis: Bei der laufenden Biene mit Progeotaxis verkleinert sich der Orientierungswinkel zur Schwerkraft mit zunehmendem Neigungswinkel der Unterlage, wogegen er bei Bienen mit Metageotaxis konstant bleibt. 2. Die Trennlinie fur die Verbreitung dieser beiden Geotaxistypen liegt innerhalb der Gattung Apis: A. dorsata, A. cerana und A. mellifica verfugen uber eine Metageotaxis; A. florea so wie alle ubrigen, hier untersuchten Bienen reagieren unter den gleichen Versuchsbedingungen mit einer Progeotaxis. 3. Da der phylogenetische Schritt von der Progeotaxis zur Metageotaxis mit dem Einbau des photo-geotaktischen Winkeltransponierens in den Bienentanz zusammenfallt, kann es als wahrscheinlich gelten, das die Evolution zur Metageotaxis von besonderer biologischer Bedeutung fur die geotaktisch orientierte Richtungsanzeige in der Tanzsprache der Honigbiene ist.

1. Bietet man Stabheuschrecken (Carausius morosus) je zwei formverschiedene schwarzweise Figuren zur Wahl, dann laufen sie bevorzugt auf die strauchahnlichere Attrappe. Mit Hilfe dieser Wahlreaktion analysierten wir das Formunterscheidungsvermogen. 2. Fur die Stabheuschrecke sind schwarze Flachen mindestens bis zu einer Ausdehnung von 25°×25° Sehwinkel um so attraktiver, je groser sie sind und je naher sie am Horizont liegen (Abb. 2–5). 3. Der hier untersuchte visuelle Perceptor der Stabheuschrecke enthalt 6 verschiedene, auf Kontrastgrenzen ansprechende, bilateral symmetrisch angeordnete Kantendetektoren, die sich untereinander dadurch klar unterscheiden lassen, das sie die Wahlbevorzugung einer Figur entweder fordern oder hemmen, das sie entweder auf glatte oder gegliederte Kontrastgrenzen optimal ansprechen, und das sie fur verschiedene Richtungen der Kontrastgrenzen optimal empfindlich sind (Abb. 22). Die Abstande zwischen diesen Optimalrichtungen sind ganze Vielfache von 30°. 4. Im Winkel von 90° liegt zu jedem der drei unterscheidbaren, die Wahl fordernden Kantendetektoren jeweils ein qualitativ gleicher, aber wahlhemmender Kantendetektor (= Prinzip der orthogonalen Inhibition). 5. Die optimalen Ansprechrichtungen der 6 Detektoren fur Kontrastgrenzen liegen in den gleichen Raumrichtungen wie die 6 unterscheidbaren Reihen der Ommatidien im hexagonalen Raster der Komplexaugen.

Mit Alternativwahlversuchen wird nachgewiesen, das folgende Formmerkmale die Zielorientierung (= Telotaxis) von laufenden, mannlichen Schmeisfliegen (Calliphora erythrocephala) stimulieren: 1. Dunkle Kontrastflachen (Abb. 1); 2. Vertikale Kontrastgrenzen (Abb. 2-6); 3. Figurengliederung (Abb. 3f und 4).

1. Bei einem Typ der Phototropotaxis, der umgekehrt proportionalen Prophototaxis (Jander, 1963), kontrollieren die Stirnocellen von Locusta migratoria und Gryllus bimaculatus photoinhibitorisch die Starke der phototaktischen Dreherregung. 2. Die Afferenzen der Stirnocellen und der Komplexaugen von Springheuschrecken (Saltatoptera) sind bei der positiven und negativen Phototropotaxis nach dem Prinzip der phototaktischen Gegenkopplung miteinander verknupft: Bei schwacher Beleuchtung greifen die Stirnocellen als Synergisten der Komplexaugen und bei starker als Antagonisten der Komplexaugen in den Regelkreis der Tropotaxis ein. 3. Die Grille Gryllus bimaculatus percipiert mit ihren beiden lateralen Stirnocellen ahnlich wie mit den beiden Komplexaugen nach dem Prinzip der Tropotaxis die vorherrschende Lichtrichtung. Diese tropotaktischen Richtungsmeldungen der Lateralocellen und der Komplexaugen werden bei Verdunkeln des Medianocellus synergistisch und bei seiner Belichtung antagonistisch zusammengeschaltet. 4. Durch das Prinzip der phototaktischen Gegenkopplung wird die Phototropotaxis gegenuber Storungen durch Helligkeitsschwankungen stabilisiert.

1. Kocherfliegen (Imagines) konnen sich in bezug zur Licht-oder Schwerkraftrichtung menotaktisch orientieren. 2. Die Menotaxiswinkel bezogen auf die entsprechenden Grundrichtungen werden von der Lichtauf die Schwereorientierung transponiert und umgekehrt. 3. Transponiert wird zweideutig, d. h. je einem Lichtwinkel sind zwei Schwerewinkel zugeordnet und umgekehrt genauso. 4. Das Transponieren ist proportionstreu, Geotaxiswinkel und Phototaxiswinkel verhalten sich wie zwei zu drei. 5. Im 90°-Konflikt zwischen gleichzeitig aktivierter Photo- und Geotaxis wird eine helligkeitsunabhangige Kompromisrichtung eingeschlagen, die 60° von der erstrebten Phototaxisrichtung und 30° von der erstrebten Geotaxisrichtung abweicht. 6. Der Vergleich der Drehtendenzen in der Kompromiswahl geschieht durch Addition derselben. 7. Die Bewegungsrichtung in bezug zur Lichtrichtung kann beim Laufen, Fliegen und Schwimmen beibehalten werden. 8. Diese Befunde erklaren sich am einfachsten und widerspruchsfrei mit dem vom Ameisenverhalten abgeleiteten (Jander 1957) Funktionsprinzip der Menotaxis.

1. Mysidium gracile (Dana) tends to move within a plane, the swimming plane, which is oriented as nearly as possible perpendicular to the directions of light and gravity.2. Horizontal illumination induces an orientation conflict which is resolved by maintaining the swimming plane in a slanted position intermediate between those positions dictated by the two stimuli.3. The turning tendencies of the dorsal light reaction increase with increasing light intensities.4. There is evidence that gravity- and light-induced turning tendencies inhibit each other.

1. Bei samtlichen daraufhin untersuchten hemimetabolen neopteren Insekten, sowie bei den Megalopteren, Mecopteren und Coleopteren, wird bei der Steuerung der Geotaxis die Richtung der Schwerkraft uberwiegend oder ausschlieslich uber das auf den Beinen lastende Korpergewicht wahrgenommen. 2. Bei Enallagma cyathigerum (Odonata), Chrysopa vulgaris (Planipennia), Pieris napi (Lepidoptera) und allen daraufhin gepruften Hymenopteren kommt dem an den Beingelenken angreifenden Korpergewicht keine entscheidende Bedeutung fur die Steuerung der Geotaxis zu. 3. Die Geotaxis von Osmylus chrysops (Planipennia) und Calliphora erythrocephala ist eine Zwischenform der unter 1. und 2. genannten Geotaxistypen. 4. In der Phylogenie der Pterygoten haben die Gelenkreceptoren der Beine mindestens viermal unabhangig voneinander ihre ursprunglich entscheidende Rolle fur die Steuerung der Geotaxis verloren.

1. Two decapod cephalopoda, Euprymna (a sepiolid) and Sepioteuthis (a squid) have been tested for their orientation behavior in a vertical beam of linearly polarized light and in horizontal light intensity patterns. 2. Like many arthropods these mollusks show four preferential swimming directions relative to the e-vector (0°, 90° and ±45°) 3. Horizontal intensity patterns induce only positive or positive and negative phototactic orientation. 4. When polarized light and intensity patterns are presented together the polarized light response predominates. 5. Polarized light vision in these decapod mollusks is a distinct perceptual process showing remarkable convergence wiht this function in arthropods.

AT least two physiological functions have been ascribed to the dorsal ocelli of locusts and insects in general. First, in response to light intensity they regulate the speed of movement (photokinesis)1 and the threshold for the initiation of certain activities2; and second, coupled with the complex eyes, they are in some unknown way involved in angular orientation, both in the phototactic1,3,4 and in the dorsal light reaction5,6.

Laboratory rats, trained to horizontal or vertical stripes, were scored on visual stripe tilt discrimination in a series of binary choice tests. The resulting choice-percent-scales can be shown to be linear measurements (interval scales) of the stripe tilt differences as perceived by the rats. A crude model system for describing and explaining the binary choice behavior of rats is propounded. Three main processes constitute this model system. The first determines the magnitude of similarity between any pattern offered and the previous training pattern. The second compares these similarity-magnitudes by subtraction and the third injects evenly distributed noise into the system, thus accounting for the scatter in the choice behavior. The similarity functions (“generalization gradients”) for the edge orientation in the visual field of the rat range over ± 90°, which appears to be typical for both vertebrates and arthropods.

Some two thousand million years ago living organisms initiated the invention of means for detecting optical signals to be reacted to by purposeful actions. This decisive evolutionary step already took place at the primitive organizational level of the bacteria, as may be inferred from present life. In collecting light energy with pigments, some of these micro-organisms swim about, “looking” for properly illuminated places. Rhodospirillum, for instance, driven on its spiral course by rotary flagellar action on both of its terminal poles, may suddenly cross the boundary into a shadow. At this instant the sensitive basal area of the leading flagella is suddenly darkened. This particular optical signal sets the switch for reversing the flagellar propulsion, and from then on the opposite pole is leading (Fig. 1). This, the most primitive photosensory system known, is selective as well as adaptive in only responding to the fast decline from average light intensity or to the sudden rise towards damaging intensities. Chromatium’s manoeuvre to avoid darkness is still less efficient than that of Rhodospirillum. This unipolar micro-organism first jumps backward after passing into a shaded area, then it remains immobile for a short period, while Brownian movement and micro-eddies push it about randomly. When it resumes swimming, it may be fortunate enough to remain in the illuminated area whence it came, otherwise the whole procedure has to be repeated after another penetration into the dark area (Fig. 1) (references: Clayton, 1964).