Stick insects do move: monitoring stick insect activity using the BBC micro

1993 ◽  
Vol 27 (4) ◽  
pp. 247-248
Author(s):  
Nicola Brown
Keyword(s):  
Stick Insect ◽  
Stick Insects ◽  
Insect Activity

Intersegmental Coordination of Walking Movements in Stick Insects

2005 ◽  
Vol 93 (3) ◽  
pp. 1255-1265 ◽  
Author(s):  
Björn Ch. Ludwar ◽  
Marie L. Göritz ◽  
Joachim Schmidt
Keyword(s):  
Motor Pattern ◽  
Central Pattern Generators ◽  
Stick Insect ◽  
Neural Mechanisms ◽  
Chordotonal Organ ◽  
Adjacent Segment ◽  
Body Segments ◽  
Stick Insects ◽  
Pattern Generators ◽  
Leg Movements

Locomotion requires the coordination of movements across body segments, which in walking animals is expressed as gaits. We studied the underlying neural mechanisms of this coordination in a semi-intact walking preparation of the stick insect Carausius morosus. During walking of a single front leg on a treadmill, leg motoneuron (MN) activity tonically increased and became rhythmically modulated in the ipsilateral deafferented and deefferented mesothoracic (middle leg) ganglion. The pattern of modulation was correlated with the front leg cycle and specific for a given MN pool, although it was not consistent with functional leg movements for all MN pools. In an isolated preparation of a pair of ganglia, where one ganglion was made rhythmically active by application of pilocarpine, we found no evidence for coupling between segmental central pattern generators (CPGs) that could account for the modulation of MN activity observed in the semi-intact walking preparation. However, a third preparation provided evidence that signals from the front leg's femoral chordotonal organ (fCO) influenced activity of ipsilateral MNs in the adjacent mesothoracic ganglion. These intersegmental signals could be partially responsible for the observed MN activity modulation during front leg walking. While afferent signals from a single walking front leg modulate the activity of MNs in the adjacent segment, additional afferent signals, local or from contralateral or posterior legs, might be necessary to produce the functional motor pattern observed in freely walking animals.

Pathological and Microbiological Study of Mortality in a Captive Breeding Colony of the Endangered Lord Howe Island Stick Insect (Dryococelus australis)

2018 ◽  
Vol 55 (5) ◽  
pp. 719-730
Author(s):  
Christine Bayley ◽  
Christina Cheng ◽  
Michael Lynch
Keyword(s):  
Captive Breeding ◽  
Positive Culture ◽  
Opportunistic Pathogen ◽  
Stick Insect ◽  
Innate Immune ◽  
Breeding Colony ◽  
Lord Howe Island ◽  
Stick Insects ◽  
Gross Lesions ◽  
Increased Susceptibility

The authors describe pathological and microbiological features of mortalities in a captive breeding colony of Lord Howe Island stick insects ( Dryococelus australis) over a period of 18 months. There were 2 peaks of mortality in this period. In the first, insects presented dead with minimal premonitory signs of illness. In the second, affected insects were ataxic with contracted limbs and inability to climb or right themselves. Gross lesions were uncommon but included pigmented plaques on the gut and cloacal prolapse. Histological lesions in both outbreaks indicated a cellular innate immune response including nodulation characterized by Gram-negative bacterial bacilli entrapped within nodules of pigmented hemocytes, and melanization characterized by melanin within hemocyte nodules and around bacteria. Hemolymph culture findings varied and often yielded a mixed growth. Pure growth of Serratia marcescens was cultured in 44% of animals in Outbreak 1, while pure growth of Pseudomonas aeruginosa was cultured in 30% of animals in Outbreak 2. Cases with S. marcescens-positive culture often showed inflammation at the foregut-midgut junction. The frequency of mixed bacterial culture results did not allow firm conclusions about causality to be made, and may indicate primary bacterial infection or increased susceptibility to hemolymph colonization with an opportunistic pathogen. These findings highlight the utility of histopathology combined with ancillary testing when investigating mortality in captive insect colonies.

scholarly journals Descending octopaminergic neurons modulate sensory-evoked activity of thoracic motor neurons in stick insects

2019 ◽  
Vol 122 (6) ◽  
pp. 2388-2413 ◽  
Author(s):  
Thomas Stolz ◽  
Max Diesner ◽  
Susanne Neupert ◽  
Martin E. Hess ◽  
Estefania Delgado-Betancourt ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Stick Insect ◽  
Neuron Activity ◽  
Sense Organs ◽  
Descending Neurons ◽  
Walking Activity ◽  
Stick Insects ◽  
Evoked Activity ◽  
Sensory Evoked ◽  
Stimulation Of

Neuromodulatory neurons located in the brain can influence activity in locomotor networks residing in the spinal cord or ventral nerve cords of invertebrates. How inputs to and outputs of neuromodulatory descending neurons affect walking activity is largely unknown. With the use of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and immunohistochemistry, we show that a population of dorsal unpaired median (DUM) neurons descending from the gnathal ganglion to thoracic ganglia of the stick insect Carausius morosus contains the neuromodulatory amine octopamine. These neurons receive excitatory input coupled to the legs’ stance phases during treadmill walking. Inputs did not result from connections with thoracic central pattern-generating networks, but, instead, most are derived from leg load sensors. In excitatory and inhibitory retractor coxae motor neurons, spike activity in the descending DUM (desDUM) neurons increased depolarizing reflexlike responses to stimulation of leg load sensors. In these motor neurons, descending octopaminergic neurons apparently functioned as components of a positive feedback network mainly driven by load-detecting sense organs. Reflexlike responses in excitatory extensor tibiae motor neurons evoked by stimulations of a femur-tibia movement sensor either are increased or decreased or were not affected by the activity of the descending neurons, indicating different functions of desDUM neurons. The increase in motor neuron activity is often accompanied by a reflex reversal, which is characteristic for actively moving animals. Our findings indicate that some descending octopaminergic neurons can facilitate motor activity during walking and support a sensory-motor state necessary for active leg movements. NEW & NOTEWORTHY We investigated the role of descending octopaminergic neurons in the gnathal ganglion of stick insects. The neurons become active during walking, mainly triggered by input from load sensors in the legs rather than pattern-generating networks. This report provides novel evidence that octopamine released by descending neurons on stimulation of leg sense organs contributes to the modulation of leg sensory-evoked activity in a leg motor control system.

Load Signals Assist the Generation of Movement-Dependent Reflex Reversal in the Femur–Tibia Joint of Stick Insects

2006 ◽  
Vol 96 (6) ◽  
pp. 3532-3537 ◽  
Author(s):  
Turgay Akay ◽  
Ansgar Büschges
Keyword(s):  
Time Course ◽  
Stick Insect ◽  
Motor Output ◽  
Chordotonal Organ ◽  
Frequency Of Occurrence ◽  
Stick Insects ◽  
Extensor Motoneuron ◽  
Motoneuron Activity ◽  
First Time ◽  
Stimulation Of

Reinforcement of movement is an important mechanism by which sensory feedback contributes to motor control for walking. We investigate how sensory signals from movement and load sensors interact in controlling the motor output of the stick insect femur–tibia (FT) joint. In stick insects, flexion signals from the femoral chordotonal organ (fCO) at the FT joint and load signals from the femoral campaniform sensilla (fCS) are known to individually reinforce stance-phase motor output of the FT joint by promoting flexor and inhibiting extensor motoneuron activity. We quantitatively compared the time course of inactivation in extensor tibiae motoneurons in response to selective stimulation of fCS and fCO. Stimulation of either sensor generates extensor activity in a qualitatively similar manner but with a significantly different time course and frequency of occurrence. Inactivation of extensor motoneurons arising from fCS stimulation was more reliable but more than threefold slower compared with the extensor inactivation in response to flexion signals from the fCO. In contrast, simultaneous stimulation of both sense organs produced inactivation in motoneurons with a time course typical for fCO stimulation alone, but with a frequency of occurrence characteristic for fCS stimulation. This increase in probability of occurrence was also accompanied by a delayed reactivation of the extensor motoneurons. Our results indicate for the first time that load signals from the leg affect the processing of movement-related feedback in controlling motor output.

scholarly journals Distance and Size Discrimination in a Water Stick Insect, ranatra linearis (Heteroptera)

1986 ◽  
Vol 120 (1) ◽  
pp. 59-77
Author(s):  
ANN CLOAREC
Keyword(s):  
Prey Capture ◽  
Stick Insect ◽  
Normal Adult ◽  
Central Position ◽  
Size Discrimination ◽  
Stick Insects ◽  
Distance Position ◽  
Prey Items

The role of vision in distance, position and size discrimination in prey capture has been investigated in normal adult water stick insects (Ranatra linearis L.: Heteroptera) and in ones with one eye covered. Both monocular and intact Ranatra were able to discriminate between two targets subtending the same angle but presented at different distances. They usually chose the target nearer to their foreleg claws. Although monocular subjects undershot more often than controls, they could still estimate distance correctly. When presented with two different-sized targets at the same distance, both monocular and intact subjects usually preferred the larger target within a 1°-10° range, even though monocular animals chose the larger object less consistently. They were able to distinguish between two targets differing in size by only 1°. Asymmetrical presentations of two identical targets stressed the importance of the central position. Intact animals always preferred the target nearer their midline. These data also revealed the unexpected ability of Ranatra to strike accurately at two targets or prey items simultaneously. When two identical targets were presented simultaneously and symmetrically, aims were directed at both targets, and one was grasped by each raptorial foreleg, thus indicating an absence of confusion.

scholarly journals Stick Insect Locomotion on a Wheel: Patterns Of Stopping And Starting

1984 ◽  
Vol 110 (1) ◽  
pp. 203-216
Author(s):  
JEFFREY DEAN ◽  
GERNOT WENDLER
Keyword(s):  
Gait Cycle ◽  
Static Stability ◽  
Stick Insect ◽  
Insect Locomotion ◽  
Stick Insects ◽  
Leg Coordination ◽  
Left Right Asymmetry ◽  
Coordination Patterns ◽  
The Relationship ◽  
Leg Position

The relationship between standing and steady walking was investigated for stick insects walking on a wheel. Normal hexapod coordination patterns ensure that each point in the gait cycle has static stability. Nevertheless, stick insects show preferred stopping sequences: the final protraction in ipsilateral metachronal sequences is most often by a front leg and least often by a rear leg (Fig. 1, Table 1). The associated preferred stance is one in which front, middle, and rear legs are spread apart (Fig. 2). This preferred stance does not conform precisely to those of steady walking, necessitating small adjustments to the walk in the final steps. First, the final leg protraction often occurs in the absence of strong retraction by the supporting legs. Second, the insect often takes advantage of the left/right asymmetry, letting rear and middle legs on the leading side retract beyond their normal endpoints while completing the metachronal sequence on the trailing side. Walking typically resumes with an initial retraction by all legs. Stances are close enough to leg configurations of steady walking that metachronal rhythms are often continuous across pauses, a feature which suggests that leg coordination is affected by peripheral parameters, such as leg position.

scholarly journals Revision of the stick insect genus Leptynia: description of new taxa, speciation mechanism and phylogeography

2012 ◽  
Vol 81 (1) ◽  
pp. 25-42 ◽  
Author(s):  
Valerio Scali ◽  
Liliana Milani ◽  
Marco Passamonti
Keyword(s):  
Genetic Differentiation ◽  
Sex Chromosome ◽  
Karyotype Analysis ◽  
Mitochondrial Gene ◽  
Gene Sequencing ◽  
Stick Insect ◽  
Clear Cut ◽  
Stick Insects ◽  
Morphological Distinction ◽  
A New Species

Leptynia specimens were analyzed by karyotype analysis, mitochondrial gene sequencing and SEM of bodies and eggs. Here we describe a new species, Leptynia annaepaulae, and three subspecies of L. attenuata Pantel (L. attenuata attenuata, L. attenuata iberica, L. attenuata algarvica). The phylogeny of the genus Leptynia is congruent with a karyotype trend toward a reduction of chromosome number and the shift from the shared XX/X0 sex chromosome formula to the unusual XX/XY one. Chromosome repatterning appears to occur ahead of genetic differentiation, following a chromosome model of cladogenesis. Chromosome and genetic differentiation, in turn, appears to precede morphological distinction, thus realizing a condition of incipient species for most of the Leptynia taxa. Actually, morphological analyses revealed that, only rarely clear cut differences exist among and between taxa, while, more often, just trends in the differentiating traits occur, since the investigated characters generally suffer from some overlapping: In this study, only the 10th:9th ratio value and the subanal vomer appear to be diagnostic for L. annaepaulae against all other Leptynia taxa. As a consequence, the subanal vomer as well as cercus tooth features with egg chorion traits are not sharply diagnostic for the remaining co-generic taxa; however, comparisons are quite helpful in reducing uncertainties. A likely phylogeographic scenario for the genus supports that Leptynia ancestors spread from Northern Africa into Southern Spain where an ancestral taxon originated L. annaepaulae (2n = 40/39, XX/X0, with 2 large dibrachial pairs). Later on, a northbound colonization, should have originated L. caprai (2n = 40/39, XX/X0, all acrocentrics), from which L. montana (2n = 38, XX/X0) and L. attenuata (2n = 36, XY/XX) originated; supporting instances of chromosome repatterning have been actually observed. In this connection we like to stress that, particularly in stick insects, androgenesis has been a preferential pathway to quickly make homozygous those odd chromosome rearrangements likely responsible for low fitness in the heterozygotes.

scholarly journals Force encoding in stick insect legs delineates a reference frame for motor control

2012 ◽  
Vol 108 (5) ◽  
pp. 1453-1472 ◽  
Author(s):  
Sasha N. Zill ◽  
Josef Schmitz ◽  
Sumaiya Chaudhry ◽  
Ansgar Büschges
Keyword(s):  
Motor Control ◽  
Stick Insect ◽  
Discrete Groups ◽  
Campaniform Sensilla ◽  
Group 4 ◽  
Muscle Insertion ◽  
Stick Insects ◽  
Group 3 ◽  
Leg Movement ◽  
Depressor Muscle

The regulation of forces is integral to motor control. However, it is unclear how information from sense organs that detect forces at individual muscles or joints is incorporated into a frame of reference for motor control. Campaniform sensilla are receptors that monitor forces by cuticular strains. We studied how loads and muscle forces are encoded by trochanteral campaniform sensilla in stick insects. Forces were applied to the middle leg to emulate loading and/or muscle contractions. Selective sensory ablations limited activities recorded in the main leg nerve to specific receptor groups. The trochanteral campaniform sensilla consist of four discrete groups. We found that the dorsal groups (Groups 3 and 4) encoded force increases and decreases in the plane of movement of the coxo-trochanteral joint. Group 3 receptors discharged to increases in dorsal loading and decreases in ventral load. Group 4 showed the reverse directional sensitivities. Vigorous, directional responses also occurred to contractions of the trochanteral depressor muscle and to forces applied at the muscle insertion. All sensory discharges encoded the amplitude and rate of loading or muscle force. Stimulation of the receptors produced reflex effects in the depressor motoneurons that could reverse in sign during active movements. These data, in conjunction with findings of previous studies, support a model in which the trochanteral receptors function as an array that can detect forces in all directions relative to the intrinsic plane of leg movement. The array could provide requisite information about forces and simplify the control and adaptation of posture and walking.

scholarly journals De novo transcriptome analysis for examination of the nutrition metabolic system related to the evolutionary process through which stick insects gain the ability of flight (Phasmatodea)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Takuma Sakamoto ◽  
Shunya Sasaki ◽  
Nobuki Yamaguchi ◽  
Miho Nakano ◽  
Hiroki Sato ◽  
...  
Keyword(s):  
De Novo ◽  
Evolutionary Process ◽  
Enrichment Analysis ◽  
Stick Insect ◽  
Metabolic System ◽  
Flight Ability ◽  
Gene Enrichment ◽  
Enolase Superfamily ◽  
Stick Insects ◽  
Insect Group

Abstract Objective Insects are the most evolutionarily successful groups of organisms, and this success is largely due to their flight ability. Interestingly, some stick insects have lost their flight ability despite having wings. To elucidate the shift from wingless to flying forms during insect evolution, we compared the nutritional metabolism system among flight-winged, flightless-winged, and flightless-wingless stick insect groups. Results Here, we report RNA sequencing of midgut transcriptome of Entoria okinawaensis, a prominent Japanese flightless-wingless stick insect, and the comparative analysis of its transcriptome in publicly available midgut transcriptomes obtained from seven stick insect species. A gene enrichment analysis for differentially expressed genes, including those obtained from winged vs wingless and flight vs flightless genes comparisons, revealed that carbohydrate metabolic process-related genes were highly expressed in the winged stick insect group. We also found that the expression of the mitochondrial enolase superfamily member 1 transcript was significantly higher in the winged stick insect group than in the wingless stick insect group. Our findings could indicate that carbohydrate metabolic processes are related to the evolutionary process through which stick insects gain the ability of flight.

scholarly journals Biomechanics of aerial righting in wingless nymphal stick insects

2017 ◽  
Vol 7 (1) ◽  
pp. 20160075 ◽  
Author(s):  
Yu Zeng ◽  
Kenrick Lam ◽  
Yuexiang Chen ◽  
Mengsha Gong ◽  
Zheyuan Xu ◽  
...  
Keyword(s):  
Flight Control ◽  
Stick Insect ◽  
Body Posture ◽  
Body Rotation ◽  
First Instar ◽  
Stick Insects ◽  
Righting Reflex ◽  
Robotic Vehicles

Numerous wingless arthropods as well as diverse vertebrates are capable of mid-air righting. We studied the biomechanics of the aerial righting reflex in first-instar nymphs of the stick insect Extatosoma tiaratum . After being released upside-down, insects reoriented dorsoventrally and stabilized body posture via active modulation of limb positions and associated aerodynamic torques. We identified specific reflexes for bilaterally asymmetric leg displacements which elicit body rotation and subsequently stabilize mid-air posture. Coordinated appendicular movements thus improve torsional manoeuvrability in the absence of wings, as may have characterized the initial origins of controlled aerial behaviour in arthropods. Design of small aerial or multimodal robotic vehicles may similarly benefit from use of such strategies for flight control.

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