Insect Movement Research Articles

Temperature and Geotaxis Preference byCryptolestes ferrugineus(Coleoptera: Laemophloeidae) Adults in Response to 5°C/m Temperature Gradients at Optimum and Hot Temperatures in Stored Wheat and Their Mortality at High Temperature

Cryptolestes ferrugineus (Stephens) is often found in abundance in association with heating stored grain. Their mortality at high temperature and their distribution at optimum and hot temperatures are important information for insect control and for models of their distribution in grain bins. The lethal exposure times of the adults were determined at 42 ± 0.2–50 ± 0.2°C and 75 ± 5% RH. Insect mortality increased with increasing temperatures and exposure time. For each temperature, there was a cumulative period of thermal stress, and after the critical exposure time an additional few hours or minutes at that temperature would kill all of the adults. The mortality was 100% at 45°C in 78 h, at 47°C in 18 h, at 49°C in 4.5 h, and at 50°C in 3 h. At 50°C, insect mortality determined at 0 h was significantly different than that determined 12 h later after the insects had been moved to room temperature. A regression equation predicted insect mortality better than published models when temperatures were above 45°C. The net displacement of the adults in both vertical and horizontal directions at 27.5–52.5°C was determined in 100 by 100 by 1,000-mm wheat columns at 14.5 ± 0.3% moisture content with or without a 5°C/m temperature gradient. The adults responded to temperature gradients and the preferred temperature was from 30 to 36.5°C. There was no obvious boundary between preference and nonpreference temperatures for the adults. In horizontal wheat columns without a temperature gradient, the adults moved in both directions, and the distribution pattern gradually became more uniform when temperature increased but was under 42°C. At hot temperatures, adults could locate and move to the cooler area in <12 h; however, the adults could not move at 50°C. Geotaxis, temperature gradient, and the interaction between these two factors affected insect distribution and movement direction; and the geotaxis was more influential than temperature gradient at any condition in the vertical columns. A pattern for adult movement was suggested.

Monitoring stored-product pests in food processing plants with pheromone trapping, contour mapping, and mark-recapture.

Distribution and movement patterns of several species of stored-product pests in a food processing plant were investigated. The objectives of this study were to determine the temporal and spatial variation in abundance of stored-product pests using pheromone traps; assess the effectiveness of trap type, location, and number on monitoring insect populations; and to evaluate the nature of pheromone trap capture hot spots by measuring patterns of insect movement. We determined that the distributions of Trogoderma variabile Ballion, Lasioderina serricorne (F.), Tribolium castaneum (Herbst), and Plodia interpunctella (Hübner) within the facility were typically clumped and that foci of high trap captures, based on visual observation of contour maps, varied among species and over time. Trap type and location influenced the number of T. variabile captured: traps on the floor and along walls captured more individuals than hanging traps and traps next to support pillars. T. variabile was the predominant insect pest at this facility and from mark-recapture studies, we found that individual beetles moved across multiple floors in the facility and from 7 to 216 m though the warehouse.

Landscape structure, habitat fragmentation, and the ecology of insects

Landscape structure, habitat fragmentation, and the ecology of insects

A simple trap to study small‐scale movement by walking arthropods

Movement is a key element of animal biology, and thus is of central importance to many studies of animal behavior and ecology. The study of insect movement at either small or large spatial scales remains technically challenging, although important progress has recently been made in quantifying movement, and especially aerial movement, using a variety of mark-release-recapture techniques (Hagler & Jackson, 2001). Here we describe a simple trapping technique that can be used to study small-scale movement by walking arthropods. The traps may be especially useful for studying patch leaving rules employed by arthropods foraging on plants.

Insect Movement: mechanisms and consequences

Journal of Applied EntomologyVolume 126, Issue 4 p. 205-206 Insect Movement: mechanisms and consequences First published: 09 October 2008 https://doi.org/10.1046/j.1439-0418.2002.06435.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume126, Issue4May 2002Pages 205-206 RelatedInformation

Simulation of insect movement with respect to plant architecture and morphogenesis

Developments in computer and three dimensional (3D) digitiser technologies have made it possible to keep track of the broad range of data required to simulate an insect moving around or over the highly heterogeneous habitat of a plant's surface. Properties of plant parts vary within a complex canopy architecture, and insect damage can induce further changes that affect an animal's movements, development and likelihood of survival. Models of plant architectural development based on Lindenmayer systems (L-systems) serve as dynamic platforms for simulation of insect movement, providing an explicit model of the developing 3D structure of a plant as well as allowing physiological processes associated with plant growth and responses to damage to be described and simulated. Simple examples of the use of the L-system formalism to model insect movement, operating at different spatial scales—from insects foraging on an individual plant to insects flying around plants in a field—are presented. Such models can be used to explore questions about the consequences of changes in environmental architecture and configuration on host finding, exploitation and its population consequences. In effect this model is a ‘virtual ecosystem’ laboratory to address local as well as landscape-level questions pertinent to plant–insect interactions, taking plant architecture into account.

Computerised video tracking, movement analysis and behaviour recognition in insects

The need for automating behavioural observations and the evolution of systems developed for that purpose are outlined. Automatic video tracking systems enable behaviour to be studied in a reliable and consistent way, and over longer time periods than if it is manually recorded. To overcome limitations of currently available systems and to meet researchers' needs as these have been identified, we have developed an integrated system (EthoVision) for automatic recording of activity, movement and interactions of insects. The system is described here, with special emphasis on file management, experiment design, arena and zone definition, object detection, experiment control, visualisation of tracks and calculation of analysis parameters. A review of studies using our system is presented, to demonstrate its use in a variety of entomological applications. This includes research on beetles, fruit flies, soil insects, parasitic wasps, predatory mites, ticks, and spiders. Finally, possible future directions for development are discussed.

Remote-sensing, telemetric and computer-based technologies for investigating insect movement: a survey of existing and potential techniques

This paper provides an overview of the recent literature on electronic, remote-sensing and computer-based techniques for observing and monitoring insect movement in the field and in the laboratory. Topics (such as entomological radar) which are covered in detail elsewhere in this Special Issue are deliberately omitted. Techniques which have been used, or which have potential for use, in monitoring insects in the field, include optical and opto-electronic devices, videography, thermal imaging, radio frequency identification (RFID), radio-telemetry, X-ray radiography and computed tomography, sodar and sonar. The discussion includes optical sensors and insect trapping, instrumented beehives, acoustic detection of insects in grain, fruit and soil, and various laboratory methods for studying insect movement, such as actographs, treadmills, automatic flight mills, and the video recording and analysis of movement in wind tunnels and in indoor arenas. Airborne and satellite imaging of insect habitats is mentioned, but only in the context of the use of these techniques to deduce changes in population distribution in some migratory species. Finally, some of the main constraints to progress in the sensing of insect movement, and areas where rapid advances seem possible, are discussed.

Testing insect movement theory: empirical analysis of pest data routinely collected from agricultural crops

Observations of an insect's movement lead to theory on the insect's flight behaviour and the role of movement in the species’ population dynamics. This theory leads to predictions of the way the population changes in time under different conditions. If a hypothesis on movement predicts a specific change in the population, then the hypothesis can be tested against observations of population change. Routine pest monitoring of agricultural crops provides a convenient source of data for studying movement into a region and among fields within a region. Examples of the use of statistical and computational methods for testing hypotheses with such data are presented. The types of questions that can be addressed with these methods and the limitations of pest monitoring data when used for this purpose are discussed.

Insects and plant defence dynamics

Phytochemical defence profiles in insect-plant interaction the role of chemical nutrients and minerals in insect resistance in crop plants synthetic chemicals of chemical defences in maize silks against corn earworm and their interaction in the flavonoid pathway semiochemistry of crucifers and their herbivores tetranorterpenoids and qusinoids - costitutive chemical defences of the rutales role of plant surface in resistance to insect herbivores host plant resistance to insects - measurement, mechanism and insect-plant environmental interactions defensive tactics of caterpillars against predators and parasitoids sluggih movement of aposematic insects as a defence mechanism against motion-oriented predators molecular approaches to host plant defences against insects.

A Graphical Method for Exploring Spatiotemporal Point Distributions

A spatiotemporal point distribution is a set of points defined by the combination of a spatial region and a time period. It is used for representing a set of discrete events, such as traffic accidents, and a set of points that characterize line and polygon objects such as the turning points of insect movement. Analysis of a spatiotemporal point distribution is more difficult than an ordinary spatial point distribution because it has to be treated in a three- or four-dimensional spatiotemporal region, where data visualization and analysis have not been fully explored. This paper proposes a new method for representing the spatiotemporal point distribution, which is useful for exploratory analysis. The method summarizes the information extracted from the point distribution, and thus helps us find important and interesting patterns in the distribution. It consists of two steps: conversion of a spatiotemporal point distribution into a surface, and graphic representation of the surface. Along with a theoretical description of the method, technical details including a computational algorithm are discussed. To test the validity of the method, an expansion of convenience stores in Tokyo, Japan, is analyzed.

Use of Radiography and Tunnel Castings for Observing Mole Cricket (Orthoptera: Gryllotalpidae) Behavior in Soil

The behavior of mole crickets, serious pests of turfgrass, is poorly understood and has been rarely studied, predominantly because these insects dwell deep in the soil and are highly mobile. To better understand how the tawny mole cricket, Scapteriscus vicinus Scudder, and the southern mole cricket, S. borellii Giglio-Tos, behave in the soil, we used nondestructive x-ray techniques and wax and fiberglass resin castings to study the tunneling patterns and interactions of these mole crickets with their environment. Both species typically constructed Y-shaped tunnels to facilitate feeding and escape routes. Herbivorous tawny mole crickets tended to have more extensive and deeper tunnel systems than predatory southern mole crickets. Mole crickets maintained Y-shaped tunnels when subsoil density increased but often bent or terminated tunnels to avoid compacted areas. Both species maintained separate tunnels in the presence of other individuals of the same species. However, southern mole crickets exhibited more extreme separation, suggesting an avoidance behavior that may have been mediated by chemical, vibrational, or auditory cues. Although tawny mole crickets did not alter the shape of their Y-shaped tunnels in the presence of southern mole crickets, they sometimes would wall-off a tunnel, presumably in defense. Tawny mole crickets avoided contact with the entomopathogenic fungi, Beauveria bassiana (Balsamo) and Metarhizium anisopliae (Melchnikoff). This behavior suggests the potential of finding biologically active compounds that inhibit soil insect movement and could be used in the management of soil insect pests.

An Optoelectronic Sensor for Monitoring Small Movements in Insects

Optical movement detectors are often used in laboratory studies of insect behavior. They offer advantages of time resolution and ease of analysis compared with video. However, design and construction have rarely been described in enough detail to allow the devices to be built easily by others. We describe a simple optoelectronic system for measuring rapid movements in one dimension, such as the protraction of an insect leg. The leg casts a bar-shaped shadow onto a photodiode chip that is masked to expose a triangular area. Movement of the leg changes the total area of the triangle that is shaded. A preamplifier converts the change in photoelectric current to a voltage signal. The preamplifier includes an optional circuit for removing 120 Hz ripple resulting from AC-powered light sources by subtracting the output of a second, reference photodiode. We have used the system to quantify leg movements in an acoustic startle response of a field cricket (Teleogryllus oceanicus LeGuillou). This system could be adapted for a wide range of other applications in laboratory and field research.

The pattern, rate, and range of within‐patch movement of a stem‐galling fly

Summary1. Information on the movement of insects is critical to understanding the spatial spread, dynamics, and genetic structure of their populations, as well as their interactions with other species. With this in mind, the movement behaviour of the stem‐galling fly Eurosta solidaginis Fitch (Diptera: Tephritidae) was investigated.2. Fluorescent‐marked adults were released at a single location within pure patches of the host plant, tall goldenrod Solidago altissima, and their distributions censused repeatedly throughout the day.3. Following their release, male and female flies redistributed themselves in a manner that was well described by a simple‐diffusion model. The diffusion rate was independent of fly density and time since flies were released.4. Female flies dispersed at a significantly faster rate, and therefore farther on average, than males. Based on the diffusion model, it was estimated that at 2.5–3.0 h post release, males and females had a median dispersal distance of only 2.0 and 2.5 m respectively. Furthermore, 95% of the males were estimated to have dispersed no more than 5.9 m, and females no more than 6.4 m.5. Post‐release censuses suggested that flies were most active during mid morning, disappeared from the site at a rate of 10–15% per hour (most likely due to mortality), and survived for less than 2 days. Based on the rate of spread, diel activity, and liberal estimates of longevity in the field, 50% of the ovipositing females were predicted to have had a maximum lifetime range of movement within a patch of hosts of ≤ 51 m (95% were expected to have been limited to ≤ 130 m).6. These data are used to assess whether the absence of a positive correlation between host‐plant preference and offspring performance in this system could be due to the limited scale of dispersal of this species relative to the spatial scale at which its oviposition behaviour has been studied.

TWO MODELS OF GRAIN TEMPERATURES AND INSECT POPULATIONS IN STORED WHEAT

Stored grain temperatures and population dynamics of rusty grain beetles, Cryptolestes ferrugineus (Stephens),predicted by a hot spot model, which included feedback from the insect model to the temperature model, and a spatial model,which did not include that feedback, were compared. For an initial grain temperature of 30C and an initial population of10,000 adult insects in stored grain at Winnipeg, Canada, the hot spot model predicted a maximum of 120 adults/kg of wheatat the center of the grain bulk toward the end of fall and a maximum temperature of 39C. The spatial model predicted anadult population of 500 adults/kg of wheat and no increases in temperatures. For the same simulation conditions but usingweather data for Topeka, Kansas, the hot spot model predicted a maximum of 150 adults/kg of wheat at the center of the bulkin fall, while the spatial model predicted a maximum of 800 adults/kg. The hot spot model is closer to reality than the spatialmodel because it simulates the effects of variable heating around the bin wall, insect heat production, and insect movement.

Methods for marking insects: current techniques and future prospects.

Tracking the movement of insects in their natural habitat is essential for understanding their basic biology, demography, and ethology. A wide variety of markers have been used to assess insect population dynamics, dispersal, territoriality, feeding behavior, trophic-level interactions, and other ecological interactions. The ideal marker should persist without inhibiting the insect's "normal" biology. Furthermore, the marker should be environmentally safe, cost-effective, and easy to use. In this article, we review the current state of knowledge regarding insect marking, document the advantages and limitations of each marking technique, and discuss advances made in marking insects over the past decade.

Effects of Grassland Fragmentation on Insect Species Loss, Colonization, and Movement Patterns

Ecological theory predicts that isolated habitat patches will experience greater rates of species loss and lower rates of recolonization compared to less isolated habitats. As a corollary, corridors of suitable habitat should reduce patch isolation, thereby decreasing species loss and enhancing colonization. Little ecological evidence exists, however, to compare species loss and colonization in habitat patches with and without corridors under field conditions. Using insects in a native grassland habitat, I performed a three-year field experiment that varied fragment size and connectivity to test the hypotheses that corridors influence patterns of insect species loss, rates of recolonization, and insect movement among habitat fragments. I detected few effects of corridors consistent with theoretical predictions. First, corridors generally failed to reduce insect species loss from otherwise isolated grassland patches, except for subtle effects in medium-sized patches. Species richness was slightly higher in medium patches with corridors than in medium isolated patches when averaged over the three years of the study. I observed the strongest positive effect of corridors in the third and driest year of the study. Second, corridors did not significantly influence overall rate of patch colonization, but slightly increased the probability of colonization by less vagile species. Interestingly, corridors did not affect recolonization by rare species, which are often the subject of conservation concern. Third, I characterized individual movement pathways of three insect species in plots with and without corridors. One of the three species significantly preferred corridors, while the other two species moved independently of corridors. Taken together, these results suggest that corridors have the potential to promote movement of organisms among habitat patches, but that their function may depend upon species characteristics, landscape context, patch size, and environmental variation.

EFFECTS OF GRASSLAND FRAGMENTATION ON INSECT SPECIES LOSS, COLONIZATION, AND MOVEMENT PATTERNS

Ecological theory predicts that isolated habitat patches will experience greater rates of species loss and lower rates of recolonization compared to less isolated habitats. As a corollary, corridors of suitable habitat should reduce patch isolation, thereby decreasing species loss and enhancing colonization. Little ecological evidence exists, however, to compare species loss and colonization in habitat patches with and without corridors under field conditions. Using insects in a native grassland habitat, I performed a three-year field experiment that varied fragment size and connectivity to test the hypotheses that corridors influence patterns of insect species loss, rates of recolonization, and insect movement among habitat fragments. I detected few effects of corridors consistent with theoretical predictions. First, corridors generally failed to reduce insect species loss from otherwise isolated grassland patches, except for subtle effects in medium-sized patches. Species richness was slightly higher in medium patches with corridors than in medium isolated patches when averaged over the three years of the study. I observed the strongest positive effect of corridors in the third and driest year of the study. Second, corridors did not significantly influence overall rate of patch colonization, but slightly increased the probability of colonization by less vagile species. Interestingly, corridors did not affect recolonization by rare species, which are often the subject of conservation concern. Third, I characterized individual movement pathways of three insect species in plots with and without corridors. One of the three species significantly preferred corridors, while the other two species moved independently of corridors. Taken together, these results suggest that corridors have the potential to promote movement of organisms among habitat patches, but that their function may depend upon species characteristics, landscape context, patch size, and environmental variation.

The spatio‐temporal distribution of adult Ceutorhynchus assimilis in a crop of winter oilseed rape in relation to the distribution of their larvae and that of the parasitoid Trichomalus perfectus

AbstractThe spatio‐temporal distribution of Ceutorhynchus assimilis Payk. (Coleoptera: Curculionidae) adults caught in a rectangular grid of flight traps in a crop of winter oilseed rape (Brassica napus L.) was mapped and was analysed using Spatial Analysis by Distance IndicEs (SADIE). Their distribution was compared to that of their larvae and that of their parasitoid Trichomalus perfectus (Walker) (Hymenoptera: Pteromalidae) in pods. The distribution of immigrating C. assimilis adults was consistent with their arrival at the crop boundaries and movement within the crop towards its centre. Adult C. assimilis were aggregated at all times, invasion being on two fronts, leading to the formation of two major clusters within the crop. Large areas of the crop remained relatively unpopulated. During the emigration phase, numbers declined simultaneously in all parts of the crop. The distributions of adult and larval C. assimilis and of larval T. perfectus were spatially associated. The distribution of the parasitoid did not show a density dependent relationship with that of its host. We discuss the movements of insects which underlie their population distributions, the value of integrating spatial information into improved management strategies for C. assimilis and the potential for the spatial targeting of insecticides to reduce the amount applied and to conserve T. perfectus.

Application of synthetic sex pheromone for management of diamondback moth, Plutella xylostella, in cabbage

AbstractOver a 2‐year period field trials were conducted to assess the potential to disrupt mating ofPlutella xylostella (L.) using a commercial rope formulation of a 70:30 mixture of (Z)‐11‐hexadecenal and (Z)‐11‐hexadecenyl acetate, two components of the sex pheromone of the female. Screened field cages were placed into blocks of cabbage which were either treated with the pheromone or left untreated. Different densities of P. xylostella pupae were placed into each cage and then larval and pupal counts were made of the subsequent generation. In addition, sentinel females at mating stations were placed in each cage to assess the influence of the pheromone on the ability of males to locate and mate with females. Likewise, we used pheromone traps to assess whether the pheromone treatment influenced the ability of males to locate a pheromone source. In both years larval and pupal populations, produced as a result of the original inoculation, did not differ between pheromone‐treated and untreated fields. The effect of pheromone treatment on larval and pupal numbers did not change with changes in inoculated P. xylostella density, however, the density of P. xylostella released caused significant differences in the density of the subsequent generation. No significant differences were detected between the number of sentinel female adult P. xylostella that successfully mated in pheromone‐treated fields compared with untreated fields. Significant differences in the numbers of male P. xylostella caught in pheromone‐baited traps occurred between pheromone‐treated and untreated fields in the first trial of 1993, and in the first trial in 1994 but not in the second trial. Such differences are often thought of as indications of mating disruption, although our other data presented in this study and reports from other studies indicate this is not always the case. Previous studies on mating disruption of P. xylostella in larger scale field tests have been performed but the results have been variable and often ambiguous. Overall, our results indicate that mating disruption of P. xylostella with the present technology does not appear to work even under the very controlled situations which we utilized to eliminate insect movement between plots.