Movement Of Moths Research Articles

Local Dispersal by the Cinnabar Moth Tyria Jacobaeae

We used mark‐recapture data to measure and model movement by the adult stage of the cinnabar moth Tyria jacobaeae (Lepidoptera, Arctiidae). Our objectives were: (1) to standardize the description of cinnabar moth movement and thereby provide a more reliable basis for comparison and extrapolation, and (2) to screen the potential influence of gender, physical condition, time, spatial location, and spatial heterogeneity in the environment on movement parameters. Recapture rates depended on wing wear (low 16%, high 11%) but were independent of behavior immediately after release (mobile 15%, immobile 14%), gender (male 13%, female 16%), or location in the study area (central 15%, peripheral 15%). Thus, mortality and/or emigration was greater for individuals with high wing wear compared to those with low wing wear. Moths were aggregated at the southwest margin of the study area both at initial capture and recapture. The direction of movement was biased in north and south directions, perhaps because forests on the east and west boundaries created a corridor channeling movement. The movement observed within a single generation did not conform to simple diffusion, which predicts that the mean square displacement (MSD) increases linearly with time. Instead, observed movement rates varied over time, and the relationship between MSD and time varied by gender, smoothly decelerating in males and erratically increasing in females. Observed movement (represented by the frequency distribution of displacements x for each time t with time measured at a daily resolution) was adequately approximated by a Weibull distribution, for which estimates of the shape and scale parameters were calculated. Male distributions were more frequently mounded, associated with higher values of the shape parameter α, and the scale of male distributions shifted sooner to longer distances, associated with higher values of the scale parameter β. The Weibull parameters varied by sex and time, suggesting that males were initially more mobile than females, but the magnitude of the difference varied over time. The speed and direction of individual movement were independent of the moth's spatial location within the field. We conclude that (1) movement speed depended on gender and time, while movement direction was related to spatial heterogeneity in the environment, and (2) much of the disagreement about movement rates among studies of the cinnabar moth can be related to researchers taking measurements and drawing inferences on different scales of observation, and therefore arriving at conflicting results.

Spatial dynamics of Helicoverpa populations in Australia: simulation modelling and empirical studies of adult movement

Two species of Helicoverpa (Lepidoptera: Noctuidae) are major pests of agricultural crops in Australia. The population ecology of these insects is dominated by their wide host range and the mobility of adults. In an effort to improve Helicoverpa management in high value crops such as cotton, a comprehensive population dynamics model (HEAPS — HElicoverpa Armigera and Punctigera Simulation) has been developed which incorporates the spatial structure of the habitat and pest population and explicity simulates adult movement within a regional cropping system. HEAPS includes modules for the spatial representation of the region, moth movement, oviposition, pest and crop development and pest mortality. The structure and current state of development of the model is described. A key aspect of the model is moth movement. Empirical studies to quantify aspects of adult behaviour and to provide parameters for HEAPS have included mark-recapture experiments in which natural, high density populations have been artificially labelled with strontium as larvae and then recaptured as adults in a widespread network of pheromone traps. The results of one such experiment are presented to highlight differences in the mobility of the two species of Helicoverpa and indicate the difficulties inherent in validation of the movement routines of the model.

The role of uncultivated hosts in the spread of pyrethroid resistance in Helicoverpa armigera populations in Andhra Pradesh, India: a simulation approach

In Andhra Pradesh, India, pyrethroid resistance in the noctuid moth, Helicoverpa armigera, follows a seasonal cycle. Levels of resistance increase from August to March, and then decrease in the hot dry period between April and July. An hypothesis expressed in the form of a simple simulation model is presented to explain these fluctuations. Uncultivated hosts, upon which there is no selection for pyrethroid resistance, act as a reservoir of more susceptible moths. A movement of moths from the reservoir to cultivated hosts is postulated to explain the drop in resistance. The model incorporates the effects of seasonal variation in host availability and of constraints on the mixing of genotypes between cultivated and uncultivated hosts. The most critical factor is the rate at which the uncultivated refuges are contaminated by resistant genotypes. This is minimised if the seasonal cycles of cultivated and uncultivated hosts are in synchrony. Rate of refuge contamination is most rapid if uncultivated hosts are scarcest one to two moth generations before availability of cultivated hosts falls to a minimum. A small population of wild plants may have a marked impact on the rate at which resistance develops in the Helicoverpa population on crops. The relationship between selection pressure and rate of resistance development is exponential, so successive reductions in insecticide usage lead to larger and larger delays in resistance.

Movements of Tortricid moths (Lep. Tortricidae) between apple orchards and adjacent ecosystems

The movements of tortricids between the apple orchard ecosystem and its surroundings were investigated. To record moth movements a bidirectional Malaise trap was placed on each margin of three IPM (integrated pest managed) and three abandoned apple orchards from the beginning of June to October 1992. Overall flight activity and activity of species associated with apple trees were considered. Diversity was explored by the Shannon-Weaver index and the two management systems were compared. Data were analysed with de-trended correspondence analysis (DCA), Mantel test and single linkage clustering. Results showed that the diversity did not correlate with management, even when the second axis of the DCA separated IPM orchards from abandoned ones. The first axis of the DCA confirmed the importance of the orchards isolation. Superposition of single linkage clustering revealed groups forming using DCA. The Mantel test allowed statistically checking of the similarity between emigrant and immigrant fauna. Two similarity model matrices were tested against data in the Mantel test. The six orchards showed no massive emigration or immigration, an indication that exchanges occurred locally.

An evaluation of potential economic returns from the strategic control approach to the management of African armyworm Spodoptera exempta (Lepidoptera: Noctuidae) populations in eastern Africa

The costs of armyworm control in candidate outbreak source areas in Ethiopia, Kenya and Tanzania were compared with estimates of the costs of potential damage if these source outbreaks were not controlled. The latter costs were estimated using a modelling approach, taking account of known moth migration trajectories, their frequency of occurrence, and of the agricultural productivity of potential destinations of the migrant moths. Two parallel studies were conducted: one for the outbreaks in the period January to June, and the other during October to December. Strategic control of armyworm using ground spraying, whereby infestations are controlled even if they are of no immediate economic importance but when their future progeny pose a potential threat, will be worthwhile during the period October to December on the basis of: (a) available estimates of control costs; and (b) a sensitivity analysis of potential losses in relation to moth reproduction. For January to June the potential outbreak sources worthy of control are fewer, but the two most important sources could lead to more devastation than any of those in October to December. The maximum estimated control cost (US$ 33 per hectare, 1987 prices) involved the use of helicopters during an operation in Tanzania. The next highest were for ground-spraying operations in Ethiopia in 1985 (US$ 17) and for an aerial operation in Kenya (US$ 16). However, even if the latter estimates are used, strategic control will still be worthwhile in one fifth of the study area regardless of season, given 20% crop damage and a moth reproductive rate per generation of at least five. Comparison of the results with those based on a hypothetical situation of no migrations showed only minor differences in many cases but the effects of moth movements were more marked for the period October to December than during January to June. This exercise also identified the Meru district in Kenya and the south Morogoro region of Tanzania, in particular, as zones which have unremarkable agricultural value of their own but which can be sources of moth populations capable of causing economically important damage elsewhere. It is proposed that strategic control operations should be restricted to those areas likely to be responsible for the most potential damage. Such target areas have been identified in the study and are mostly in east central and southwestern Kenya and northern and central Tanzania.

Estimates of male dispersal in Yponomeuta padellus (Lepidoptera: Yponomeutidae), the small ermine moth, by means of simulation

A model of male dispersal is described which simulates the observed recaptures from a series of mark-release-recapture experiments. The model aims to obtain an unbiased estimate of the dispersal parameter, σ, for males of Yponomeuta padellus (Lepidoptera: Yponomeutidae). Five parameters, each considered to be potentially important in an analysis of the dispersal patterns of Y. padellus, were incorporated into the model. Parameter values were varied individually in a stepwise fashion to create a large number of simulated data sets. The method of maximum likelihood was used to test the goodness of fit of each simulated data set against the observed distribution of recaptures to determine the optimal combination of parameter values. Using these same parameter values, the model was then modified by examining the movement of male moths in the absence of traps to obtain an estimate of σ. The ‘best’ estimate of σ was found to be 2.9 m gen−1/2, with an approximate upper confidence limit of 6.4 m gen−1/2. The results suggest that dispersal in Y. padellus is extremely restricted relative to the area occupied by the total population and that Y. padellus is characterized by an extremely fine-scale population structure.

Control of Codling Moth in Apple and Pear with Sex Pheromone-Mediated Mating Disruption

During 1987-1988 replicated 0.3-ha plots of apple and pear were used to measure the efficacy of sex pheromone-mediated mating disruption of codling moth, Cydia pomonella (L.). Comparisons of fruit injury were made between pheromone-treated and untreated plots either with or without releases of field-collected moths. In IH87, one moth per tree was released twice during the season in two apple orchards and total season fruit injury in untreated plots ranged from 7.0 to 21.2%. Levels of fruit injury in the pheromonetreated plots were 1.0-4.0%. In 1988, either one moth was released per five trees three times during the season or no moths were released in replicated apple plots. Seasonal fruit injury ranges in untreated plots were 1.41-1,65% and 0.39-1.21% with and without moth releases, respectively. Correspondingly, levels of fruit injury in the pheromonetreated plots were 0.09-0.27% and 0.05-0.07% with and without moth releases, respectively. In 1988, fruit injury in the pheromone-treated and untreated pear plots with moth releases were 0.05 and 0.16%, respectively. Average emission levels of (E, E)-8,10- dodecadien-l-ol at dusk for a 14-d period after releases were 8.4-40.9 mg/ha per h each year. Spatial analysis of fruit injury showed that fruit injury was aggregated and moth movement within orchards was limited and not influenced by the presence of pheromone. Our data suggested that more fruit injury occurred on ‘Golden Delicious’ than ‘Red Delicious’.

Atmospheric Trajectory Analysis to Project Long-Range Migration of Black Cutworm (Lepidoptera: Noctuidae) Adults

The black cutworm, Agrotis ipsilon (Hufnagel), larva is a pest of seedling corn in the Midwest. Adults migrate from the south during the spring. Determination of their arrival date is critical to anticipate accurately the time of appearance of larvae in the field. A simplified and easily applied procedure called the moth influx potential (MIP) system was developed to project black cutworm moth movement. The procedure uses National Weather Service atmospheric trajectory forecasts in a backtracking trajectory strategy that projects moth movement from source regions estimated by soil temperature analysis. The MIP system was tested for its ability to determine nights of introduction of A. ipsilon moths into central Iowa; estimates were compared with numbers of adult males captured in traps baited with synthetic sex pheromone. Pooled data from 5 yr (1978-1981 and 1983) were used for these comparisons. Regression analysis revealed a significant (P < 0.01) but weak correlation ( r = 0.210) between square-root transformations of daily MIPs and trap captures. The correlation of 4-d ( r = 0.292), 5-d ( r = 0.311), 6-d ( r = 0.366), and 7-d averages ( r = 0.369) of MIP and trap captures increased sequentially. Significant linear ( r = 0.400) and quadratic trends ( r = 0.366) were also detected between calendar week and trap captures. Stepwise regression of 7-d MIP and time variables provided a model for predicting trap captures.

Onset and spread of an African army worm upsurge

Abstract. 1. Onset and spread of the severe outbreaks of African armyworm, Spodoptera exempta (Walk.), over Ethiopa, Kenya, Tanzania and Burundi in late 1984 have been analysed in relation to trap and weather records.2. Although first outbreaks in each country appeared progressively further south, winds on the best estimated dates of moth concentration and egg laying blew from directions precluding moth movements between them.3. Such independently developing outbreaks are called ‘primary’ to distinguish them from any ‘secondary’ outbreaks that may develop from them.4. Parent moths giving rise to all seven areas of primary outbreaks were derived from low‐density populations that had persisted through the dry season, probably near the coast of East Africa.5. Primary outbreaks developed on the south‐eastern sides of individual rainstorms over the highlands, most likely because windborne moths were concentrated there by convergent winds.6. Of the secondary outbreaks within Kenya, Tanzania and Burundi, most were derived from only one area of primary outbreaks in Kenya, which were therefore critical for effective control of spread; the paucity of other secondaries was presumably due to a lack of timely rainstorms or other concentrating mechanisms.

The use of biogeographical techniques in the study of migrant noctuid moths

The use of biogeographical techniques for monitoring, mapping and predicting seasonal changes in the distribution of migrant noctuid moths in a country or region, can lead to timely and effective control of infestations of the larvae of international pest species like the African armyworm, Spodoptera exempta (Wlk.); the American bollworm, Heliothis armigera (Hub.); the Black cutworm, Agrotis ipsilon (Hufn ); the cotton leafworm, Spodoptera littoralis (Boisd.) etc., and hence to the protection of crops and pasturelands. Methods of data collection include the establishment of national and regional networks of monitoring devices such as light and pheromone traps, and the introduction of regular or periodic standard procedures for recording, reporting and assessing infestations of larvae. Techniques for collecting and analysing the data include the use of: (a) dots, circles or similar marks on topographic or weather maps to plot the occurrence of moths and/or larvae at the latitudes and longitudes of outbreak sites, followed by the dates when infestations were confirmed; (b) numerical symbols (e.g. 1–12 for January to December) on the above maps in order to summarize periodic (e.g. monthly) shifts in the distribution of populations within or across neighbouring countries; (c) colour codes or other graphic symbols to plot maps of pest distribution and migration over the required time-scale, followed by the study of appropriate synoptic weather charts, particularly streamline wind charts showing surface and low-level wind convergence zones over the distribution areas. Successful application of these techniques have included studies of changes in the distribution and migration of: (a) A. ipsilon worldwide; (b) Desert locust in Africa and Asia; (c) S. exempta in Africa and S.W. Arabia etc. In the 1981/82 outbreak season, for example, dots (•) were used to map out and date south-to-north displacement of populations of S. exempta across eastern Africa from Tanzania to Ethiopia between November 1981 and June 1982; while in 1980/81, numbers (1–12 for January-December) were plotted to summarize outbreaks developing between Ethiopia and Tanzania. Successful monitoring and assessment of mass movement of moths between Tanzania, Kenya and Uganda early in the 1981/82 season, for example, enabled the Armyworm Forecast Service to issue accurate forecasts for the first cross-border migrations of moths between the three countries from the second week of February 1982, leading to effective control of larvae to save cereal crops, sugar-cane and pasture grasses in East Africa.

The role of migration in the life system of the African armyworm Spodoptera exempta

The African armyworm is a migrant moth which, in its larval form, can cause severe plagues which destroy cereal crops, sugarcane and pastures in many parts of Africa. This paper reviews the relevant aspects of a multidisciplinary study into the dispersal behaviour and re-concentration of moths, migratory flight, source areas, population upsurges and the seasonal movement of moths. It introduces the new concepts of primary and critical outbreaks.

THE INFLUENCE OF TRAP DENSITY, TRAP HEIGHT, OUTSIDE TRAPS AND TRAP DESIGN ON CYDIA POMONELLA (L.) CAPTURES WITH SEX PHEROMONE TRAPS IN NEW SOUTH WALES APPLE ORCHARDS

AbstractIn order to standardize the use of sex pheromone traps for Cydia pomonella population monitoring in apple orchards, the influence of trap design, trap density, trap height and the use of outside traps were evaluated.The commercial Zoecon 1CP trap was more efficient than a triangular shaped metal trap. Traps at a density of 1 per ha were adequate to estimate C. pomonella populations. Traps in the upper third of apple trees caught more moths than traps at head height when the 2 were in direct competition. When the high traps were removed, however, the low traps caught nearly as many moths as both high and low traps combined. Outside traps greatly reduced the movement of moths into monitored sites and also indicated the source of migrating moths.

Further evidence for windborne movement of armyworm moths, Spodoptera exempta, in East Africa

Abstract. 1. Comparison of dominant wind directions with seasonal redistribution of Spodoptera exempta caterpillar outbreaks in East Africa provides further circumstantial evidence to support the hypothesis of downwind migration by adult moths.2. Calculated backward and forward tracks for sixty‐nine nights during the 1973–74 and 1974–75 seasons, when there were sudden increases in numbers of moths caught at six light traps, illustrate the variability of downwind movement due to the effects of temporary atmospheric disturbances.3. Comparison of calculated tracks with known outbreaks before and after the nights of increased moth catch suggests that some outbreaks are derived from unreported sources, especially eariy in the season, and it is therefore unwise to link new outbreaks only with known earlier ones.

Sunflower Moth Larval Distribution in Sunflower Heads 1

The distribution and movement of sunflower moth, Homoeosoma electellum (Hulst), larvae in flowering sunflower heads was determined. Sampling was initiated 3 days after first bloom and was continued at 3-day intervals untill larval numbers substantially declined. Flowers were divided into eight sections and each section into five subsections before larvae were counted. Larval counts from adjacent eighth sections were combined to create quarters and halves. There were no statistical differences ( P < 0.05) In larval densities among eighth sections in 91% of the heads, quarter sections in 86% of the heads, and half sections in all heads sampled. Larval movement among subsections of a head was influenced by floret and seed maturation, and to a lesser degree by instar.

Further studies on the industrial melanic moth Biston betularia (L.) in the northwest of the British isles.

The frequencies of the three phenotypes carbonaria, insularia and typical of the moth Biston betularia are given for a number of new localities and new samples from old localities in northwest England and the Isle of Man. In one locality (Caldy) the frequency of carbonaria has been decreasing at the rate of 1% per three years since 1959, probably due to the introduction of smokeless zones. Two methods have been used to measure the relative degree of camouflage at Caldy, where the melanic is common, and in the Isle of Man where it is much rarer. In Caldy carbonaria was the better camouflaged, but there was no evidence for this on the Isle of Man. One possible selective agent not previously reported is the bat, P. pipistrellus The rôle of moth movement over land and water is discussed in relation to the maintenance of the polymorphism and the steepness of the clines between North Wales and Liverpool.

Integration of Sanitation, Insecticides, and Sterile Moth Releases for Suppression of Populations of Codling Moths 1 in the Wenas Valley of Washington

The second step in a program of integrated control of Laspeyresia pomonella (L.) was undertaken in approximately 32 square miles of the Wenas Valley in 1971. The first step was a program of sanitation plus insecticides in 1970 that reduced the overwintering larval population 96% from that for the previous year. The 1971 program included the release of a total of over 1½ million sterile codling moths of both sexes between April and September; concurrently, noncommercial trees in the area were sprayed 4–6 times, 10 acres of commercial orchard were sprayed twice with cover sprays, and 332 acres were sprayed once with a cover spray; the remaining 90 acres were not sprayed. Catches in sex-attractant traps indicated that the ratio of sterile to native moths exceeded 40: 1 during most of the season but was below this desired minimum ratio in the noncommercial area. However, the number of moths caught per trap in 1971 was 91 % less than the number caught in 1970. Also, despite the movement of native moths into the valley, the number of overwintering larvae was reduced 92% over that for 1970, and only 0.005% of the fruit produced mature larvae.

A Flight-Cage Actograph for Recording Circadian Periodicity of Pink Bollworm1 Moths2

The activity recording system used to monitor circadian periodicity in pink bollworm moths, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), is presented. The actograph provides a permanent record while eliminating the use of light and direct observation for studying nocturnal periodicity. A graphic recorder, preamplifier, and power supply register the output of a vibration-sensitive transducer mounted on an isolated metal cage. Vibrations produced by movements of moths in the cage indicate the overall levels of activity which are associated with specific behavioral events. Response to light, foraging behavior, mating, and relative inactivity are indicated by characteristic patterns. Rhythms produced by 20 moths during a continuous 14-day trial include entrainment, free-run in dark, and subsequent reentrainment. Circadian periodicity was dependent on photoperiodic induction. This system is highly adaptable and may be used with a variety of arthropods.

A minor immigration of the diamond-back moth Plutella xylostella (L.) ( maculipennis Curtis)

The sudden appearance of adults of the diamond-back moth Plutella xylostella (L.) ( maculipennis Curtis) in the Aberdeen area and the Orkney and Shetland Islands in June, 1966, and subsequent damage to cruciferous crops in these areas, suggested that a minor immigration of moths had occurred. Evidence to support this was based on known sources of potential migrants in Finland and other areas to the east of Britain earlier in June, and on the meteorological synoptic charts covering the relevant period of movement of moths. It was found that the movement was affected by a similar synoptic pattern as in 1958, with an easterly to southeasterly air-flow between an anticyclone to the north and northeast and a depression to the west and southwest of the area of movement. It is suggested that immigrant moths probably augment the indigenous population in Britain more frequently than is realised, and only when migrations are on the scale of those in 1891, 1914 and 1958 have entomologists been conscious of the phenomenon.

The Evolution, Ontogeny and Quantitative Control of the Settling Movements of Some New World Saturniid Moths, With Some Comments On Distance Communication By Honey-Bees

"The Evolution, Ontogeny and Quantitative Control of the Settling Movements of Some New World Saturniid Moths, With Some Comments On Distance Communication By Honey-Bees" published on 01 Jan 1960 by Brill.

THE ROLE OF CLIMATE AND DISPERSAL IN THE INITIATION OF OUTBREAKS OF THE SPRUCE BUDWORM IN NEW BRUNSWICK: II. THE ROLE OF DISPERSAL

In Part I of this paper consideration was given to the role of climate in the initiation of outbreaks of the spruce budworm in New Brunswick. Analysis of the available weather data showed that the 1912 and 1949 outbreaks developed after several consecutive dry summers. Support was given to the theory of climatic release, which explains the time and place of outbreaks on a climatic basis. However, the recorded history of the spruce budworm also shows that high populations appeared in New Brunswick shortly after "spreading" through Quebec, and this suggests that the New Brunswick outbreaks are also a continuation of this spread. In the present part of the paper consideration is given to the role of dispersal. Moth dispersal is a more effective agent of spread than larval dispersal. Moths may be transported by convectional and turbulent air currents for long distances. Light traps used to detect the incidence of moth movements, showed that large segments of a population may be transferred from one area to another. Unspent females often predominate in these movements. Moth invasion was not detected before the 1949 outbreak although there is evidence from other sources that it occurred in 1948. When deposited in dense, mature, softwood stands, the moths can create outbreaks, but when deposited in young, open, or mixed-wood stands the ensuing high populations soon decline unless bolstered by repeated invasions. Populations in New Brunswick showed gradual and general increases as early as 1947. It is thought probable that these increases resulted from the build-up of local populations through climatic release. The nearest highly-populated centers were over 100 miles to the west in 1947. Later, invasion of moths from centers outside of the Province may have hastened the process.