Moth Catches Research Articles

Enhancement of Attraction to Sex Pheromones of Spodoptera exigua by Volatile Compounds Produced by Host Plants

We measured the effects of exposure to volatile compounds produced by host plants on the rate of capture of male Spodoptera exigua using synthetic sex pheromones. Exposure to volatile compounds stimulated strong electroantennographic responses of male S. exigua. The behavioral responses of male moths to combinations of sex pheromone and volatile compounds were tested in wind tunnel experiments. When lures were baited with synthetic sex pheromone plus benzaldehyde, phenylacetaldehyde, (Z)-3-hexenyl acetate, or linalool, respectively, the landing rate of S. exigua males was increased by 101.4%, 79.6%, 60.6%, and 34.3%, respectively, compared to sex pheromone alone. In field tests, traps baited with either pheromone + (E)-2-hexenal, pheromone + phenylacetaldehyde, pheromone + (Z)-3-hexenyl acetate, or pheromone + (Z)-3-hexenol enhanced moth catches by 38.8%, 34.6%, 24.6%, and 20.8%, respectively compared to traps baited with pheromone alone. In a second field experiment, more S. exigua males were trapped with a combination of a synthetic sex pheromone blend and several individual host plant volatiles compared to synthetic sex pheromone alone. These results suggest that some host plant volatiles enhance the orientation response of S. exigua male moths to sex pheromone sources.

Spatial analysis of pheromone trap catches of codling moth (Cydia pomonella) in two heterogeneous agro-ecosystems, using geostatistical techniques

From 2000 to 2002, local distribution and dispersion patterns of the codling moth,Cydia pomonella (L.) (Lepidoptera: Tortricidae), captured in pheromone traps were investigated in two heterogeneous agro-ecosystems (A and B) of the Molise region, in central Italy. The main objectives of this study were to determine the temporal and spatial variations in distribution and abundance of codling moth inside and outside apple orchards located in these study areas, and to evaluate the importance of the presence of several host plants in relation to the observed distribution. Trap catches of male moths were clumped during almost all sampling weeks. Spatial characterizations obtained by means of geostatistical methods illustrate that the high trap capture foci were confined to the productive apple orchards for both agro-ecosystems or in small groups of apple trees, and in the case of study area B, in a zone containing pear trees, service trees and walnut trees. Occasionally moths were found in traps installed outside these zones. Furthermore, the position of high male population foci seems not to change during a single flight period. The results obtained are discussed with respect to the improvement of Integrated Pest Management programs employed in apple orchards situated in heterogeneous landscapes.

Oriental Fruit Moth (Lepidoptera: Tortricidae) Phenology and Management with Methoxyfenozide in North Carolina Apples

The phenology of oriental fruit moth, Grapholita molesta (Busck), on apple (Malus spp.) in North Carolina was studied using pheromone traps and egg sampling in abandoned and commercial orchards in 2000 and 2001, with subsequent development of an oviposition degree-day model and management studies in relation to codling moth, Cydia pomonella (L.), phenology. Oriental fruit moth eggs were found in greater numbers on leaves early and on fruit later in the growing season, on the top versus the bottom of the leaf surface, and on the calyx area versus the side or stem end of the fruit. A degree-day (DD) model to predict oriental fruit moth oviposition was developed based on temperature accumulations from peak moth trap capture of the first (overwintering) generation, by using 7.2 and 32.2°C as the temperature limits. The model predicted four ovipositing generations of oriental fruit moth with the second beginning 507 DD after peak moth catch. Using predictions of the oriental fruit moth and codling moth degree-day oviposition models, an experiment was conducted to determine the level of second generation oriental fruit moth control with methoxyfenozide applied under different scenarios for first generation codling moth. Methoxyfenozide was equally effective in managing codling moth and oriental fruit moth for all treatment timings.

Oriental fruit moth (Lepidoptera: Tortricidae) phenology and management with methoxyfenozide in North Carolina apples.

The phenology of oriental fruit moth, Grapholita molesta (Busck), on apple (Malus spp.) in North Carolina was studied using pheromone traps and egg sampling in abandoned and commercial orchards in 2000 and 2001, with subsequent development of an oviposition degree-day model and management studies in relation to codling moth, Cydia pomonella (L.), phenology. Oriental fruit moth eggs were found in greater numbers on leaves early and on fruit later in the growing season, on the top versus the bottom of the leaf surface, and on the calyx area versus the side or stem end of the fruit. A degree-day (DD) model to predict oriental fruit moth oviposition was developed based on temperature accumulations from peak moth trap capture of the first (overwintering) generation, by using 7.2 and 32.2 degrees C as the temperature limits. The model predicted four ovipositing generations of oriental fruit moth with the second beginning 507 DD after peak moth catch. Using predictions of the oriental fruit moth and codling moth degree-day oviposition models, an experiment was conducted to determine the level of second generation oriental fruit moth control with methoxyfenozide applied under different scenarios for first generation codling moth. Methoxyfenozide was equally effective in managing codling moth and oriental fruit moth for all treatment timings.

Modelling a forest lepidopteran: phenological plasticity determines voltinism which influences population dynamics

Mnesampela privata is an Australian geometrid moth that is considered to have resource-driven outbreaks. An autumnal oviposition/larval development cycle is considered the “norm” in this species, but spring/summer activity has also been observed. This apparent plasticity of phenology and probable concomitant changes in voltinism have not been considered as possible causes of moth outbreaks. We developed GumMoth, a phenological model for M. privata that uses temperature to predict development times of immatures. Photoperiod determines whether individuals undergo direct development or pupal diapause. We used known catch dates of moths (in the same moth-active season or 365-day period) to simulate population phenologies on the Australian mainland (27°28′S to 38°14′S) and in Tasmania (40°54′S to 42°57′S). GumMoth successfully simulated phenological patterns that agreed with published records and demonstrated for the first time that multivoltinism is possible in M. privata. In seven paired simulations using dates for first and last moth catches, the earliest moth activity resulted in the pupae of four out of 11 generations undergoing diapause, whereas the latest moth activity resulted in pupae of five out of eight generations undergoing diapause (diapause individuals emerged the following moth-active season). Almost two-thirds of offspring of spring/summer active moths reached adulthood within that same moth-active season (i.e. no delay in development), whereas those of autumn active moths always reached adulthood the following moth-active season (i.e. development was delayed). Records from foresters and in the scientific literature confirmed that the more common autumn phenology is supplemented by spring/summer activity in many localities. At half of these localities, populations that required insecticide control or caused substantial defoliation also developed. Because plantation eucalypts are suitable M. privata hosts for only four to five tree-growth seasons after planting, local moth populations must increase quickly if an outbreak is to occur. We suggest that large populations are more likely when plantations are colonised in the first moth-active season after planting and population growth commences in the spring/summer of each subsequent year. Foresters can use catch dates and regional weather data in GumMoth to estimate the number and phenology of generations of M. privata. This information can be used to assess risk posed by regional populations and thereby adjust future surveillance intensity.

Light trap transects – a field method for ascertaining the habitat preferences of night-flying Lepidoptera, using Mythimna turca (Linnaeus 1761) (Lepidoptera: Noctuidae) as an example

The habitat associations of the noctuid moth Double Line Mythimna turca (Linnaeus 1761) were studied in three areas in Britain by setting up light traps equidistant alon0g transects which passed through different habitat types. Counts were made of M. turca at each trap station and the results compared with the habitat present in the vicinity of each trap. The results using chi-square analysis indicate that the preferred habitats for M. turca are woodland and Pteridium aquilinum scrub, especially where the grasses Agrostis capillaris and Holcus mollis occur. The environmental factors affecting moth catches are discussed and chi-squared expectations are adjusted to take account of the different efficiency of light traps in open grassland and woodland situations. The light trap transect method is shown to be useful for moth species where little is known of their ecology and can be used to provide a straightforward insight informing additional targeted autecological studies. The methodology may be less suited to those species which occur at low density, are poorly attracted to light or are known to migrate.

Mating disruption of the pink bollworm Pectinophora gossypiella (Saund.) (Lepidoptera: Gelechiidae) using gossyplure PB-rope dispensers in cotton fields

The effects of mating disruption on population densities and percentage of damage of the pink bollworm Pectinophora gossypiella (Saunders) were investigated in a cotton field in central Greece, in 1992 and 1993. A 10-ha field was divided in two parts of 5 ha each. PB-rope dispensers were installed in mid-season in one part, whereas the other was used as a control field. Catches of pink bollworm moths in pheromone-baited traps and damage caused were recorded in both the treated and control fields. Results showed that moth catches were highly reduced in the treated field and, therefore, mid-season installation of dispensers was successful. Damage (%) was significantly less in the treated compared with the control field. Consequently, the field size of 5 ha seems to be adequate for the effective implementation of mating disruption.

Long-term seasonal abundance patterns of Helicoverpa zea and Heliothis virescens (Lepidoptera: Noctuidae) in the Texas High Plains.

Bollworm, Helicoverpa zea (Boddie), and tobacco budworm, Heliothis virescens (F.), male adult (moth) activities were monitored between 1982 and 1995 by using sex pheromone traps in the Texas High Plains. Moths were monitored weekly from early March to mid-November near Lubbock and Halfway, two prominent cotton production areas in the Texas High Plains region. Based on trap captures, the bollworm-budworm complex consisted of approximately 98% bollworms and approximately 2% tobacco budworms. Seasonal activity patterns varied between location for bollworm but not for tobacco budworm. The 14-yr average (+/- SE) bollworm moth abundance (moths per trap per week) at Lubbock was significantly higher (226.5 +/- 10.4) compared with that at Halfway (153.7 +/- 8.1). Correlation analyses showed a significant positive relationship between moth abundance and average weekly temperatures, whereas a significant negative relationship was observed between moth abundance and average weekly wind velocity for both species. Analyses also showed a positive correlation between moth abundance and cumulative degree-days (> 0.0 degrees C) from 1 January. A strong positive relationship was observed between moth abundance and weekly average precipitation for both species. Average weekly abundances were positively correlated between adjacent months during most of the active cotton fruiting season (June-September). However, the relationship between populations that contributed to the overwintering generation and the following spring populations varied between species and study sites. Nevertheless, data from this study indicated that late-season moth catches could be indicative of the dynamics of the early-season moth catches the following year in the High Plains. The mean population abundance curve based on 14-yr averages showed two bollworm population peaks at Lubbock, but only one peak at Halfway. Separate degree-day-based models were developed to describe long-term seasonal abundance patterns of bollworm moths for the Lubbock and Halfway sites.

Field trials with the synthetic sex pheromone of the oak processionary moth Thaumetopoea processionea.

The biological activity of synthetic (Z,Z)-11,13-hexadecadienyl acetate, the major pheromone component found in female gland extracts of the oak processionary moth Thaumetopoea processionea, was evaluated in field trials. Traps baited with 10 mg of the chemical efficiently attracted a large number of males provided they were placed in the upper crown region of the oaks. Devices positioned 10-15 m high in the trees attracted significantly more males than those traps installed at 2 or 6-8 m above the ground. Pherocon traps were slightly more efficient than Delta traps, and lower or higher amounts of the attractant in the baits did not significantly influence the number of moths caught. The importance of the stereomeric purity of the lure and the easy isomerization of the (Z,Z)-acetate to other isomers, particularly to the E,E isomer, should be considered for the development of efficient formulations in the field.

Can Parasitoid Sex Pheromones Help in Insect Biocontrol? A Case Study of Codling Moth (Lepidoptera: Tortricidae) and Its ParasitoidAscogaster quadridentata(Hymenoptera: Braconidae)

Abstract Synthetic female sex pheromone was used to monitor the phenology of male Ascogaster quadridentata Wesmael, an egg-larval parasitoid of codling moth, Cydia pomonella (L.), in conjunction with pheromone trapping of the moth and the banding of trees to determine larval parasitism. Catch of this parasitoid was typically ≈10 times less than the moth catch, and larval parasitism varied from 7 to 12%. The emergence of the parasitoid occurred slightly later than the female moth emergence, by both outdoor emergence cages and pheromone trapping. The seasonal activity of male parasitoids was otherwise synchronous with male codling moth flight. A survey of orchards in four regions of New Zealand showed considerable regional variation in the capture of the parasitoid in pheromone traps. The potential value of the parasitoid may be limited by the nil tolerance of the pest in export fruit, but pheromone trapping of this parasitoid could improve the understanding of biological control in non-export situations, w...

Field and Laboratory Responses of Male Codling Moth (Lepidoptera: Tortricidae) to a Pheromone-Based Attract-and-Kill Strategy

A case study of a pheromone-based attract-and-kill management strategy for codling moth, Cydia pomonella (L.), was conducted to examine key insect behavioral factors mitigating the possible effectiveness of this strategy. Last Call CM is a newly registered attracticide product that combines the primary component of codling moth sex pheromone with the insecticide permethrin. Studies of competition between pheromone point sources within caged trees showed individual attracticide droplets were significantly more attractive to male moths than calling females. In commercial orchard blocks, marked male moths were recaptured after visiting attracticide droplets applied at rates of 50, 100, and 200 droplets/ha, although no marked moths were recaptured in plots with 500 droplets/ha. This experiment also revealed no significant differences among 0, 50, 100, and 200 droplets/ha in suppressing total catch in female-baited traps, nor were total numbers of females attracting at least one male reduced significantly. In plots with 500 droplets/ha applied, male moth catch was suppressed significantly compared with catches in untreated control plots, and the number of females attracting at least one male was reduced significantly as well. Experiments investigating sublethal physiological effects of attracticide exposure upon mating competency of male codling moths demonstrated male leg autotomy at 1, 24, 48, and 72 h after exposure. Male codling moth at 1, 24, 48, and 72 h after exposure placed near calling virgin females exhibited significant behavioral differences from sham-treated males in courtship and mating. These results clarify some of the possible mechanisms, and strengths and weaknesses of this attract-and-kill management strategy for codling moth.

Population dynamics and natural mortality factors of the Oriental armyworm, Mythimna separata (Lepidoptera: Noctuidae), in South-Central India

The population dynamics and key mortality factors of the Oriental armyworm, Mythimna separata (Walker) (Lepidoptera: Noctuidae), a serious pest of cereal crops in Asia and Australia, were studied in southern India. Adults were generally caught in light traps 15–20 days after the initiation of the monsoon rains in the first week of June, and reached a peak in September, nearly one month after the peak in larval density. Rainfall, and maximum and minimum relative humidity were positively associated moth catches in the light traps, while maximum temperature, open pan evaporation, solar radiation, sunshine hours, and wind velocity showed a negative correlation with moth abundance. Stepwise regression analysis of moth catches with weather conditions over the previous 2 and 4 weeks explained 54–68% of the variation in the number of moths caught in the light traps. Five hymenopteran parasitoids [ Costesia ruficrus (Haliday), Metopius rufus Cameron, Disophyrys sp., Compoletis chlorideae Uchida, Enicospilus sp.], and five dipteran parasitoids [ Carcelia illota (Curran), Sturmiopsis inferens Townsend, Palexorista solennis (Walker), P. laxa (Curran), and Megasellia sp.], mermithid ( Neoplectana sp.), and nuclear polyhedrosis virus (NPV) regulated its populations under natural conditions. Parasitism levels were much greater in sorghum (34.6%) than in pearl millet (17.6%). Cotesia ruficrus was the principle mortality factor, which caused up to 47% parasitism in October. Its activity was greater in sorghum (24.6%) than in pearl millet (14.9%). This parasitoid species could be exploited for the biological control of this pest.

Relationship among abundance of yellow stem borer moths, egg population, and egg parasitism in rice

This paper studies the relationship among YSB moth catch in a light trap, egg mass density, and parasitism in the field to correlate light trap data with levels of pest eggs in the field and to learn whether parasites respond to increased egg density.

Day‐degree models for predicting the generation time and flight activity of local populations of Lobesia botrana (Den. & Schiff.) (Lep., Tortricidae) in Greece

The generation time of Lobesia botrana (Den. & Schiff.) was estimated as the number of day‐degrees required between the start of a flight and the start of the following flight in two regions in northern Greece. The day‐degrees required for the first generation (x=339.3, Naoussa; x=275.6, Thessaloniki) were significantly shorter than for the second (x=751.5, Naoussa; x=833.8, Thessaloniki) and the third generations (x=899.5, Naoussa; x=1197.0, Thessaloniki). Nonlinear models were developed using trap catches of male L. botrana during 1987–1989 for predicting its flight activity. A lower threshold temperature of 6.45°C was used in calculating daily day‐degrees from 1 March. The models predicted with sufficient accuracy the accumulated male moth catch and they accounted for the 60–78% and 86–91% of year‐to‐year variation in male flight activity in Thessaloniki and Naoussa, respectively.

Trapping Alfalfa Looper Moths (Lepidoptera: Noctuidae) with Single and Double Component Floral Chemical Lures

Abstract Both sexes of the alfalfa looper moth, Autographa californica (Speyer), were captured in traps baited with chemicals and combinations of chemicals that are odorants from “moth-visited” flowers. When presented alone, phenylacetaldehyde was strongly attractive and benzyl acetate was more weakly attractive to alfalfa looper moths. Few alfalfa looper moths were captured in traps baited with cis-jasmone, linalool, phenethyl alcohol, benzyl acetate or benzyl alcohol. In a comparison of varied amounts of phenylacetaldehyde, accomplished by varying the diameter of the hole in the lid of vial dispensers, greatest captures of alfalfa looper moths occurred with the largest hole size tested, 6.3 mm in diameter. Catches of alfalfa looper moths were enhanced when phenylacetaldehyde was presented with cis-jasmone and when benzyl acetate was presented along with benzaldehyde, compared with these chemicals presented singly.

Apple damage, pest phenology, and factors influencing the efficacy of tebufenozide for control of obliquebanded leafroller (Lepidoptera: Tortricidae).

Fruit damage by obliquebanded leafroller, Choristoneura rosaceana (Harris), was examined on four different apple cultivars during 1997-1999 in heavily infested orchards in New York State. Inital fruit damage occurred 354+/-26 degree-days base 6 degrees C (DD6) after the first moth catch from the overwintering generation and continued to increase until after the typical spray season (approximately 1,300 DD6). In addition to apple damage by late instars, fruit damage occurred by early instars of the summer and overwintering generations. The insect growth regulator tebufenozide was used as a model insecticide to determine how a slow-acting insecticide and its relative toxicity to early (neonate) and late (fourth and fifth) instars may influence the efficacy of sprays for the control of the obliquebanded leafroller. Because tebufenozide is a slow-acting compound, bioassays were conducted to determine what percentage of the total mortality to neonates occurs at each 24 h interval until 10 d. Based on a polynomial regression, half of the total mortality to larvae at the LC25, LC50, LL90 and LC99 occurred at 7.2, 5.0, 4.1, and 3.0 d, respectively. Late instars were three times more tolerant to tebufenozide than neonates.

Monitoring codling moth (Lepidoptera: Tortricidae) with passive interception traps in sex pheromone-treated apple orchards.

Male and female codling moth, Cydia pomonella (L.), were monitored with passive interception traps (PI-traps) in apple orchards treated with sex pheromone dispensers. The proportion of mated females recaptured by PI-traps was significantly higher than the proportion released after the release of both sexes into a codling moth-infested orchard. However, no significant difference occurred between the proportion of mated females recaptured and released when only females were released into uninfested orchards. Replicated nine-tree apple plots situated either on the edge or in the center ofpheromone-treated apple orchards were monitored with PI-traps during first moth flight in 1995 and during both flights in 1996. Moths caught on PI-traps were predominately males. The first male moths were captured 7-10 d before females during the first flight in both years. Initial capture of virgin and mated females on PI-traps coincided in 1995. Mated females were captured 14 d after the first virgin females in 1996. The mean proportion of females that were mated ranged from 32 to 55% during the first flight and 85 to 92% during the second flight. Moth catch and fruit injury were significantly higher in the edge versus the center plots. The numbers of total and female moths caught with PI-traps were significantly correlated with fruit injury for each generation. The percentage of female moths caught on PI-traps that were mated was 32% lower and the mean oocyte load of all females was 42% higher in a pheromone-treated apple orchard than in the untreated crabapple grove monitored during May and June 1997.

A Phenology Model for Seasonal Occurrence of Plodia interpunctella (Lepidoptera: Pyralidae) in Stored Product Storage

A phenology model of Indianmeal moth, Plodia interpunctella (Hübner), was constructed to predict the moth emergence in stored product storage. The moth emergence curve based on the physiological time (summation of developmental rate per day) could be well described by both Weibull function and Stinner function. The phenology on the basis of the models showed that the moth could have five to six generations per year, which agreed to the trends of the moth catch in the warehouses in Ansung and Taegu. The phenology model on the basis of Weibull function predicted generations with no overlap except of the first and second generations, whereas Stinner model showed generations with overlap. Although the moth generations overlapped, the peak time of the moth catch in the pheromone traps coincided with that predicted by the model on the basis of Weibull function. The results showed a possibility that continuous monitoring of temperature in a storage and prophylactic control of the moth on the basis of the phenology model could be a base of successful eradication of moth from stored food materials.

Phenological forecasting model for Cydia funebrana*

A simulation model of the phenology of Cydia funebrana (plum fruit moth) is presented. The Logan function was used to determine the temperature‐dependent developmental rates of the eggs, larvae and pupae; a linear equation was used for the ageing rate of females. The mean fecundity of females as a function of age was expressed by a modified Bieri's function. In order to simulate the stochastic process, a time‐distributed delay model was used. Results from the validation of the model in northern Italy (1995 and 1997) are reported. Catches of male moths in pheromone traps and oviposition activity were monitored in orchards of mid‐ and late‐ripening plum cultivars. The model was then run using temperature data from each farm. When the oviposition activity forecast by the model was compared with that actually observed in the orchards, good correlations between actual and forecast oviposition were obtained. The model is already available for technicians in Emilia‐Romagna and is a valuable tool in integrated fruit production; it gives an indication of the right moment to apply insecticides or to carry out further monitoring activity to assess the risk of C. funebrana damage (e.g. by sampling actual oviposition on just a single occasion).

On-farm evaluation of measures to monitor and control soybean pod-borer Etiella zinckenella in East Java, Indonesia

The incidence levels of moths and larvae of Etiella zinckenella were studied in the reproductive stage of soybean at eight farmers' field sites. A positive relationship was found between moths, caught by sweeping during flowering and pod-formation, and seed damage. Hence, rough predictions of damage can be made based on moth catches. Damage incidence was recorded in unsprayed plots and in plots sprayed with deltamethrin during flowering and pod-formation. Spraying did not affect the densities of moths and larvae or damage to pods and seeds. Larvae of H. armigera, Spodoptera litura and Plusiinae were not affected by spraying, but the pod-sucking bug Riptorus linearis, and two groups of predators, spiders and coccinellids, were reduced.