Moth Populations Research Articles

Nocturnal pollinators strongly contribute to pollen transport of wild flowers in an agricultural landscape.

Dramatic declines in diurnal pollinators have created great scientific interest in plant-pollinator relationships and associated pollination services. Existing literature, however, is generally focused on diurnal pollinating insect taxa, especially on Apidae (Hymenoptera) and Syrphidae (Diptera) pollinators, while nocturnal macro-moths that comprise extremely species-rich flower-visiting families have been largely neglected. Here, we report that in agricultural landscapes, macro-moths can provide unique, highly complex pollen transport links, making them vital components of overall wild plant-pollinator networks in agro-ecosystems. Pollen transport occurred more frequently on the moths' ventral thorax rather than on their mouthparts that have been traditionally targeted for pollen swabbing. Pollen transport loads suggest that nocturnal moths contribute key pollination services for several wild plant families in agricultural landscapes, in addition to providing functional resilience to diurnal networks. Severe declines in richness and abundance of settling moth populations highlight the urgent need to include them in future management and conservation strategies within agricultural landscapes.

Population genetics of the Mediterranean corn borer (Sesamia nonagrioides) differs between wild and cultivated plants.

The population genetic structure of crop pest populations gives information about their spatial ecology, which helps in designing management strategies. In this paper, we investigated the genetic structure of the Mediterranean Corn Borer (MCB), Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae), one of the most important maize pests in the Mediterranean countries, using microsatellite markers for the first time in this species. Insects were collected in twenty-five locations in southwest and southeast France from cultivated and wild host plants (Zea mays, Sorghum halepense and Typha domingensis). Contrary to what has been reported so far in France, we found that MCB populations could be locally abundant on wild poales plants. Analysis was carried out at 11 polymorphic microsatellite markers. Molecular variance was significantly determined by geography, then by host plant, with 17% and 4%, respectively, when considered as a major effect, and with 14% and 1%, respectively, when considered as a marginal effect in permutational analysis. Multidimensional scaling (MDS) and GENELAND Bayesian clustering suggested that populations infecting wild plants (T. domingensis and S. halepense) were more structured locally than those affecting cultivated maize. In S. halepense, significant Isolation By Distance (IBD) indicated that this factor could explain genetic differentiation of the moth populations. In T. domingensis, local population differentiation was strong but did not depend on distance. The implication of this absence of population structure in maize and the heterogeneity of population genetics patterns in wild plants are discussed in the context of the population dynamics hypothesis and population management strategies.

Efficacy of mating disruption compared with chemical insecticides for controlling Tuta absoluta (Lepidoptera: Gelechiidae) in Kuwait

The efficacy of mating disruption with Isonet®-T at the rate of 30, 45 or 60 g a.i. ha –1 of sex pheromone to control Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in greenhouse tomato crops was compared with conventional insecticides (flubendiamide, 60 mg L–1 and azadirachtin, 3 g L–1) in winter and summer. In both trials, significantly fewer moths were captured in mating disruption and insecticide-treated plots compared with the control. Differences in male captures between plots disrupted with 60 g a.i. ha –1 of sex pheromone and the insecticide-treated was significant only in summer. In plots disrupted with 60 g a.i. ha –1 of sex pheromone, male captures were significantly reduced by 90% in both trials. No significant differences were found in foliage and fruit damage between plots disrupted with 60 g a.i. ha –1 of sex pheromone and the insecticide-treated. The lower pheromone doses did not achieve a reduction in moth population, foliage, or fruit damage compared with the high pheromone dose or the insecticide treatments. The results suggest that mating disruption applied at high doses could be as effective as insecticides in managing T. absoluta, and could serve as a key component of an IPM program for the pest.

Molecular phylogeny of the yellow peach moth, Conogethes punctiferalis (Lepidoptera: Crambidae): distribution of two genetic lineages across Japan

Mating disruption using synthetic sex pheromones is an effective pest-control method to prevent the evolution of insecticide resistance. Although the sex pheromone of the yellow peach moth Conogethes punctiferalis (Guenee) (Lepidoptera, Crambidae) has already been identified and artificially synthesized, mating disruption in the field has been less successful than expected. Such ineffectiveness may be caused by genetic variation in the attractiveness of the sex pheromone across moth populations. To evaluate this possibility, we evaluated the genetic population structure of this species across 10 populations in Japan. We found that two clades were present at the mtDNA COI region, each clade was sympatrically distributed, and no genetic structure was detected among the populations. In addition, the frequencies of the two clades did not differ between the samples in pheromone traps using two types of blend and those hand collected from infested fruit. Our mating experiment revealed random mating between the two clades. Our results strongly suggest that the genetic variation in the attractiveness of the sex pheromone is minimal and symmetrical gene flow likely occurs between the clades in the field.

Efficient hybrid algorithm based on moth search and fireworks algorithm for solving numerical and constrained engineering optimization problems

The moth search algorithm (MS) is a novel intelligent optimization algorithm based on moth population behavior, which can solve many problems in different fields. However, the algorithm is easy to fall into local optimization when solving complex optimization problems. This study develops a new hybrid moth search-fireworks algorithm (MSFWA) to solve numerical and constrained engineering optimization problems. The explosion and mutation operators from the fireworks algorithm are introduced into the MS, which not only preserves the advantages of fast convergence and strong exploitation capability of the algorithm, but also significantly enhances the exploration capability. The performance of the MSFWA is tested using 23 benchmark functions. The hybrid algorithm is superior to other highly advanced metaheuristic algorithms for most benchmark functions, demonstrating the characteristics of fast convergence and high stability. Finally, the ability of the MSFWA to solve practical constrained problems is evaluated on six well-known engineering application problems. Compared with other optimization algorithms, the MSFWA is very competitive in its solution of these complex and constrained practical problems.

Comparing Asian Gypsy Moth [Lymantria dispar asiatica (Lepidoptera: Erebidae) and L. dispar japonica] Trap Data From East Asian Ports With Lab Parameterized Phenology Models: New Tools and Questions

Abstract Management of the European gypsy moth [Lymantria dispar dispar (Linnaeus)] in North America has benefited from more than a century of research. The East Asian strains of the gypsy moth, however, bring new challenges including multiple subspecies (Lymantria dispar asiatica Vnukovskij and Lymantria dispar japonica Motschulsky), broad distributions across heterogeneous habitats, and a lack of data on the variation in the phenology of source populations, which may affect risk. To address these issues, published phenology parameters for eight populations of Asian gypsy moth were used to develop eight strain-specific agent-based phenological models. These models were applied to 47 ports in East Asia where the Asian gypsy moth is native, and output was compared with available trap data to assess the role of interpopulation variation in phenological parameters in predicting moth flight among varied locations, assess variation in the performance of models among years, and assess the importance of modeling phenology using parameters from a ‘local’ moth population. Variation in phenological parameters among the eight populations yielded variation in predicted flight times among the 47 ports analyzed, and the use of ‘local’ populations did not generally improve model fit. Model accuracy varied substantially among ports and among years within some ports. The larva-to-adult agent-based models described here have utility in estimating flight periods for some ports in their current form, but variation in model quality across the landscape suggests that there is potential for unsampled and unparameterized moth populations and factors that remain to be quantified.

Effect of soil treatment on pest infestation and crop disease distribution in black soil fields with short rotation crops

We have established the influence of four tillage systems on pest distribution and development of diseases in cultivated cereals during three-year research (2017-2019) in the field stationary of the Bila Tserkva National Agrarian University, Ukraine (chernozem grain sprouting with five-course rotation). The population of turnip moth in winter wheat, spring barley, and soya was the highest under application of disk tillage, the lowest – under moldboard tillage. The moldboard treatment limited while the beardless and disk treatments stimulate the development of beet webworm in the cereal crops. The number of pests in soya, winter wheat, spring barley, and maize was higher under combined soil treatment compared to moldboard. We recorded no significant difference in pests towards tillage systems in sunflower crops. In soya, winter wheat and maize crops, the number of wireworm was significantly higher in molded than in molded cultivation; the opposite pattern was observed in the sunflower field, while for spring barley these values were at the same level. The distribution and development of root rot in cereal crops was higher in comparison with control, but this difference was insignificant in spring barley. The development of powdery mildew in spring barley crops was almost the same for these tillage options. In cereal crops, septoriosis lesions were almost at the same level in case of moldboard and combined tillage. Significant deterioration of phytosanitary condition at beardless and disk tillage resulted in significant reduction of crop rotation productivity in comparison with control. In the fields with combined and disk treatments, the productivity value was almost the same.

Habitat fragmentation and eradication of invading insect herbivores

Abstract Invasions by non‐native pests and diseases represent serious threats to biodiversity, agriculture and human health. Under current border arrival rates associated with international trade not all such invasions can be prevented, so early detection and eradication (forced extinction) are important strategies for preventing establishment and long‐term impacts. Removal of host plants has historically been a common tool used alone and in concert with other tools for eradication of plant pests but there is little scientific theory specific to the management of invasive species to guide the application of this eradication strategy. We drew upon extensive conservation biology literature documenting the effect of habitat destruction or fragmentation driving extinction. We applied a previously developed spatially explicit model of gypsy moth, Lymantria dispar, spatial dynamics to explore how fragmentation affects population persistence. This model accounts for a component Allee effect driven by mate‐finding failure that interacts with dispersal. We observed a nonlinear dependency of population persistence on the fraction of habitat cover and the level of habitat fragmentation. Simulation of active habitat fragmentation via the removal of habitat in swaths of varying widths or the application of pesticide in varying swaths showed that removal of hosts or pesticide application in narrow swaths (i.e. 40 m wide) caused the greatest probabilities of extinction. Generally, habitat removal was more effective than one‐off pesticide treatments at causing extinction. Synthesis and applications. Spatially explicit modelling of Allee dynamics in invading gypsy moth populations showed that host removal can be an effective method to eradicate invasive plant‐feeding insects especially when habitat fragmentation is applied at a desirable level. Furthermore, this can be used as an alternative to, or in conjunction with, pesticide treatments, to provide more options for carrying out eradications and to increase the probability of eradication success.

Short term effects of Bacillus thuringiensis and diflubenzuron aerial applications on non-target arthropods in a Mediterranean Forest

Several products are widely used to control gypsy moth (Lymantria dispar) populations. The main purpose of the present study is to evaluate the aerial application effects of B. thuringiensis and diflubenzuron on non-target arthropods in a Mediterranean holm-oak forest. The density of gypsy moth population at the time of application of treatments was the same in the three forests and the defoliation levels in the three holm-oak forests were between level 0 (no apparent defoliation) and level 1 (small defoliations of new leaf). Sampling litter, soil, ground-dwelling, and epiphytic arthropods showed that the holm-oak forests treated with diflubenzuron had a better quantitative faunal outcome than the Control, whereas the highest taxonomic diversity was found in the site treated with B. thuringiensis. These results could probably be explained by a temporary competitive decrease due to the huge number of gypsy moth caterpillars on plants, as well as the enormous accumulation of their excrements in the soil during a prolonged period of time.

Locomotor response of diamondback moth (Plutella xylostella) populations to a neurotoxic insecticide under laboratory conditions

ABSTRACT: The present study aimed to evaluate changes in the locomotor activity of diamondback moth (Plutella xylostella) populations exposed to surfaces treated with the insecticide chlorantraniliprole under laboratory conditions. Diamondback moth populations from municipalities incorrectly using the insecticide [Camocim de São Félix, PE (CSF); Sairé, PE (SR); and Lajedo, PE (LJ)] and two laboratory populations from Recife, PE (RCF), and Viçosa, MG (VÇS) were exposed to dry insecticide residues in increasing concentrations. The following behavioral parameters of the populations were analyzed: walking time (WT), mean walking speed (MWS), and rest time (RT). Regarding RT, the SR and CSF populations demonstrated a behavior of irritability and increased WT with increased exposure concentration. The RCF population presented a contrasting response. The MWS values in the SR and CSF populations showed a decreasing trend with increased exposure concentration. The LJ and RCF populations showed no changes in terms of MWS. The RT values in the SR population decreased with increased insecticide concentration. In general, the SR and CSF populations presented a behavioral pattern different from that of laboratory populations. The changes in locomotor activity observed may result in lower control efficacy of the insecticide due to repellency or escape of insects. Regarding the effect of insecticide concentrations used in the populations, a defined pattern was not observed, and the effect alternated between an increase, a decrease, and an undefined pattern for the variables studied.

Population dynamics of brinjal shoot and fruit borer Leucinodes orbonalis guenée

The effect of abiotic factors on population dynamics of brinjal shoot and fruit borer Leucinodes orbonalis during summer was observed on brinjal. The trap catch revealed that the moth population was active throughout the cropping season and it had a peak of 13.42 moths/trap/day during 19th standard week (second week of May) whereas the effect of weather factors on trap catch was found to be non-significant. The shoot damage was observed only during initial periods which reduced with fruiting. The shoot damage showed a significant positive correlation with maximum and minimum temperature; negative one with morning and evening relative humidity; however the damage on fruits showed an increasing trend during initial periods which reduced later on, and revealed only a non-significant correlation with weather factors.

Популяция кольчатого шелкопряда (Malacosoma neustria L., Lasiocampidae, Lepidoptera) во время эруптивной фазы

Популяция кольчатого шелкопряда (Malacosoma neustria L., Lasiocampidae, Lepidoptera) во время эруптивной фазы

Cocoon quantitative traits and grainage behaviour in Jhanji crop of wild Modal ecorace of Tasar silkworm in Similipal

The present study describes the quantitative cocoon traits and egg production behaviour during Jhanji crop in three different locations. The wild cocoons were kept in pagoda during March and quantitative cocoon traits were recorded. The results indicated wide range of variation for all traits except shell ratio. The pupal weight and cocoon volume values were highest at Kendujauni than Sarat and Astabeda. In case of female, cocoon weight, pupal weight and cocoon volume values were significantly highest at Kendujauni followed by Sarat and lowest at Astabeda. Shell weight and cocoon length values were significantly highest for Kendujuani where as Sarat and Astabeda were at par. The grainage parameters were recorded from April to June. A total of 2111, 1803 and 1876 female moths emerged in Kendujuani, Sarat and Astabeda, respectively. The total number of couplings were 1405 (66.56%), 1158 (64.23%) and 898 (47.87%) respectively. From this it is evident that availability of wild males in the forest of Astabeda area of Similipal is significantly less. The pattern of emergence at one week interval also varied, early mass emergence followed by one more peak in June was recorded in Astabeda and Kendujuani. But in Sarat, almost uniform emergence with one peak in June was recorded. Thus, more attention is warranted for the proliferation of wild silk moth populations in Astabeda and eastern part of Similipal.

Classroom education effect evaluation model based on MFO intelligent optimization algorithm

In order to improve the evaluation effect of classroom education, this paper proposes the MFO intelligent optimization algorithm based on the idea of machine learning, and builds the classroom education effect evaluation model based on the MFO intelligent optimization algorithm. Moreover, this paper uses a logarithmic spiral to simulate the path of the moth to the flame and invert the pending parameters in the mathematical model, and adds vertical and horizontal algorithms and chaos operators on this basis. The crisscross algorithm allows different moth individuals and the same moth to perform cross calculations with different computing dimensions to increase the diversity of moth populations, so that moths in the search space can traverse the entire search space as much as possible to find a better solution. Moreover, in view of the problems of BP neural network such as low fitting accuracy, this paper applies the CCMFO algorithm to improve the BP neural network to form the CCMFO-BP algorithm, and improves the weight and threshold update process of the BP neural network to make the network operation more efficient and accurate. Finally, this paper designs experiments to analyze the performance of the model constructed in this paper. The research results show that the model constructed in this paper meets the expected requirements.

From a rare inhabitant into a potential pest – status of the nun moth in Finland based on pheromone trapping

Forests are affected by climate change in various ways. This includes abiotic factors such as droughts, but also biotic damage by pest insects. There are numerous examples from cases where pest insects have benefitted from longer growing seasons or from warmer summers. Similarly, new pest insects have been able to expand their range due to climatic conditions that have changed from hostile to tolerable. Such seems to be the case with the nun moth (), an important defoliator of coniferous trees in Europe. For centuries, the species has had massive outbreaks across Central-Europe, while it has been a rare inhabitant in Northern Europe. Recently, the nun moth population in Finland has not only expanded in range, but also grown more abundant. This research note describes the results from the first years (2018–2019) of a monitoring program that is being conducted with pheromone traps across central and southern Finland. So far, the northernmost individuals were trapped near the 64 N degrees. However, there were more southern locations where no moths were trapped. The species was present in every trapping site below the latitude of 62 N degrees. More importantly, at some sites the abundance of the nun moth suggested that local forest damage may already occur. Given the current climatic scenarios for Fennoscandia, it is likely that the nun moth populations will continue to grow, which is why systematic surveys on their abundance and range expansions will be topical.Lymantria monacha

Effect of Diallyl Trisulfide on the Reproductive Behavior of the Grain Moth, Sitotroga cerealella (Lepidoptera: Gelechiidae).

The Angoumois grain moth, Sitotroga cerealella (Olivier, 1789) (Lepidoptera: Gelechiidae), is primarily a pest of stored products, that feeds inside the grain as larvae inducing significant economic loss in various stored commodities. Our previous studies proved that garlic essential oil and its active substances inhibit oviposition in moths. To further explore the effect on reproductive behavior and accurately interpret the results in terms of effective control of the moth population, moths were treated with diallyl trisulfide (DATS), an active substance of garlic essential oil, at a dose of 0.015 µL/L in air (LC20, sub-lethal concentration). The results showed that fecundity and the proportion of viable eggs significantly decreased when the moths were treated with LC20 DATS. Furthermore, female circadian mating rhythms and calling periodicity changed significantly after treatment. Compared with controls, the peak in mating occurred approximately 1 h earlier on the first day after DATS treatment, while it was significantly later on days 2 and 3. Moreover, mating frequency declined in presence of DATS compared with the controls. The percentage of females engaging in calling behavior decreased significantly with time, to less than 50%, 2 days after treatment, while a high calling percentage (>80%) was recorded for control moths on all 4 days. In addition, DATS had an inhibitory effect on the mating duration of S. cerealella. Moreover, a significant reduction was observed in the amount of sex pheromones extracted 8 h and 9 h after treatment. Our findings suggested that DATS has the potential to manipulate the moth population at LC20 and would be an efficient alternative to synthetic insecticides for the control of pests having low toxicity to non-target organisms and ecosystems.

Prototype Spatio-temporal Predictive System of pest development of the codling moth, Cydia pomonella, in Kazakhstan

Summary A prototype for pest development stages forecasting is developed in Kazakhstan exploiting data from the geoinformation technologies and using codling moth as a model pest in apples. The basic methodology involved operational thermal map retrieving based on MODIS land surface temperature products and weather stations data, their recalculation into accumulated degree days maps and then into maps of the phases of the codling moth population dynamics. The validation of the predicted dates of the development stages according to the in-situ data gathered in the apple orchards showed a good predictivity of the forecast maps. Predictivity of the prototype can be improved by using daily satellite sensor datasets and their calibration with data received from a network of weather stations installed in the orchards.

Something old, something new: revisiting the diamondback moth (Lepidoptera: Plutellidae) life table after 65 years

AbstractNearly 65 years ago, D.G. Harcourt developed the first of 74 life tables of the diamondback moth, Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae), on the Central Experimental Farm in Ottawa, Ontario, Canada and at nearby sites. This work is cited whenever authors discuss the life history of the diamondback moth and its parasitoids in Canada. Since Harcourt’s study, climate change, urbanisation, and crop diversity may have altered the population dynamics of both the diamondback moth and its natural enemy community in the original study area. To follow up on Harcourt’s work, we used two approaches to build life tables to describe mortality factors in the field and the natural enemies attacking diamondback moth in Ottawa: destructive sampling of mature cabbage, Brassica oleracea Linnaeus (Brassicaceae), plants similar to Harcourt’s approach and a modern sentinel-based approach with an enemy exclusion cage treatment. After 65 years, the primary parasitoids attacking diamondback moth remained the same, although more parasitoid diversity was revealed by the destructive sampling technique. Total mortality and parasitism levels also remained similar. In one notable difference, we attributed more diamondback mortality to predation. Overall, however, diamondback moth population dynamics have changed little in Ottawa in the decades since Harcourt’s studies.

A DNA-based description of a new carpenter moth species (Lepidoptera: Cossidae) from Morocco.

We used a combination of morphological data (genitalia structure) and a molecular marker (a 658bp fragment of the COI gene) to demonstrate that carpenter moth populations from central and southern Morocco, previously identified as Cossus cossus (Linnaeus, 1758) based on external morphology, represent a new species, described herein as C. romantsovi Yakovlev Shapoval, sp. n. The genetic divergence of the new species with respect to other members of genus Cossus is significant and includes at least 23 fixed nucleotide substitutions in the 658 bp of the COI barcode.

Identification of winter moth (Operophtera brumata) refugia in North Africa and the Italian Peninsula during the last glacial maximum.

Numerous studies have shown that the genetic diversity of species inhabiting temperate regions has been shaped by changes in their distributions during the Quaternary climatic oscillations. For some species, the genetic distinctness of isolated populations is maintained during secondary contact, while for others, admixture is frequently observed. For the winter moth (Operophtera brumata), an important defoliator of oak forests across Europe and northern Africa, we previously determined that contemporary populations correspond to genetic diversity obtained during the last glacial maximum (LGM) through the use of refugia in the Iberian and Aegean peninsulas, and to a lesser extent the Caucasus region. Missing from this sampling were populations from the Italian peninsula and from North Africa, both regions known to have played important roles as glacial refugia for other species. Therefore, we genotyped field‐collected winter moth individuals from southern Italy and northwestern Tunisia—the latter a region where severe oak forest defoliation by winter moth has recently been reported—using polymorphic microsatellite. We reconstructed the genetic relationships of these populations in comparison to moths previously sampled from the Iberian and Aegean peninsulas, the Caucasus region, and western Europe using genetic distance, Bayesian clustering, and approximate Bayesian computation (ABC) methods. Our results indicate that both the southern Italian and the Tunisian populations are genetically distinct from other sampled populations, and likely originated in their respective refugium during the LGM after diverging from a population that eventually settled in the Iberian refugium. These suggest that winter moth populations persisted in at least five Mediterranean LGM refugia. Finally, we comment that outbreaks by winter moth in northwestern Tunisia are not the result of a recent introduction of a nonnative species, but rather are most likely due to land use or environmental changes.