Flighted spongy moths (Lepidoptera: Erebidae), defoliating invasive forest pests

2 Abstract: Female gypsy moths, Lymantria dispar dispar (Linnaeus, 1758), commonly deposit their egg masses on tree trunks in Europe and North America. However, in northern Japan (Hokkaido and northern Honshu) females of L. umbrosa (Butler, 1881) and L. dispar japonica (Motschulsky, 1860) show a strong preference for white birch, Betula platyphylla Sukatschev var. japonica (Miq.) Hara (Betulaceae), trunks. In those areas of Japan where white birches are absent, it has been unclear where most oviposition occurs. In southern part of Hiroshima Prefecture, southwestern Japan, where evergreen broad-leafed trees exist, a preliminary egg mass survey failed to find egg masses on any tree trunks. Subsequently an intensive survey of 1115 individual trees (of 36 different species) in three broad-leafed forest plots found 126 egg masses of which 125 (99.2%) were on Quercus glauca (Thunb.) (Fagaceae), Camellia japonica L. (Theaceae), Eurya japonica Thunb. (Theaceae), or Ilex purpurea Hassk (Aquifoliaceae), and 111 egg masses were positioned on the undersurface of new- growth Q. glauca leaves. In southern part of Hiroshima Prefecture, gypsy moth egg mass surveys in the future should focus on the evergreen leaves of broad-leaved trees, especially Q. glauca.

Studies were conducted in Maryland between 1984 and 1988 using racemic disparlure to manage gypsy moth, Lymantria dispar (L.), populations at low levels. Laminated plastic dispensers were manually applied in 1984, 1986, and 1988 at a dose rate of 50 g (AI)/ha (release rate of 12.0 g/ha/yr; 100 release points/hal. Biological effects were measured as reduction of male trap catch in (+)-disparlure traps and mating of monitor females. Efficacy was measured by intensive annual egg mass surveys. Significant reductions in male trap catch and mating of females clearly demonstrated that the disruptant remained biologically active for two consecutive seasons. Nevertheless, egg mass surveys showed that repeated applications of racemic disparlure failed to maintain gypsy moth populations at low levels over the 5-yr period. We attributed lack of efficacy to inadequate levels of mating disruption during peak male activity, ineffective permeation of disruptant throughout the upper canopy of trees, and close proximity of treated woodlots to dense gypsy moth populations. Improvements in the efficacy of this technique might be achieved by higher application rates of plastic laminated tape, identification of formulations which deliver higher release rates (particularly during peak male flight) and use of this tactic only on isolated populations.

Simple SummaryThe brown marmorated stink bug, Halyomorpha halys, is an invasive pest species of global economic importance. It has a very broad host range and causes severe damages in agricultural, horticultural, and fruit crops. Control measures, including available chemical and mechanical options, have often proved insufficient. Surveys of natural enemies in the newly invaded areas have also shown that natural biological control is generally too low to control H. halys populations in the long run. In its native Asian range, egg parasitoids in the genus Trissolcus play an important role in controlling H. halys. Since the mid-2010s, adventive populations of Trissolcus japonicus, a dominant egg parasitoid of H. halys in Asia with a narrow host range, have been reported from several countries with prior establishment of H. halys. Here, we report the first discovery of T. japonicus in Germany. This finding corroborates a northbound expansion of the range of T. japonicus in Europe, along with H. halys.The brown marmorated stink bug, Halyomorpha halys, is a polyphagous pest species of worldwide economic importance. Since the mid-1990s, it has invaded and become established in various countries outside its native Asian range. In the newly invaded areas, biological control by native natural enemies has been shown to be insufficient in the long-term control of this severe pest. Adventive populations of Trissolcus japonicus, an important biological control agent of H. halys in Asia, have been reported from North America and some European countries since the mid-2010s. This egg parasitoid species seems to follow in the wake of the establishment of H. halys populations outside their native Asian range. Here, we report the first discovery of an adventive population of T. japonicus in Germany. In 2020, adult T. japonicus were recovered from parasitized H. halys egg masses (naturally laid and sentinel egg masses) and collected in ruderal areas using an insect suction sampler. The arrival of T. japonicus in Germany, unintentional through pathways yet unknown, corroborates a northbound expansion of its range within Europe. Further field surveys will show the extent of its dispersal and establishment capacities within this new distribution area.

In insects, flight and sophisticated olfactory systems go hand in hand and are essential to survival and evolutionary success. Females of many Lepidopteran species have secondarily lost their flight ability, which may lead to changes in the olfactory capabilities of both larval and adult stages. The gypsy moth, Lymantria dispar, an important forest pest worldwide, is currently undergoing a diversification process with three recognized subspecies: the Asian gypsy moth (AGM) L. dispar asiatica, the Japanese gypsy moth L. dispar japonica (JGM) and the European gypsy moth (EGM) L. dispar dispar. Females of EGM populations from North America have lost their flight capacity whereas the JGM and AGM females are flight capable, making this an ideal system to investigate the relationship between flight and olfaction. We used next-generation sequencing to obtain female antennal and larval head capsule transcriptomes in order to (i) investigate the differences in expression of olfaction-related genes among populations; (ii) identify the most similar protein sequences reported for other organisms through a BLAST search, and (iii) establish the phylogenetic relationships of these sequences with respect to other insect species. Using this approach, we identified 115 putative chemosensory genes belonging to five families of olfaction-related genes. A principal component analysis revealed that the gene expression patterns of female antennal transcriptomes from different subspecies were more similar among them than to the larval head capsules of their respective subspecies supporting strong chemosensory differences between the two developmental stages. An analysis of the shared and exclusively expressed genes for three populations shows no evidence that loss of flight affects the number or type of genes being expressed. These results indicate either that (a) loss of flight does not impact the olfactory gene repertoire or that (b) the secondary loss of flight in the American EGM populations may be too recent to have caused major changes in the genes being expressed. However, we found higher expression values for IRs, OBPs GRs and ORs in EGM females, suggesting that differences in transcription rates could be an adaptation of flightless females to their chemical environment. Differences in olfactory genes and their expression in the

The gypsy moth, Lymantria dispar (L.) (Lepidoptera: Erebidae), is a non‐native defoliating insect that continues to expand its range in North America and undergo periodic outbreaks. In management efforts to suppress outbreaks, slow its spread and eradicate populations that arrive outside of the invaded range, aerial deployments of mating disruption tactics and pesticides are generally used. However, in some cases, such as in heavily urbanized areas or other landscapes where aerial deployments are not feasible or permitted, ground applications are required. Ground applications tend to be labour‐intensive to ensure adequate coverage. To better inform optimal deployment of ground applications of mating disruption, we measured the effectiveness of a pheromone formulation designed for ground application, SPLAT® GM, in forested areas of Virginia from 2011 to 2014 using different dosages and number of point applications. We observed that SPLAT® GM applied to the tree trunks at the dosages of 49.4 and 123.6 g AI/ha in 11 × 11 systematic grids (i.e., every 11 m) reduced male trap catch by >90% relative to untreated control plots, which based on previous studies corresponds to >95% reduction in gypsy moth mating success. Our observations suggest that ground applications of gypsy moth mating disruption can be a successful management tool when circumstances require it.

In zebrafish, the expression of long-wavelength cone (LC) opsin mRNA fluctuated rhythmically between the day and night. In a 24-h period, expression was high in the afternoon and low in the early morning. This pattern of fluctuation persisted in zebrafish that were kept in constant darkness, suggesting an involvement of circadian clocks. Functional expression of Clock, a circadian clock gene that contributes to the central circadian pacemaker, was found to play an important role in maintaining the circadian rhythms of LC opsin mRNA expression. In zebrafish embryos, in which the translation of Clock was inhibited by anti-Clock morpholinos, the circadian rhythms of LC opsin mRNA expression diminished. CLOCK may regulate the circadian rhythms of LC opsin mRNA expression via cyclic adenosine monophosphate (cAMP)-dependent signaling pathways. In control retinas, the concentration of cAMP was high in the early morning and low in the remainder of the day and night. Inhibition of Clock translation abolished the fluctuation in the concentration of cAMP, thereby diminishing the circadian rhythms of opsin mRNA expression. Transient increase of cAMP concentrations in the early morning (i.e. by treating the embryos with 8-bromo-cAMP) restored the circadian rhythms of LC opsin mRNA expression in morpholino-treated embryos. Together, the data suggest that Clock plays important roles in regulating the circadian rhythms in photoreceptor cells.

Pulmonary function has circadian rhythm in humans proven in diseased in conditions. These variations will contribute to better understanding the relationship between biorhythms and lung physiology for better management of pulmonary diseases.To study PFT in medical students during different time of the day and to study whether there is diurnal variation in PFT. The I MBBS students chosen as subjects were apparently normal and non-smokers. The study group included 113 students. They underwent PFT during different time of the day, i.e. at 6am, 11am, 4pm and 9pm. PFT was done using computerized Spirometer and the parameters studied were FEV1, FVC, FEV1/FVC, PEF, FEF2575% and FEF.2-1.2L. The data was tabulated and statistically analyzed. There were changes in all the PFT parameters recorded during different time of the same day. Mean of FEV1 and FVC were highest in the recording taken at 9:00pm. % change noted was 1.74% and 1.32% respectively, when compared to the recording at 6:00am. Mean of FEV1/FVC ratio also showed diurnal rhythm with highest % at 11:00am and lowest % at 6:00am. The % change noted was 0.76%. Mean of PEFR, FEF25-75% and FEF0.2-1.2L showed diurnal rhythm. They were high in the recording done at 4:00pm and low in the recording done at 6:00am. % change noted in PEFR, FEF25-75% and FEF.2-1.2L were 2.25%, 3.66% and 2.08% respectively. % change noted for each parameter was statistically not significant. The diurnal variation in PFT parameters is noted in healthy subjects. The % change noted is minimal in young healthy individuals. This diurnal rhythm amplitude increase in asthma and bronchitis patients.

Global phylogeography reveals the origin and the evolutionary history of the gypsy moth (Lepidoptera, Erebidae)

It is necessary to distinguish new and old gypsy moth, Lymantria dispar (L.), egg masses when conducting gypsy moth population surveys. Egg masses within reach from the ground are touched to determine if they contain unhatched eggs and thus are considered new. The following 2 methods are used for egg masses not within reach: (1) visual discrimination between new and old egg masses or (2) by calculating the percentage of new egg masses at ground level and using this value to adjust counts of all egg masses not within reach. To evaluate these methods, egg-mass persistence and color between generations, the percentage of new and old egg masses at ground level and in the canopy, the ability of observers to visually distinguish new and old egg masses, and the effect of errors on the accuracy of estimates of the percentage of new egg masses was examined. Fifty-five percent of exposed new egg masses studied were still at least 25% intact at the time of the following year's egg-mass survey. However, the color of the egg masses was markedly lighter, providing a mechanism for visually distinguishing new and old egg masses. When egg masses are visually distinguished as new or old with an error rate >0, the resulting estimate of the percent new egg masses is usually biased. The magnitude of the bias varies with the rate of error and the actual percentage of new egg masses in the population, and can result in serious reductions in the accuracy of these estimates. In a field evaluation, new egg masses were incorrectly classified as old 16% of the time and old egg masses were incorrectly classified as new 16% of the time. Because it is unbiased, use of the ratio method to estimate the percentage of new egg masses is recommended whenever 10 or more egg masses are within reach from the ground.

Preventing the introduction and establishment of forest invasive alien species (FIAS) such as the Asian gypsy moth (AGM) is a high-priority goal for countries with extensive forest resources such as Canada. The name AGM designates a group of closely related Lymantria species (Lepidoptera: Erebidae: Lymantriinae) comprising two L. dispar subspecies (L. dispar asiatica, L. dispar japonica) and three closely related Lymantria species (L. umbrosa, L. albescens, L. postalba), all considered potential FIAS in North America. Ships entering Canadian ports are inspected for the presence of suspicious gypsy moth eggs, but those of AGM are impossible to distinguish from eggs of innocuous Lymantria species. To assist regulatory agencies in their identification of these insects, we designed a suite of TaqMan® assays that provide significant improvements over existing molecular assays targeting AGM. The assays presented here can identify all three L. dispar subspecies (including the European gypsy moth, L. dispar dispar), the three other Lymantria species comprising the AGM complex, plus five additional Lymantria species that pose a threat to forests in North America. The suite of assays is built as a “molecular key” (analogous to a taxonomic key) and involves several parallel singleplex and multiplex qPCR reactions. Each reaction uses a combination of primers and probes designed to separate taxa through discriminatory annealing. The success of these assays is based on the presence of single nucleotide polymorphisms (SNPs) in the 5’ region of mitochondrial cytochrome c oxidase I (COI) or in its longer, 3’ region, as well as on the presence of an indel in the “FS1” nuclear marker, generating North American and Asian alleles, used here to assess Asian introgression into L. dispar dispar. These assays have the advantage of providing rapid and accurate identification of ten Lymantria species and subspecies considered potential FIAS.

The gypsy moth, Lymantria dispar L., is one of the most destructive forest pests in the world. While the subspecies established in North America is the European gypsy moth (L. dispar dispar), whose females are flightless, the two Asian subspecies, L. dispar asiatica and L. dispar japonica, have flight-capable females, enhancing their invasiveness and warranting precautionary measures to prevent their permanent establishment in North America. Various molecular tools have been developed to help distinguish European from Asian subspecies, several of which are based on the mitochondrial barcode region. In an effort to identify additional informative markers, we undertook the sequencing and analysis of the mitogenomes of 10 geographic variants of L. dispar, including two or more variants of each subspecies, plus the closely related L. umbrosa as outgroup. Several regions of the gypsy moth mitogenomes displayed nucleotide substitutions with potential usefulness for the identification of subspecies and/or geographic origins. Interestingly, the mitogenome of one geographic variant displayed significant divergence relative to the remaining variants, raising questions about its taxonomic status. Phylogenetic analyses placed this population from northern Iran as basal to the L. dispar clades. The present findings will help improve diagnostic tests aimed at limiting risks of AGM invasions.

Female Ooencyrtus kuvanae (Howard) were attracted to odors from gypsy moth, Lymantria dispar (L.), egg masses in a 4-way olfactometer. Responses to egg mass odors varied with the difference of larval diet of the host. The number of gypsy moth generations on a particular larval diet also appeared to affect parasitoid orientation to the resulting egg masses. The plant species on which gypsy moth larvae fed affected characteristics of both the egg masses and the emerging wasps. Gypsy moth egg masses derived from plant-fed larvae had larger, but fewer, eggs than those derived from larvae fed artificial diet. The effects of host larval food on egg parasitoid emergence appeared in the 2nd generation, apparently because wasp developmental substrate affected their fecundity. O. kuvanae that developed in eggs derived from oak-fed gypsy moths produced more offspring than those that developed in eggs derived from tamarack-fed gypsy moths, regardless of subsequent ovipositional substrate. The offspring sex ratio was influenced by the ovipositional and parental substrates. The proportion of females was highest in larval treatments and egg mass sections that yielded the largest eggs. O. kuvanae generally parasitized more eggs in the section of the egg mass that was laid first by the gypsy moth.

ECOSTRESS estimates gross primary production with fine spatial resolution for different times of day from the International Space Station

We studied predation of gypsy moth, Lymantria dispar (L.), egg masses in two study areas. In Connecticut, individual egg masses were mapped and examined from February to April. Predation rate, expressed as the mean amount removed from an individual egg mass, increased gradually from 30% in February to 53% in April. The percentage of all egg masses upon which some predation was observed increased from 67% to 89% over the same period. Sixteen of 105 egg masses were completely destroyed. Three species of birds were observed feeding on egg masses in the field. In an aviary study, four out of five bird species fed on egg masses with and without alternative foods. Three species of captive small mammals never ate egg masses. In West Virginia, an exclosure experiment revealed that vertebrate predators accounted for 9.3% of egg mass predation from August to April, whereas invertebrates accounted for only 1.5%. Only 5 of 146 egg masses were completely destroyed. Although it is theoretically possible that mammals were responsible for some predation, the gradual nature of egg removal, direct observations of avian predation, and the fact that no mammal has ever been observed to eat an egg mass in field or laboratory leads us to believe that birds were responsible for the observed predation. We conclude that egg mass predation is a variable but potentially important gypsy moth mortality factor worthy of further study.

Interest in seasonally flooded pools, and the status of associated amphibian populations, has initiated programs in the northeastern United States to document and monitor these habitats. Counting egg masses is an effective way to determine the population size of pool-breeding amphibians, such as wood frogs (Rana sylvatica) and spotted salamanders (Ambystoma maculatum). However, bias is associated with counts if egg masses are missed. Counts unadjusted for the proportion missed (i.e., without adjustment for detection probability) could lead to false assessments of population trends. We used a dependent double-observer method in 2002–2003 to estimate numbers of wood frog and spotted salamander egg masses at seasonal forest pools in 13 National Wildlife Refuges, 1 National Park, 1 National Seashore, and 1 State Park in the northeastern United States. We calculated detection probabilities for egg masses and examined whether detection probabilities varied by species, observers, pools, and in relation to pool characteristics (pool area, pool maximum depth, within-pool vegetation). For the 2 years, model selection indicated that no consistent set of variables explained the variation in data sets from individual Refuges and Parks. Because our results indicated that egg mass detection probabilities vary spatially and temporally, we conclude that it is essential to use estimation procedures, such as double-observer methods with egg mass surveys, to determine population sizes and trends of these species.