The European strain of the gypsy moth, Lymantria dispar L. (Lepidoptera: Erebidae) was accidentally introduced to North America over 100 years ago and despite its explosive population growth there, the species still only occupies less than 1/3 of its potential range. While this slow rate of spread can be attributed in part to the limited dispersal capacities of this strain, its constrained distribution mainly reflects the success of efforts to limit range expansion of this species. Currently, two major area-wide programmes are operated to limit the spread of the gypsy moth in the USA, in addition to a third programme that suppresses gypsy moth outbreaks in the infested areas. The detection / eradication programme is led by the United States Department of Agriculture Animal and Plant Health Inspection Service (USDA-APHIS) in cooperation with state governments and utilizes networks of pheromone traps to detect newly invaded populations of the gypsy moth in the uninfested portions of the USA. Over the last decades, hundreds of isolated populations have been detected and eradicated. Most eradication treatments in the USA are conducted using aerial sprays of Bacillus thuringiensis. The USDA Forest Service also operates another area-wide programme entitled “Slow the Spread” (STS) in cooperation with state agencies that operates at the edge of the generally infested area and aims to slow the gypsy moth’s spread. This programme also uses grids of pheromone traps to locate isolated populations, which are then treated. The STS programme has adopted several major innovations that make it one of the most advanced area-wide programmes for managing invading species. Among these innovations, the STS programme adopts a complex geographic information system (GIS)-based decision algorithm for processing trap data, identifying treatment areas and evaluating programme efficacy. Also, the STS programme is unique in that it largely has adopted mating disruption to eradicate or suppress isolated populations ahead of the invading front.

Mating disruption tactics involve the deployment of pheromones to interfere with mate finding behaviors in insect populations. This management strategy is the dominant one used against expanding gypsy moth populations in the United States, and historically it has been assumed to be most effective against low-density populations. Operationally, mating disruption is used in areas where the season-long trap catch is <30 males/trap, however the maximum population density at which mating disruption is effective remains unknown. We analysed historical gypsy moth mating disruption treatment data from 2000 to 2010, and used this information to guide the mating disruption field studies conducted from 2012 to 2015 against artificially-created populations of various densities, from 0 to 116 males/trap/day. We observed that mating disruption tactics at a dose of 15g AI/ha were effective against gypsy moth populations with a season-long trap catch of at least 115 males/trap. This research highlights the utility of mating disruption in higher gypsy moth densities than what is currently recommended in management programs.

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 (R) GM, in forested areas of Virginia from 2011 to 2014 using different dosages and number of point applications. We observed that SPLAT (R) GM applied to the tree trunks at the dosages of 49.4 and 123.6 g AI/ha in 11 x 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.

Mating disruption, the broadcast application of sex-attractant pheromone to reduce the ability of insects to locate mates, has proven to be an effective method for suppressing populations of numerous moth pests. Since the conception of mating disruption, the species-specificity and low toxicity of pheromone applications has led to their consideration for use in area-wide programs to manage invasive moths. Case histories are presented for four such programs where the tactic was used in the United States: Pectinophora gossypiella (pink bollworm), Lymantria dispar (gypsy moth), Epiphyas postvittana (light brown apple moth), and Lobesia botrana (European grapevine moth). Use of mating disruption against P. gossypiella and L. botrana was restricted primarily to agricultural areas and relied in part (P. gossypiella) or wholly (L. botrana) on hand-applied dispensers. In those programs, mating disruption was integrated with other suppression tactics and considered an important component of overall efforts that are leading toward eradication of the invasive pests from North America. By contrast, L. dispar and E. postvittana are polyphagous pests, where pheromone formulations have been applied aerially as stand-alone treatments across broad areas, including residential neighborhoods. For L. dispar, mating disruption has been a key component in the program to slow the spread of the infestation of this pest, and the applications generally have been well tolerated by the public. For E. postvittana, public outcry halted the use of aerially applied mating disruption after an initial series of treatments, effectively thwarting an attempt to eradicate this pest from California. Reasons for the discrepancies between these two programs are not entirely clear.

Mating disruption is the primary control tactic used against the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae) under the gypsy moth Slow the Spread (STS) program. In this paper, we present the results of the multiyear study designed to evaluate a new liquid SPLAT GM™ (ISCA Tech, Riverside, CA, USA) Organic formulation, which is approved by the USDA to meet National Organic Program Standards for use in organic certified farms, for its ability to disrupt gypsy moth mating, and to evaluate the environmental persistence of SPLAT GM™ and SPLAT GM™ Organic formulations. Environmental persistence of the pheromone beyond the year of application is a significant concern since STS relies on trap catch data to evaluate treatment success. The study was conducted in 2007–2012 in forested areas in Virginia and Wisconsin, USA. We observed that SPLAT GM™ Organic reduced gypsy moth trap catch by ≥90% for 10 weeks in a similar manner as SPLAT GM™ and Hercon Disrupt® II (Hercon Environmental, Emigsville, PA, USA). Although we observed persistent effects in all products one year after application, the persistence observed in SPLAT GM™ and SPLAT GM™ Organic was significantly lower than that of Hercon Disrupt® II plastic laminated flakes.

Mating disruption techniques are used in pest control for many species of insects, yet little is known regarding the environmental persistence of these pheromones following their application and if persistence is affected by climatic conditions. We first studied the persistent effect of ground applications of Luretape® GM in Lymantria dispar (L) mating disruption in VA, USA in 2006. The removal of Luretape® GM indicated that the strong persistent effect of disparlure in the environment reported by previous studies is produced by residual pheromone in the dispensers as opposed to environmental contamination. In 2010 and 2011, we evaluated the efficacy of two formulations, Disrupt® II and SPLAT GM(TM), in VA and WI, USA, which presented different climatic conditions. In plots treated in WI and VA, male moth catches in pheromone-baited traps were reduced in the year of treatment and one year after the pheromone applications relative to untreated controls. However, similar first- and second-year effects of pheromone treatments in VA and WI suggest that the release rate over one and two years was the same across markedly different climates. Future applications that use liquid or biodegradable formulations of synthetic pheromones could reduce the amount of persistence in the environment.

Increases in global trade and travel have resulted in a number of species being inadvertently (or, in a few cases, deliberately) introduced into new geographical locations. In most cases, there is generally a lack of information regarding a species' biology and ecology, and its potential to cause environmental and economic harm. Regardless, management decisions concerning these new species often need to be made rapidly, even in the absence of this information. The gypsy moth, Lymantria dispar (L.), is an exception insofar as it is a non-native species that, due to its considerable potential for damage, has been extensively studied and managed in the United States following its introduction in 1869. In this review, we attempt to highlight the ecology, geopolitics, and economics of managing L. dispar in the United States, integrating the lessons learned from over 100 years of research and management. In doing so, we attempt to provide a framework that could be applicable to the management of other non-native insect species, for which we often lack information upon which to develop and implement management strategies.

Increases in global trade and travel have resulted in a number of species being inadvertently (or, in a few cases, deliberately) introduced into new geographical locations. In most cases, there is generally a lack of information regarding a species' biology and ecology, and its potential to cause environmental and economic harm. Regardless, management decisions concerning these new species often need to be made rapidly, even in the absence of this information. The gypsy moth, Lymantria dispar (L.), is an exception insofar as it is a non-native species that, due to its considerable potential for damage, has been extensively studied and managed in the United States following its introduction in 1869. In this review, we attempt to highlight the ecology, geopolitics, and economics of managing L. dispar in the United States, integrating the lessons learned from over 100 years of research and management. In doing so, we attempt to provide a framework that could be applicable to the management of other non-native insect species, for which we often lack information upon which to develop and implement management strategies.

The Slow the Spread (STS) Program operates along the expanding population front of the gypsy moth, from Minnesota to North Carolina. The primary objective of the program is to eliminate newly-founded colonies that form ahead of the leading edge to reduce the gypsy moth’s rate of spread and delay the costs associated with infestation and outbreaks. Although the majority of areas under the STS Program are treated with control methods specific to the gypsy moth, commercial formulations of Bacillus thuringiensis var. kurstaki (Btk) are the second most used tactic. Bacillus thuringiensis kurstaki can directly affect other Lepidoptera, as well as indirectly affect species that depend on Lepidoptera for pollination services or as a food source. Because of these nontarget effects, proposed treatment areas are always reviewed by the US Department of Interior–Fish and Wildlife Service as well as state agencies that are responsible for the conservation of threatened and endangered species to ensure that government programs to control gypsy moth are not likely to have an adverse effect. In this report, we used a variety of sources to compile a spatial database of the historical distributional ranges of 21 threatened and endangered species that occur within the STS management area. We then quantified the area of overlap between areas treated with Btk under the STS Program from 1996 to 2010 and the distributional ranges of these species to evaluate the use of Btk with regard to federal and state management guidelines. The percentage of overlap between the distributional ranges for each of the 21 nontarget species was< 1 percent in any year, while …

ABSTRACT Traps baited with disparlure, the synthetic form of the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), sex pheromone are used to detect newly founded populations and estimate population density across the United States. The lures used in trapping devices are exposed to field conditions with varying climates, which can affect the rate of disparlure release. We evaluated the release rate of disparlure from delta traps baited with disparlure string dispenser from 1 to 3 yr across a broad geographic gradient, from northern Minnesota to southern North Carolina. Traps were deployed over ≈12 wk that coincided with the period of male moth flight and the deployment schedule of traps under gypsy moth management programs. We measured a uniform rate of release across all locations when considered over the accumulation of degree-days; however, due to differences in degree-day accumulation across locations, there were significant differences in release rates over time among locations. The initial lure load seemed to be sufficient regardless of climate, although rapid release of the pheromone in warmer climates could affect trap efficacy in late season. Daily rates of release in colder climates, such as Minnesota and northern Wisconsin, may not be optimal in detection efforts. This work highlights the importance of local temperatures when deploying pheromone-baited traps for monitoring a species across a large and climatically diverse landscape.

Several integrated pest management programs rely on the use of mating disruption tactics to control insect pests. Some programs specifically target non-native species, such as the gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae). We evaluated SPLAT (R) GM, a new sprayable formulation of the gypsy moth sex pheromone disparlure, for its ability to disrupt gypsy moth mating. The study was conducted in 2006, 2007, and 2008 in forested areas in Virginia, USA. Mating success of gypsy moth females was reduced by > 99% and male moth catches in pheromone-baited traps by > 90%, in plots treated with SPLAT (R) GM at dosages ranging from 15 to 75 g of active ingredient (a.i.) ha-1. Dosage-response tests conducted in 2008 indicated that SPLAT (R) GM applied at a dosage of 7.5 g a.i. ha-1 was as effective as a 15 g a.i. ha-1 dosage.

The Slow the Spread of the Gypsy Moth Project (STS) is a USDA strategy that seeks to mitigate the effects of the European gypsy moth (Lymantria dispar L.) in the United States. The STS project has developed a proven infrastructure to meet the operational monitoring, data management, risk assessment, and management needs of this national pest mitigation effort over the last 15 years. With an ever increasing threat of invasive species due to globalization, there is a need for greater emphasis on the development of data life cycle (collection, quality control, management) and risk assessment/ management (decision support system) strategies during the early stages of emergency program development and deployment. The implementation of a well thought out data life cycle and decision support framework will allow quality data to feed the decisionmaking and planning processes of an emergency program increasing its effectiveness. Emerald ash borer (EAB) (Agrilus planipennis) has rapidly become one of the most important invasive forest pests since it was first identified in the U.S. in 2002. To date, survey methods for EAB have varied substantially among cooperating states and agencies. Methods may include regulatory trace-backs of infested ash trees or logs, visual surveys for symptomatic trees, and girdled trap trees. Even in states where trap trees are the primary survey tool, implementation methods differ and data collected from the trap trees are not consistent. If EAB is to be effectively managed, survey methods and data management must advance. Delays in developing and implementing a proven data management strategy will only hinder the effective management of EAB. This will be particularly important given the potential for increased trap efficacy and greater systematic trapping. The STS framework encompasses a range of applications that not only could be applied to additional managed pest surveys (e.g., EAB and Sirex woodwasp), but also could strengthen future detection surveys.

Populations of the gypsy moth, Lymantria dispar (L.), are extensively monitored in the United States through the use of pheromone-baited traps. We report on use of automated pheromone-baited traps that use a recording sensor and data logger to record the unique date-time stamp of males as they enter the trap. We deployed a total of 352 automated traps under field conditions across several U.S. states over a 5-yr period. In many cases, there was general congruence between male moth capture and the number of recorded events. Although it was difficult to decipher an individual recording event because of the tendency for over-recording, the overall distribution of recorded events was useful in assessing male gypsy moth flight behavior and phenology. The time stamp for recorded events corroborated a previous report of crepuscular gypsy moth male flight behavior, because, although most moths were trapped between 12 and 16 h, there was a consistent period of flight activity between 20 and 22 h. The median male flight duration was 24 d (228 DD, base threshold = 10 degrees C), but there were several traps that recorded flight periods >42 d that could not be explained by overcounting given the congruence between moth capture and the number of recorded events. Unusually long flight periods could indicate the introduction of male moths or other life stages that developed under different climatic conditions.

1 Aerial applications of Disrupt II, a plastic laminated flake formulation containing a racemic form of the gypsy moth sex pheromone, disparlure, achieved > 99% reduction of mating among females on individual, isolated trees surrounded by an area cleared of trees. 2 These results support the use of mating disruption to eradicate isolated gypsy moth populations in open landscapes, such as parks, residential areas and commercial settings. 3 Mating success in both treated and untreated areas varied with the initial distance between males and females. When the initial distance between males and females was < 5 cm in an area receiving a dosage of 37.5 g of racemic disparlure per ha, mating success was reduced by 27% compared with a similar deployment in an untreated area. Mating was eliminated in areas treated at the same dosage when males and females were initially deployed 1 m apart but on separate trees. 4 This suggests that mating disruption may not be an effective tactic for gypsy moth eradication in cases where the infestation is concentrated on a small number of trees and males and females are in close proximity in space and time.

The study was conducted during 2000, 2001, 2003 and 2004 in forested areas in Virginia, USA to evaluate the 3M™ MEC‐GM Sprayable Pheromone® formulation of the gypsy moth sex pheromone, disparlure, for its ability to disrupt mating in gypsy moth, Lymantria dispar (Lep.: Lymantriidae). Both mating success of gypsy moth females and male moth catches in pheromone‐baited traps were significantly reduced in plots treated with the 3M™ MEC‐GM formulation at dosages ranging from 15 to 75 g of active ingredient/ha. However, the 3M™ MEC‐GM formulation reduced trap catch to a lesser extent than did the currently registered Hercon Disrupt® II plastic flakes used as a positive control and applied at similar or lower dosages. Furthermore, the effectiveness of the 3M™ sprayable formulation declined through time, so that by the end of the male flight season, male moth catches in traps were significantly higher than in plots treated with Hercon plastic flakes. Based on the reported results, 3M™ MEC‐GM Sprayable Pheromone® formulation was never integrated into the operational treatment projects of USDA Forest Service Cooperative Slow‐the‐Spread of the Gypsy Moth management programme.

In forest plots treated aerially with a plastic laminated flake formulation (Disrupt® II) of the gypsy moth sex pheromone disparlure to disrupt gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), mating was monitored the year of treatment and 1–2 years after treatment to determine the effects of the treatment on suppression of trap catch and mating success. In the year of treatment, there was a greater than 95% reduction in trap catch and a greater than 98% reduction in mating success compared to controls. One year after treatment at a dosage of 37.5 g active ingredient (a.i.) ha−1, trap catch was reduced by 46–56% and mating success was reduced by 60–79%. Both trap catch and mating success were significantly reduced compared to controls in plots treated 1 year previously at 15 g a.i. ha−1. Trap catch, but not mating success, was significantly reduced 2 years after treatment at 37.5 g a.i. ha−1. The efficacy of mating disruption (MD) treatments in the Slow‐the‐Spread of the Gypsy Moth program was significantly reduced 2 years compared to 1 year after treatment. No such reduction was observed in plots treated with aerial applications of Bacillus thuringiensis kurstaki. The higher apparent efficacy of MD treatments 1 year after application may result to some extent from the suppression of moth capture in pheromone traps from the persistent effects of the previous year's treatment.

Mating disruption is the primary tactic used to reduce rates of gypsy moth population spread in the United States Department of Agriculture's Slow-the-Spread of the gypsy moth programme (STS). Because STS targets very low-density gypsy moth populations within which it is extremely difficult to collect females or egg masses, mating success in native populations cannot be determined. Therefore, the evaluation of mating disruption treatments in field experiments such as those designed to test new formulations and application methods requires deploying and recovering laboratory-reared female moths to determine mating success.Five methods of deploying females were evaluated for cost, rates of female and egg mass recovery, and female mating success. The deployment methods tested were: modified delta trap, square barrier, single and double trunk bands, and tethered females.Deployment of tethered females had the highest cost and mating success rate, but it did not yield the highest rates of female and egg mass recovery. Deployment of females in delta traps produced the lowest cost and mating success rate, but yielded the highest recovery rate. Neither of these deployment methods is recommended because of unacceptably high cost (tethered female) or low mating success (delta trap).There were no significant differences in cost or mating success among the other three deployment methods.The differences among the square barrier, single trunk band, and double trunk band methods in cost, female and egg mass recovery, and mating success are too small to recommend any one over the others.

The study was conducted during 2001 and 2002 in forested areas in Virginia, US to examine the effects of gaps in coverage of pheromone on gypsy moth, Lymantria dispar (L.) (Lep., Lymantriidae), mating disruption. Gypsy moth male moth catches in pheromone-baited traps were significantly reduced in plots treated with the gypsy moth sex pheromone, disparlure, at an overall application rate of 37.5 g of active ingredient (AI)/ha but with untreated gaps of 30 or 90 m between 30-m wide treated swaths. In one of the two plots with 90 m gaps, significantly more males were captured in traps in the untreated areas compared with the treated areas within the plot. However, in another plot, significant differences in trap catches between treated and untreated areas were not observed. No difference in male moth catches in the pheromone-baited traps was observed between treated and untreated areas within the plots treated with 30 m gaps. Female mating success did not differ significantly between treated and untreated areas within the one plot in which it was measured. These results suggest that it may be possible to lower costs associated with gypsy moth mating disruption applications by alternating treated and untreated swaths, which would reduce flight time and fuel costs, without a reduction in efficacy.