Attraction of male gypsy and nun moths to disparlure and some of its chemical analogues

Summary The attractive power of disparlure—the sex attractant of the gypsy moth (Lymantria/Porthetria dispar)—vs. four synthetic analogous epoxides was tested in 1972 in a pine forest near Heidelberg. With two levels of concentration in the traps (2 and 20 g), a total of 1112 nun moths (Lymantria/Porthetria monacha) and 257 gypsy moths were caught in 9 experiments. Approximately equal percentages of the two species were caught with a given compound. Disparlure was by far the most effective attractant. The other substances were between three and twenty times less effective. These experiments support the assumption that disparlure is also at least part of the sexual attractant of the nun moth. In two additional experiments, moth captures by a series of increasing disparlure concentrations (2–100 g/trap) were determined. The catches of both species increased nonlinearly with the bait concentration. The experiments are discussed with respect to new (unpublished) electrophysiological recordings from disparlure receptor cells in both species. Special attention is given to the supposed masking effect of the disparlure precursor (an olefin). This substance is ineffective as an attractant, but has been reported to reduce the attraction of gypsy moth males to disparlure or to live females. However, the olefin elicits excitatory reactions in the same type of receptor cell that responds to disparlure and the related epoxides. Furthermore, no masking of the electrophysiological response was observed with the receptor cells when the olefin was added to disparlure.Supported by the Deutsche Forschungsgemeinschaft.     

Effects of SPLAT® GM sprayable pheromone formulation on gypsy moth mating success

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^® 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^® 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^® 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.     

Rapid identification of the Asian gypsy moth and its related species based on mitochondrial DNA

The gypsy moth—Lymantria dispar (Linnaeus)—is a worldwide forest defoliator and is of two types: the European gypsy moth and the Asian gypsy moth. Because of multiple invasions of the Asian gypsy moth, the North American Plant Protection Organization officially approved Regional Standards for Phytosanitary Measures No. 33. Accordingly, special quarantine measures have been implemented for 30 special focused ports in the epidemic areas of the Asian gypsy moth, including China, which has imposed great inconvenience on export trade. The Asian gypsy moth and its related species (i.e., Lymantria monocha and Lymantria xylina) intercepted at ports are usually at different life stages, making their identification difficult. Furthermore, Port quarantine requires speedy clearance. As such, it is difficult to identify the Asian gypsy moth and its related species only by their morphological characteristics in a speedy measure. Therefore, this study aimed to use molecular biology technology to rapidly identify the Asian gypsy moth and its related species based on the consistency of mitochondrial DNA in different life stages. We designed 10 pairs of specific primers from different fragments of the Asian gypsy moth and its related species, and their detection sensitivity met the need for rapid identification. In addition, we determined the optimal polymerase chain reaction amplification temperature of the 10 pairs of specific primers, including three pairs of specific primers for the Asian gypsy moth (L. dispar asiatic), four pairs of specific primers for the nun moth (L. monocha), and three pairs of specific primers for the casuarina moth (L. xylina). In conclusion, using our designed primers, direct rapid identification of the Asian gypsy moth and its related species is possible, and this advancement can help improve export trade in China.     

Electroantennogram and behavioural responses of the gypsy moth to enantiomers of disparlure and its trans analogues

The attractive power of both enantiomers of disparlure and its trans analog was tested electrophysiologically (electroantennogram = EAG) and behaviourally (whole organism response). EAG responses correlated very well with the behaviourally determined effectiveness sequence: cis(+)-disparlure was the most effective substance; the authentic racemic disparlure came second; cis(?)-disparlure inhibited the activity of cis(+)-disparlure; and trans enantiomers were not significantly different from the control. These results allow us to conclude that cis(+)-disparlure is the natural sex pheromone of the gypsy moth, and that the male antennae have a chiral receptor system in the antenna for the reception of the sex pheromone.     

Optimization of pheromone dosage for gypsy moth mating disruption

The effect of aerial applications of the pheromone disparlure at varying dosages on mating disruption in low‐density gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), populations was determined in field plots in Virginia, USA during 2000 and 2002. Six dosages [0.15, 0.75, 3, 15, 37.5, and 75 g active ingredient (AI)/ha] of disparlure were tested during the 2‐year study. A strongly positive dose–response relationship was observed between pheromone dosages and mating disruption, as measured by the reduction in male moth capture in pheromone‐baited traps and mating successes of females. Dosages of pheromone 15 g AI/ha (15, 37.5, and 75 g AI/ha) reduced the mating success of females by >99% and significantly reduced male moth catches in pheromone‐baited traps compared to untreated plots. Pheromone dosages <15 g AI/ha also reduced trap catch, but to a lesser extent than dosages 15 g AI/ha. Furthermore, the effectiveness of the lower dosage treatments (0.15, 0.75, and 3 g AI/ha) declined over time, so that by the end of the study, male moth catches in traps were significantly lower in plots treated with pheromone dosages 15 g AI/ha. The dosage of 75 g AI/ha was initially replaced by a dosage of 37.5 g AI/ha in the USDA Forest Service Slow‐the‐Spread (STS) of the Gypsy Moth management program, but the program is currently making the transition to a dosage of 15 g AI/ha. These changes in applied dosages have resulted in a reduction in the cost of gypsy moth mating disruption treatments.     

Field evaluation of effect of temperature on release of disparlure from a pheromone-baited trapping system used to monitor gypsy moth (Lepidoptera: Lymantriidae)

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 approximately 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.     

Discrimination and production of disparlure enantiomers by the gypsy moth and the nun moth

ABSTRACT. Two odour receptor cells were physiologically identified within male antennal hair sensillae of the gypsy moth, Lymantria dispar L, and the nun moth, L. monacha L. In the gypsy moth, one cell responded to (+)-disparlure, while a neighbouring cell responded to (-)-disparlure. In the nun moth both cells responded to (+)-disparlure. The lack of sensitivity to (-)-disparlure in the nun moth was corroborated by electroantennogram (EAG) recordings, which indicated no affinity to this enantiomer. Single cell responses of male gypsy moth to different concentrations of the synthetic enantiomers of disparlure were then compared to responses elicited by hexane extracts of female glands of both species. The gypsy moth's extracts stimulated almost exclusively the receptor cell specialized for (+)-disparlure, while both cells were simultaneously stimulated by the extracts of the nun moths. From the response characteristic of the cells it is estimated that pheromone production of the nun moth is about 10% (+) and 90% (-)-disparlure, and that of the gypsy moth is almost 100% (+)-disparlure. Stimulation of the antenna of each species by female gland extracts of both species did not indicate the presence of receptors for other hexane elutable pheromone components in either species.     

Diadromus pulchellus in North America: field release against leek moth and new characters to distinguish it from Diadromus subtilicornis,a native diamondback moth parasitoid

We report successful overwintering of Diadromus pulchellus in North America (Ontario) following introduction of this species from Europe to control the leek moth, Acrolepiopsis assectella, a recently established alien species. Field rearing revealed that the native Diadromus subtilicornis emerged only from diamondback moth, Plutella xylostella, whereas D. pulchellus was reared almost exclusively from leek moth. The single D. pulchellus reared from diamondback moth was anticipated because host range studies found this species could develop on both leek moth and diamondback moth in the laboratory, although, it had not been previously reported from diamondback moth in the field in Europe. DNA barcoding of specimens of both Diadromus spp. confirmed their species status and novel morphological characters are presented to distinguish D. pulchellus from D. subtilicornis. In addition, DNA from specimens of D. subtilicornis from Europe clustered with DNA from specimens across Canada, confirming that it is a single Holarctic species. Finally, a new host association for D. subtilicornis is recorded from the dame's rocket moth: Pseudoplutella porrectella.     

Persistent effects of aerial applications of disparlure on gypsy moth: trap catch and mating success

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.     

Comparative efficacy of two controlled-release gypsy moth mating disruption formulations

The effects of aerial applications of the gypsy moth sex pheromone, disparlure, on mating disruption and suppression of growth of populations of the gypsy moth, Lymantria dispar (L.), were investigated. Two formulations of disparlure, plastic laminate flakes applied in a single application and polymethacrylate beads applied in two applications, were compared in two separate tests conducted in 1993 and 1994. The beads were applied in two applications spaced 2 weeks apart because preliminary tests had indicated that they released pheromone too rapidly to maintain adequate emission rates throughout the period of male flight. In 1993, the flakes were applied at a rate of 50 g a.i./ha, and the beads were applied at a rate of 15 g a.i./ha for each application. In 1994, the flakes were applied at a rate of 75 g a.i./ha and the beads were applied at rates of 32.5 and 42.5 g a.i./ha for the two applications. Beads with larger average particle size were used in 1994 to prolong disparlure release. The treatments applied in 1993 resulted in >97% reduction in mating and >82% suppression of population growth in the following year. Because of a 1995 collapse of gypsy moth populations in the vicinity of the tests, reliable population growth data were not available for the treatments applied in 1994, but significant mating disruption did occur under both treatments. Based on measurements of residual disparlure after field aging, the flakes released 32 and 48% of their disparlure content during the 6 weeks of male moth flight in 1993 and 1994, respectively. The smaller beads used in 1993 released 75% of their disparlure content, and the larger beads used in 1994 released 52% of their disparlure content, during the 6 weeks of male flight. The biological efficacy data suggest that the bead and flake formulations, as applied in these tests, have similar effects on gypsy moth mating disruption and subsequent population growth. Based on the observed release rates from both 1993 and 1994, a single application of the beads would provide emission rates equal to or greater than those provided by the flakes when applied at an equal dose.     

Evaluation of preventive treatments in low-density gypsy moth populations using pheromone traps

Pheromone traps can be used for evaluating the success of treatments that are applied to either eradicate or delay the growth of isolated low-density populations of the gypsy moth, Lymantria dispar (L.). We developed an index of treatment success, T, that measures the reduction in moth counts in the block treated adjusted by the change in moth counts in the reference area around it. This index was used to analyze the effectiveness of treatments that were conducted as part of the USDA Forest Service Slow-the-Spread of the gypsy moth project from 1993 to 2001. Out of 556 treatments that were applied during this period, 266 (188,064 ha) were selected for the analysis based on several criteria. They included 173 blocks treated with Bacillus thuringiensis (Berliner) variety kurstaki and 93 blocks treated with racemic disparlure. Analysis using general linear models indicated that disparlure treatments were significantly more effective than B. thuringiensis treatments in reducing moth captures. The frequency of repeated treatments in the same area was higher after B. thuringiensis than after disparlure applications. Treatments were more successful if the pretreatment moth counts outside of the block treated were low compared with moth counts inside the block.     

Ten polymorphic microsatellite markers developed in the masson pine moth Dendrolimus punctatus Walker (Lepidoptera: Lasiocampidae)

A set of 10 polymorphic di‐ and trinucleotide microsatellite loci were developed for the forestry pest insect, masson pine moth, Dendrolimus punctatus Walker. The expected heterozygosity at these loci ranges from 0.285 to 0.859, and the observed allele numbers from five to 19. Cross species amplification of these loci in four other congeneric pine moth species indicates variable levels of loci conservation and thus cross‐applicability. Therefore, the microsatellite loci reported here should be useful for population genetic and other related studies in the masson pine moth and other closely related species.     

Variation in the ability of larvae of phytophagous insects to develop on evolutionarily unfamiliar plants: a study with gypsy moth Lymantria dispar and Eucalyptus

• 1 By examining variation in the abilities of polyphagous insects to develop on host plants with secondary metabolites that they have never encountered previously, we may be able to gain some insights into the nature of evolution of biochemical mechanisms to process plant secondary metabolites by phytophagous insects.
• 2 The present study aimed to examine variation in the ability of gypsy moth larvae Lymantria dispar (Lymantriidae) to complete development on different species of the plant genus Eucalyptus (Myrtaceae). Leaves of at least some Eucalyptus species contain formylated phloroglucinol derivatives. These are secondary metabolites that are evolutionarily unfamiliar to the gypsy moth.
• 3 Larvae of gypsy moth showed extremely variable responses in larval performance between Eucalyptus species, between individual trees within host plant species, between moth populations, and between individuals within moth populations.
• 4 Larval survivorship was in the range 0–94%, depending on the host. Failure of at least some larvae to complete development on some Eucalyptus species indicates that gypsy moth larvae have a limited ability to process secondary metabolites in eucalypt leaves.
• 5 At least some individuals, however, appear to already possess biochemical mechanisms that process the secondary metabolites in leaves of Eucalyptus species, and therefore the abilities of larvae to complete development on phylogenetically and chemically unfamiliar hosts are already present before the gypsy moth encounters these potential hosts.

     

Odour quality discrimination for behavioural antagonist compounds in three tortricid species

The antennal and behavioural response of three tortricid species (Lepidoptera: Tortricidae) to their corresponding sex pheromones and known or putative behavioural antagonists was tested by electroantennography and in field trials. The species and their pheromones and known or proposed behavioural antagonist were lightbrown apple moth, Epiphyas postvittana (Walker) [pheromone: 95% (E)‐11‐tetradecenyl acetate (E11‐14Ac) and 5% (E,E)‐9,11‐tetradecadienyl acetate (E9E11‐14Ac); antagonist: (Z)‐11‐tetradecenyl acetate (Z11‐14Ac)], codling moth, Cydia pomonella (L.) [pheromone: (E,E)‐8,10‐dodecadien‐1‐ol (codlemone); antagonist: (E,E)‐8,10‐dodecadienyl acetate (codlemone acetate)], and gorse pod moth, Cydia ulicetana (Haworth) [pheromone: (E,E)‐8,10‐dodecadienyl acetate (codlemone acetate); putative antagonist: (E,E)‐8,10‐dodecadien‐1‐ol (codlemone)]. In all three species, the antennal response to the antagonists was not significantly different from the antennal response to con‐specific sex pheromone compounds. In the field trapping experiments, significantly fewer males of all three species were attracted to the respective pheromone when blended with the behavioural antagonist compound. However, this response varied between the species, with lightbrown apple moth and codling moth showing stronger responses to the antagonist compounds than gorse pod moth. Both lightbrown apple moth and codling moth males were able to discriminate between pure pheromone and pheromone blended with the antagonist when placed in traps side‐by‐side separated by ca. 10 cm. The presence of the behavioural antagonist not only affected the catch of males of both species within their own traps but also affected the catch in the neighbouring trap that contained con‐specific sex pheromone; the catch of gorse pod moth was not reduced by the presence of codlemone in the neighbouring trap. These results suggest that strong behavioural antagonists such as codlemone acetate for codling moth and Z11‐14Ac for lightbrown apple moth induce their inhibition effect at a substantial distance downwind from the odour source; however, most of those males that were able to overcome this inhibition effect at the early stage of orientation to odour source, were able to discriminate between the pheromone source and the pheromone source admixed with behavioural antagonist. Moderate behavioural antagonists such as codlemone for gorse pod moth did not elicit a discrimination effect.     

Increasing abundance and diversity in the moth assemblage of east Loch Lomondside,Scotland over a 35 year period

Macro-moths caught in a Rothamsted trap, operating from 1968 to 2003 as part of the Rothamsted Insect Survey, were used to investigate the long-term population trends of moth populations on East Loch Lomondside. In total 367 species of macro moth were recorded during this study. Over the 35 years of this study, an increase was recorded in both the overall number of individuals and moth diversity. Mean annual temperature significantly predicted the change in moth diversity but not number of individuals caught. Four of the most consistently abundant species, collectively constituting 27% of the average annual catch, were subjected to more detailed analysis. The three species that emerge during the summer months Eulithis populata (the northern spinach), Hydriomena furcata (july highflier) and Idaea biselata (the small fan-footed wave) became more abundant throughout the study period, (although for the latter species not significantly so). For Eulithis populata and Idaea biselata their emergence time became earlier, over the study period and in Eulithis populata and Hydriomena furcata, the flight duration also became longer. In contrast, the species that emerges as an adult during autumn and winter, Epirrita dilutata (the november moth) did not exhibit a significant change in abundance, emergence date or flight duration in this study. The results suggest that climate change is at least in part, responsible for the observed changes in species dynamics.     

Local outbreaks of Operophtera brumata and Operophtera fagata cannot be explained by low vulnerability to pupal predation

• 1 One of the unresolved questions in studies on population dynamics of forest Lepidoptera is why some populations at times reach outbreak densities, whereas others never do. Resolving this question is especially challenging if populations of the same species in different areas or of closely‐related species in the same area are considered.
• 2 The present study focused on three closely‐related geometrid moth species, autumnal Epirrita autumnata, winter Operophtera brumata and northern winter moths Operophtera fagata, in southern Finland. There, winter and northern winter moth populations can reach outbreak densities, whereas autumnal moth densities stay relatively low.
• 3 We tested the hypothesis that a lower vulnerability to pupal predation may explain the observed differences in population dynamics. The results obtained do not support this hypothesis because pupal predation probabilities were not significantly different between the two genera within or without the Operophtera outbreak area or in years with or without a current Operophtera outbreak.
• 4 Overall, pupal predation was even higher in winter and northern winter moths than in autumnal moths. Differences in larval predation and parasitism, as well as in the reproductive capacities of the species, might be other candidates.

     

Is the timing of scent emission correlated with insect visitor activity and pollination in long‐spurred Satyrium species?

Plants are expected to emit floral scent when their pollinators are most active. In the case of long‐tubed flowers specialised for pollination by crepuscular or nocturnal moths, scent emissions would be expected to peak during dawn. Although this classic idea has existed for decades, it has rarely been tested quantitatively. We investigated the timing of flower visitation, pollination and floral scent emissions in six long‐spurred Satyrium species (Orchidaceae). We observed multiple evening visits by pollinaria‐bearing moths on flowers of all study species, but rarely any diurnal visits. The assemblages of moth pollinators differed among Satyrium species, even those that co‐flowered, and the lengths of moth tongues and floral nectar spurs were strongly correlated, suggesting that the available moth pollinator fauna is partitioned by floral traits. Pollinarium removal occurred more frequently during the night than during the day in four of the six species. Scent emission, however, was only significantly higher at dusk than midday in two species. Analysis of floral volatiles using gas chromatography coupled with mass spectrometry yielded 168 scent compounds, of which 112 were species‐specific. The scent blends emitted by each species occupy discrete clusters in two‐dimensional phenotype space, based on multivariate analysis. We conclude that these long‐spurred Satyrium species are ecologically specialised for moth pollination, yet the timing of their scent emission is not closely correlated with moth pollination activity. Scent composition was also more variable than expected from a group of closely related plants sharing the same pollinator functional group. These findings reveal a need for greater understanding of mechanisms of scent production and their constraints, as well as the underlying reasons for divergent scent chemistry among closely related plants.     

Host range and impact of the flower-feeding moth,Cochylis campuloclinium – a biological control agent for Campuloclinium macrocephalum,in South Africa

Campuloclinium macrocephalum (Less.) DC. (Asteraceae) (pompom weed), an invader in South Africa and Swaziland, threatens biodiversity conservation, agriculture and tourism in the region. We report on the host range and impact of the flower-feeding moth, Cochylis campuloclinium Brown (Lepidoptera: Tortricidae), the second insect biological control agent to be considered for C. macrocephalum in South Africa. Laboratory host-specificity tests were conducted on 31 Asteraceae species. Field host range studies included 17 non-target Asteraceae species. Results of both C. campuloclinium laboratory and field host-range trials indicated that it is suitably host specific. In laboratory host-range trials, only C. macrocephalum and the closely related native, Adenostemma caffrum DC. (Asteraceae), received feeding damage, while in field host-range trials, the moth was only recorded on the target. Laboratory impact studies showed that C. campuloclinium destroyed a significant number of florets in flower buds (76%) and seeds in mature flowers (54%). Based on evidence from the native range, there appears to be no competitive interactions between C. campuloclinium and the already established stem- and leaf-deforming thrips, Liothrips tractabilis Mound & Pereyra (Thysanoptera: Phlaethripinae). The two insect agents should perform a complementary role of reducing flowering (L. tractabilis) and seed production (C. campuloclinium). Based on the above data, permission for the release of the moth was sought in August 2015.     

Moth pollination of woody species in the Cerrados of Central Brazil: a case of so much owed to so few?

We present a survey of moth pollination in woody species of the Cerrado of Central Brazil. Although with the exception of Roupala montana (which has simple polysepalous flowers arranged in dense cymes) all moth pollinated species in this community have tubular flowers, or a pseudo-tube formed from a single folded petal in Qualea grandiflora, settling moth flowers (tube less than 15 mm) vs. hawkmoth flowers (tube more than 50 mm) are markedly different in size. Moths visit some 20 woody Cerrado species, but they are probably effective pollinators of only 13 species or ca.14% of the woody taxa studied, and even in these latter species they are often very sparse visitors. Nevertheless, it is notable that moths are pollinators for 21% of the 38 most commonly distributed woody Cerrado species. Moreover, the reproductive efficacy of the studied moth pollinated species was similar to that of species pollinated by other kind of vectors.     

Potential interactions between invasive woody shrubs and the gypsy moth (Lymantria dispar), an invasive insect herbivore

As the range of the invasive and highly polyphagous gypsy moth (Lymantria dispar) expands, it increasingly overlaps with forest areas that have been subject to invasion by non-native shrubs. We explored the potential for interactions between these co-occurring invasions through a gypsy moth feeding trial using the following three highly invasive, exotic shrubs: honeysuckle (Lonicera maackii), privet (Ligustrum sinense) and burning bush (Euonymus alatus). We compared these with two native shrubs: spicebush (Lindera benzoin) and pawpaw (Asimina triloba). We fed gypsy moth caterpillars foliage exclusively from one of the five shrubs and measured their relative consumptive rate (RCR), relative growth rate (RGR), and development time (DT). The RCR of gypsy moth was strongly influenced by the species of foliage (F = 31.9; P < 0.0001) with little or no consumption of honeysuckle and privet. Caterpillar RGR was influenced by the shrub species (F = 66.2; P < 0.0001), and those caterpillars fed spicebush, honeysuckle or privet lost weight over the course of the assay. Caterpillar DT was also significantly (F = 11.79, P < 0.0001) influenced by the shrub species and those fed honeysuckle, privet and spicebush died prior to molting. Overall, our data suggest that honeysuckle, privet, and spicebush could benefit (indirectly) from the invasion of gypsy moth, while burning bush and pawpaw could be negatively impacted due to direct effects (herbivory). Similarly, invading gypsy moth populations could be sustained on a shrub layer of burning bush and pawpaw in the event of canopy defoliation. Further field and laboratory analysis is needed to clarify herbivore resistance of invasive shrubs, and to investigate the potential interactions among co-occurring insect and plant invasions.