Nantucket Pine Tip Moth Research Articles

Winter diet of bats in working forests of the southeastern U.S. Coastal Plain

Working forests comprise a large proportion of forested landscapes in the southeastern United States and are important to the conservation of bats, which rely on forests for roosting and foraging. While relationships between bat ecology and forest management are well studied during summer, winter bat ecology remains understudied. Hence, we aimed to identify the diet composition of overwintering bats, compare the composition of prey consumed by bat species, and determine the potential role of forest bats as pest controllers in working forest landscapes of the southeastern U.S. Coastal Plain. During January to March 2021–2022, we captured 264 bats of eight species. We used DNA metabarcoding to obtain diet composition from 126 individuals of seven bat species identifying 22 orders and 174 families of arthropod prey. Although Coleoptera, Diptera, and Lepidoptera were the most consumed orders, we found that bats had a generalist diet but with significant differences among some species. We also documented the consumption of multiple insect pests (e.g., Rhyacionia frustrana) and disease vectors (e.g., Culex spp). Our results provide important information regarding the winter diet of bats in the southeastern U.S. Coastal Plain and their potential role in controlling economically relevant pest species and disease vectors.

Loblolly Pine Susceptibility to Nantucket Pine Tip Moth: Do Tree Genetics Play a Role?

Abstract The Nantucket pine tip moth (NPTM) (Rhyacionia frustrana Comstock) is a regeneration pest of young loblolly pines (Pinus taeda L.) that causes tree deformity, shoot dieback, and growth declines. Different silvicultural techniques are used to grow loblolly pine more effectively, including improved genotypes. Some scientists and growers have hypothesized that more expensive full-sibling families (control-pollinated [CP]) seedlings may be more susceptible to NPTM than open-pollinated (OP) families. The study objective was to assess the susceptibility to NPTM of seven loblolly OP and CP families commonly planted in the southeastern United States by observing NPTM infestation rates and pine growth metrics (height, groundline diameter, volume index, and stem form) over two growing seasons. The NPTM infestation rates varied throughout both growing seasons; however, there was no difference in infestation rates among any of the families. Pine growth metrics varied among families at the time of planting; however, growth metrics did not vary after the first and second growing seasons. Results of this study suggest that NPTM management tactics, such as insecticide use, should not be prioritized based on loblolly pine families alone, as the CP families assessed in this study were not more susceptible to NPTM than OP families.

Efficacy of four systemic insecticides for reducing Nantucket pine tip moth (Rhyaciona frustrana) (Lepidoptera: Tortricidae) infestation levels and improving growth metrics in loblolly pines.

The Nantucket pine tip moth (NPTM) (Rhyacionia frustrana Comstock) is a native, regeneration pest of young loblolly pines (Pinus taeda L.), causing shoot dieback, tree deformity, and growth and volume declines. Soil applications of systemic insecticides may be an effective strategy to suppress NPTM populations. The study objective was to assess the efficacy of four systemic insecticide treatments (chlorantraniliprole, dinotefuran, fipronil, and imidacloprid) for two growing seasons in outplanted bareroot and containerized seedling trials. Response variables included NPTM infestation rates, along with tree height, groundline diameter, volume index, and stem form. Infestation rates significantly decreased for each systemic insecticide treatment during the first year compared to controls, although dinotefuran and imidacloprid provided season-long control in one trial. Chlorantraniliprole reduced NPTM infestation rates for two growing seasons in both trials. While imidacloprid treatments did not alter growth metrics except for one comparison, fipronil and dinotefuran treatments improved several growth metrics. Chlorantraniliprole consistently improved growth metrics throughout the study.

Management Implications for the Nantucket Pine Tip Moth From Temperature-Induced Shifts in Phenology and Voltinism Attributed to Climate Change.

Forest insect pest phenology and infestation pressure may shift as temperatures continue to warm due to climate change, resulting in greater challenges for sustainable forest management . The Nantucket pine tip moth (NPTM) (Rhyacionia frustrana Comstock) (Lepidoptera: Tortricidae) is a native forest regeneration pest in the southeastern U.S. with multiple generations per year. Changes in NPTM voltinism may result from temperature-induced shifts in NPTM phenology. Degree-day models have been used to develop optimal spray dates (OSDs) for NPTM. The 2000 Spray Timing Model (STM), based on temperature data from 1960 to 2000, provided generation-specific 5-d OSDs to effectively time applications of contact insecticides. An updated degree-day model, the 2019 STM, is based on temperature data from 2000 to 2019 and was used to detect changes in voltinism as well as shifts in phenology and OSDs. Based on the model, increased voltinism occurred at 6 of the 28 study locations (21%). Changes in voltinism occurred in the Piedmont and Coastal Plain of Georgia, U.S., with shifts from three to four or four to five generations a year, depending on location. The OSDs from the 2019 STM were compared to the 2000 STM OSDs. Over half (57%) of the OSDs differed by 5-15 d, with the majority (66%) resulting in earlier spray dates. The 2019 STM will help growers adapt NPTM control tactics to temperature-induced phenology shifts. NPTM serves as an example of temperature-induced changes attributed to climate change in a forest insect pest with important implications to forest management.

Assessing imidacloprid for Nantucket pine tip moth (Rhyacionia frustrana) suppression through regional collaborative research and focus group evaluation

Nantucket pine tip moth (NPTM) [Rhyacionia frustrana (Lepidoptera: Tortricidae)] is a pest of young pine trees. The goal of this research project was two-fold: 1) to evaluate imidacloprid for NPTM suppression in South Georgia and 2) to incorporate county agents into a research project to facilitate knowledge transfer and extension training. Research sites in one-year planted loblolly pine stands were established by an extension specialist and county agents in five counties in South Georgia. Loblolly pines were assigned one of three treatments: untreated control, soil drench, and foliar spray. Trees were treated at a rate that would treat 500 trees per acre. Pines were assessed for NPTM infestation five times during the year, set to coincide with each NPTM generation. Tree height was measured at the end of the growing season. Qualitative data was collected on the agents' experience during a Zoom focus group and with emailed questionnaires.Imidacloprid drench and spray treatments resulted in lower NPTM infestation rates compared to untreated controls. However, while infestations rates were significantly lower, benefits were not conveyed to increased tree height. Imidacloprid treated trees were no taller than control trees.Collaborating with county agents enhanced this research project and benefitted both agents and the extension specialist. County agent involvement enhanced their job performance, allowed them to positively influence county stakeholders, contributed to core job competencies, and increased knowledge in forest health. Incorporating extension with research throughout the course of this study has been beneficial for both research outcomes and knowledge transfer.

Limited Scope Risk Assessment for Nontarget Ground-Dwelling Arthropods From Systemic Insecticide Applications to Young Pines.

The Nantucket pine tip moth (NPTM) [Rhyacionia frustrana (Comstock)], a native regeneration pest on young loblolly pines (Pinus taeda L.), negatively impacts pine growth. An emerging management approach is to apply systemic insecticides to seedlings to reduce NPTM damage. These systemic insecticide applications generally occur once, perhaps twice, during the first few years of loblolly pine growth. However, these applications could lead to unintended environmental consequences to nontarget organisms. The purpose of this study was to assess potential nontarget effects from four systemic insecticide applications by assessing ground-dwelling arthropod trap catch, with a focus on collembolan trap catch and genera richness. Loblolly seedlings (24 seedlings per plot) at three sites in southeast Georgia were treated with either chlorantraniliprole, dinotefuran, fipronil, or imidacloprid or left untreated as a control. Arthropods were collected with pitfall traps that were deployed for 5 d in July, August, and September 2019, 7-9 mo after treatment. Ground-dwelling arthropod trap catch, arthropod order trap catch, collembolan trap catch, and collembolan genera richness did not vary among insecticide treatments and the untreated control in this mid-term insecticide risk assessment. While no significant effects of insecticide treatment were observed, ground-dwelling arthropod trap catch, collembolan trap catch, and collembolan genera richness differed among collection times. This study was the first of its kind in a young pine stand setting and is an important first step to understanding risk in these settings. Information on nontarget risks of management practices informs growers of the level of environmental risk associated with systemic insecticides.

A review of the introduced forest pests in Brazil

Abstract: Special attention should be given to forest plantings in order to minimize the probability of exotic pest introduction and, consequently, of production losses. The objective of this review was to present, under a historic perspective, the main exotic insects that harm the Brazilian forest sector. Therefore, to better describe the phytosanitary context of introduced forest pests in Brazil, the main information regarding these insects was gathered here. Introduced species and species with a risk of introduction were listed. The following species were registered: 12 exotic introduced species related to eucalyptus, non-quarantine; 9 species related to pine, one quarantine; and 1 species related to teak, quarantine. Overall, the core problems for 57 pest species were addressed, followed by projections on current risks and priorities. Biological control programs and their respective agents were also mentioned. For eucalyptus plantations, the species belonging to the genera Ophelimus and Leptocybe are priorities and should be emphasized. Regarding pine species, the main current concerns are Bursaphelenchus xylophilus (transmitted by species of Monochamus), Rhyacionia frustrana, and Dendroctonus frontalis. Better risk management requires reinforcement of phytosanitary inspections and constant refinement of contingency plans, whose actions include monitoring by visual sampling, employment of sentinel plants, and preventive breeding programs aiming at pest resistance.

Systemic Control of Nantucket Pine Tip Moth (Rhyacionia frustrana Scudder in Comstock, 1880) Enhances Seedling Vigor, Plantation Establishment, and Early Stand-Level Productivity in Pinus taeda L.

Establishment is a vulnerable and expensive stage of stand development in intensively managed pine plantations. We evaluated the capacity of establishing loblolly pine (Pinus taeda L.) plantations to increase productivity by systemic control of Nantucket pine tip moth (Rhyacionia frustrana Scudder in Comstock, 1880). In January 2009, four genotypes of improved genetics loblolly pine were planted in whole-plot treatments of herbaceous competition control at an upper coastal plain (UCP) site and phosphorus fertilization at a lower coastal plain (LCP) site, and split-plot treatments of tip moth control. Trees were monitored for tip moth infestation levels, vigor, survival, and stand-level biomass production for 2 years. During this time, tip moth infestation levels were very high at both sites, averaging 69% at UCP and 70% at LCP. However, levels averaged only 8% at UCP and 39% at LCP in treatments that included applications of systemic insecticides at planting. At LCP, biomass production averaged 2,159 kg ha 1 after 2 years. Protection from tip moth increased LCP biomass by 11% averaged across genotypes and 20 –30% for the most responsive genotypes. At UCP, 2-year pine biomass production was much lower at 114.5 kg ha 1 and was increased 150% by protection from tip moth. At UCP, there was a strong effect of genetics whereby one genotype experienced very high mortality (mean of 30%) attributed to meteorological conditions of the establishment year; however, this was greatly decreased (17%) by protection from the interacting stress of tip moth damage. We conclude that systemic control of tip moth using imidacloprid soil tablets has the potential to greatly enhance pine plantation establishment success and early productivity in areas of heavy pest pressure, which may compound through stand development.

Use of Systemic Fipronil and Imidacloprid to Control Regeneration Pests of Loblolly Pine

Regeneration pests of loblolly pine (Pinus taeda L.) threaten growth and survival in intensively managed loblolly pine plantations throughout the southeastern United States. The Nantucket pine tip moth, Rhyacionia frustrana (Comstock), in particular, often reduces growth of loblolly pine but has been difficult to control with traditional insecticides due to multiple annual generations and multi-year infestations which are difficult to predict in timing and location. Relatively new systemic insecticide products offer a solution in that their efficacy persists through multiple generations and years after a single application. Efficacy of systemic imidacloprid and fipronil were evaluated side by side across multiple sites in Virginia. Significant reductions in Nantucket pine tip moth damage were noted in trees treated with either the imidacloprid or fipronil product compared with check trees. After 2 yr, growth improvement of treated trees relative to controls was modest and not significant at all sites, but per acre volume indices were significantly greater in treated blocks as a result of higher tree survival. Reduced seedling mortality was attributed primarily to prevention of damage by pales weevil, Hylobius pales Herbst (Coleoptera: Curculionidae), by both insecticide treatments. Control of pales weevil in addition to pine tip moth suggests that systemic insecticide products with a long window of efficacy might control additional nontargeted pests.

History, Distribution, Damage, and Life Cycle of a Pine Shoot Gall Sawfly, Xyela gallicaulis (Hymenoptera: Xyelidae)

Larvae of Xyela gallicaulis Smith cause shoot stem galls in young pines. Loblolly pine, Pinus taeda L., is the most seriously damaged, but galls have been observed on slash pine, P. elliottii var. elliottii Engelm., and shortleaf pine, P. echinata Mill. Studies in Virginia and Georgia confirm a 2-year life cycle. Larval development takes 4 - 6 wks. After feeding, larvae bore out of the galls and drop to the ground where they form a papery cocoon in the soil to pupate, and where they remain for 22 - 25 months. Adults emerge from cells constructed in the soil from early-December to mid-January of the second year. Eggs are inserted into the vegetative buds during odd-numbered years. Insect associates found feeding in or on gall tissues are the Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Tortricidae), and the weevil Conotrachelus carolinensis Schoof (Curculionidae).

Operational Considerations for Augmentation of <I>Trichogramma exiguum</I> (Hymenoptera: Trichogrammatidae) for Suppression of <I>Rhyacionia frustrana</I> (Lepidoptera: Tortricidae) in <I>Pinus taeda</I> Plantations

Studies were performed to assess the operational feasibility of Trichogramma exiguum Pinto & Platner (Hymenoptera: Trichogrammatidae) augmentation for suppression of the Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae), in commercial loblolly pine, Pinus taeda L., plantations. Single inundative releases containing two cohorts of encapsulated T. exiguum at a potential rate of 224,200 +/- 27,600 females per ha per cohort were made into two 4-ha plots during the second R. frustrana generation in 2000. Augmentation failed to increase parasitism rates above those occurring naturally; yet, 10% fewer shoots were attacked by R. frustrana, but not below acceptable levels. Quality control data suggest that low emergence levels and intense predation by ants upon developing T. exiguum lowered actual release rates to 13,000 +/- 900 females per ha per cohort. The effect of capsule distribution and microclimate on the discovery of capsules by predators (indicated by some E. kuehniella egg removal), parasitoid predation (percentage of eggs removed or destroyed), and subsequent parasitoid emergence was investigated. Uniformly distributed capsules experienced significantly higher predation levels than clustered capsules, and capsules exposed to field conditions for 5 d experienced higher predation than those exposed for 3 d, independently of distribution. Discovery of capsules by predators was unaffected by distribution or exposure period. Microhabitat significantly impacted average maximum daily temperature, the number of consecutive hours per day at or above 35 degrees C, and parasitoid emergence percentages. Parasitoid emergence declined significantly in response to increasing number of consecutive hours per day above 35 degrees C. Microclimate did not impact capsule discovery by predators or predation levels. Augmentation of T. exiguum for suppression of R. frustrana damage may not be practical within P. taeda plantations.

Operational Considerations for Augmentation of Trichogramma exiguum (Hymenoptera: Trichogrammatidae) for Suppression of Rhyacionia frustrana (Lepidoptera: Tortricidae) in Pinus taeda Plantations

Studies were performed to assess the operational feasibility of Trichogramma exiguum Pinto & Platner (Hymenoptera: Trichogrammatidae) augmentation for suppression of the Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae), in commercial loblolly pine, Pinus taeda L., plantations. Single inundative releases containing two cohorts of encapsulated T. exiguum at a potential rate of 224,200 ± 27,600 females per ha per cohort were made into two 4-ha plots during the second R. frustrana generation in 2000. Augmentation failed to increase parasitism rates above those occurring naturally; yet, 10% fewer shoots were attacked by R. frustrana, but not below acceptable levels. Quality control data suggest that low emergence levels and intense predation by ants upon developing T. exiguum lowered actual release rates to 13,000 ± 900 females per ha per cohort. The effect of capsule distribution and microclimate on the discovery of capsules by predators (indicated by some E. kuehniella egg removal), parasitoid predation (percentage of eggs removed or destroyed), and subsequent parasitoid emergence was investigated. Uniformly distributed capsules experienced significantly higher predation levels than clustered capsules, and capsules exposed to field conditions for 5 d experienced higher predation than those exposed for 3 d, independently of distribution. Discovery of capsules by predators was unaffected by distribution or exposure period. Microhabitat significantly impacted average maximum daily temperature, the number of consecutive hours per day at or above 35°C, and parasitoid emergence percentages. Parasitoid emergence declined significantly in response to increasing number of consecutive hours per day above 35°C. Microclimate did not impact capsule discovery by predators or predation levels. Augmentation of T. exiguum for suppression of R. frustrana damage may not be practical within P. taeda plantations.

New Characters for Determining the Gender of Rhyacionia frustrana Pupae (Lepidoptera: Tortricidae)

The Nantucket pine tip moth, Rhyacionia frustrana (Scudder in Comstock) is a common pest of several southern pine species. Some tip moth research requires the sexing of pupae in order to collect emerging adults of known ages or unmated females. Characters for determining the sex of tip moth pupae were originally described in 1969. Here, we revise one of the published characters and describe seven new characters that may be used for gender determination. The new sexually dimorphic characters are: articulation of the seventh abdominal segment, dorsal spines of the second abdominal segment, length of the metathoracic tarsi, distribution of cremasteral setae, shape of the mandibular sclerite, antenna length and antenna shape.

Occurrence ofRhyacionia frustrana onPinus brutia in the Aegean Region of Turkey

The Nantucket pine tip moth (Rhyacionia frustrana (Comstock) (Lep., Tortricidae)) has been found on Turkish red pine (Pinus brutia L.) in the Aegean Region of Turkey.

Control of Low-Level Nantucket Pine Tip Moth Populations: A Cost-Benefit Analysis

Abstract The Nantucket pine tip moth, Rhyacionia frustrana, an important pest of intensively managed loblolly pine, can cause significant long-term volume loss in plantations. The primary objective of this study was to establish an economic damage threshold beyond which chemical control of this pest becomes cost-effective. Tip moth damage estimates were obtained from 200 trees for each generation over a 3-year period after planting on two sites in the Georgia Piedmont. A volume index (D2H) was obtained for each of these trees at the end of the study. Significant reductions in volume were observed among trees with relatively low damage levels (10–30% of shoots infested on average over a 3-year period) compared with those trees sprayed with insecticide throughout the study. Growth projection models were used to extrapolate 3-year volume differences among treatments to a full rotation. These and other parameters were used to calculate land expectation values and, subsequently, willingness to pay values for tip moth control at the beginning of the rotation using various discount rates. The results of this analysis suggest that an economic injury level for R. frustrana may be reached when damage levels, on average, exceed 30% infested shoots. South. J. Appl. For. 30(4):182–187.

Interactions among prescribed fire, herbivore pressure and shortleaf pine ( Pinus echinata) regeneration following southern pine beetle ( Dendroctonus frontalis) mortality

We monitored natural and artificially regenerating shortleaf pine ( Pinus echinata) seedlings and their associated herbivores in forests stands that suffered extensive overstory mortality due to the southern pine beetle ( Dendroctonus frontalis). Seedling performance was evaluated based on survival and absolute and relative growth rates. Trapping stations were established to monitor the abundance and seasonal activity of pine regeneration insects. Seedlings were regularly inspected for the frequency and severity of herbivore pressure. Seedling performance, insect abundance and activity, and herbivore pressure were compared between stands treated with prescribed fire and untreated controls. Survival and absolute growth rates were greatest for naturally regenerating seedlings. Naturally regenerating seedlings grew more vigorously in the burned areas, but prescribed fire did not influence the growth of planted seedlings. Relative height growth comparisons indicated the growth potential of planted seedlings was not significantly different from that of the natural seedlings. Herbivore pressure was greater on natural regeneration, possibly due to superior seedling health and vigor. Pine weevil ( Hylobius pales and Pissodes nemorensis) and Nantucket pine tip moth ( Rhyacionia frustrana) abundance and herbivore pressure did not differ between the burned and unburned stands, but there was a significant interaction between sampling date and prescribed fire on their seasonal activity. Conifer sawfly (Hymenoptera: Diprionidae) abundance and activity was effectively suppressed by prescribed fire treatments. Pine webworm ( Tetralopha robustella) infestations occurred with greater frequency and severity on seedlings growing in burned areas. Mammalian herbivory was minimal. Herbivore-induced seedling mortality was low, and herbivory did not reduce seedling growth. Growth of naturally regenerating shortleaf pine seedlings was greater in burned plots.

Effects of fertilization and herbicides on growth of young loblolly pine and infestations of Nantucket pine tip moth (Lepidoptera: Tortricidae)

A 2-year-old pine plantation was selected to receive treatments of fertilizers and herbicides to evaluate effects on Nantucket pine tip moth infestations and the tree growth parameters of height, diameter and volume increment. Nitrogen and phosphorus fertilizers, and hexazinone and sulfometuron methyl herbicides were used in creating six treatments: (i) control; (ii) phosphorus; (iii) nitrogen and phosphorus; (iv) phosphorus and herbicide; (v) nitrogen, phosphorus and herbicide; and (vi) herbicide. Treatments were applied in 1987 and 1988. In 1987, trees treated with nitrogen, phosphorus and herbicide had significantly greater height, diameter and volume growth than trees not receiving fertilizer treatments, but did not have significantly higher tip moth infestations than control trees. Treatments receiving phosphorus only had much lower tip moth infestation rates than other treatments except nitrogen and phosphorus. In 1988, tip moth infestations were uniformly low, with no differences in treatment effects observed.

Evaluation of Biological and Biorational Control Tactics for Suppression of Nantucket Pine Tip Moth Damage in Virginia Pine Christmas Trees

A study was performed to evaluate the potential of the egg parasitoid Trichogramma exiguum Pinto and Platner (Hymenoptera: Trichogrammatidae), the newly registered insect growth regulator (IGR) tebufenozide (Confirm), and a modified spray technique (top whorl only pesticide application) for suppression of Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae), damage in Virginia pine, Pinus virginiana Mill., Christmas trees. Augmentative releases of T. exiguum failed to increase parasitism levels in release plots compared with controls, and significant reduction in tip moth damage did not occur. High predation levels on released T. exiguum may have contributed to the failure of parasitoid augmentations. Whole-tree and top whorl tebufenozide treatments provided significantly greater damage control than corresponding applications of acephate (Orthene), a commonly used pesticide in Christmas trees. Damage to trees receiving whole-tree chemical applications did not differ significantly from trees receiving top whorl treatments for most measurements of damage. Top whorl chemical treatments resulted in a 67% reduction in time required for application and a 70% reduction in pesticide used.

Evaluation of Biological and Biorational Control Tactics for Suppression of Nantucket Pine Tip Moth Damage in Virginia Pine Christmas Trees

A study was performed to evaluate the potential of the egg parasitoid Trichogramma exiguum Pinto and Platner (Hymenoptera: Trichogrammatidae), the newly registered insect growth regulator (IGR) tebufenozide (Confirm), and a modified spray technique (top whorl only pesticide application) for suppression of Nantucket pine tip moth, Rhyacionia frustrana (Comstock) (Lepidoptera: Tortricidae), damage in Virginia pine, Pinus virginiana Mill., Christmas trees. Augmentative releases of T. exiguum failed to increase parasitism levels in release plots compared with controls, and significant reduction in tip moth damage did not occur. High predation levels on released T. exiguum may have contributed to the failure of parasitoid augmentations. Whole-tree and top whorl tebufenozide treatments provided significantly greater damage control than corresponding applications of acephate (Orthene), a commonly used pesticide in Christmas trees. Damage to trees receiving whole-tree chemical applications did not differ significantly from trees receiving top whorl treatments for most measurements of damage. Top whorl chemical treatments resulted in a 67% reduction in time required for application and a 70% reduction in pesticide used.

Preliminary Tests of an Attracticide Formulation for Control of the Nantucket Pine Tip Moth (Lepidoptera: Tortricidae)

Preliminary Tests of an Attracticide Formulation for Control of the Nantucket Pine Tip Moth (Lepidoptera: Tortricidae)