Lycorma Delicatula Research Articles

Climate and host plant availability are favourable to the establishment of Lycorma delicatula in Europe

Climate and host plant availability are favourable to the establishment of <i>Lycorma delicatula</i> in Europe

Lifecycle of Anastatus orientalis (Hymenoptera: Eupelmidae) and synchrony with its host, the spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae).

Anastatus orientalis Yang & Choi (Hymenoptera: Eupelmidae), an egg parasitoid of spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), has been documented emerging from host eggs in both autumn and spring, at the beginning and end of the period that spotted lanternfly eggs are present in the field, suggesting parasitoid-host specificity and synchrony. This study was designed to test whether, under conditions that simulate native and introduced ranges of spotted lanternfly, (a) A. orientalis has 2 and only 2 generations per year, (b) A. orientalis adults sometimes emerge when only nontarget species would be available for parasitization, and (c) emerging parasitoid adults can parasitize unhatched host eggs in the spring. Parasitized spotted lanternfly eggs were collected in 2019 and 2020 from Beijing, China and in 2020 and 2021 from Yantai, China. They were shipped for laboratory study in growth chambers programmed to simulate temperature and daylength for collection locations in China and in the invaded range in Pennsylvania, United States. Anastatus orientalis had a flexible lifecycle depending on environmental conditions and possibly genetic makeup, with 1-3 generations per year, and parasitoid emergence was not always synchronous with host egg availability. Additionally, given the cooler temperatures in Pennsylvania, autumn parasitoid emergence was often delayed until late October or November, no progeny were produced, and parasitoid populations died out. Anastatus orientalis does not exhibit host synchrony characteristics that would make it a good candidate for a classical biological control program.

Evaluation of Volatile Organic Compounds from Spotted Lanternfly (Lycorma delicatula) Eggs Using Headspace Odor Sampling Methods.

The spotted lanternfly (SLF) is an invasive species native to China. It was first discovered in the United States in Pennsylvania in 2014. It is known to cause great economic damage by destroying various crops, specifically grape vines, and therefore, several efforts have been made to control and mitigate its spread from the Northeast. Canine detection is a useful detection tool; however, it is crucial to understand the volatile organic compounds emitting by this pest to better direct canine training paradigms to prevent false alerts and to understand potential volatile markers of importance indicative of this species. The purpose of this study is to address the gap in research regarding the volatile organic compound (VOC) profile of SLF to better inform pest control mitigation strategies. Instrumental analysis was performed utilizing SPME-GC/MS on cold-killed SLF eggs, dried crickets, and tree bark. Differences in detected VOCs within each sample set depicted distinctive odor profiles for each matrix tested. Storage of these samples also depicted VOC accumulation variation as a function of time, thereby providing implications for long-term storage and sample handling for these types of training aids in canine applications.

Is Lycorma delicatula (Hemiptera: Fulgoridae) a blooming threat to citrus?

Examining the host range of emerging invasive insects is essential to assess their invasion potential and to anticipate the negative impacts of their spread. The ongoing North American invasion of spotted lanternfly (SLF) [Lycorma delicatula (White, 1845)] threatens agricultural, urban, and natural areas. The survival and development of SLF nymphs on Washington navel orange [Citrus sinensis (L.) Osbeck (Sapindales: Rutaceae)] trees were assessed in a quarantine facility. Results indicated that SLF nymphs can develop to at least the third instar by feeding exclusively on Washington navel orange. This finding suggests that, at least up to the third stage of nymphal development, Washington navel orange might be a suitable host for SLF, highlighting the possibility that this invasive pest represents an unrecognized threat to this globally important crop and possibly to other Citrus species.

Globally suitable areas for Lycorma delicatula based on an optimized Maxent model.

Lycorma delicatula, a globally invasive pest, has caused considerable economic losses in many countries. Determining the potential distribution range of L. delicatula is crucial for its effective management and control; however, our understanding of this species remains limited. In this study, Maxent model with occurrence records and environmental variables were fit first and then optimized by selecting the best combination of feature classes and regularization multipliers using the lowest score of corrected Akaike information criterion. Subsequently, we predicted global suitable areas for L. delicatula both currently and in the future (2041-2060, 2061-2080, and 2081-2100). The results indicated that the mean temperature of the driest quarter is the most important environmental variable limiting L. delicatula distribution. Currently, the suitable areas are concentrated in East Asia (mainly in China, South Korea, and Japan), central and eastern United States, and southern Europe. Compared with current environmental conditions, in all future climate scenarios, the number of suitable areas for L. delicatula increased. In addition, we revealed that suitable areas are likely to expand northward in the future. Our study results suggest that policymakers and governments should prioritize the development of pest management measures in suitable areas for L. delicatula, especially in high suitable areas, to control this invasive pest and minimize global economic losses.

Modeling human activity-related spread of the spotted lanternfly (Lycorma delicatula) in the US.

The spotted lanternfly (Lycorma delicatula) has recently spread from its native range to several other countries and forecasts predict that it may become a global invasive pest. In particular, since its confirmed presence in the United States in 2014 it has established itself as a major invasive pest in the Mid-Atlantic region where it is damaging both naturally occurring and commercially important farmed plants. Quarantine zones have been introduced to contain the infestation, but the spread to new areas continues. At present the pathways and drivers of spread are not well-understood. In particular, several human activity related factors have been proposed to contribute to the spread; however, which features of the current spread can be attributed to these factors remains unclear. Here we collect county level data on infestation status and four specific human activity related factors and use statistical methods to determine whether there is evidence for an association between the factors and infestation. Then we construct a network model based on the factors found to be associated with infestation and use it to simulate local spread. We find that the model reproduces key features of the spread 2014 to 2021. In particular, the growth of the main infestation region and the opening of spread corridors in the westward and southwestern directions is consistent with data and the model accurately forecasts the correct infestation status at the county level in 2021 with 81% accuracy. We then use the model to forecast the spread up to 2025 in a larger region. Given that this model is based on a few human activity related factors that can be targeted, it may prove useful to incorporate it into more elaborate predictive forecasting models and in informing management efforts focused on interstate highway transport and garden centers in the US and potentially for current and future invasions elsewhere globally.

The Spotted Lanternfly Contains High Concentrations of Plant Hormones in its Salivary Glands: Implications in Host Plant Interactions.

The spotted lanternfly (SLF), Lycorma delicatula is an invasive species in the United States that has emerged as a significant pest in vineyards. This polyphagous insect causes significant damage to grapevines and tree of heaven (TOH). SLF feeds voraciously on plant tissues using its piercing and sucking mouthparts through which it injects saliva and uptakes plant sap. Despite its impact, research on fundamental mechanisms mediating SLF interactions with their predominant hosts is limited. This study documents the morphology of salivary glands and quantifies plant hormones in salivary glands of SLF adults fed on grapevines and TOH using Liquid Chromatography-Mass Spectrometry (LC/MS). SLF adults have one pair of large salivary glands, ranging from 10 to 15mm in length that extend from the insect's head to the last sections of the abdomen. The salivary glands of SLF contain salicylic acid (89 ng/g), abscisic acid (6.5 ng/g), 12-oxo-phytodienoic acid (5.7 ng/g), indole-3-acetic acid (2 ng/g), jasmonic acid (0.6 ng/g), jasmonic acid isoleucine (0.037 ng/g), and the cytokinin ribosides trans-zeatin (0.6 ng/g) and cis-zeatin (0.1 ng/g). While the concentrations of these hormones were similar in insects fed on grapevines and TOH, abscisic acid was more abundant in insects fed on grapevines, and jasmonic acid isoleucine was only detected in insects fed on grape. These results are discussed in the context of the possible implications that these hormones may have on the regulation of plant defenses. This study contributes to our understanding of the composition of SLF saliva and its potential role in plant immunity.

Influence of Spotted Lanternfly (Lycorma delicatula) on Multiple Maple (Acer spp.) Species Canopy Foliar Spectral and Chemical Profiles

Invasive species have historically disrupted environments by outcompeting, displacing, and extirpating native species, resulting in significant environmental and economic damage. Developing approaches to detect the presence of invasive species, favorable habitats for their establishment, and predicting their potential spread are underutilized management strategies to effectively protect the environment and the economy. Spotted lanternfly (SLF, Lycorma delicatula) is a phloem-feeding planthopper native to China that poses a severe threat to horticultural and forest products in the United States. Tools are being developed to contain the spread and damage caused by SLF; however, methods to rapidly detect novel infestations or low-density populations are lacking. Vegetation spectroscopy is an approach that can represent vegetation health through changes in the reflectance and absorption of radiation based on plant physiochemical status. Here, we hypothesize that SLF infestations change the spectral and chemical characteristics of tree canopies. To test this hypothesis, we used a full range spectroradiometer to sample canopy foliage of silver maple (Acer saccharinum) and red maple (Acer rubrum) trees in a common garden in Berks County, Pennsylvania that were exposed to varying levels of SLF infestation. Foliar spectral profiles separated between SLF infestation levels, and the magnitude of separation was greater for the zero-SLF control compared with higher infestation levels. We found the red-edge and portions of the NIR and SWIR regions were most strongly related to SLF infestation densities and that corresponding changes in vegetation indexes related to levels of chlorophyll were influenced by SLF infestations, although we found no change in foliar levels of chlorophyll. We found no influence of SLF densities on levels of primary metabolites (i.e., pigments, nonstructural carbohydrates, carbon, and nitrogen), but did find an increase in the phenolic compound ferulic acid in response to increasing SLF infestations; this response was only in red maple, suggesting a possible species-specific response related to SLF feeding. By identifying changes in spectral and chemical properties of canopy leaves in response to SLF infestation, we can link them together to potentially better understand how trees respond to SLF feeding pressure and more rapidly identify SLF infestations.

Experimental evidence supports the ability of spotted lanternfly to hitchhike on vehicle exteriors as a mechanism for anthropogenic dispersal.

Historically, anecdotal observations support the likelihood of human-assisted invasive insect dispersal to new environments. No previous studies have investigated the ability of insects to remain attached to moving vehicles; however, such information is critical for prioritizing research, mitigation activities and understanding anthropogenic effects on biotic communities. Lycorma delicatula (White), spotted lanternfly (SLF), an invasive insect whose range is currently expanding throughout the United States, is commonly observed in urban settings and near transportation hubs. We developed a novel method to test SLF's ability to remain on vehicle surfaces including bonnet, nose wing, windscreen, wipers and scuttle panel using laminar wind flow from 0 to 100 ± 5 km h-1. We found all mobile life stages (nymphs and adults) could remain on the vehicle up to 100 km h-1. First instar nymphs and early season adults remained attached at significantly higher wind speeds than other stages. A brief acclimatization period prior to wind delivery increased attachment duration for all life stages except later season adults. The importance of outliers in the success of invasive species is well established. Given these results, any hitchhiking SLF could potentially establish incipient populations. This methodology will be beneficial for exploring human-assisted dispersal of other invasive arthropods.

Proactive biological control of spotted lanternfly: Parasitism and host feeding behavior of Anastatus orientalis (Hymenoptera: Eupelmidae) on Lycorma delicatula (Hemiptera: Fulgoridae) egg masses

Lycorma delicatula (Hemiptera: Fulgoridae) is a recognized threat to perennial vine, tree crops, and forest ecosystems. Native to China, L. delicatula has invaded eastern Asian countries (The Republic of Korea [i.e., South Korea] and Japan) and is spreading rapidly through the eastern and mid-western regions of the USA. Stablished populations in these regions present a significant incursion threat to California’s multi-billion-dollar perennial crops (e.g., grape and nut production). As a part of a proactive classical biological control program targeting L. delicatula in California, USA, the egg parasitoid, Anastatus orientalis (Hymenoptera: Eupelmidae), is being evaluated for possible use against this pest should it establish in California. In support of this proactive research, the oviposition and host feeding behavior of A. orientalis was investigated. The effect of time exposure (i.e., 48-, 72-, 96-, 168-hours) on the percentage of eggs parasitized by 7-day old female parasitoids previously exposed to L. delicatula egg masses in presence/absence of a conspecific male was also investigated. Parasitism rates were significantly higher after 96 h of exposure time and offspring sex ratio did not change in any of the treatments (i.e., exposure time, presence/absence of a male). In another experiment, mated and unmated female parasitoids of three different ages (i.e., ≤ 24-, 72- and 120 h of age) were digitally video recorded for 24 h while foraging on L. delicatula egg masses and host use behaviors were quantified. Anastatus orientalis females that were 72 h old (mated) and 120 h (mated and unmated) spent significantly more time antennating and probing/ovipositing in L. delicatula egg masses than younger unmated females. An increase in host feeding behavior was always associated with increased oviposition behavior. No detrimental effects of host feeding on rates of parasitism and A. orientalis offspring emergence were detected. This finding confirms that A. orientalis is a concurrent parasitoid and can use the same host egg for feeding and parasitism. Implications of these results on possible rearing and release strategies of A. orientalis as a biological control agent of L. delicatula are discussed.

Evaluation of insecticide residues against spotted lanternfly (Hemiptera: Fulgoridae).

Lycorma delicatula White (Hemiptera: Fulgoridae), spotted lanternfly, is a univoltine, phloem-feeding, polyphagous and invasive insect in the United States. Although a primary host for this species is Ailanthus altissima (Mill.) Swingle, tree of heaven, L. delicatula also feeds on many other plant species, including cultivated grapevines. As this species continues to spread, it is important to develop effective management tools. Here, we evaluated the residual efficacy of 4 insecticides commonly used in tree fruit management programs: dinotefuran, bifenthrin, carbaryl, and thiamethoxam. First, all mobile life stages (early instars, late instars, and adults) of L. delicatula were exposed for 1 h to dry insecticide residues (18 h old) applied to glass or A. altissima bark surfaces. While some mortality was detected immediately following the 1 h exposure period, 100% mortality occurred within 24 h for all materials and life stages exposed on both glass and bark surfaces. To evaluate longer residual activity of these materials, groups of adult L. delicatula were introduced into cages containing A. altissima trees treated with the same individual insecticides and exposed 6 h to residues that were 18 h or 7 days old. Paired, untreated A. altissima served as controls. In these bioassays, 48 h mortality for 18 h old residue reached 95% for thiamethoxam and 100% for bifenthrin and dinotefuran. Seven-day-old bifenthrin and dinotefuran residues again yielded 100% mortality, while thiamethoxam resulted in 58% mortality, and carbaryl yielded only 13.3% and was not significantly different from the control. These results clearly document the efficacy of specific insecticide applications as management tools against L. delicatula.

Using Pose Estimation and 3D Rendered Models to Study Leg-Mediated Self-righting by Lanternflies.

The ability to upright quickly and efficiently when overturned on the ground (terrestrial self-righting) is crucial for living organisms and robots. Previous studies have mapped the diverse behaviors used by various animals to self-right on different substrates, and proposed physical models to explain how body morphology can favor specific self-righting methods. However, to our knowledge, no studies have quantified and modeled all of an animal's limb motions during these complicated behaviors. Here, we studied terrestrial self-righting by immature invasive spotted lanternflies (Lycorma delicatula), an insect species that must frequently recover from being overturned after jumping and falling in its native habitat. These nymphs self-righted successfully in 92-100% of trials on three substrates with different friction and roughness, with no significant difference in the time or number of attempts required. They accomplished this using three stereotypic sequences of movements. To understand these motions, we combined 3D poses tracked on multi-view high-speed video with articulated 3D models created using photogrammetry and Blender rendering software. The results were used to calculate the mechanical properties (e.g., potential and kinetic energy, angular speed, stability margin, torque, force, etc.) of these insects during righting trials. We used an inverted physical pendulum model (a "template") to estimate the kinetic energy available in comparison to the increase in potential energy required to flip over. While these insects began righting using primarily quasistatic motions, they also used dynamic leg motions to achieve final tip-over. However, this template did not describe important features of the insect's center of mass trajectory and rotational dynamics, necessitating the use of an "anchor" model comprising the 3D rendered body model and six articulated two-segment legs to model the body's internal degrees of freedom and capture the role of the legs' contribution to inertial reorientation. This anchor elucidated the sequence of highly coordinated leg movements these insects used for propulsion, adhesion, and inertial reorientation during righting, and how they frequently pivot about a body contact point on the ground to flip upright. In the most frequently used method, diagonal rotation, these motions allowed nymphs to spin their bodies to upright with lower force with a greater stability margin compared to the other less frequently used methods. We provide a concise overview of necessary background on 3D orientation and rotational dynamics, and the resources required to apply these low-cost modeling methods to other problems in biomechanics.

Effects of host plants on spotted lanternfly (Hemiptera: Fulgoridae) nymphal survival and development.

Spotted lanternfly, Lycorma delicatula (White), is an invasive planthopper from China, which was first detected in Berks County, PA, in 2014 and has since spread to adjacent states including New Jersey in 2018. Lycorma delicatula is a polyphagous species that gregariously feeds on over 172 known hosts. We investigated development on key host plants Ailanthus altissima (Miller) (Sapindales: Simaroubaceae), Juglans nigra (L.) (Fagales: Juglandaceae), Acer rubrum (L.) (Sapindales: Sapindaceae), and Vitis vinifera (L.) (Vitales: Vitaceae) for each instar to elucidate potential host use throughout the season and target monitoring efforts. Our study indicated significant differences in survivorship and time spent in each nymphal life stage between host plants. We applied a host suitability index as a function of survivorship and development for each host plant and instar, which indicated A. altissima and J. nigra as suitable hosts for all 4 nymphal instars. Vitis vinifera was highly suitable for first and second instars but had low indices for the third and fourth instars, although suitability of V. vinifera may have varied based on variety and age of the vine. Lycorma delicatula nymphs had the lowest survivorship and longest development time on A. rubrum across all 4 life stages, despite this being a preferred oviposition host. Host had a significant effect on the morphometrics we measured within the first and second instars.

The subapical labial sensory organ of spotted lanternfly Lycorma delicatula.

Deciphering how spotted lanternfly (SLF), an invasive polyphagous planthopper in North America, engages with its environment is a pressing issue with fundamental biological significance and economic importance. This interaction primarily depends on olfaction. However, the cellular basis of olfaction in SLF remains elusive. Here we investigate the neuronal and functional organization of the subapical labial sensory organ using scanning electron microscopy and electrophysiological recordings. This organ is believed to supply planthoppers with crucial sensory information that influences their subsequent feeding behaviour. We find in SLF that this organ comprises two identical placoid sensilla, each housing two distinct neurons. The A neuron displays a remarkable sensitivity to changes in airflow speed. Importantly, the same neuron also exhibits robust excitatory responses exclusively to three aldehydes out of a diverse pool of 85 tested odorants and inhibitory responses to 62 other odorants. By contrast, the B neuron solely serves as an olfactory detector, showing strong excitatory responses to 17 odorants and inhibitory responses to only three. The results provide a potential cellular basis for the behavioural responses of SLF to its ecologically relevant stimuli. Our study also identifies new odorants that may be useful for managing this serious pest.

Antennal Sensitivity of Spotted Lanternflies, Lycorma delicatula: Differential Electrophysiological Responses of Males and Females to Compounds Derived from Host Plants and Conspecifics.

In herbivorous insects, antennae play a crucial role in chemical communication and orientation when locating host plants and mates. To evaluate antennal sensitivity in response to odor stimuli, electroantennography (EAG) has been a practical technique. In the current study of the invasive spotted lanternfly (SLF), Lycorma delicatula (Hemiptera: Fulgoridae), we evaluated and compared their antennal sensitivity to a series of volatile chemicals collected from their bodies, honeydew, and host plants. To do this, we exposed the antennae of SLF fourth-instar and adult males and females to individual chemicals at a fixed dose of 50 ng. Further, a series of dose-response tests were carried out within a range of 0.5 to 100 ng. Although the amplitude of antennal responses varied among stages and sexes, adult males generated the strongest antennal responses in both experiments. In dose-response experiments, increased doses of chemicals up to 50 ng revealed the saturation points except in adult females which required a higher dose (100 ng) to reveal the saturation point. Although EAG does not provide any information on behavioral responses, our results are consistent with the olfactory bioassays in previous publications in which adult males, not females, were attracted to natural volatiles of their conspecifics. EAG indicated a higher sensitivity of adult male antennae to odor stimuli, particularly conspecific volatiles, than female antennae and highlighted sexual differences in the perception of chemical cues in SLF.

In-Depth Analysis of Spotted Lanternfly Intrusion Patterns

The Spotted Lanternfly (SLF), Lycorma delicatula, is an invasive pest that originates from Asia and poses a significant threat to agricultural and forest ecosystems in regions where it has been introduced. Its ability to feed on a wide range of host plants allows for rapid population growth and spread, making it a growing concern for ecologists and agriculturalists. Current research efforts are focused on understanding the invasion dynamics of SLF, utilizing spatial analysis and population modeling to predict its spread. Extensive field surveys and citizen science data are being leveraged to map the current distribution and identify factors contributing to its expansion. Analytical models are being refined to include climatic, geographical, and human-mediated factors to enhance the accuracy of predictions. The impact of human trade and travel as vectors for SLF dissemination is assessed, highlighting critical control points for intervention. A cost-benefit analysis of various management strategies offers a pragmatic perspective on resource allocation for containment and eradication. Moreover, the paper explores the ecological repercussions of SLF establishment, including the disruption of native species interactions and the cascading effects on biodiversity. This research aims to provide a robust framework for predicting and managing the spread of SLF, informing policy decisions and resource management. Looking forward, this research paves the way for adaptive management approaches tailored to the changing dynamics of invasive species threats in the context of global environmental change.

Effects of temperature on the survival of spotted lanternfly active life stages when held without food

Abstract Spotted lanternfly, Lycorma delicatula White (Hemiptera: Fulgoridae), is an invasive Southeast Asian planthopper that was recently introduced into the eastern United States and spreads along human transportation corridors by ‘hitch‐hiking’ on vehicles and cargo. To better understand the risk of establishment when mobile life stages are moved, it is critical to know how long spotted lanternfly mobile life stages will survive without food and water under different temperatures. This work reports on spotted lanternfly first, second, and third instar nymphal and adult survival without food over the 10–30°C temperature range. Survival time without food declined exponentially as temperature increased for all life stages of spotted lanternfly that were evaluated. At temperatures &lt;30°C, first instar nymphs survived longer than second or third instar individuals. Female adults survived about 1 day longer than male adults at all but 10 and 25°C. Without food, 99% of all adults of both sexes are predicted to be dead in less than a week over the temperature range evaluated. First instars, which were the smallest, survived the longest and their survival exponentially decreased as temperature increased. This suggests that more attention to first instar movement may be warranted. The data presented here will provide a basis for assessing the risk of survival of transported spotted lanternfly active life stages along various pathways.

Radio Telemetry and Harmonic Radar Tracking of the Spotted Lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae).

Lycorma delicatula (White) (Hemiptera: Fulgoridae), spotted lanternfly (SLF), is an invasive pest that feeds and oviposits on numerous woody and herbaceous plants important to agricultural, forest, ornamental, and nursery industries. Describing and understanding SLF movements is key to implementing surveillance and control strategies for this pest and projecting population spread. We used radio telemetry (RT) and harmonic radar (HR) to track the movements of individual SLF at field sites in eastern Pennsylvania and northwestern New Jersey. SLF equipped with HR or RT tags were tracked in 2019 and 2020 from adult emergence until oviposition time, and their movements are described. Although the bulkier RT tags disproportionately affected the distance traveled by males, which are smaller than females, both males and females were more likely to be lost due to signal attenuation when affixed with the lighter-weight HR tags. Females were tracked moving longer distances than males, with maximum distances of 434 m by a single female and 57 m by a single male. A significant positive relationship was found between their height in trees and the distance of subsequent movement. Adult SLF were found in trees predominantly at heights between 6-9 m high. For the fraction of SLF found at eye level, males, but not females, significantly moved above eye level in the weeks prior to mating, likely resulting in the observed sex ratio shift that defines the Early-2 stage. During mating time, tracked SLF were significantly higher than 8 m and oriented to trees where tight aggregations of SLF were present. This orientation towards tight aggregations started when mating began and peaked in the following 2.5 weeks for males in Late-1 and the beginning of Late-2 (after oviposition began), whereas females started this orientation behavior a half-week after males, and this activity peaked for two weeks. Male and female SLF adults exhibited slight differences in host preference, and strong preferences for wild grape, black walnut, sweet birch, and tree-of-heaven were observed. The HR-tagged nymphs moved up to 27.6 m over a five-day period in a cornfield. Nitinol wire HR tags performed better than Wollaston process or tungsten wire tags. SLF movement parameters in the field are described.

Additional host range testing of Eucryptorrhynchus brandti (Coleoptera: Curculionidae) for the biological control of tree-of-heaven, Ailanthus altissima (Simaroubaceae) in the U.S.A.

ABSTRACT Ailanthus altissima, native to China, is a highly invasive plant in North America, Europe, and other continents. This species displaces native plants by forming dense clonal thickets. Ailanthus altissima is shade intolerant, quickly invades fields, rights-of-way, urban areas, and areas in forests disturbed by logging, fire, or pests. This species is also a primary host of the economically damaging spotted lanternfly, Lycorma delicatula, recently introduced into the U.S. Eucryptorrhynchus brandti is native to China and has been identified as a potential biological control agent of A. altissima. Oviposition studies conducted on 11 non-target plant species demonstrated that E. brandti oviposited only on the U.S. native Leitneria floridana. All non- Leitneria species had adult feeding of less than 2% compared to A. altissima, with no oviposition or larval development. Longevity of E. brandti in no-choice tests with L. floridana and L. pilosa subsp. ozarkana, was shorter and the weevils consumed less foliage compared to A. altissima. Seventeen percent of the L. floridana trees tested had larval feeding and 18 E. brandti adults emerged from 10 replicates. No L. floridana trees with larval feeding died. All the A. altissima trees with larval development died. Eucryptorrhynchus brandti is projected to be an effective agent against A. altissima and pose no significant risk to native North American plant species, with potential to be an additional management tool for the spotted lanternfly.

The Detection of Tree of Heaven (Ailanthus altissima) Using Drones and Optical Sensors: Implications for the Management of Invasive Plants and Insects

Tree of heaven (Ailanthus altissima) is a highly invasive tree species in the USA and the preferred host of an invasive insect, the spotted lanternfly (Lycorma delicatula). Currently, pest managers rely solely on ground surveys for detecting both A. altissima and spotted lanternflies. This study aimed to develop efficient tools for A. altissima detection using drones equipped with optical sensors. Aerial surveys were conducted to determine the optimal season, sensor type, and flight altitudes for A. altissima detection. The results revealed that A. altissima can be detected during different seasons and at specific flight heights. Male inflorescences were identifiable using an RGB sensor in the spring at &lt;40 m, seed clusters were identifiable in summer and fall at &lt;25 m using an RGB sensor, and remnant seed clusters were identifiable in the winter at &lt;20 m using RGB and thermal sensors. Combining all seasonal data allowed for the identification of both male and female A. altissima. This study suggests that employing drones with optical sensors can provide a near real-time and efficient method for A. altissima detection. Such a tool has the potential to aid in the development of effective strategies for monitoring spotted lanternflies and managing A. altissima.