Spotted Lanternfly (SLF) is an invasive insect that was first detected in Pennsylvania in 2014 and is able to spread quickly through human activity, like transportation, due to the insects’ ability to lay eggs in various environments (Urban, 2020). Since its detection, the SLF threatened many farms and natural ecosystems across North America; with at least 70 known species of hosts and an estimated 255 candidates, without increased intervention the SLF will easily travel westward toward the breadbasket states (Huron & Helmu, 2022). Researchers predict by 2033, SLF will be notably present towards California; moreso, though SLF’s preferred host is Tree of Heaven, agricultural produce like grapes, apples, peaches, and cherries are also at-risk (Jones et. al., 2022). Between 2014 and 2018, the insect has contributed to 25 millions acres of forest loss in the U.S. (Huron & Helmu, 2022). With containment efforts implemented in high infestation areas as late as this year, time is short to control the SLF before serious agricultural and economic consequences unfold. Although there are methods of reducing the SLF with traditional insecticides, there is little research focused on the cost of and effectiveness of applying alternative control methods as viewed by the farmers.
Authors (Names and Percentages): Zheyu Cui (100%)
In this study, our team looks to answer the following:
Do physical deterrents–introducing trained dogs and chickens–and traps–BugBarrier tree tape and tree systematic treatment–reduce SLF populations more than traditional insecticide use at tri-state areas farms producing grapes, apples, peaches, and cherries?
Measuring the SLF population control, which method do farmers prefer and how does their crop yield compare once treatments are implemented?
The first research question will measure the number of SLF within a farm, and the second research question will measure crop yield and a likert opinion survey. The following hypotheses frame our study’s direction:
Research Question 1: H0: Compared to traditional insecticide use, other methods of SLF controls will not be as effective in reducing the SLF populations found on farms. HA: At least one of the other methods will reduce SLF counts on participating farms better than traditional insecticide use.
Research Question 2: H0: Compared to traditional insecticides use, farmers will not experience notable improvements in crop yields once using other methods for SLF population control. Simultaneously, their surveyed opinion will reflect no difference regarding the method. HA: At least one of the other methods for SLF population control will be better than traditional insecticide use in terms of improving crop yields and the farmers’ surveyed opinion will also reflect this.
Authors (Names and Percentages): Yujie Lu (20%), Yuan Shen (20%), Zheyu Cui (20%), Jacob Brandt (20%), Jessica Lee (20%)
Scholarly articles and research were pooled to assist in our study’s design and establish foundational understandings of SLF infestation in the US. Primarily, of the broad-spectrum insecticide classes–pyrethroid, neonicotinoid, and organophosphate– Leach et. al. in her 2019 study discovered that “only the organophosphate chlorpyrifos provided 100% mortality of egg masses,” while exposure caused slowed activity among nymph and adult stages; “only neonicotinoid thiamethoxam and the pyrethroid bifenthrin, however, were able to offer residual mortality”. Building from this study, Coyle et. al. propose using a “trap tree” management approach to contain the SLF identifying the Tree of Heaven as the preferred host of the insect (2019). This requires coating the Tree of Heaven with insecticide and separating male and female variants due to their invasiveness.
As Leach et. al. note, nymph and adult stage SLF not only threaten plants due to their feeding but also their honeydew liquid bi-product can cause a build up of mold that inhibits photosynthesis, especially on fruit plants (2019). Turning to another study focusing on traps, Francese et. al. tested a few traps in their study and found between two brands of tree tape, BugBarrier had a higher catch rate than Web-Cote for catching nymphs and early adult stages during the trapping period; however, comparing the BugBarrior, a circle trunk trap “was significantly more effective at capturing… fourth-instar nymphs than the BugBarrier bands, with no significant difference… between the two trap types for [early] nymph stages’’ (2020). Considering our own research project, while all spotted lanternflies are targeted, containing the population in early stages may promote long-lasting management of SLF.
On the other hand, physical deterrent methods are found useful to reduce the number of SLF as well. Although more research is needed to substantiate the impacts native predators will have on SLF populations, Johnson and Hoover found that chicken is one of the top two predators invading the SLF in their ongoing research project involving the predator-prey relationship of Asian invaders (2021). According to Johnson, chicken as a widespread species has a significant impact on the reduction of SLF by eating them, ranking first among the bird predators (2021).
Furthermore, Decker in his recent study discovered that trained dogs could be beneficial detection tools for targeting SLF (2021). In his proof-of-concept study, he trained six pet dogs to detect the SLF. The dogs completed a training phase and five tests. In the five tests, the mean sensitivity of six dogs was nearly 80% and the mean positive predictive power was around 67% (Decker, 2021). The results showed that pet dogs’ scent detection capability is unparalleled. Also, as Essler et. al. notes, the trained dogs can find live or dead SLF egg masses and learn to ignore the relevant control with high sensitivity and specificity (2021). Based on these findings, the potential of dogs as detection tools to combat the spread of invasive species or agricultural threats can be expanded. In our research, if we use dogs, we can more effectively mitigate the threat of SLF.
Authors (Names and Percentages): Yujie Lu (50%), Jacob Brandt (50%)
Participants
Once farms are recruited as potential participants, they will be asked quality control questions and then randomly assigned to the treatment or control for which they likely qualify.
For the experiment, the study will separate participating farms randomly into five groups based on their treatment and the control being insecticide. Specifically, we will be working with grape, peach, apple and cherry farms in New York, New Jersey, and Pennsylvania. For the trap approach with systemic insecticide application, participating farms will include those with Trees of Heaven on their property.
Sample size (to be discussed in next checkpoint).
Procedures
The research design is structured by comparing SLF control methods. Participants will be treated to either of the five methods of control: introducing trained dogs, chicken, BugBarrier tree trap, Tree of Heaven insecticide systemic trap, and the control group of traditional insecticide use. The control group will use organophosphate insecticide as it can provide 100% egg mass mortality (Leach et al., 2019).
The first the trap treatment involves wrapping trees with BugBarrier tree tape, as the tape targets younger stage SLF most effectively. Furthermore, this trap exploits the behavior pattern of SLF when the nymphs and adults climb up the trunk of their host tree after emerging from eggs.
The second treatment is also a trap but exploits another behavior pattern of SLF. SLF live mainly by sucking sap secreted from their host trees. From the research, we know the Tree of Heaven is the preferred host of SLF; by removing and destroying most female Trees of Heaven and leaving only a few male trees as trap trees, we can then inject systemic insecticides into these trees. Trap trees will kill the SLF when the insect feeds organophosphate-infused sap secretion. If there are no Trees of Heaven on farms, the tree should not be introduced due to its invasiveness.
The third treatment is a physical deterrent by training dogs to detect SLF and their eggs as a means of prevention. During the overwintering period, adults of lanternflies will disappear based on the temperature, and dogs can search out live egg masses, which is an opportunity for quarantine and management of the spread of lanternflies (Essler et al., 2021). The last treatment, a physical deterrent, is replacing dogs with chickens considering they spontaneously feed on SLF or their egg masses.
Data Collection
In the data collection process, we adopt harmonic radar tracking method from Tree of Heaven in NY, NJ, and PA farms to acknowledge the population of SLF before and after the control based on research question 1. Our radar approach sends a light microwave signal to the harmonic tagged sample, which the stimulus signal will radiate back to and be recorded in our receiving system. This advanced tracking system is noticeably improved to capture the size of small insects without impacting their survival abilities under field conditions (Jung et al., 2016). Another data collection for research question 2 is taken by field survey amongst participating farmers in the tri-state area. The survey will ask participating farmers’ their perceptions of the SLF control implemented through a likert scale (1 - Not that effective, and 5 - Very effective), and then tangibly measured through the reported crop yields.
Limitations
The study may contain limitations in sample selection and treatment groups. Firstly, the Tree of Heaven could limit the representation of lanternfly population size. Urban (2019) argues that even though the Tree of Heaven is the preferred host plant for lanternfly, its preference could be assemblage of trees anywhere. Second, the treatment group such as dog and chicken deterrents could be costly for SLF control; for instance, dog training and the chicken method may be a double edged sword solution because while also reducing SLF populations, the chickens may contribute to crop yield loss if they are not monitored when near edible produce.
Authors (Names and Percentages): Yuan Shen (50%), Jessica Lee (50%)
Coyle, D. R., Chong, J. H., & Blaauw, B. A. (2019). Spotted Lanternfly Management in Nurseries, Orchards, Vineyards, and Natural Areas in South Carolina and Georgia. Clemson (SC): Clemson Cooperative Extension, Land-Grant Press by Clemson Extension. http://lgpress.clemson.edu/publication/spotted-lanternfly-management-in-nurseries-orchards-vineyards-and-natural-areas-in-south-carolina-and-georgia/.
Decker, H. (2021). Citizen Science: Training Pet Dogs to Detect the Spotted Lanternfly (Doctoral dissertation, Virginia Tech).
Essler, J. L., Kane, S. A., Collins, A., Ryder, K., DeAngelo, A., Kaynaroglu, P., & Otto, C. M. (2021). Egg masses as training aids for spotted lanternfly Lycorma delicatula detection dogs. PLOS ONE, 16(5). https://doi.org/10.1371/journal.pone.0250945
Francese, J. A., Cooperband, M. F., Murman, K. M., Cannon, S. L., Booth, E. G., Devine, S. M., & Wallace, M. S. (2020). Developing Traps for the Spotted Lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae). Environmental Entomology. https://doi.org/10.1093/ee/nvz166
Harper, J. K., Stone, W., Kelsey, T. W., & Kime, L. F. (2019). Potential economic impact of the spotted lanternfly on agriculture and forestry in Pennsylvania. The Center for Rural Pennsylvania, Harrisburg, PA, 1-84. https://cpb-us-w2.wpmucdn.com/sites.udel.edu/dist/a/9656/files/2021/01/Harper-et-al-2019-Potential-Economic-Impact-of-the-Spotted-Lanternfly-on-Agriculture-and-Forestry-in-Pennsylvania.pdf
Huron, N., & Helmus, M. (2022). Predicting host associations of the invasive spotted lanternfly on trees across the USA. bioRxiv. https://www.biorxiv.org/content/10.1101/2022.09.12.507604v1.full
Jones, C., Skrip, M.M., Seliger, B. J., Jones, S., Wakie, T., Takeuchi, Y., Petras, V., Petrasova, A., & Meentemeyer, R. K. (2022). Spotted lanternfly predicted to establish in California by 2033 without preventative management. Communications Biology, 5, 558. https://doi.org/10.1038/s42003-022-03447-0
Jung, M., Kim, J., Kim, H. G., & Lee, D. H. (2016). Effect of harmonic radar tagging on Lycorma delicatula (Hemiptera: Fulgoridae) nymphal mobility and survivorship. Florida Entomologist, 47-51.
Leach, H., Biddinger, D. J., Krawczyk, G., Smyers, E., & Urban, J. M. (2019). Evaluation of insecticides for control of the spotted lanternfly, Lycorma delicatula, (Hemiptera: Fulgoridae), a new pest of fruit in the Northeastern U.S.. Crop Protection, 124. https://doi.org/10.1016/j.cropro.2019.05.027.
Murman, K., Setliff, G. P., Pugh, C. V., Toolan, M. J., Canlas, I., Cannon, S., … & Cooperband, M. F. (2020). Distribution, survival, and development of spotted lanternfly on host plants found in North America. Environmental entomology, 49(6), 1270-1281. https://academic.oup.com/ee/article/49/6/1270/5947504
Schneck, M. (2021, March 18). Chickens, praying mantises appear to be top predators on spotted lanternfly, study says. Pennlive. https://www.pennlive.com/life/2021/03/chickens-praying-mantises-appear-to-be-top-predators-on-spotted-lanternfly-study-says.html
Urban, J.M. (2020). Perspective: shedding light on spotted lanternfly impacts in the USA. Pest Manag Sci, 76, 10-17. https://doi.org/10.1002/ps.5619
Authors (Names and Percentages): Yujie Lu (20%), Yuan Shen (20%), Zheyu Cui (20%), Jacob Brandt (20%), Jessica Lee (20%)