Invaded Range

Lilah Shtino¹

Matthew R. Helmus²

07 August 2026

# attaching necessary packages
library(lydemapr)
library(sf)
library(tidyverse)
library(tigris)

Citation

Keller, J., S De Bona, & MR Helmus. Leveraging spatial scale and temporal variation to track the spread rate of invasive spotted lanternflies (Lycorma delicatula). NeoBiota, 106: 287-307. https://doi.org/10.3897/neobiota.106.177041

knitr::kable(sampling_effort())

| | | 0% | |================================================= | 70% | |======================================================================| 100%

Biological Year	Number of presences	Number of presences with confirmed establishment	Number of absences	Invaded area (km²)	Invasion boundary length (km)	Sampling effort (Obs. per km² area)	Sampling effort (Obs. per km boundary)
2014	84	36	326	38.9	27.6	10.5	14.9
2015	12689	8582	33756	272.2	77.0	170.6	603.2
2016	8953	7122	19706	1706.4	187.6	16.8	152.8
2017	3528	2807	11730	7233.0	401.4	2.1	38.0
2018	7445	5868	102945	16352.6	669.6	6.8	164.9
2019	11194	8050	124220	29391.7	1080.4	4.6	125.3
2020	9118	4422	57712	39837.1	1720.1	1.7	38.9
2021	11167	5540	54770	54451.1	2582.1	1.2	25.5
2022	14753	8175	58462	86886.2	3584.2	0.8	20.4
2023	18332	12313	54493	121495.4	4353.2	0.6	16.7
2024	16834	10007	50322	140571.7	5616.7	0.5	12.0
2025	11254	8770	33089	163333.2	7266.9	0.3	6.1

scale_selection()

Scale selection for α hulls by Youden’s J

## [1] "Please be patient: the large dataset might cause the map to load slowly"

Output of the map_alphahull() function for the 2025 biological year

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1. Temple University, lilah.shtino@temple.edu↩︎

2. Temple University, mrhelmus@temple.edu↩︎