Evaluating invasion risk and population dynamics of the brown marmorated stink bug across the contiguous United States

Abstract

Background: Invasive species threaten the productivity and stability of natural and managed ecosystems. Predicting the spread of invaders, which can aid in early mitigation efforts, is a major challenge, especially in the face of climate change. While ecological niche models are effective tools to assess habitat suitability for invaders, such models have rarely been created for invasive pest species with rapidly expanding ranges. Here, we leveraged a national monitoring effort from 543 sites over 3 years to assess factors mediating the occurrence and abundance of brown marmorated stink bug (BMSB, Halyomorpha halys), an invasive insect pest that has readily established throughout much of the United States.

Results: We used maximum entropy models to estimate the suitable habitat of BMSB under several climate scenarios, and generalized boosted models to assess environmental factors that regulated BMSB abundance. Our models captured BMSB distribution and abundance with high accuracy, and predicted a 70% increase in suitable habitat under future climate scenarios. However, environmental factors that mediated the geographical distribution of BMSB were different from those driving abundance. While BMSB occurrence was most affected by winter precipitation and proximity to populated areas, BMSB abundance was influenced most strongly by evapotranspiration and solar photoperiod.

Conclusion: Our results suggest that linking models of establishment (occurrence) and population dynamics (abundance) offers a more effective way to forecast the spread and impact of BMSB and other invasive species than simply occurrence-based models, allowing for targeted mitigation efforts. Implications of distribution shifts under climate change are discussed. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Keywords: climate change; distribution change; ecological niche models; invasive species; species distribution models.

Figure 1

Map showing the geographical extent of the study. Sites monitored in each of three study years (2017–2019) are shown in different colors (points overlap across years). The diameter of the circles in each year represents the average weekly captures of adult Halyomorpha halys per three pheromone‐baited traps throughout each season at each site.

Figure 2

The relative contribution of each climate and landscape metric in MAXENT (occurrence) models and GBMs (abundance). Values shown are the result of the ten‐fold model averaging. Scale bars show the proportion of variance explained by each factor in the combined models with both climate and landscape factors. (i) cdl: landcover class; (ii) dem: elevation; (iii) evapot: evapotranspiration; (iv) gdd: growing degree days; (v) hidro: distance to water bodies; (vi) ppt_jan: precipitation in January; (vii) ppt_jul: precipitation in July; (viii) tmax_jul: maximum temperature in July; (ix) tmin_jan: minimum temperature in January; (x) soilph: soil pH; (xi): sol_pho: interaction solar radiation and photoperiod; (xii): urban: distance to urban areas.

Figure 3

Predicted change in habitat suitability for Halyomorpha halys in the 2080s compared to current conditions under the climate scenarios (A) B1 (emphasis on global solutions to economic, social, and environmental sustainability, but without additional climate initiatives) and (B) A1B (a future world of very rapid economic growth, low population growth and rapid introduction of new and more efficient technology) (both rated as moderate). Both panels show changes in climatic habitat suitability from cold (decrease in suitability) to warm colors (increase in suitability). Green tonalities denote no change in habitat suitability for BMSB.