Spatio-Temporal Model for Predicting Spring Hatch of the Spotted Lanternfly (Hemiptera: Fulgoridae)

Abstract

The effect of temperature on the rate of spotted lanternfly, Lycorma delicatula (White) (Hemiptera: Fulgoridae), egg development was investigated for a population in Pennsylvania. Mean developmental duration (days ± SE) for egg hatch was evaluated at five constant temperatures of 19.9, 24.2, 25.1, 26.7, and 30°C using egg masses laid during the fall of 2018 and collected in 2019 from Berks Co., Pennsylvania. Base temperature thresholds for egg development were estimated using intercept and slope parameters by fitting a linear relationship between average temperature and developmental rate for the Pennsylvania study, two Korean studies, and the combined data sets. The base threshold estimates were then used to calculate seasonal accumulated degree-days (ADD) and construct logistic equations for predicting cumulative proportion of hatch in the spring. The fitted logistic prediction equations were then graphed against the egg hatch observations from field sites in Pennsylvania (2017) and Virginia (2019). When base temperature estimates from the three studies and combined studies were used to calculate ADD, the logistic models predicted similar timing for seasonal egg hatch. Because the slopes and intercepts for these four data sets were not statistically different, a base temperature threshold of 10.4°C derived from the combined model is a good estimate for computing ADD to predict spotted lanternfly spring emergence across a spatio-temporal scale. The combined model was linked with open source weather database and mapping programs to provide spatiotemporal prediction maps to aid pest surveillance and management efforts for spotted lanternfly.

Ecology and genetic structure of the invasive spotted lanternfly Lycorma delicatula in Japan where its distribution is slowly expanding

“…Various biotic and/or abiotic factors seem to be involved in this relatively slow expansion of distribution in Hokuriku, Japan. The most likely factor is the influence of climate, as shown previously 22 , 30 , 31 . Hokuriku has a large amount of precipitation, including snowfall in winter.…”

Temperature sensitivity of pest reproductive numbers in age-structured PDE models, with a focus on the invasive spotted lanternfly

“…(2.1), ν i (t) (units: day −1 ) denotes the rate of development for i ∈ I/{d}, and that of diapause advection for i = d. Due to insect poikilothermy, these advective rates depends on t through temperature, T (units: o C), so that ν i (t) = ν i (T (t)) ≥ 0. Development typically occurs when temperatures exceed some minimal threshold, T ν i ,1 , with development rates increasing with temperature until a plateau is reached at high tempertures [38]. We therefore restrict ourselves to nondecreasing, continuous functions ν i (T ) (i ∈ I/{d}) that satisfy: ν i (T ) = 0 for T < T ν i ,1 , and ν i (T ) → ν i,max > 0 as T → ∞.…”

“…The relative developmental age variable, a, is defined for each of the four life stages with respect to the duration of each stage in typical developmental units. For all life stages of the system except diapausing eggs, the developmental unit is the spotted lanternfly degree day-a measure of heat accumulation, which, in turn, tracks development [38]. Developing individuals accumulate degree days throughout periods of exposure to sufficiently warm temperatures, and, once certain threshold degree day counts are reached, transition to the next life stage.…”

“…Development speeds in SLF are quantified by the degree day function, through which each temperature, T , is assigned a certain number of degree days by which an individual ages in one day of constant exposure to that temperature. The advection coefficients, ν i (T ), have the common piecewise-linear form of the degree day function [38] for i ∈ I/{d}:…”

Performance and host association of spotted lanternfly (Lycorma delicatula) among common woody ornamentals

“…The invasion success of this pest may be partly due to its broad host range 2 , apparent capacity for dispersal 6 , 7 and its potential to occupy a wide range of climatic conditions and ecosystems, especially disturbed habitats where the preferred host Ailanthus altissima (Mill.) Swingle (Simaroubaceae) (tree-of-heaven) is abundant 3 , 8 , 9 .…”