Assessing factors associated with detection probability of the Japanese burrowing cricket (Velarifictorus micado) on point count surveys

Conservationists are tasked with developing effective monitoring regimes
for wildlife of interest. Effective monitoring is especially important for
invasive species to map their spread and develop management strategies.
One invasive species, the Japanese burrowing cricket (Velarifictorus
micado), is steadily spreading across the eastern United States, however,
aural monitoring protocols have never been developed. To inform potential
monitoring efforts for this invasive insect, we conducted aural point
count surveys for V. micado across the Inner Bluegrass Region of central
Kentucky, USA, at all hours of the day from 19 September - 5 November
2024. We generated single-season occupancy models which allowed us to
assess the variables (windspeed, barometric pressure, temperature, time of
day, and ordinal date) that best predicted variation in detection
probability. We detected V. micado at 16 of 49 sites (naive occupancy =
0.33). Detection probability was generally low (p = 0.30 (95% CI: 0.15 –
0.51) and our top model indicated that time of day and ordinal date were
the strongest predictors of detection probability. Specifically, detection
probability was maximized at sunset (p = 0.93) and declined linearly to
sunrise (p = 0.24) and approached zero before noon. The effect of ordinal
date was less dramatic and included a linear decline from 19 September (p
= 0.71) to 5 November (p = 0.10). Our results clearly demonstrate that the
optimal conditions for V. micado point count surveys are during the month
of September and in the hours immediately preceding sunset. Future work
assessing patterns of occupancy probability would be valuable in
understanding the ecology of this invasive insect.