High Temperatures Decrease the Flight Capacity of Diaphorina citri Kuwayama (Hemiptera: Liviidae)

Area of Science:

• Entomology
• Pest Management
• Climate Change Impact

Background:

• Asian citrus psyllid (Diaphorina citri Kuwayama) is an invasive pest and vector of Huanglongbing (HLB).
• ACP spread varies across US citrus-producing regions due to climatic differences.
• The impact of high temperatures and low humidity on ACP flight capacity remains largely unknown.

Purpose of the Study:

• To investigate the effect of high temperatures (>30 °C) and varying relative humidity on ACP flight capacity and propensity.
• To determine temperature and humidity thresholds affecting ACP flight behavior.

Main Methods:

• Utilized a custom-made, temperature-controlled flight mill arena.
• Assessed flight capacity and propensity of ACP under different temperature (26-43 °C) and relative humidity (20-40% and 76-90%) conditions.

Main Results:

• Temperature and humidity significantly influence ACP flight propensity for short (<60 s) and long (≥60 s) flights.
• High relative humidity decreased the proportion of long flights at 26 and 40 °C.
• Flight capacity was affected by temperature but not humidity; higher temperatures negatively correlated with flight distance and duration.

Conclusions:

• ACP can fly across a broad temperature range and is efficient in both high and low humidity.
• Temperatures exceeding 40 °C are detrimental to ACP flight capacity, particularly in semi-arid environments.
• Flight capacity is optimized at 26 °C, with reduced capacity at 32-37 °C and significantly impaired capacity at 40-43 °C.