Diaphorina citri (Hemiptera: Psyllidae) is the vector of the putative causal agent for Huanglongbing. Huanglongbing is an incurable and lethal disease of citrus. Insect feeding behavior influences the rate at which the vector can move this phloem limited pathogen through the environment. Many behaviors are tied to photoperiod and therefore it is reasonable to inquire if the presence or absence of light influences feeding behavior. In EPG research recordings are typically done in a room well-lit by human standards, but still dark relative to a sunny day. Light is further dimmed by the Faraday cage that encloses the insect and host. Recording durations greater than 12 hours could disrupt light triggered circadian rhythms if room lights remain on. Alternatively, analyses would have to identify the light-dark transition and adapt the statistical methodology to account for the change. We compared behaviors from a 24-hour light versus 24-hour dark recording interval. Only a few pathway (collectively behaviors from stylet penetration of the plant cuticle to contact with phloem or xylem but not including behaviors specific to phloem or xylem) related variables were significant. No variables associated with ingestion or salivation into the phloem nor xylem ingestion showed any significant change. Examining marginally significant variables did not materially change this outcome. There were 149 variables examined. Only the standard deviation of the mean duration of pathway was significant, and only the mean duration of pathway was marginally significant after applying the Bonferroni correction.
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