Feeding behavior increases strength and frequency of vibrational communication signals of Neoaliturus tenellus (Hemiptera: Cicadellidae)

Abstract Leafhoppers (Hemiptera: Cicadellidae) use substrate-borne vibrations to communicate, and characteristics of these vibrational signals help identify, locate, and assess suitability of potential mates. The strength and frequency composition of signals influence behavioral responses in conspecifics. Leafhoppers are known to produce these vibrational signals while probing, but it is unclear whether this dual activity degrades signal transmission, inducing a trade-off between nutrient acquisition and mate attraction. In contrast, we hypothesized that inserted mouthparts could provide an additional point of contact with the plant, improving signal transmission. Here, we combine simultaneous electropenetrography (EPG) and accelerometer recordings to assess how beet leafhopper Neoaliturus tenellus (Baker) vibrational signals vary with probing behavior, including xylem ingestion, phloem salivation/ingestion, and probing of epidermis and mesophyll cells. Signals documented during 6-h recordings of male leafhoppers had significantly higher amplitude and dominant frequency when leafhoppers were probing than when they were not probing. However, the dominant frequency of signals was similar when leafhoppers were engaged in pathway phase, phloem ingestion, and xylem ingestion. Of the different probing behaviors, xylem ingestion had the strongest positive effect on signal amplitude, but phloem ingestion did not influence signal amplitude. Additional contact between the leafhopper and the plant surface, provided by leafhopper mouthparts, may improve vibration transmission, potentially increasing signal active space. In light of our finding that the act of probing plant tissues influences information conveyed in leafhopper vibrational signals, we suggest further research to evaluate the impacts these signal changes have on the behavior of other mates and natural enemies.