Rapid Analysis of Electronically Monitored Homopteran Feeding Behavior

Abstract

Historically, a bottleneck in the analysis of electronically monitored insect feeding behavior (EMIF) of homopterans has been the conversion of raw waveform data into a format that is easy to analyze. Here we present an efficient method for the analysis of EMIF recordings using Microsoft Excel, a popular spreadsheet program. Recordings were made with WinDaq, data-acquisition software from Dataq Instruments. Waveform transitions were saved to file using WinDaq's annotation utility. Subsequent data analysis of the WinDaq data file was performed using a custom-designed Microsoft Excel EMIF workbook. After experiment-specific variables are entered and the data file is imported by the user, a complete analysis is performed automatically. The Excel workbook summarizes the results and generates an output file for further statistical analysis. Any EMIF data file containing waveform codes and cumulative time (i.e., time from the beginning of the recording, in seconds) can be analyzed. The new method described in this article was used to analyze EMIF recordings of 2 homopteran species, Aphis gossypii Glover (Aphididae) and Empoascakraemeri Ross & Moore (Cicadellidae). Identification and file export took an average of 5 s per waveform occurrence; the total time required to identify all waveforms and export them to file will depend on the number of occurrences of each waveform in the EMIF recording, quality of the recording, waveform variability, level of user experience, and computer speed. The subsequent analysis of each recording with the EMIFworkbook took between 1 and 2 min. Use of the EMIF workbook has the following advantages: (1) it can be used to analyze EMIF recordings of any homopteran species; (2) it is compatible with any data acquisition software capable of exporting data files containing waveform codes and cumulative time, as well as with data files with a similar format; (3) it can be used in conjunction with both AC and DC EMIF systems; and (4) it is fast, flexible, and user-friendly.