Probing behavior comparisons of squash bugs (Heteroptera: Coreidae) on cucurbit hosts

Probing behaviors of first-instar squash bugs, Anasa tristis (De Geer), were electronically monitored and net weight gains of nymphs were determined on leaves of cucurbit hosts in the genera Cucurbita, Citrullus, and Cucumis. Force required to puncture cucurbit leaves was also examined. Squash bugs monitored for approximately 8 h produced three waveforms (Wa, Wb, and Wc) on which comparisons could be made. Wc was the dominant waveform on all hosts, Histological examinations of squash bug salivary sheaths in leaf tissues taken during Wc revealed that the sheath tips were located in vascular bundles. Among hosts, differences were seen in mean probing duration per probe and in the waveform durations per probe for Wa and Wb. Net weight gains of squash bug nymphs were not different among hosts. Although leaf hardness was significantly different among hosts, it was not definitively determined to be a factor affecting squash hug feeding.