NS-6 Mating Calls of Male Encenopa binotata Halesia, a Proposed New Member of the Two-marked Treehopper Species Complex

The Enchenopa binotata species complex consists of 11 recognized species that have evolved through sympatric speciation in eastern North America. A newly discovered twelfth species, tentatively named E. binotata Halesia, has been identified using the Common Silverbell (Halesia tetraptera var. tetraptera) as its host tree. We found that mating activity occurs within this new species between early August and late September, with peak calling from early to mid-September. We analyzed sonograms of field recorded mating calls in Audacity and compared their acoustics with the other members of the species complex. Like other members, E. binotata Halesia males produce vibrational mating calls that propagate through tree branches and play a crucial role in mate selection. We found that male mating calls exhibited features consistent with several other members of the complex, with an initial frequency-modulated whine followed by a series of pulses. The mean ± SE signal length of calls was 0.87 ± 0.05 seconds, with the whine portion lasting 0.55 ± 0.04 seconds. The dominant frequency at the end of the whine averaged 213.03 ± 2.88 Hz, aligning most closely with males calls from E. binotata Viburnum. The number of pulses per call ranged from 4 to 6, with a mean of 5.00 ± 0.27. The pulse rate measured 18.23 ± 0.79 pulses per second, and individual pulses averaged 0.07 ± 0.00 seconds in duration. Our findings indicate that while E. binotata Halesia shares some key acoustic traits with E. binotata Viburnum and E. binotata Cercis, there are subtle differences in call structure that likely contribute to species recognition and reproductive isolation from other members of the species complex.