Nyssa sylvatica (tupelo or black gum)
Six specialists of Nyssa sylvatica Marshall (Nyssaceae) are known to occur on Block Island. All have been found at UV light in the only location on the island where tupelo grows in numbers, on the Sandsland Boy Scout camp southeast of the island’s airport. The property is low-lying with marshes interspersed among hillocks and is protected by a conservation easement. The property has a 0.03 ha stand of beech trees surrounded by 0.30 ha of tupelo forest; this forested area was surveyed with UV lights and sheets 31 times from 2019 to 2021, including 25 times with comprehensive recording of all moths seen. Additionally, three light traps were set within, 50 m from, and 230 m from the forest on 9 June 2021. 250 to 300 meters to the southeast are two more likely tupelo patches, though the identity of these populations has yet to be confirmed on the ground due to difficulty of access.
Recorded abundances of the six tupelo specialist species on Block Island in 25 UV light surveys at sheets in the tupelo forest from 2019 to 2021 range from 11 (Ectoedemia nyssaefoliella) to ~323 (Polygrammate cadburyi). Just five individuals of three of the six species have been seen anywhere on Block Island other than at Sandsland Scout camp despite UV light surveys having been conducted throughout the warm months at sites about 1 km distant from the tupelo forest at the camp.
The one trapping night in Sandsland (9 June 2021) was near peak flight times of two tupelo specialists, Antispila nysaefoliella and Polygrammate carburyi, and early in the flight periods of two more, Ectoedemia nyssaefoliella and Actrix nyssaecolella; only P. cadburyi was found. The traps had to be non-kill due to the presence on Block Island of the federally endangered American burying beetle (Nicrophorus americanus). The smallest moths were likely destroyed by beetles within the trap, and none were found on examination in the morning, so the absence of A. nysaefoliella and E. nyssaefoliella from the traps was not meaningful. 23 P. cadburyi were found in the trap within the forest, one in the trap at 50 m distance, and none in the trap at 230 m distance, confirming extremely limited dispersal of the species away from its host plant. The traps all contained almost exactly the same number of moths in total (172, 174, and 176, respectively).
Specialists of tupelo (Nyssa sylvatica) on Block Island
Ectoedemia nyssaefoliella (Chambers, 1880) is a linear-blotch leafminer of tupelo. Eleven individuals have been recorded at lights on Block Island, all in the tupelo-beech forest on the Scout camp property.
Antispila nysaefoliella Clemens, 1860 is a blotch leafminer of tupelo. 35 individuals have been recorded at lights on Block Island, all in the tupelo-beech forest on the Scout camp property. Additionally, a dozen or more individuals were found on the undersides of beech leaves at the site on 14 June 2020.
Actrix nyssaecolella (Dyar, 1904) is a leaffolder of tupelo. Of the 26 individuals recorded on Block Island since 2018, all but one were recorded in the tupelo-beech forest on the Scout camp property. One individual was found at the Hunt property in 2016.
Allotria elonympha (Hübner, 1818) is the largest tupelo specialist on Block Island. Of the 17 adults recorded on Block Island since 2018, all but one were recorded in the tupelo-beech forest on the Scout camp property. Additionally, a final instar larva was found wandering at the site on 25 July 2019.
Polygrammate hebraeicum Hübner, 1818 feeds externally on leaves of tupelo. Of the 69 individuals recorded on Block Island since 2018, all but one were recorded in the tupelo-beech forest on the Scout camp property. Additionally, one individual was recorded on 17 July 2017 at a site about 1.2 km to the west.
Polygrammate cadburyi (Franclemont, 1939) feeds externally on leaves of tupelo. This species has been found at lights in the tupelo-beech forest on the Scout camp property on five occasions during its brief flight window from late May into June. It has never been recorded anywhere else on the island despite its great abundance in the forest, where an estimated 100 individuals were seen on 5 June 2019 and 115 on 11 June 2019, the two greatest abundances recorded of any one moth species in one night in this survey.
