bayberry | Block Island Moths

Myrica pensylvanica (bayberry)

Figure 1. Eight of the moth species specializing on bayberry on Block Island (left to right, top to bottom): Ornixolinae *n. Gen. n. sp.* (Gracillariidae), *Coleophora comptoniella* (Coleophoridae), *Neotelphusa n. sp.* (Gelechiidae), *Olethreutes myricana* (Tortricidae), *Strepsicrates smithiana* (Tortricidae), *Archips myricana* (Tortricidae), Cyclophora myrtaria (Geometridae), and *Catocala muliercula* (Erebidae).

Figure 2. Solitary young bayberry in summer.

Figure 3. Bayberry along inland margin of dunes, mid-June.

Figure 4. Bayberry flowers. Credit Oregon State University.

Figure 5. Coastal shrubland on Block Island in late May, east coast looking north; nearly all the bare branches in this photo are bayberry. The bayberry pictured are in bloom with inconspicuous flower clusters; the striking white flowers are of beach plum (*Prunus maritima*).

Figure 6. Coastal shrubland on Block Island in late May, east coast with due west just left of up following property lines; the foreground of Fig. 5 is just past the right edge of this picture. Nearly all the bare branches in this photo are bayberry; just right of center, several patches of flowering beach plum (*Prunus maritima*) appear whitish. Most of the light green is invasive Oriental bittersweet (*Celastrus orbiculatus*) and Japanese honeysuckle (*Lonicera japonica*). Another invasive, beach rose (*Rosa rugosa*), is a main constituent of dune habitats on Block Island and appears dark green here, most noticeably where is forms nearly a monoculture at bottom right.

Specialists of bayberry (Myrica pensylvanica) on Block Island

Block Island’s populations of all the species listed below are presumed to rely exclusively on bayberry, which is the only species of Myricaceae present on the island. Other Myricaceae have been reported as suitable hosts for many of the species below. Coleophora comptoniella also feeds on Betulaceae, a family scarcely found on Block Island.

Nepticulidae

Stigmella myricafoliella (Busck, 1900) is a linear leafminer of Myricaceae. Larvae develop rapidly, making the species somewhat hard to rear despite being fairly common on Block Island. While mines of this species are easily distinguished from those of the four other bayberry specialist leafminers found on Block Island, they may be indistinguishable from those of Stigmella corylifoliella (Clemens, [1862]), an adult of which was collected at light on Block Island and confirmed by DNA barcode. S. corylifoliella is one of the most polyphagous leafmining moths known, having been reared from various Betulaceae, Ericaceae, Myricaceae, Rhamnaceae, and Rosaceae. The color of the larva (pale green in myricafoliella and yellow in corylifoliella) is thought to be a consistent character separating these species. Adults of both species are externally identical to each other and a number of other Stigmella species.

Heliozelidae

Aspilanta argentifera (Braun, 1927) is a blotch miner of Myricaceae. As in all Heliozelidae, the mature larva forms a portable case out of a pair of discs cut out of the upper and lower epidermis of its host leaf and drops to the ground to pupate in its case, leaving an oval-shaped hole at the edge of its completed mine. I have never seen mines of this species, but Mike Nelson and Dave Wagner reported finding them on Block Island in their 1998 survey of leafminers. Adults are externally identical to those of Aspilanta ampelopsifoliella (Braun, 1927), which feeds on Virginia creeper (Parthenocissus virginiana). Nelson and Wagner (1998) reported mines of A. ampelopsifoliella on Block Island, and I found a vacant mine in 2019. I have seen four unidentified adults of this genus.

Gracillariidae

Caloptilia flavella (Ely, 1915) forms an underside blotch mine in bayberry and feeds within a folded leaf in later instars. We have found three adults apparently belonging to this species in our survey but have not found mines. Nelson and Wagner (1998) reported this species.

Ornixolinae n. Gen. n. sp. mines leaves of Myricaceae. The larva initially forms a linear mine before entering the midrib and feeding within in for a time. The larva then leaves the midrib and forms a large, irregular blotch mine, exiting the mine to pupate on the leaf edge or elsewhere. The larva pupates within an oblong, white cocoon ornamented with a 20 or 30 froth spherules.

Cameraria picturatella (Braun, 1916) forms an upper surface blotch mine in bayberry. Mines are brownish and occupy most of the leaf surface when completed, making them highly conspicuous. In my limited experience, the rate of parasitism is very high. The species is common on Block Island, where it is univoltine, with larvae mining July into August. Adults evidently overwinter but are rare at lights, with records from August, September, and June.

Depressariidae

Agonopterix walsinghamella (Busck, 1902) is a leaftier of Myricaceae evidently rare on Block Island, with one rearing record and five adult records.

Coleophoridae

Coleophora comptoniella (McDunnough, 1926) is a case-bearing leafminer of Myricaceae and Betulaceae that eats a series of windows in multiple leaves of the host plant from within its leaf case. The species is univoltine on Block Island with adults on wing in July and August.

Gelechiidae

Neotelphusa n. sp. is a common leaftier of Myricaceae. The species is univoltine and flies mainly in July on Block Island.

Filatima confusatella Darlington, 1949

Aroga epigaeella (Chambers, 1881)

Tortricidae

Olethreutes myricana Kearfott, 1910 is a leaftier of bayberry univoltine on Block Island with adults on wing in summer. The species is currently treated as a junior synonym of Olethreutes sericoranum (Walsingham, 1879) in the MONA checklist. If this synonymy is unwarranted, O. myricana is a specialist of Myricaceae.

Strepsicrates smithiana Walsingham, 1891

Archips myricana (McDunnough, 1923)

Pyralidae

Acrobasis comptoniella Hulst, 1890

Geometridae

Cyclophora myrtaria (Guenée, [1858])

Erebidae

Catocala muliercula Guenée, 1852

Catocala badia badia Grote & Robinson, 1866

Host specialization unclear

Pyralidae: Condylolomia participalis Grote, 1873

Notodontidae: Coelodasys apicalis Grote & Robinson, 1866