Moths of North Carolina

Scientific Name:	Common Name:		Family (Alpha):

View PDF	Sesiidae Members:	Synanthedon Members:	42 NC Records
Synanthedon exitiosa (Say, 1823) - Peachtree Borer Moth

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Taxonomy

Superfamily: Sesioidea	Family: Sesiidae	Subfamily: Sesiinae	Tribe: Synanthedonini	P3 Number: 55a0124	MONA Number: 2583.00
Comments: North America has 136 or more species in the family Sesiidae, and the large genus Synanthedon constitutes around half of the 37 species found in North Carolina, many being similar in appearance to one another. Some sesiids, known broadly as clearwing borers, are significant pests of commercial crops. Almost all are mimics of wasps and hornets.
Species Status: While sample size has been small, DNA barcoding points to S. exitiosa probably being a complex of about three species, with two of these found in the western US.

Identification

Field Guide Descriptions: Covell (1984); Beadle and Leckie (2018)

Online Resources: MPG, BugGuide, iNaturalist, Google, BAMONA, GBIF, BOLD

Technical Description, Adults: Eichlin and Duckworth (1988)

Technical Description, Immature Stages: Snapp and Thomson (1943)

Adult Markings: Synanthedon exitiosa is both strongly sexually dimorphic and polymorphic, with several color forms that vary in frequency across its broad geographic range. The females are distinct in being almost entirely violaceous-black except for a broad orange band that encircled the fourth, and sometimes fifth, abdominal segment. The males have palps that are black above and yellow below and a head tuft that is yellowish. The abdomen is black with variable numbers of fine yellow stripes. The hindleg is black with narrow yellow rings at the spurs and on the segments of the tarsi. The anal tuft is black and lanceolate-shaped, with the scales narrowly white-tipped. The following description of the male is based mostly on the descriptions by Engelhardt (1946) and Eichlin and Duckworth (1988) and applies to the typical form that is present in the eastern US. Engelhardt (1946) described some other forms that are either rare or found mostly in the West.

The antenna is black and finely ciliate on the inner sides, while the palp is yellow beneath and black above. The head is mostly black, with a black vertex that has varying amounts of intersperse yellow scales (often predominantly yellowish). The occipital fringe at the back of the head is black laterally and yellowish dorsally. The thorax is black and has two longitudinal yellow stripes at the base of the wing. The wings are mostly hyaline with very narrow black margins and veins, and often with an amber tinge. The hindleg is black with narrow yellow rings at the spurs and on the segments of the tarsi. The abdomen is black above, with narrow pale-yellow banding on the posterior margin of some or all of the segments. The markings on the basal and fourth segments are usually the best expressed, but some individuals may lack yellow banding altogether. The anal tuft is conspicuously wedge-shaped and edged with pale yellow or yellowish-white laterally.

The females are markedly different in being almost entirely violaceous-black except for a broad orange band that encircled the fourth, and sometimes the fifth, abdominal segment. The antennae, palps, head, thorax, and legs are all violaceous-black, and the forewing is entirely opalescent, and violaceous-black. The hindwing is transparent and heavily scaled at the costal margin, while the outer margin and fringes are violaceous-black.

Wingspan: Males 18-30 mm; females 23-32 mm (Engelhardt, 1946).

Forewing Length: 10-15 mm (Eichlin and Duckworth, 1988).

Structural photos

Adult ID Requirements: Identifiable from good quality photos of unworn specimens.

Immatures and Development: Due to their economic importance, numerous comprehensive studies of the life history of the adults and larvae have been conducted for over 100 years, particularly in Peach orchards (e.g., Snapp and Thomson, 1943; Hollaway et al., 1977). The time required to complete the life cycle varies with latitude and climate, with populations in Canada often requiring one or two years (Armstrong, 1940). Populations in Florida have two generations per year, while those at intermediate latitudes common have either one, or one with a partial second brood that overwinters (Strickland, 2014). The females typically lay their chestnut-brown eggs either singly or in small batches on the ground or vegetation immediately next to trunks, or on the base of trunks and within 15 cm of the ground. They will also lay on the limbs, twigs, and leaves (Snapp and Thomson, 1943; Solomon, 1995). Clutch sizes are typically around 200-800 eggs, but can exceed 1,000, and the eggs develop to hatching in 1-3.5 weeks depending on ambient temperatures. The hatchlings make their way to the base of host plant at or near ground level, bore into the bark, and make their way to the cambium of the tree base or larger roots, which is the primary food source. The larvae feed in galleries and in most populations overwinter. Frass, wood chips and gummy secretions from the damaged tissues of the tree are often evident near the base of the tree (Snapp and Thomson, 1943). Overwintering larvae resume feeding in the spring and pupate in cocoons that are constructed either beneath the bark, on the trunk beneath the ground surface, or in the soil near the ground surface (Solomon, 1995). Larvae that pupate in the soil leave the roots and create channels to within a few centimeters of the soil. Wood chips and frass are then brought up from the root channel and are used with silk to make the cocoon (Snapp and Thomson, 1943). The adults emerge within 2-4 weeks after the larvae pupate, typically from early morning to early afternoon, and mating and egg-laying commonly occurs on the day of emergence. The older larvae have a white to cream-colored body, a brown head, and a yellowish prothorax.

Distribution in North Carolina


Distribution: Synanthedon exitiosa is broadly distributed across much of southern Canada and the US where mesic habitats are present. It occurs in Canada in British Columbia, and from Manitoba eastward to New Brunswick, Nova Scotia, Prince Edward Island and Newfoundland. In the US the range extends from Maine southward to northern Florida and westward to southern California, Oregon and Washington. This species is generally uncommon in the southeastern Coastal Plain and in arid regions in the West. It occurs in all three physiographic provinces in North Carolina, but is far less common in the Coastal Plain compared to elsewhere in the state.
County Map: Clicking on a county returns the records for the species in that county.


Flight Dates: High Mountains (HM) ≥ 4,000 ft. Low Mountains (LM) < 4,000 ft. Piedmont (Pd) Coastal Plain (CP) Click on graph to enlarge
Flight Comments: The adults have been documented from January through October in different areas of the range, with a seasonal peak typically in July and August. Specimens have been found in Florida from January through October, while the most northern populations fly from June through August. As of 2024, our records extend from early-May through late-October. Populations in North Carolina appear to have more than one brood per year.

Habitats and Life History

Habitats: Local populations are commonly found in mesic forest and forest-edge habitats, and in orchards, nurseries and residential neighborhoods where the host plants are found.

Larval Host Plants: This species is an economically important pest of Peach (Prunus persica), but also uses other Prunus species that are cultivated or used as ornamentals (Covell, 1984; Eichlin and Duckworth, 1988; Heppner, 2007). These include Almond (P. amygdalus), Apricot (P. armeniaca), Sweet Cherry (P. avium), Sour Cherry (P. cerasus), European Plum (P. domestica), Hortulan Plum (P. hortulana), Nectarine (P. persica var. nectarina), Japanese Flowering Cherry (P. serrulata) and Western Chokecherry (P. virginiana var. demissa). The larvae undoubtedly used native Prunus species and perhaps other members of the Rosaceae prior to the introduction of cultivated orchard species into North America, but these are rather poorly documented. Native species in the eastern US that have been reported as hosts include Downy Serviceberry (Amelanchier arborea), American Plum (P. americana), Carolina Laurel Cherry (P. caroliniana), Chokecherry (P. virginiana) and Black Cherry (P. serotina). Heppner (2007) reported American Persimmon (Diospyros virginiana) as a host, which seems unlikely. - View

Observation Methods: The diurnally-active adults are not attracted to lights or bait, but females may be seen around food plants and nectaring on flowers. Males are unlikely to be seen in the wild, but readily come to pheromone traps using synthetic sex attractants (Taft et al., 2004).

Wikipedia

Status in North Carolina

Natural Heritage Program Status:

Natural Heritage Program Ranks: G5 [S4S5]

State Protection: Has no legal protection, although permits are required to collect it on state parks and other public lands.

Comments: Given its economic importance, this is among the most-studied of sesiids. It is a common and widespread species in North Carolina and is easily attracted to pheromone lures. While sample size has been small, DNA barcoding points to S. exitiosa probably being a complex of about three species, with two of these found in the western US.

Photo Gallery for Synanthedon exitiosa - Peachtree Borer Moth		Photos: 23
	Recorded by: Emily Stanley on 2024-07-11 Buncombe Co. Comment:	Recorded by: Brian Bockhahn on 2022-08-18 Rockingham Co. Comment:
	Recorded by: tom ward on 2022-07-16 Buncombe Co. Comment:	Recorded by: David George, L. M. Carlson on 2022-06-21 Caswell Co. Comment:
	Recorded by: Jim Petranka on 2022-06-09 Madison Co. Comment:	Recorded by: K. Radewicz on 2021-08-05 Orange Co. Comment: Male
	Recorded by: Rob Van Epps on 2020-08-28 Mecklenburg Co. Comment: Female	Recorded by: Jim Petranka and Becky Elkin on 2020-06-28 Madison Co. Comment:
	Recorded by: Gary Maness on 2019-08-23 Guilford Co. Comment:	Recorded by: Jim Petranka and Becky Elkin on 2019-07-29 Madison Co. Comment:
	Recorded by: Jim Petranka and Becky Elkin on 2019-06-21 Madison Co. Comment:	Recorded by: Jim Petranka and Becky Elkin on 2019-05-26 Madison Co. Comment:
	Recorded by: Jim Petranka and Becky Elkin on 2019-05-26 Madison Co. Comment:	Recorded by: Jim Petranka and Becky Elkin on 2018-09-08 Madison Co. Comment:
	Recorded by: Jim Petranka and Becky Elkin on 2018-07-16 Madison Co. Comment:	Recorded by: Jim Petranka and Bo Sullivan on 2018-07-15 Madison Co. Comment:
	Recorded by: J.B. Sullivan on 2017-05-08 Brunswick Co. Comment:	Recorded by: Darryl Willis on 2016-08-01 Cabarrus Co. Comment:
	Recorded by: F. Williams, S. Williams on 2014-08-20 Gates Co. Comment:	Recorded by: Vin Stanton on 2012-07-22 Buncombe Co. Comment:
	Recorded by: Doug Blatny/Jackie Nelson on 2012-07-03 Ashe Co. Comment:	Recorded by: Harry Wilson on 2010-09-02 Wake Co. Comment:
	Recorded by: Jeff Beane on 2010-06-10 Wilkes Co. Comment:

Synanthedon exitiosa (Say, 1823) - Peachtree Borer Moth

Photo Gallery for Synanthedon exitiosa - Peachtree Borer Moth

Photos: 23