Moths of North Carolina

Scientific Name:	Common Name:		Family (Alpha):

View PDF	Prodoxidae Members:	Tegeticula Members:	9 NC Records
Tegeticula yuccasella (Riley, 1872) - Yucca Moth

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Taxonomy

Superfamily: Incurvarioidea	Family: Prodoxidae	Subfamily: Prodoxinae	Tribe: [Prodoxini]	P3 Number: 210029.00	MONA Number: 198.00
Comments: Tegeticula yuccasella was the traditional name applied to a wide-ranging species that pollinates yuccas. Pellmyr (1999) subsequently split the North American forms north of Mexico into 13 species, and restricted the name T. yuccasella to populations that occur in the central and eastern US. It is the only Tegeticula that occurs in North Carolina. This and a second species (Prodoxus decipiens) are the only two yucca moths that are found in the state.

Identification

Field Guide Descriptions: Covell (1984); Beadle and Leckie (2012)	Online Photographs: MPG, BugGuide, BOLD	Technical Description, Adults: Pellmyr (1999)	Technical Description, Immature Stages: Riley (1892)
Adult Markings: The following is based on a redescription of the species by Pellmyr (1999). The head and thorax have white scales. The maxillary palp has a fully developed brown tentacle in the female, and sometimes a small trace of it in the male. The labial palp has brown scales on all of segment 1, dorsally on segment 2, while elsewhere it is white-scaled. The female has 30-40 sensory setae ventrally on the second segment, while the male has 1-3 setae near the basal bend of the second segment. The proboscis is yellow, and has the same brightness but is yellower than the maxillary palp. The antenna is 0.41-0.46 times the length of the forewing, with 42-50 segments. White scales cover the basal 17-21 segments, while the remainder are brown. The legs are brownish yellow with white scales, except for darker specimens that have brown scales anteriorly on the foreleg and mid tibia. The dorsal surface of the forewing is white, with dark brown scales on the costa from the base to 15-30% of the entire length. The underside of the forewing is dark brown except for the white costa beyond the dark scales, and a yellowish white portion that overlaps the hindwing. The forewing fringe is white. The hindwing is brownish gray. It is darkest by the apex, and gradually turns white toward the hind corner. The underside is light brown, often with a darker apical region that reaches M3. The hindwing fringe has the basal third brown, sometimes with a rusty tinge, and the remainder white. The abdomen is tan dorsally, with lighter linear scales along the posterior edge of each segment. In both sexes the last two segments have erect scales that form a brush. The underside of the abdomen is white. Our two yucca moths (Prodoxus decipiens and T. yuccasella) often co-occur locally and can be found resting inside yucca flowers during the day. They are very similar externally and are best identified via genitalia or by examination of the head region. Female T. yuccasella have a conspicuous tentacle at the base of each maxillary palp that is used to pollinate flowers (Pellmyr and Krenn, 2002), while P. decipiens does not. The species also differ in size (Althoff et al., 2001, Pellmyr, 1999) as follows: T. yuccasella; wing length = 8.4-10.0 mm for males and 9.3- 11.7 mm for females, P. decipiens; 4.0–8.8 mm for males and 4.6–11.0 mm for females.
Wingspan: 18-24 mm for males and 19.5-27.5 mm for females (Pellmyr, 1999).
Forewing Length: 8.4-10.0 mm for males and 9.3-11.7 mm for females (Pellmyr, 1999).
Adult Structural Features: The following description of the genitalia is from Pellmyr (1999). Males: The Vinculum-saccus is 1.3-1.6 mm long. There is a relatively small valvae with a broadly tapering cucullus, and a slightly asymmetric pectinifer consisting of 6-12 fused spines. The aedeagus is 1.4-.9 mm long, and 0.035-0.040 mm in diameter. Females: The posterior apophyses are 5.0-6.9 mm long. The ovipositor is 0.35-0.50 mm long, with a 0.03-0.04 mm high keel of fine teeth rising 0.09-0.11 mm behind the tip. The ductus bursae is 1.8-2.8 mm, and the corpus bursae has two 0.95-1.20 mm signa.
Adult ID Requirements: Identifiable only by close inspection of structural features or by DNA analysis.
Immatures and Development: Tegeticula yuccasella is a specialist on yuccas, and appears to rely heavily on Y. filamentosa as a host in North Carolina. This species is an obligate mutualist with Yucca, since the fitness of individuals directly depends upon their effectiveness as pollinators. After a female has collected pollen into a ball using special tentacles on the head, she oviposits into a yucca ovary and then takes some of the pollen from the pollen mass and actively pushes it into the stigmatic cavity. A moth may oviposit into the ovary and pollinate a flower several times before moving to another flower to repeat the procedure. A female may self-pollinate a flower, or fly to another plant and outcross, which enhances fruit set (Marr et al., 2000). Active pollination assures that seeds will be available as a food source for her offspring. The larvae feed on developing seeds for about a month, then bore out of the seed pods and drop to the ground where they move into the soil and spin silken cocoons (Riley, 1892). The larvae remain in diapause until shortly before the yuccas bloom the following year. They then pupate and emerge as the plants begin to bloom.
Larvae ID Requirements: Identifiable from good quality photos, especially where associated with known host plants.

Distribution in North Carolina


Distribution: Tegeticula yuccasella occurs throughout the Great Plains from southernmost Canada to as far south as Texas. The range extends eastward from the Great Plains to cover most of the eastern US, from Florida and the Gulf Coast states northward to at least central Michigan, southern Ontario and Connecticut (Pellmyr, 1999). As of 2019, we have only a few records from North Carolina. The species is patchily distributed statewide where local populations of yucca occur.
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 flight season is strongly tied to the local flowering of yuccas. As of 2019, we have records from June and July.

Habitats and Life History

Habitats: Tegeticula yuccasella primarily uses Yucca filamentosa as a host in North Carolina. This species grows in relatively dry, open habitats such as open woods, the edges of granitic flatrocks, maritime forests, and dunes near beaches. Yucca filamentosa has also been widely planted as an ornamental, and has escaped in most areas of the state. It often occurs around abandoned homesites and other disturbed habitats.

Larval Host Plants: Tegeticula yuccasella uses a variety of yucca species outside of North Carolina, including Curlyleaf Yucca (Y. filamentosa), Soapweed Yucca (Y. glauca), Buckley Yucca (Y. constricta), Twisted-leaf Yucca (Y. rupicola), Pale-leaf Yucca (Y. pallida), San Angelo Yucca (Y. reverchoni), and Spanish Dagger (Y. aloifolia). The only documented hosts in North Carolina is Y. filamentosa and Y. flaccida, which has traditionally been treated as a variety of Y. filamentosa.

Observation Methods: The adults are active on the wing for 3-4 hours after dark as they fly between flowers (Marr et al., 2000). They are attracted to lights, but are most easily collected by checking inside flowers during the day. They sometimes co-occur with Prodoxus decipiens on the same plant, so care should be taken to correctly identify the adults. Local populations can be documented by checking the seed pods for larval bore holes - a signal that this species is present at a site.

Wikipedia

See also Habitat Account for General Dry-Xeric Glades and Barrens

Status in North Carolina

Natural Heritage Program Status:

Natural Heritage Program Ranks: G4 S2S3

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

Comments: This species is probably more widespread within the state than our records suggest. Additional effort is needed to survey flowers for adult moths, and fruits for the distinctive bore holes.

Photo Gallery for Tegeticula yuccasella - Yucca Moth		Photos: 5
	Recorded by: Jim Petranka on 2020-08-29 Madison Co. Comment:	Recorded by: on 2020-06-26 Buncombe Co. Comment: A female that was on Yucca filamentosa flowers; note the companion photo that shows a tentacle.
	Recorded by: on 2020-06-26 Buncombe Co. Comment: A female that was on Yucca filamentosa flowers; note the companion photo that shows a tentacle.	Recorded by: on 2020-06-26 Buncombe Co. Comment:
	Recorded by: on 2020-06-22 Madison Co. Comment:

Tegeticula yuccasella (Riley, 1872) - Yucca Moth

Photo Gallery for Tegeticula yuccasella - Yucca Moth

Photos: 5