Scientific Name: Tegeticula yuccasella
Taxonomy Group: Arthropods
COSEWIC Range: Alberta
COSEWIC Assessment Date and Status Change: May 2013
COSEWIC Status: Endangered
COSEWIC Status Criteria: B1ab(iii)+2ab(iii)
COSEWIC Reason for Designation: Only two populations of the Yucca Moth are known from an extremely small and restricted area. This moth species has an obligate mutualistic relationship with Soapweed; Yucca Moth is the sole pollinator of Soapweed and its larvae depend on Soapweed seeds as a food source. One population may not be sustainable as it persists with human intervention that prevents severe herbivory of the flowers, fruits and stalks by wild ungulates. The Non-pollinating Yucca Moth larvae consume Soapweed seeds and compete with Yucca Moth for food. The loss of flowers or seeds as a result of ungulate herbivory is an ongoing threat, while in the long term Soapweed populations may be limited by the lack of fire and other disturbances that provide sites for the establishment of seedlings.
COSEWIC History of Status Designation: Designated Endangered in May 2002. Status re-examined and confirmed in May 2013.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2005-01-12
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
Image of Yucca Moth
The name Yucca Moth is used here to refer to the species Tegeticula yuccasella, whereas elsewhere it may be used to refer to a larger group of species that exhibit similar life history and behaviour.
The Yucca Moth is a relatively small, slender-winged brown moth with a whitish head. It has a wingspan of 18 to 28 mm, and females are slightly larger than males. The early developmental stages of the moth (the larvae, or caterpillars), are found inside Yucca flowers (also known as Soapweed), where they feed on developing seeds. They are small, white, and grub-like, turning pink to dark red with age.
Distribution and Population
The Yucca Moth is found in populations of Yucca plants throughout the Great Plains from southern Texas to southern Canada and in all regions east of the plains northward to Michigan and Connecticut. The moth reaches the northern extent of its distribution in Canada, where two Soapweed populations exist in Alberta – one on the Lost River and one on the Milk River. There is a huge fluctuation in the number of Yucca Moths in Alberta, both within and among years. Without long-term data it is difficult to determine if there are enough individuals to sustain the species over the long term. The moth population on the Lost River occurs in densities similar to those of moths in populations further south. However, moths are notably absent from the Soapweed plant population on the Milk River, and the plants there have not produced any seeds for at least five years.
The host plant, and therefore the moth, is restricted to well-drained, mostly south-facing slopes. These slopes characteristically also have sparse populations of prickly pear cactus and Sagebrush.
The Yucca Moth and the Soapweed plant have an interesting relationship that is necessary to both of them. Moth larvae feed only on Soapweed seeds, and in turn the Soapweed is only able to produce seeds if the plant is pollinated by Yucca Moths. Most moths emerge from the soil between mid-June and mid-July. They become active shortly after sunset and fly between Soapweed plants in search of recently opened flowers, where they congregate and mate. The females actively collect pollen from one plant and then usually fly to another flower. After arriving at the new flower the female inserts an egg next to the developing ovules (future seeds of the plant). The moth then climbs to the tip of the flower, ensuring the transfer of pollen. The moths do not feed as adults, and they die after three to five days. The eggs hatch in 7 to 10 days, and the larvae feed on the developing seeds. After 50 to 60 days the larvae chew their way out of the fruit and drop to the ground on a silken thread. The larvae burrow from 5 to 20 cm into the soil and enter a dormant state, emerging as adults at least one year later. If conditions are unsuitable, larvae can remain dormant for several years, but mortality rates increase with extended dormancy.
Scientists believe that in Canada, threats to the survival of the moth are mainly related to its northerly distribution. At the northern edge of its range, the moth, or its host plant, is likely limited by temperature. The isolation (by at least 200 km) of the Alberta populations from other populations in the main range means that the moths would probably not be able to recolonize the Soapweed plants if the local population was wiped out by a chance event, or a series of climatically unfavourable years. Other threats that are not related to latitude include feeding by other insects as well as wild Mule Deer and Pronghorn on Soapweed flowers and fruit, habitat alteration, and the collection of plants for horticultural purposes.
The Yucca Moth is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Soapweed (Yucca glauca) and Yucca Moth (Tegeticula yuccasella) in Canada
Status Final posting on SAR registry
Name Amended Recovery Strategy for the Soapweed (Yucca glauca) and Yucca Moth (Tegeticula yuccasella) and Recovery Strategy for the Non-pollinating Yucca Moth (Tegeticula corruptrix) and the Five-spotted Bogus Yucca Moth (Prodoxus quinquepunctellus) in Ca
Status Final posting on SAR registry
Soapweed and Yucca Moth Recovery Team
Joel Nicholson - Chair/Contact - Government of Alberta
Phone: 403-528-5202 Fax: 403-362-5212 Send Email
Recovery Progress and Activities
Summary of Progress to Date A provincial recovery action plan has been developed and implementation underway. Recovery actions aim to develop a multi-species habitat conservation strategy and prioritize habitat stewardship activities within the Milk River Drainage Basin in southern Alberta. Summary of Research/Monitoring Activities Population monitoring is taking place in collaboration with other planned recovery activities. Summary of Recovery Activities Yucca Moth populations are being translocated from sites with successfully fruiting Soapweed plants to the site where the plants are not reproducing successfully. Translocation helps to maintain the interdependent relationship of Soapweed and the Yucca Moth and to prevent the extirpation of the species. Management of industrial and agricultural impacts is taking place. Recovery actions will include collaboration with university graduate student research projects. URLs MULTISAR: The Milk River Basin Project:http://www3.gov.ab.ca/srd/fw/speciesatrisk/pdf/SAR_87.pdf
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
10 record(s) found.
- COSEWIC Status Reports (2 record(s) found.)
- Response Statements (2 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Permits and Related Agreements (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Assessment and Status Report on the Yucca Moth Tegeticula yuccasella, Non-pollinating Yucca Moth Tegeticula corruptrix and the Five-spotted Bogus Yucca Moth Prodoxus quinquepunctellus in Canada (2013-12-24)Yucca Moths are small white moths with an 18-27.5 mm wingspan. They have specialized maxillary tentacles used to handle the pollen of Yucca spp., with which they engage in an obligate pollination-seed predation mutualism.
Response Statement - Yucca Moth (2013-12-18)Only two populations of the Yucca Moth are known from an extremely small and restricted area. This moth species has an obligate mutualistic relationship with Soapweed; Yucca Moth is the sole pollinator of Soapweed and its larvae depend on Soapweed seeds as a food source. One population may not be sustainable as it persists with human intervention that prevents severe herbivory of the flowers, fruits and stalks by wild ungulates. The Non-pollinating Yucca Moth larvae consume Soapweed seeds and compete with Yucca Moth for food. The loss of flowers or seeds as a result of ungulate herbivory is an ongoing threat, while in the long term Soapweed populations may be limited by the lack of fire and other disturbances that provide sites for the establishment of seedlings.
Response Statements - Yucca Moth (2004-04-21)A response statement is a communications document that identifies how the Minister of the Environment intends to respond to the assessment of a wildlife species by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The document provides a start to the listing and recovery process for those species identified as being at risk, and provides timelines for action to the extent possible.
Amended Recovery Strategy for the Soapweed (Yucca glauca) and Yucca Moth (Tegeticula yuccasella) and Recovery Strategy for the Non-pollinating Yucca Moth (Tegeticula corruptrix) and the Five-spotted Bogus Yucca Moth (Prodoxus quinquepunctellus) in Canada (2019-02-18)The Minister of Environment and Climate Change is the competent minister under SARA for the Soapweed, Yucca Moth, Non-pollinating Yucca Moth and the Five-spotted Bogus Yucca Moth and has prepared the federal component of this recovery strategy (Part 1), as per section 37 of SARA. To the extent possible, it has been prepared in cooperation with the Province of Alberta and Agri and Agri-Food Canada, as per section 39(1) of SARA. SARA section 44 allows the Minister to adopt all or part of an existing plan for the species if it meets the requirements under SARA for content (sub sections 41(1) or (2)). The Province of Alberta led the development of the attached recovery strategy for the Soapweed and the Yucca Moth (Part 2) in cooperation with Environment and Climate Change Canada.
COSEWIC Annual Reports
COSEWIC Annual Report – 2012-2013 (2013-09-24)Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings in this reporting year (October, 2012 to September 2013) from November 25 to November 30, 2012 and from April 28 to May 3, 2013. During the current reporting period, COSEWIC assessed the status or reviewed the classification of 73 wildlife species. The wildlife species assessment results for the 2012-2013 reporting period include the following: Extinct: 0 Extirpated: 2 Endangered: 28 Threatened: 19 Special Concern: 19 Data Deficient: 4 Not at Risk: 1 Total: 73 Of the 73 wildlife species examined, COSEWIC reviewed the classification of 50 species that had been previously assessed. The review of classification for 26 of those species resulted in a confirmation of the same status as the previous assessment.