Editing Yucca (section)

==Ecology==
[[File:Tegeticula yuccasella - Marissa Calvert 01.jpg|thumb|alt=A cream white flower with thick fleshy petals with one petal pulled back to show at least five white moths inside with the large stamens |Yucca moths inside a yucca flower, [[Candler County, Georgia]]]]
Yuccas have a very specialized [[Mutualism (biology)|mutualistic]] system of [[pollination]].{{sfn|Irish|Irish|2000|p=36}} Yuccca moths of in genus ''[[Tegeticula]]'' or ''[[Parategeticula]]'' pollinate the flowers and then lay their eggs in the seed capsules of yuccas.{{sfn|Smith|Leebens-Mack|2024|p=376}} Though, the some species of ''Tegeticula'' provide no benefit to the yuccas, laying eggs but not pollinating the flowers due to lacking the specialized parts for carrying pollen.{{sfn|Althoff et al. 2006|p=398}} All species of yucca are pollinated by at least one species of yucca moth.{{sfn|Pellmyr|2003|p=36}} The mutualism was first documented by [[Charles Valentine Riley]] in 1873.{{sfn|Smith|Leebens-Mack|2024|pp=377, 390}} This created much excitement in the scientific community. In a 1874 letter to his friend [[Joseph Dalton Hooker]], [[Charles Darwin|Darwin]] called it, "the most wonderful case of fertilisation ever published".{{sfn|Smith|Leebens-Mack|2024|pp=376, 387}}

Instances of animal behavior that are exclusively aimed at pollination of plants, rather than just accompanying the animal gathering food, are quite rare. Female yucca moths have tentacle-like mouth parts that they use to gather pollen and then to deposit it on the reproductive parts.{{sfn|Smith|Leebens-Mack|2024|p=376}} In the 150 years following the discovery of this relationship it became one of the most famous of the documented plant and animal mutualisms along with the [[fig wasp]]s and [[fig tree]]s.{{sfn|Smith|Leebens-Mack|2024|pp=375–376}} The association between the yuccas and the yucca moths is quite ancient with a [[molecular clock]] estimate that it began between 51.3 and 31.7 million years ago with them beoming pollinators 35.6 million years ago ±9 million years.{{sfn|Pellmyr|Leebens-Mack|1999|p=9182}}

About two-thirds of the moth species are limited to just one species of yucca. There is some evidence that the moths that visit a single species are guided to the flowers by distinct scents. All yucca moths species gather together inside of blooms to mate. The females of ''Tegeticula'' gather pollen and then pierce the yucca ovaries or styles to lay their eggs. After this they deposit their load of pollen to ensure the development of seeds. The female ''Parategeticula'' moths cut groves into [[Pedicel (botany)|flower stems]], petals, or other parts to lay their eggs, but also use their mouthparts to deposit pollen on [[Stigma (botany)|stigmas]] and into [[Style (botany)|styles]].{{sfn|Smith|Leebens-Mack|2024|p=376}} In order to limit the numbers of seeds eaten by moth larvae yucca plants abort fruits with large numbers of eggs deposited within them, but also drop fruits without sufficent polination for good seed set.{{sfn|Pellmyr|Huth|1994|p=259}} In order to limit the numbers of seeds eaten by moth larvae yucca plants abort fruits with large numbers of eggs deposited within them, but also drop fruits without sufficient pollination for good seed set.{{sfn|Pellmyr|Huth|1994|p=259}}

Though the reduction or local extinction of yucca moths can reduce the fertility of seeds or the numbers produced, there is not yet evidence that it reduces the populations of yuccas as they are relatively long lived.{{sfn|Oldfield|1997|p=5}} The scientist Robert William Cruden and his collaborators speculated in 1976 that yucca species are limited to lower elevations by the inability of their moth pollinators to tolerate colder temperatures at high elevations.{{sfn|Addicott|1985|p=219}}

However, [[aloe yucca]] (''Yucca aloifolia'') has been shown to be pollinated by [[European honeybee]]s (''Apis mellifera''). This is first documented case of a plant reverting away from a highly specialized mutualism to a generalist pollinator.{{sfn|Rentsch|Leebens‐Mack|2014|pp=2065–2066}}

The [[bogus yucca moth]]s (''Prodoxus''), also lay their eggs on yucca species, but do not pollinate the flowers. They also do not eat the seeds, instead forming gall-like structures as they feed on fruits, stems, or leaves.{{sfn|Smith|Leebens-Mack|2024|pp=376–377}}

[[File:Megathymus yuccae ssp. yuccae - Athena Philips 01.jpg|thumb|Larva of a yucca giant-skipper butterfly on a yucca leaf in Florida]]
Yucca species are the host plants for the [[caterpillar]]s of the widespread but uncommon [[yucca giant-skipper]] butterfly (''Megathymus yuccae''), which is found across the southern United States and northern Mexico.{{sfn|Daniels|2009}} The [[ursine giant skipper]] butterfly (''Megathymus ursus''), from southern Arizona, southern New Mexico, western Texas, and [[Nuevo León]], also feeds on yuccas such as [[Schott's yucca]] (''Yucca'' × ''schottii'') and [[datil yucca]] (''Yucca baccata''). As does the more northerly [[Strecker's giant skipper]] (''Megathymus streckeri''), though on smaller species of yucca.{{sfn|Opler|Tilden|1999|p=476}} The [[giant skippers]] (Megathymini) are species that feed in the roots of yuccas and inside the leaves of agaves.{{sfn|Cong et al. 2019|p=2}}

Beetle herbivores include [[Rhinostomus frontalis|yucca weevils]], in the [[Curculionidae]].{{sfn|Chamorro|Anderson|2019|pp=875, 883}}

In desert environments, yuccas are an important part of the ecology, improving the environment by enriching the soil with organic material and reducing errosion. The shelter the yuccas provide attract small animals and their waste and remains also concentrate nutrients in the immediately surrounding areas creating a microhabitat along with small plants.{{sfn|Webber|1953|p=1}} Tree-like species of yucca, such as the Joshua tree, provide nesting sites for birds, materials for small rodents, and the fallen trunks provide shelter for lizards.{{sfn|Gray|Adolph|2024|p=137}} In the plains biome, species like ''Yucca glauca'' provide perches for birds as well as cover for small birds, small reptiles, and small mammals.{{sfn|Rohde et al. 2021|p=62}} In the plains, yuccas are not a significant source of food for either native grazers or for livestock,{{sfn|Rohde et al. 2021|p=62}} but in desert environments cattle will learn to avoid the sharp ends of the leaves and eat the base instead.{{sfn|Webber|1953|p=1}} Similarly, goats will eat the whole head of leaves when there is no other forage available.{{sfn|Webber|1953|p=1}}

Yucca seeds remain viable for many years in the environment due to being well protected and having plenty of energy reserves. To start germination they require a large amount of moisture.{{sfn|Webber|1953|p=5}} Due to the scarcity of water in much of their habitat the reproduction of yuccas by seed is limited and the majority of new plants sprout from rhizomes.{{sfn|Alexander|Pond|Rodgers|2008|p=1175}}

===Conservation===
According to the [[International Union for Conservation of Nature]] only five species are [[Conservation status|endangered]], including [[plains yucca]] (''Yucca campestris''),{{sfn|Puente|Hodgson|Salywon|2020}} [[nodding yucca]] (''Yucca cernua''),{{sfn|Clary et al. 2020}} [[Yucca lacandonica|quim]] (''Yucca lacandonica''),{{sfn|Ayala-Hernández|Solano|Véliz|2020}} [[pitilla]] (''Yucca endlichiana''),{{sfn|Solano|Ayala-Hernández|Puente|2020}} and ''[[Yucca queretaroensis]]''.{{sfn|Hernández Sandoval et al. 2020}}