Saturday, March 16, 2013

[Entomology • 2005] Siamusotima aranea | Lygodium Spider Moth • a New Stem-Boring Musotimine (Lepidoptera: Crambidae) from northern Thailand Feeding on Lygodium flexuosum (Schizaeaceae)

Lygodium Spider Moth (Siamusotima aranea, Musotiminae, Crambidae)
By itchydogimages | John Horstman |

Siamusotima aranea
Solis, Yen, Goolsby, Wright, Pemberton, Winotal, Chattrukul, Thagong & Rimbut, 2005

Siamusotima aranea Solis & Yen, is a new stem-boring musotimine species from Thailand. It was discovered in the stems of Lygodium flexuosum (L.) Sw. (Schizaeaceae) during exploration for biological control agents of Lygodium microphyllum (Cav.) R. Br., the Old World climbing fern. This is the first report in the Pyraloidea of a stem-boring larva with unique modifications of the anal segment resembling that of tenebrionid beetle immatures and with observations of possible mimicry between the adult moth and spiders.

Keywords: Pyraloidea, Old World climbing fern, pteridophagy, spiders, tenebrionid beetles

2005. Siamusotima aranea, a New Stem-Boring Musotimine (Lepidoptera: Crambidae) from Thailand Feeding on Lygodium flexuosum (Schizaeaceae). Annals of the Entomological Society of America. 98(6):887-895. doi:[0887:SAANSM]2.0.CO;2
Newly Discovered Species of Moth Mimics a SPIDER!

Lygodium Spider Moth (Siamusotima aranea, Musotiminae, Crambidae)
By itchydogimages | John Horstman |

This recently described moth (originally from Thailand in 2005) is called the Lygodium Spider Moth because it feeds on Lygodium species, an invasive Old World climbing fern, and has markings that look like a spider (possibly mimicry to protect it from predators).

This moth has risen to significance because of it's appetite for the Lygodium ferns, which have developed as an invasive weed that threatens Florida's wetlands.

While there are many stem-boring moths, S. aranea is the first to be identified among fern-feeders in Asia. The moth is unique in a number of ways. For one, its caterpillar form looks more like some beetle larvae. The moth has armored segments on its rear similar to those on beetles but unlike anything seen before in a moth. And the adult moth may mimic spiders, a characteristic that has led to its scientific name, "aranea," as well as its unofficial moniker.

This discovery expands possibilities for biological control of the Old World climbing fern in the United States. The plant is not a pest in its native Australia, South and Southeast Asia, and Africa, perhaps because its enemies keep it in check there.

Pu'er, Yunnan, China