Thyrocopa spp. (Lepidoptera: Oecophoridae)

Endemic

Larvae

Most seem to be generalists on decaying leaf tissue, but the larva shown on the right (I call it Thyrocopa sp. 3) appears to be a specialist borer in Broussaisia arguta. It has a slightly different appearance from the generalist species, which are similar as larvae. The others generally make webby frass structures on a leaf, in which they hide.

Adults

The lower right adult is the only identified species, T. phycidiformis, which may not actually occur in the swamp - two were reared from larvae collected from mesic forest (along the `Awa`awapuhi Trail). One of these was reared from maile, another from Hedyotis terminalis.

Host plants recorded from the Alaka`i Swamp:

• Alyxia oliviformis (Apocynaceae) Maile; Endemic
• Broussaisia arguta (Hydrangeaceae) Kanawao; Endemic
• Coprosma elliptica (Rubiaceae) Pilo; Endemic
• Dicranopteris linearis (Gleicheniaceae)Uluhe; Indigenous
• Dubautia raillardioides (Asteraceae) Na`ena`e `ula; Endemic
• Hedyotis terminalis (Rubiaceae) Manono; Endemic
• Melicope clusiifolia (Rutaceae) Kukaemoa; Endemic
• Metrosideros polymorpha (Myrtaceae) `Ohi`a; Endemic
• Psychotria spp. (Rubiaceae) Kopiko; Endemic
• Rubus argutus* (Rosaceae) Blackberry;Alien
• Styphelia tameiameiae (Epacridaceae) Pukiawe; Endemic
• Vaccinium calycinum (Ericaceae) `Ohelo; Endemic

Only Thyrocopa sp. 3 in the right larval picture above was reared from B. arguta. Other plants on which Thyrocopa were collected but on which they did not reach adulthood are:
Astelia argyrocoma, Athyrium microphyllum, Carex spp., Cheirodendron platyphyllum, C. trigynum, Coprosma kauensis, Dianella sandwicianum, Dryopteris spp., Elaphoglossum spp., Myrsine punctata, and Smilax melastomifolia.

It is quite possible that these are all legitimate hosts since the larvae feed on decaying matter.

Development time in the laboratory at 20°C:

• Larva: 2-20 weeks
• Pupa: 2-8 weeks

The huge range in development times likely reflects differences among species. Thyrocopa are most common in the winter months, when development seems especially slow (despite rearing at a constant temperature).

Larval parasitoids recorded from the Alaka`i Swamp:

• Chaetogaedia monticola* (Diptera: Tachinidae); Alien
• Eriborus sinicus* (Hymenoptera: Ichneumonidae); Alien
• Meteorus laphygmae* (Hymenoptera: Braconidae); Alien
• Pristomerus hawaiiensis* (Hymenoptera: Ichneumonidae); Alien

Chaetogaedia monticola was reared only once, from a larva feeding on Rubus argutus. It is a highly generalist fly that was introduced unintentionally over a hundred years ago. Eriborus sinicus was reared only from the stem-boring species. Pristomerus hawaiiensis was reared only from Thyrocopa on uluhe(from which at least two species of Thyrocopa were collected).