Final Comprehensive Conservation Plan - U.S. Fish and Wildlife ...

Proterhinus (Coleoptera: Aglycyderidae)
Hakalau Forest National Wildlife Refuge
Comprehensive Conservation Plan
A large diversity of beetles are found at the HFU of the Hakalau Forest NWR. Twenty-three species
of weevils in the genus Proterhinus (Coleoptera: Aglycyderidae) are endemic to Hawai„i Island.
These tiny, slow-moving beetles bore into leafs, twigs, stems, and wood and are known to have a
very narrow host range (Haines and Foote 2005). This species exhibits a wide array of morphological
diversity, making species level identification difficult. Proterhinus spp. were determined to be scarce
throughout the HFU (Howarth et al. 2003).
A total of 71 Proterhinus specimens within five species (P. affinis, P. ferrugineus, P. hawaiiensis,
P. similis, and P. subangularis) were collected from the KFU. Of the five species encountered,
P. similes was the most abundant and was collected from eight different plant species (Haines and
Foote 2005).
Plagithmysus (Coleoptera: Cerambycidae)
There are about 140 species of endemic longhorned beetles in the genus Plagithmysus (Coleoptera:
Cerambycidae) in the State and 12 are considered species of concern on the island (Howarth et al.
2003). These wood-boring beetles are more showy and active than Proterhinus beetles (Haines and
Foote 2005). Larvae pupate in the wood and adults emerge by chewing out, leaving visible exit holes.
Typically adults lay eggs on recently fallen tree branches, but live trees are also used. Plagithmysus
help with forest decomposition and serve as food for birds and other species.
Three species of longhorned beetles have been recorded as widespread throughout the HFU – P.
varians, P. clavigeris, and P. vicinus (Howarth et al. 2003, Goldsmith 2007). Both P. varians and P.
clavigeris are host-specific to dead koa (Howarth et al. 2003). At HFU, the density of longhorned
beetles at low-elevation sites was double the density found at high-elevation sites. There are also
seasonal differences in population size and characteristics. Because of their importance in forest
ecology, longhorned beetles have been used as indicator species to assess recent reforestation efforts
at the HFU (Goldsmith 2007).
At the KFU, three different species of longhorn beetles were collected: P. bilineatus, P.debilis, and
P. nodifer. The host plant for P. bilineatus is „ōhi„a, while P.debilis and P. nodifer were both reared
from koa. A new Plagithmysus species was also found on the unit. This new species was found on
dead or dying branches of „a„awa (Pittosporum hosmeri) (Haines and Foote 2005).
Omiodes (Lepidoptera: Crambidae)
Several moths and butterflies (Lepidoptera) have been recorded on the HFU. Ten species of endemic
leaf roller moths in the genus Omiodes (Lepidoptera: Crambidae) are listed as species of concern.
This group gets its name because the larvae roll or fold leaves, or bind them together with silk, to
create a retreat (Haines and Foote 2005). Most species utilize monocots as host plants.
Omiodes pritchardii, which is restricted to Pritchardia palms, was found at the lower elevation site
in Pua „Ākala at the HFU (Howarth et al. 2003). Omiodes accepta, O. asaphombra, O. localis and
O. scotaea have been collected from the KFU. Omiodes accepta, the sugarcane leafroller, was found
to be the most abundant (27 of 49 total specimens) and is common on grasses and sedges. Omiodes
asaphombra only breeds on rare „ohe (Joinvillea ascendens), which is not known to occur on the
Chapter 4. Refuge Biology and Habitats 4-51