Understory, Forest Gap, and Meadow Herbivores
There are probably more sensitive understory, forest gap, and meadow herbivores than canopy herbivores, because many rely either directly or indirectly on the modifications of temperature and humidity afforded by the surrounding canopy. Further, the understory has many more plant species. For example, several moss and liverwort feeders are found chiefly in mature and old-growth forests. These include the lacebugs (Acalypta spp.). Unfortunately, there is no data on the identity of specific bryophytes fed on in nature.
Small forest gaps or meadows are important to several sensitive species, including the highly limited grasshoppers (Boonacris spp.) (Boone and Randell, 1962) and the moth Annaphila casta , whose caterpillars eat the foliage of Mimulus moschatus in small meadows or marshy openings (Comstock and Henne, 1967).
Specialist herbivores on small shrubs in the understory of mature forests are reliant on the physical conditions that allow their hosts to thrive. one example is Cameraria sadlerianella which is a tiny leaf-mining moth found only on Sadler's oak (Quercus sadleriana), an understory shrub found only in a few sites in the western Siskiyou Mountains (Opler and Davis, 1981).
The bryophyte-feeders are intolerant of any changes in forest conditions that change their thermal or moisture environment. These changes could include cutting of trees in or near their population areas that would alter the temperature or thermal environments or return the habitats to an earlier seral stage.
The feeders on small understory shrubs or other vascular plants are probably intolerant of changes to the physical conditions of the forest understory, while the sensitive forest gap and meadow species rely on certain plants and a certain conditions of light and temperatures. These species, although they live in openings, would not tolerate losses of surrounding forest, because such loss would result in changes to their habitat constitution and would cause loss of population focus and orientation.
Order Orthoptera (Crickets, katydids, grasshoppers)
Family Acrididae
Boonacris alticola Rehn and Randell
Boonacris polita (Scudder)
Order Heteroptera (true bugs)
Family Miridae (plant bugs)
Allorhinocoris speciosus Bliven
Pithanus maerkelii (H.-S.)
Derephysia foliacea (Fallen)
Polymerus castilleja Schwartz
Family Tingidae (lace bugs)
Acalypta lillianis Torre-Bueno
Acalypta saundersi (Downes)
Acalypta vanduzeei Drake
Kleidocerys sp. undescribed
Family Scutelleridae (shield-backed bugs)
Vanduzeeina borealis californica Van Duzee
Order Coleoptera (beetles)
Family Elateridae (click beetles)
Eanus hatchii, Hatch's click beetle
Family Chrysomelidae
Timarcha intricata Haldeman
Order Mecoptera (scorpionflies)
Family Boreidae (snow scorpionflies)
Caurinus dectes Russell
Hesperoboreus brevicaudus (Byers)
Order Lepidoptera (butterflies and moths)
Suborder Ditrysia
Family Gracillariidae
Cameraria sadlerianella Opler and Davis
Family Pyralidae
Udea sp. undescribed
Family Noctuidae (owlet moths)
Annaphila casta Henry Edwards
Abagrotis pulchrata (Blackmore)
Euxoa vetusta (Walker)
Lithophane dilatocula (Smith)
Nedra dora Clarke
Platypolia contadina (Smith)
Pseudocopivaleria sonoma (McDunnough)
Order Hymenoptera (bees, wasps, ants)
Family Tenthredinidae
Monophadnoides geniculatus (Hartig)
Phymotocera similata (MacGillivray)
Family Cephidae
Caenocephus aldrichi Bradley