'', the Ivory Marked Borer
Diet All known longhorn beetle larvae feed on plant tissue such as stems, trunks, or roots of both herbaceous and woody plants, often in injured or weak trees. A few species are serious
pests. The
larvae, called
roundheaded borers, bore into
wood, where they can cause extensive damage to either living
trees or untreated lumber (or, occasionally, to wood in
buildings; the
old-house borer,
Hylotrupes bajulus, is a particular problem indoors). Many longhorns locate and recognize potential hosts by detecting
chemical attractants, including
monoterpenes (compounds released en masse by woody plants when stressed),
ethanol (another compound emitted by damaged plant material), and even bark beetle
pheromones. Many
scolytine weevils share the cerambycid's niche of weakened or recently deceased trees; thus, by locating scolytinids, a suitable host can likely be located as well. The arrival of cerambycid larvae is often detrimental to a population of scolytinids, as the cerambycid larvae will typically either
outcompete them with their greater size and mobility, or act as direct
predators of them (this latter practice is less common, but has been observed in several species, notably
Monochamus carolinensis). Cerambycids, in turn, have been found to play a role in attracting other wood-borers to a host. Borgemeister, et al. 1998, recorded that cerambycid activity in girdled twigs released
volatiles attractive to some
bostrichids, especially
Prostephanus truncatus. A few cerambycids, such as
Arhopalus sp., are adapted to take advantage of trees recently killed or injured by
forest fires by detecting and pursuing smoke volatiles. Adults of Lamiinae, most Lepturinae and some Cerambycinae also feed. Adults of Parandrinae, Prioninae and Spondylidinae do not feed. In those taxa with feeding adults, common foods are nectar, pollen, fruit and sap exudates. Some (mainly Lamiinae) feed on bark, plant stems, needles or developing cones. Roots are consumed by larvae and sometimes also adults of soil-dwelling
Dorcadion. The genus
Leiopus is known to feed on fungi. Lastly, the genus
Elytroleptus is unusual in having carnivorous adults, which prey on
lycid beetles.
Pollination In addition to feeding on other plant tissue, some species feed on pollen or nectar and may act as pollinators. Assessing the efficacy of beetle pollinators is difficult. Even if pollination of one species by beetles is shown, that same beetle may also act as a flower predator toward other species. In some cases, beetles may act as both pollinators and predators on the same flowers. Flowers specializing in pollination by beetles typically display a
particular set of traits, but pollination by longhorn beetles is not limited to these cantharophilous flowers. A review of angiosperm pollination by beetles shows that Cerambycidae, along with Curculionidae and Scarabaeidae, contains many taxa that are pollinators for not only specialist but also generalist systems. Beetles in the New Zealand genus
Zorion are known to feed on pollen and have a specialized structure similar to that of
pollen baskets found in bees. Species in this genus are thought to be important pollinator species for native plants such as
harakeke. Some orchid species have been found to be largely reliant on longhorn beetles for pollination. The species
Alosterna tabacicolor was found to be the main pollinator of a rare orchid species (
Dactylorhiza fuchsii) in Poland. Another rare orchid
Disa forficaria, found in the
Cape Floristic Region in South Africa, relies on the species
Chorothyse hessei for pollination.
D. forficaria uses
sexual deception targeting male
C. hessei, possibly indicating a long history of
co-evolution with longhorn beetle pollinators. ''. The proportion of longhorn beetle species that act as pollinators is unknown. The fact that two species of longhorn species from distinct subfamilies (
Lepturinae and
Cerambycinae) found on different continents both with significant roles as pollinators could suggest that some capacity for pollination may be common among longhorn beetles.
Predators Parasitoids In
North America some native cerambycids are the hosts of
Ontsira mellipes (a
parasitoid wasp in the family
Braconidae).
O. mellipes may be useful in controlling a
forestry pest in this same family,
Anoplophora glabripennis, that is invasive in North America. ==Classification==