Beetle larvae and adults have a wide range of habits. The majority of the beetles 
are terrestrial but some species, even entire families, are aquatic both as larvae and 
as adults. Some feed on vegetable matter; others feed on animal matter. Many are 
phytophagous, many are predacious, some are scavengers, some feed on mold and 
fungi, and a few are parasitic. Beetles that feed on plants are of primary interest. 
The order Coleoptera contains many of the most destructive forest insects. Adults 
and larvae of the phytophagous species have certain modifications in form and 
habits that enable them to feed on different portions of plants. A beetle species may 
cause damage to tree flowers. fruits, and seeds; roots, stems, or foliage of living 
trees; dead or dying trees: drying logs and lumber: or wood products many years 
after wood is placed into use. Considering the invaluable resources provided by 
forests—wood and wood products, clean air and water, recreation and wildlife as 
well as esthetic wilderness values—humanity is inadequately appreciative of the 
fact that parasites and predators help to limit the damage beetles might cause in 
most situations. 
Beetles annually cause enormous losses to valuable timber or shade trees; to 
forest products by degradation, often through the introduction of blue-stain fungi or 
other pathogens: to seedlings in nurseries, plantations, seed orchards, or natural 
stands by growth loss or mortality; and to seed orchards by reducing harvest of 
viable seed. Most of the destruction results from feeding by larvae. Charac- 
teristically, initial attack by adults of many species is restricted to wood that is in a 
certain condition—either living, recently dead or dying, or decaying. Larvae of the 
Cerambycidae, Buprestidae, and some other families may continue to survive 
within wood that is too dry for initial attack. Some other beetles, e.g., the Lyctidae 
and some of the Anobiidae, are capable of repeatedly infesting seasoned wood in 
storage or service. 
Identification.— Adult beetles in many families feed as defoliators or predators, 
but the most serious damage to forests and forest products results during the 
extended feeding period of the larvae of most families. Frequently the adults are 
short-lived or nocturnal and the feeding larvae are hidden, either beneath bark or 
deeply within the wood, and not readily available for identification. Although 
larvae are found more often than adults, specific or generic identification of larvae 
is often a difficult task, even for a taxonomic specialist. The family, group, and 
sometimes even the species can often be quickly and easily identified from careful 
attention to the general appearance of larvae and to what is being damaged, 1.e., 
seeds, twigs, bark, wood of living, dying, or dead trees, logs, and wood products, 
ec. 
Beetle larvae from various families can be grouped by general appearance 
according to their body form or shape. For a few families, larvae have a different 
body form with each molt. Larvae characterized by the absence of legs on the 
thorax are the weevil or curculionid type. They have thick crescent-shaped bodies 
and a well-developed head (families Curculionidae, Scolytidae, and late-stage 
Bruchidae). Larvae with thoracic legs are either very active with flattened bodies 
(thysanuriform) or slow moving with thick caterpillarlike bodies (eruciform). The 
thysanuriform type is further subdivided into the caraboid and triunguloid types. 
The caraboid type larvae have strongly developed mandibles and are mostly 
predacious (families Carabidae, Cicindelidae, Cleridae, Staphylinidae, Histeridae, 
etc.). The first instars of the Meloidae and Rhipiphoridae are about the only 
triunguloid examples. 
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