Euchroma giganteum

Geographic Range

The giant metallic ceiba borer, Euchroma gigantea , is native to the Nearctic and Palearctic regions. It occupies much of Central and South America and a lower portion of North America. The beetles range from southern Arizona and New Mexico through Mexico. They are also known to live in Brazil and Argentina.

• Biogeographic Regions
• nearctic nearctic
  • native native
• neotropical neotropical
  • native native

Habitat

Ceiba borers live in warm regions of up to 1,200 meters in elevation with specifically high numbers found in the Amazon. The larvae are typically found in the soft wood of trees in the Bombacaceae family. The adult beetles are found mostly on acadia branches in arid desert flats on summer days. The adult beetles are also found walking or flying around the trunks of trees. The beetles frequently visit flowers, and various other deciduous trees or large shrubs, where they feed on pollen.

• Habitat Regions
• temperate temperate
• tropical tropical
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest
• rainforest rainforest

Physical Description

Adults of Euchroma gigantea usually measure between 5 to 8 cm in length, the largest of their type. The body shape resembles a bullet that is slightly flattened. The beetles have wing cases, called elytra, which are covered with metallic purplish blue bumps and occasionally will contain a green or slight reddish color. There are typically two dark, round spots on the pronotum. They will also secrete a yellow wax to protect them from the sun and hold moisture in their body. They have large dark eyes and segmented antennae. The larva can reach up to 15 cm but are generally smaller.

• Other Physical Features
• ectothermic ectothermic
• heterothermic heterothermic
• bilateral symmetry bilateral symmetry

Development

Eggs are laid in late summer in trees or stumps. The eggs hatch after about 19 days and remain in the wood for up to a year or more with no light exposure. They go through several larval instar stages, as well as a pupal stage. When the emerge as adults, they leave their tree or stump.

• Development - Life Cycle
• metamorphosis metamorphosis

Reproduction

Males of Euchroma gigantea use their hard fore-wings, known as the elytra, to make a clicking sound that will attract a female mate. Mating takes place mainly in August.

Once the pair have mated, the female finds a tree that has damage due to disease, insect infestation, lighting strikes, or physical damage. The female beetle will lay her eggs in rough bark after chewing a shallow hole into the bark. The beetle will lay 240 eggs total throughout her life span. The eggs will be laid in 4 groups of 10 eggs on one plant. They will keep this pattern until all 240 eggs are laid on multiple plants.

• Key Reproductive Features
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
  • internal internal
• oviparous oviparous

Females of Euchroma gigantea provide provisioning in their eggs. They also place the eggs on a suitable tree or stump that the larvae will feed on and burrow into upon hatching. After they lay the eggs, the provide no more parental care.

• Parental Investment
• pre-hatching/birth
  • provisioning
    • female

Lifespan/Longevity

As larvae, they spend up to two years of their lifetime in the tree that they are laid in, until they are capable of flight. Once they are adults, they can live anywhere from two to four years.

Behavior

Euchroma gigantea is diurnal, with most of its activities occurring during the day. They can sometimes be found sunning themselves on trees, while their movements are sluggish unless alarmed. When the larvae hatches from its egg it buries itself into the wood that it was laid on. Here, they spend most of their larvae stage. Once they mature and become adults, they grow wings and gain the ability to fly. This allows them to migrate to new trees where they can mate and lay eggs. These beetles also have the capability to damage the tree that they reside in. They do this by eating the roots and other parts of the tree, causing them to unroot and fall.

• Key Behaviors
• arboreal arboreal
• flies
• diurnal diurnal
• motile motile
• sedentary sedentary
• solitary solitary

Communication and Perception

Euchroma gigantea has a unique way of communicating. The males will make a clicking sound to attract the females for mating reasons. To make these sounds, they use their elytra, the hard fore-wing of the beetle. There is little information available about other means of communication and perception, though they have well developed eyes and likely communicate with others and view their environment visually.

• Communication Channels
• visual visual
• acoustic acoustic

• Perception Channels
• visual visual

Food Habits

Giant metallic ceiba borers have different diet trends throughout their life. In the larval stage,they feast on the decomposing parts of the trees in which they were hatched in. Although the larvae have the ability to move in the tree, they do not have the ability to move between trees or to other plants, so they have to feed on the plant that they are born in. Adults eat leaves and pollen among a large variety of plants, though there is very little known about the specific eating habits of the Buprestidae family of beetles.

• Primary Diet
• herbivore herbivore
  • folivore folivore

• Plant Foods
• leaves
• roots and tubers
• wood, bark, or stems
• seeds, grains, and nuts
• pollen

Predation

The only known predator to the metallic ceiba borer is humans; the Tzeltal-mayan Indian tribe in Mexico as well as Amazonian tribes eat the adult beetles and use the beetles wing casing as jewelry or ornaments. The thick, hard elytra of E. gigantea likely protects it from many other predators. The color of the elytra may also function as camouflage.

Ecosystem Roles

The larvae of Euchroma gigantea have been known to eat decomposing trees in their habitat. This is made possible by bacteria in their stomach, which breaks down the cellulose in the tree, allowing them to aid in biodegradation. This decomposition process is very important because it allows the ecosystem to remain diverse by placing nutrients needed by other organisms back into the environment.

• Ecosystem Impact
• biodegradation biodegradation

Economic Importance for Humans: Positive

The giant metallic ceiba borer is harvested by humans, especially by many amazonian tribes, for jewelry. They use the colorful and hard elytra for things such as necklaces or earrings. The jewelry has a large impact on the economy of these tribes because it can be sold for money. One tribe is also known to eat these beetles. These beetles are also considered a prize or trophy specimen for insect collectors, due to their large size and colorful appearance.

• Positive Impacts
• food food
• body parts are source of valuable material

Economic Importance for Humans: Negative

The diet of the metallic ceiba borer consists mainly of plant matter. There have been numerous accounts of Euchroma gigantea eating the roots and bark of cultivated and ornamental trees. Plants are at risk when they are newly planted from a nursery, along with trees whose trunks are exposed to direct sunlight.

• Negative Impacts
• crop pest

Conservation Status

Euchroma gigantea has no special conservation status.

Additional Links

Encyclopedia of Life

BioKIDS Critter Catalog

Contributors

Sebastian Fannan (author), Bridgewater College, Albert FitzPatrick (author), Bridgewater College, Quinn Morgan (author), Bridgewater College, Tamara Johnstone-Yellin (editor), Bridgewater College, Angela Miner (editor), Animal Diversity Web Staff.

References

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Hawkeswood, T., P. Magnus. 1985. A review of larval hosts records for Australian jewel beetles. Victorian Naturalist , 99: 240-251.

Hogue, C. 1993. Latin American Insects and Entomology . Los Angeles, California: University of California Press.

Nichols, M. 1910. The spermatogenesis of Euchroma gigantea . The Biological Bulletin , 19/3: 167-178.

O'Toole, C. 1993. The encyclopedia of insects . New York, New York: Facts on File Inc.

Schwab, I. 2004. Jewels of the jungles. British journal of opthalmology , 88/7: 857.

Sutherland, C. 2006. Wood Boring Bettles. O & T Guide , 10: 1-5.

Utah State University, 2014. "Top 20 insects" (On-line). Accessed February 03, 2014 at https://utahpests.usu.edu/uppdl/htm/top-20-insects#flathead_beetle .

2013. "Giant metallic ceiba borer ( Euchroma gigantea )" (On-line). Arkive. Accessed February 03, 2014 at http://www.arkive.org/giant-metallic-ceiba-borer/euchroma-gigantea/image-G103396.html .

2009. "Giant metallic ceiba borer beetle" (On-line). Glasgow Museum. Accessed February 03, 2014 at http://www.lifeintherainforest.org/giant-metallic-ceiba-borer-beetle .