Adult ceiba borers are huge beetles, measuring between 5 to 8 cm in length. They are the largest of their kind. The body shape is flat and is shaped like a bullet, coming to a point at the rear end. The beetles have thick wing coverings called elytra. Their elytra are metallic, bumpy, and usually purplish-blue, but also may have a green or slightly reddish color. They also usually have two dark, round spots on the body section just behind their eyes. Their eyes are large and dark, and their antennae are made up of many segments. Adults also produce a yellow wax that covers their bodies, which protects them from the sun and prevents them from losing water. Larvae can reach up to 15 cm in length, but are usually smaller. ("Giant metallic ceiba borer (Euchroma giganteum)", 2013; Evans, 2008; Utah State University, 2014)
The giant metallic ceiba borer, Euchroma giganteum, is found in much of Central and South America and a lower portion of North America. The beetles live from southern Arizona and New Mexico through Mexico. They are also known to live in Brazil and Argentina. ("Giant metallic ceiba borer (Euchroma giganteum)", 2013; "Giant metallic ceiba borer beetle", 2009; Evans, 2008; O'Toole, 1993)
Giant metallic ceiba borers live in warm regions up to 1,200 meters in elevation. The larvae are typically found in the soft wood of trees in the Bombacaceae family. The adult beetles are usually found walking or flying around the trunks of trees in forest and rainforest habitats. The beetles frequently visit flowers, and various other deciduous trees or large shrubs, where they feed on pollen. ("Giant metallic ceiba borer (Euchroma giganteum)", 2013; Evans, 2008)
Giant metallic ceiba borers have four life stages: egg, larva, pupa, and adult. Their transformation from egg to adult is called complete metamorphosis. Eggs are laid in late summer in trees or stumps. The eggs hatch after about 19 days and stay in the wood for up to a year or more. They go through several larval stages called instars, and then become pupae. After developing as pupae, they emerge from the tree and leave as adults. (Schwab, 2004)
Ceiba borers use their hard wing coverings, called elytra, to make a clicking sound. This clicking sound communicates with possible female mates and lets the females know that the male is there and ready to mate. Mating takes place mainly in August for this species. ("Giant metallic ceiba borer (Euchroma giganteum)", 2013; Nichols, 1910)
Once the male and female 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 female 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. (Nichols, 1910; Schwab, 2004; Sutherland, 2006)
Female giant metallic ceiba borers provide nutrients in their eggs for their offspring to grow and develop. They also lay the eggs on trees or stumps that the larvae will eat and live in once they hatch. However, after the eggs are laid, the female leaves and does not give any more parental care. (Nichols, 1910; Sutherland, 2006)
As larvae, these beetles spend up to two years of their lifetime in the tree that they hatched on, until they become adults. Once they are adults, they can live anywhere from two to four years. (Schwab, 2004)
Ceiba borers are active during the day, and can often be seen sitting on the sun on trees to warm their bodies. They move slowly unless they are threatened. Larvae bury themselves in the trees where they hatch and spend most of their time here. Once they become adults, they grow wings and are able to fly. This allows them to fly to different trees to find mates and lay eggs. These larvae can also cause damage to the trees they live in. They do this by eating the roots and other parts of the tree, causing them to unroot and fall over. (Hawkeswood and Magnus, 1985; Nichols, 1910; O'Toole, 1993; Schwab, 2004)
Ceiba borer beetles have a unique way of communicating. When males want to mate, they will make a clicking sound to attract the females. To make these sounds, they use their elytra, the hard fore-wing of the beetle. These beetles have well developed eyes and likely can see each other and their environment. (Nichols, 1910; Schwab, 2004)
Giant metallic ceiba borers have different diets during different parts of their life cycle. As larvae, they eat the decaying wood and plant matter of the trees and stumps that they hatched on. Larvae are not able to move between plants, so they are stuck eating the plant that their parent left them on. Once the beetle is an adult and is able to fly to other plants, it can eat leaves and pollen among a large variety of plants. ("Giant metallic ceiba borer beetle", 2009; Gervais, et al., 2012)
The only known predator to the metallic ceiba borer is humans. Tribes of people in Mexico and the Amazon eat the adult beetles and also use the colorful beetle body as jewelry or ornaments. The thick, hard wing covers of these beetles likely protect them from many predators. Their colors may also act as camouflage and make it hard for predators to see them. (Hogue, 1993; Schwab, 2004)
The larvae of the giant metallic ceiba borer eat decomposing and decaying trees in their habitat. They have bacteria in their stomach that break down the material from the trees. The larvae cannot digest the woody material alone without the help of the bacteria. This process is very important, because the larvae speed up the natural rate of decay, and break down the material. This releases nutrients back into the ecosystem, which other organisms can now use. ("Giant metallic ceiba borer beetle", 2009; Schwab, 2004)
Metallic ceiba borers eat mainly plant matter. There have been numerous times where these beetles have been found to eat the roots and bark of trees. This can cause damage to the trees, and cause them to uproot and fall over. (Utah State University, 2014)
The giant metallic ceiba borer is used by humans, especially by many tribes in the Amazon, for jewelry. They use the colorful and hard wing coverings 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 for insect collectors, due to their large size and bright colors. (Hogue, 1993; Schwab, 2004)
Giant metallic ceiba borers are not an endangered species.
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.
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