How has Calopteron reticulatum evolved and how does it reproduce?

  Over time, the wing colors and patterns on C. reticulatum and other beetles in the Lycidae family have evolved. According to a study conducted in Asia performed by Bocak and Yagi (2010), these beetles have due to their movement to different land environments have evolved color change on their wings. Some of the beetles were observed to have a lighter and more yellow color on their wings whereas others had black, and orange on their wings. Split by water bodies, these beetles were split by allopatric speciation which in turn may have resulted in sympatric speciation which means that even though the beetles may have been from the same species, their wing color may have made such a difference that they couldn't mate or reproduce. Additionally, these beetles may have evolved their orange color on their wings to increase their own defense against predators (Bocak and Yagi 2010). In order for these beetles to mate, male beetles have to send out chemical signals to attract and locate female beetles (Grzimek 2004:319-322). After a male has attracted a female, mating occurs. Once fertilization occurs, the eggs are laid in the tunnel of a dead tree log or under tree bark(Grzimek 2004: 321; Bocak and Matsuda 2003). By hiding the eggs in the tunnel of a dead tree or under a log, they eggs are less likely to be eaten by a predator. Additionally, the eggs can take at least two weeks to hatch and transform into the larval stage.  


 Larval Stage: Once C. reticulatum hatch out of their eggs, they are considered larvae. The larvae are white in color when they hatch and once they're out of their eggs, they begin to eat. These larvae eat a variety of foods that range from eating other organisms that share their habitat with them to drinking plant juices. Near other organisms though, C. reticulatum larvae are carnivorous because they eat the organism that they are sharing a habitat with (Miller 1988). In addition to eating other organisms and drinking plant juices, C. reticulatum larvae also feed on slime molds, decaying from which they hatch from. As C. reticulatum eats, it grows longer and longer until it reaches a length of approximately 10 to 15 mm (Hall and Braham 2013).
 

: Pupal Stage: Following the larval stage, C. reticulatum remains in its instar exoskeleton and begins its pupal stage. It is believed that C. reticulatum unlike other beetles may actually save energy by staying in the same exoskeleton throughout its larval and pupal stages (UW-Milwaukee 2013) Prior to this stage, hundreds of full grown C. reticulatum larvae will aggregate in one location of a tree where they begin and finish their pupation stage. One theory to the aggregation behavior of these beetles is that aggregation increases their safety (Hall and Branham 2013). In addition to the pupa aggregating for safety, their exoskeletons have black and orange spikes on them. Additionally, once the pupa aggregate, they will stay on the log for as long at two weeks or even months (Hall and Branham 2013). These pupae do not eat or drink rather, they stay in a dormant stage (University of Michigan).   


 Adult stage: After staying dormant and not eating for a period of time, the C. reticulatum pupa shed their last instar exoskeleton and emerge as full grown adults(Hall and Branham 2013). Once they emerge, some will fly away from pupation site and some will stay (Hall and Branham 2003). These newly emerged adults can be identified by the black and orange banding pattern on their wings. These black and orange banding patterns also give predators the signal that they should not eat C. reticulatum beetles (Hall and Branham 2013). As adults, they will mate by sending out chemical signals. Female beetles can mate multiple times and each time they mate, not only will their eggs be fertilized, but the extra sperm will be stored within their bodies(Grzimek 2004: 321-322.). These adults will also continue to feed on fermenting plant juices, slime molds and decaying wood. One more point to keep in mind about eating wood is that when these beetles eat wood, they are also making tunnels for their eggs to grow and hatch into larvae (Bocak and Matsuda 2003).

 

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