Sample introduction from report for unit BIOL114 “The effects of the processing of polystyrene plastics in Darkling Beetle larvae (Tenebrio molitor Linnaeus) upon growth and development.“

Introduction:

Since the 1970’s, petroleum-based plastic production and use has expanded at an alarming rate (Laist 1987). In 2013, 299 Mt of this plastic was consumed globally, 7.1% of this being in the form of polystyrene, otherwise known as Styrofoam (Yang 2015). One main cause of concern on this subject is the direct impact this has on our oceans and marine life, as it is estimated that every one minute, at least one garbage truck of plastic is dumped into our oceans (Earthday.org 2018). Plastic in general takes hundreds of years to decay, meaning once the pollutants are in our ecosystems they stay there for extensive periods of time. It is estimated that by 2050 there will be more plastic in Earth’s oceans than fish, which is of exponential concern for our wildlife (Earthday.org 2018). Large numbers of marine organisms ingest the plastic fibers or become ensnared by lose fishing line or other whole pieces of plastic causing serious injury, illness and in many cases death (Jambeck 2018).
As well as this, 72% of plastics are disposed of via landfills, and the rest are either burned and are deposited directly into the atmosphere or recycled (Leluk et. Al 2017). The chemicals produced by plastics buried in these landfills can run off into underground water supplies and contaminate them, causing extensive damage to Earth’s ecosystems.

If scientists can find a way to accelerate the biodegradation of plastics, we may be able to save our aquatic and terrestrial environments in time for them to be able to restore to their former healthy state. In recent years, scientists have discovered a species of pest beetle whose larvae are able to ingest and process plastic – the Darkling beetle, otherwise known as Tenebrio molitor Linnaeus or yellow mealworms. Several similar experiments have been conducted in the past, and have provided encouraging results and directions for further research.

The use of yellow mealworms can be highly beneficial to scientists and our environment. In their natural habitat, these mealworms infest homes and destroy stored grain supplies (Yang et al 2018). This species’ larvae are mass produced to be fed to pets such as reptiles and insects, which is beneficial to scientists as large amounts of them are readily available and highly accessible. These insects also have shorter lifespans and have less ethical considerations surrounding their use in scientific experiments. They are relatively low maintenance as they do not need to be fed very specific diets and can be kept in relatively small confinement e.g. small to medium sized containers (Yang et. At 2015). Yellow mealworms are also a credible choice of species because their guts contain forms of bacteria (Enterobacter asburiae YT1 and Bacillus sp. YP1) which have the ability to process petroleum-based plastics in the guts of other species such a Waxworms (Yang et. Al 2015).
The aim of this experiment is to determine whether consuming plastic effects the growth and development of T. molitor Linnaeus. It is hypothesized that larvae in polystyrene treatments will be negatively impacted while those in wheat germ treatments will have a higher life expectancy due to the presence of nutrients. If it becomes known that there is no negative impact, there is a possibility that mealworms may be used to reduce the impact of plastics on the Earth’s aquatic, terrestrial and atmospheric environments.