Beetles: First At A Lot of Things

The world stands on the shoulders of beetles. Some of the oldest and most diverse insects known to science, beetles are believed to have emerged around 300 million years ago, at a time when most of our global coal deposits were still living plants waiting to be subducted underneath the planet’s crust. 

Beetles have survived multiple mass extinctions, including the Permian-Triassic event some 250 million years ago, believed to be the deadliest event in history, killing off over 90% of the oceanic life at the time and around 70% of land animals. Their incredible resilience has allowed them to fill basically every niche in nature imaginable. Because of their ancient lineage, beetles have also tended to be the first at a lot of things. Scientists believe beetles take the cake for the first pollinators and first fungus farmers, and beetles are living legends in the fields of dung collection, ground predation, biolumination, pantry raids, and even a small degree of social interaction. Although most ancient beetles were monstrous armored fiends compared to the beetles of today, modern beets aren’t exactly slouches either. For example scientists recently discovered a beetle that, when eaten by hungry frogs, simply takes it upon itself to bodily crawl through the frog’s digestive tract to the rear exit, plopping out to continue its day seemingly unharmed. New beetle species are discovered almost daily, however there are already a large number of amazing beetles known to science that are easily observed in and around the garden.

 There are around 400,000 species of beetle catalogued at this time, which makes up around 40% of all known insects. The largest family, that of the elephantine weevils, has more members than all of the known bees, butterflies, and wasps combined. The overwhelming variety of beetles is mostly due to their survival strategies. Over hundreds of millions of years, each beetle species has developed unique ways to survive in their particular environments. Some beetles can change their mode of reproduction depending on the season, reproducing as either larvae or fully grown adults if local conditions demand it. Similar to bees and wasps, most beetles possess 2 pairs of wings, however the outer pair tends to be a hardened shell that sets them apart from other insects. The protective shell of beetles and most other insects is made out of chitin, a lightweight yet strong material made from a derivative of glucose. An example of chitin’s strength can be found in the aptly named ironclad beetle, mostly found on the west coast, which is able to withstand forces almost 40,000 times its body weight without being crushed. Chitin has protected countless organisms on Earth from the elements and predators for millions of years, however it might also play a key role in humans’ expansion into the universe as well. Researchers studying space travel have determined that chitin could make an excellent building material for structures on the Martian surface and beyond. In future astro-societies where insects are grown and harvested as a food source, this chitin would be a valuable byproduct, providing free material as we consume the nutrient and protein-rich flocks. 

Beetle habitats come in as many flavors as the insects themselves, but most beetle habitat is easy to maintain. Freshly cut and rotting wood is a favorite for many beetle larvae, who rely on fungi and other methods to break it down into an edible form. Wood-nesting beetle larvae usually excavate tunnels in their wood of choice. Insects of all shapes and sizes reuse these tunnels after the beetle has emerged, including wood nesting bees and wasps. Leave as much fallen dead wood on your property as possible to help foster local populations of these beneficial insects. Fireflies, the flashiest of nocturnal beetles, live in the soil for up to several years before venturing out to perform their mate-attracting light shows. A wide range of other beetles also spend most of their lives underground, preying on other insects or helping to recycle dung and carrion back into the ecosystem. All of these beetles appreciate dense, tall grass or shrubs for shelter, and are heavily impacted by pesticide exposure, offering another reason to minimize the chemicals you spray in and around your property.

A note on ladybugs

Perhaps the most well-known garden beetle is the ladybug. Over 400 types of ladybugs, or lady beetles, take up residence in the states. The colorations of ladybugs usually consist of reds, yellows, oranges, or pinks mixed with spots and stripes. Their flamboyant shells advertise a bitter taste to hungry predators, and in many cases the beetle is also able to secrete poisonous concoctions from their chitinous exoskeleton. Ladybugs are a gardener’s best friend from a pest control perspective, as they eat plant grazers and sap suckers in both their larval and adult forms. Some ladybugs only hunt specific prey, however most eat a balanced diet including aphids, scale insects, mealybugs, and the eggs of larger pest insects such as European corn borers and Colorado potato beetles. Each ladybug is believed to consume thousands of insects in its lifetime, and they have been documented consuming around 25 pests a day even in their young larval forms. The tenacity and effectiveness that ladybugs exhibit while hunting was quickly noticed, and they were some of the first insects to be widely used in the biological control of agricultural pests. This has led to several exotic ladybug species being introduced into the states in an effort to help with pest control, leading to some unexpected results. 

 Many of the introduced ladybug species in the States seem to co-exist alongside our native ladybugs rather well, however there is a certain species among them that is not so friendly. Hidden among our backyard beetles is a voracious intruder, a ladybug that dwarfs our native species in both size and appetite. Hailing from eastern Asia, the Asian lady beetle has established a foothold in the US and Europe. Asian lady beetles eat with reckless abandon, and they are remarkably resistant to pesticides. While this allows them to thrive in most agricultural settings, research is showing that they are also heavily disrupting our native ladybugs. Simply put, the Asian lady beetles’ diet includes the eggs and larvae of our local beetles as well as aphids and other pests. Unfortunately, most commercially available ladybugs sold to gardeners are populations of this invasive species. To help control the spread of these invaders, refrain from releasing any store-bought ladybugs onto your property. If you desire more ladybugs in your garden, simply leave colonies of aphids and other garden pests where they are. If you leave them, beetles will come.