|Depending on the day you visit, you may encounter literally thousands of ladybugs as you stroll through our tropical gardens. Why are they all here?
Ladybugs, or lady beetles, are a gardener's friend because they eat the bugs that eat the plants. Small insects such as aphids and mealybugs can become detrimental to a plant collection if their populations are left unchecked.
Both as larvae and adults, ladybugs are voracious predators of these "pests". After hatching from an oval yellow egg, the spiny larva immediately starts searching out an aphid meal. During its two weeks of eating & growing, a single ladybug larva can devour hundreds of aphids every day. In fact, the young ladybug is so voracious it is sometimes nicknamed the "aphid wolf."
After snacking on aphids for a couple weeks, the larva forms a hard pupa and transforms into an adult beetle which we so lovingly call "ladybug." This complete metamorphosis takes about two weeks. When the freshly emerged ladybug comes out of the pupa, it is typically pale yellow and lacks any spots.
After their wings darken and harden, the adult ladybugs can fly away to find new sources of aphids and mealybugs to feast upon. The female ladybugs will only lay their eggs where they feel there's an abundant food source for their young. Interestingly, some species have been observed to lay both fertilized and unfertilized eggs to provide a bonus breakfast for the young larvae when they hatch out of the fertilized eggs.
Many people don't realize that we have dozens of ladybug species native to Canada, although some are much more common than others. Unfortunately, many of them have become less abundant since the introduction of the Multi-coloured Asian Lady Beetle which arrived to Ontario in 1994. It is thought that this species is displacing many of our native ladybugs. If you're passionate about searching out ladybugs, you may want to check out the Lost Ladybug Project and report your sightings of native ladybugs.
The species you will encounter inside the Conservatory is a Canadian-native, the Convergent Lady Beetle. We release thousands on a regular basis so they may help to keep our plants healthy! Using natural predators, like ladybugs, to aid with gardening and agriculture is referred to as biological control. It just makes sense to encourage native bugs to help you combat the unwanted bugs, as opposed to fighting them with harsh pesticides and herbicides that harm our environment.
Introducing beneficial bugs as biological control has been a practice widespread in use for hundreds of years. Since there are already insects out there that eat other insects, why not invite them to your house & garden to partner with you in your fight against pests? Join us on April 25 for Ladybug Release Day to help us release tens of thousands of ladybugs inside the Conservatory, and learn more about how you can partner with them in your own garden.