A shipment of 9,000 Ladybugs (Coccinellidae septempunctata, also called seven-spot ladybird beetles), as well as Black Lady Beetle (Lindorus lophanthae) and Common Lacewings (Chrysoperla carnea) were released. Praying mantis egg cases were placed in a viewing chamber and will hatch in the coming sunny days.
Why, you might ask.
These beneficial insects will travel throughout the Conservatory and the adjoining greenhouses, controlling thrips, mites, scale insects and other pests without the use of chemical pesticides. Perfect, and simple.
And I, for one, am glad that the ladybugs could bring people together for a moment of interest, excitement and childish magic.
It was heart-warming to see parents crouching to point out ladybugs finding their way on the ferns and other tropical plants. It was wonderful to see the inquiry on the faces of children as they studied a ladybug crawling on their arm or their fingers. I don't think anyone who spent time at the Conservatory today will look at ladybugs quite the same way.
I realized there were a lot of things about ladybugs that I didn't know; I decided to investigate.
Ladybugs (C. septempunctata) "has a broad ecological range", according to Wikipedia, "generally living where there are aphids for it to eat. Both the adults and the larvae are voracious predators of aphids, and because of this, C. septempunctata has been repeatedly introduced to North America as a biological control agent to reduce aphid numbers." This little insect is now well established in North America.
What is the lifecycle of a ladybug?
Ladybugs undergo what is called a 'true metamorphosis'. Like butterflies, they begin life as an egg, hatch into a larva, form a pupa and then emerge as an adult insect. The pupa stage in a ladybug lasts about one week.
What about those spots?
The seven-spot ladybird's colour develops over time. The red colour deepens over the weeks after the adult emerges form the pupa. The dark colours are derived from melanins and the lighter ones from carotenes. The entry in the Invasive Species Compendium states that, "although some adults vary considerably in colour pattern, C. septempunctata show little variation, although spot number ranges between 0 and 9, and variation in spot strength is said to be 'considerable'." Typically, adults are red with seven black spots. Those distinctive spots and attractive colours apparently make them unappealing to predators. Ladybugs can secrete a fluid from joints in their legs which gives them a foul taste.
I would say there is enough. From a ladybug's perspective, our Conservatory is a big place. According to Buglogical Control Systems, a commercial supplier of beneficial insects, "Ladybugs are capable of consuming up to 50 to 60 aphids per day, but will also eat a variety of other insects and larvae including scales, mealy bugs, leaf hoppers, mites, and various types of soft-bodied insects... Ladybugs are natural enemies of many insect pests and it has been demonstrated that a single ladybug may consume as many as 5,000 aphids in its lifetime." The release of ladybugs has been the insect management practice at the Conservatory for several years.
By the way, ladybugs are usually thirsty when they are released. That explains why they congregate on moist leaves.
A cold, wet afternoon in March. Little beetles finding their way on a big space filled with tropical plants. Who knew that could spark such interest? Wonderful.
Where you at the Thunder Bay Conservatory when the ladybugs were released?
What did you think? Leave a comment.