Monday, June 12, 2017

How to Grow your Own Ladybugs in 6 Easy Steps

A common question on gardening forums is "How do I attract ladybugs?".  It's easy. All you have to do is attract aphids.
  1. Have plants for the aphids. 
  2. Do nothing!
  3. Ladybugs will appear.
  4. Ladybugs lay eggs on the infested plants and eat aphids.
  5. Eggs hatch into aphid-eating larvae, grow up and make pupae.
  6. Adult ladybugs emerge from pupae and eat more aphids and lay more eggs.
Congratulations! You have grown ladybugs*.
Have plants for the aphids:  If you have plants, especially ones with tender leaves or stems, aphids will appear in the spring.  One day there are a couple of winged aphids on the lettuce or roses, and the nest time you look there are hordes and herds of them.

Do nothing:  For many gardeners, this is the difficult part. The urge to DO SOMETHING, ANYTHING in defence of your precious plants will be strong.  But if you kill the aphids, or wash them off with a blast of water, the plants will never be infested enough to be attractive to ladybugs or other predators.

You can help control this urge by using some about-to-bolt, overwintered or deliberately planted early crop as aphid-bait instead of your favorite roses.  An early lettuce would work.

Ladybugs appear:  Trust me. they will appear because the infested plants release chemical signals called herbivore-induced plant volatiles (HIPVs)**.  The ladybugs will always eat a few aphids, and evaluate the infestation for its ability to nurture their offspring. I don't know what the criteria are, but "lots of tasty aphids" is probably the main thing.
Ladybug on my lettuce.

Ladybugs lay eggs:
The beetles will lay one or more clusters of yellow eggs on the underside of the plant leaves. A few days later the eggs will hatch into aphid-eating larvae.
Ladybird eggs
By David Short, from

Eggs hatch into aphid-eating larvae:
For the next 10 to 14 days, the larvae eat and eat and eat, chewing through several hundred aphids.  They pass through 4 instars (larval stages) that only vary in size, shedding their skin at each stage.
Two Ladybug Larvae and Aphids
Ladybug Larvae Eating an Aphid.

Larvae become pupae:
Between the 4th instar and adulthood, the ladybug has to grow wings and become a mature beetle.  It goes into an outwardly inactive form called a pupa so the body restructuring can happen inside the pupa.
Very early pupa stage, with shed larval skin under it
If you see lumps like this, leave them alone. They are becoming adults.

Pupa on lettuce leaf
Adult Ladybugs emerge from pupae:
And it all starts again, with the newly emerged adult first seeking food, then a mate, then the females look for a place with an ample food supply for their own offspring. 
Ladybug (Hippodamia convergens) Emerging from its pupa
Newly emerged ladybugs are often pale orange with barely visible spots instead of red and black. Their color darkens over a few hours.

* Yes, it's really a beetle but what the heck.
** Look HIPVs up - it's truly fascinating chemical signals between the plants being eaten by insects and not only predators of those insects, but neighboring plants and even fungi that will infect the plant-eating insects.

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