Harmful insects

What is this Insect? It’s the Calligrapha

By Julie Boudreau

The arctic willow hedge needs to be trimmed. But just before plunging the shears into the hedge, you discover a magnificent silver insect with its back marked by strange hieroglyphs: the calligrapha! Fascinated, or should I say, blinded by so much beauty, you completely forget the leaves he is chewing on.

The Willow Calligrapha is a very beautiful insect, probably one of our prettiest! Photo: Julie Boudreau

Recognize a Calligrapher by His Handwriting

The Willow Calligrapha (Calligrapha multipunctata) is a beautiful round-shaped beetle, somewhat larger than a ladybug. It bears its name very well, because its abdomen (its back) has patterns that look like they have been drawn with ink. In Quebec, you”ll come across a dozen species of calligraphas, each with its own particular design. More or less thick lines, horseshoe shaped spots, scattered dots… The Willow Calligrapha is more specifically recognizable by the presence of a whitish band on its thorax (the part just behind the head).

It is in the middle of summer that this insect is most active. Being a close cousin of leaf beetles, calligrapher feeds on plant leaves. Luckily, it is not as voracious as leaf beetles and it is very rare that it manages to completely defoliate its victim.

What is generally scary with calligraphas is that there are a lot of them! Looks like an invasion. It’s a bit like morels: the first one is hard to see, but as soon as you see it… you see them all! On a shrubby willow plant, it’s possible to count hundreds of adults!

You can recognize the Willow Calligrapha by the whitish stripe along the edge of the thorax, just behind the black head. Photo: Wikimedia Commons

A Year in the Life of a Calligrapha

The calligrapha gives birth to a single generation of adults per year. Eggs are laid in early spring on host plants. Five days after being laid, the eggs hatch and the small white larvae begin to nibble the underside of the leaves. At this stage, the damage is so subtle that it is rarely noticed. After about twenty days, the larvae drop to the ground for the great metamorphosis. Then, another twenty days later, around mid-July, the adults emerge. This is when the nibbling of the leaves begins. Finally, in the fall, our well-fed friends drop to the ground and hide in the trash to let the winter pass.

The Willow, Its Main Victim

Calligraphers are quite specific when it comes to food. They usually stick to one species. Thus, the willow calligrapha feeds almost exclusively on willow. There is an elm calligrapha, who is interested in elms and an alder calligrapha whose preference is, yes, alders. There is also a tattooed dogwood calligrapha (C. rowena). Guess its host! The latter is sometimes confused with the willow calligrapha.

The willow leaves are slightly damaged by the passage of calligraphas. It is rarely necessary to intervene. Photo: Julie Boudreau

Do We Get Rid of It?

Given the not very voracious appetite of calligraphas, they rarely present a problem. The damage goes almost unnoticed. You can therefore conclude that it is an insect that can be tolerated. However, if the infestation were to take on extraordinary proportions, it is possible to control the populations by manually collecting the adults. For my part, the bowl of soapy water remains my intervention of choice. I wonder if the little hand held vacuum could work for calligraphas as it works wonders with Colorado potato beetles!

Finally, knowing that it spends the winter on the ground, near its food station, a good cleaning in the fall and a little mixing of the mulch (if there is mulch at the base of the shrubs) can complicate the adult overwintering.

Ultimately, the Calligrapha poses very little danger and deserves to be the target of our contemplation, because that’s about all there is to do with this garden insect. I even think that by connecting the dots of its calligraphic marking, you can read wow! on his back!

Julie Boudreau is a horticulturist who trained at the Institut de technologie agroalimentaire in Saint-Hyacinthe, Québec. She’s been working with plants for more than 25 years. She has published many gardening books and hosted various radio and television shows. She now teaches horticulture at the Centre de formation horticole of Laval. A great gardening enthusiast, she’s devoted to promoting gardening, garden design, botany and ecology in every form. Born a fan of organic gardening, she’s curious and cultivates a passion for all that can be eaten. Julie Boudreau is “epicurious” and also fascinated by Latin names.

3 comments on “What is this Insect? It’s the Calligrapha

  1. Debora Gage

    very pretty! i believe its Calligrapha knabi slope game

  2. Christine Lemieux

    I found a couple of these a few years back, except they were more of a coppery gold colour. So beautiful! Good to know they can be tolerated!

  3. Laurie Macdonald

    Interesting ! It’s rather nice to have such a beauty NOT be overly destructive ! Hope fully our climate crisis will not spur them to harmful populations..

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