Google+ Followers

Sunday, June 19, 2011

A Different Ladybug

The 14-spotted ladybug, Propylea quatuordecimpunctata, or P-14. 

Square spots. Tan background. Ladybug? Yes! It's Propylea quatuordecimpunctata.

Propylea quatuordecimpunctata, also called the 14-spotted ladybug, or P-14, is one of the common ladybugs of Europe. There are about 5000 species of ladybugs worldwide. And now P-14 can be added to the roughly 400 kinds of ladybugs that live in North America.

I found this one on an ornamental plant in the garden of the River Cafe on the Brooklyn shore of the East River near the base of the Brooklyn Bridge. It's the first one I have ever seen and I was lucky because it is a shy and fast-moving beetle. It passed artfully through the shadows of  leaves and kept to the undersurfaces -- especially when it noticed that I was watching. It eventually slipped into the shade and ran down a plant stem as fast as six legs can go.

A riverbank in a port city is a fitting spot to find a P-14,  since its ancestors probably traveled to North America by water from Europe. Some of them are thought to have arrived in Canada via the St. Lawrence River by ship; it is not known exactly when they entered or became established. They may have been helped by the opening of the Saint Lawrence Seaway in 1959, which linked the Atlantic to ports as far as 2000 miles inland on Lake Erie. Stowaways could easily fly off. P-14s were found in the wild near Quebec City in 1968. They are now established in New England, Pennsylvania, New York, and New Jersey.

Identifying ladybugs can be challenging because there are so many of them. Even worse, individuals of some species don't look much alike. For instance, the 10-spotted ladybug comes in a spotless form. The Asian ladybug comes in colors from yellow to orange to black and can have 0 to 22 spots.

P-14 itself is never red but can by creamy, tan, or pale orange. Its spots are sometime round and distinct but most often they look square and they run together in places. Like the one in the picture, the overall effect is of a black checkerboard pattern on a tan background. P-14 has the familiar domed ladybug shape and is about one-quarter of an inch long.

Like other ladybugs, p-14 is a voracious predator on aphids and a consequently welcome visitor to gardens and farms. The immigrant ladybugs have found their way to agricultural regions where they are probably munching on crop pests right now. Ladybugs are particularly good at aphid control because both the adult and larval stages eat aphids.

Ladybug stories tend to end with ladybug lore or cute poems. Almost all of these say something about black polka dots and red wings, things that do not apply to P-14. But voracious appetites apply to all ladybugs, so here is a stanza from "A Ladybug's Complaint" by Mayme Baker Cunningham.

My children have such appetites;
I don't see how they do it. 
They eat large quantities of pie,
and hardly stop to chew it!

4 comments:

  1. I don't know if you are interested in this observation, but out of the (approximately) 210 species of ladybugs represented in Bugguide.net (http://bugguide.net/node/view/179/tree/all), 22 are non-natives (http://bugguide.net/node/view/248891#Anchor_Coleo). So, I wouldn't be surprised if the total of introduced species in North America comes to around 40.

    ReplyDelete
  2. Interesting! They are small, so they stow away easily. They seem ready to take advantage of new opportunities. I bet they are not too fussy about what they will eat.

    ReplyDelete
  3. They are fast! I was lucky enough to get off two photos of one in Queens Botanical Gardens, NYC

    ReplyDelete
    Replies
    1. They are! I followed this one for a long time. It kept ducking under leaves. :-)

      Delete