Backyard and Beyond

Starting out from Brooklyn, an amateur naturalist explores our world.

As John Burroughs said, “The place to observe nature is where you are.”

Ladybugs: Aphid-Eaters

Checker Spot ladybug (Propylea quatuordecimpunctata) munching on an aphid wing. Laval-stage lady beetles are also great aphid-devourers. This is why a number of different species of lady bugs have been introduced into North America over the years: to attack the real destruction aphids can cause. The Checker Spots were one such introduction.The Multi-colored Asian lady beetle (Harmonia axyridis) were another. Above and below are two examples of this species. These, and numerous other examples of the species, which is quite varied in color and spot number, were found, in both adult and pupal stages, almost exclusively on widely separated Catalpa trees in the park.
Variegated lady beetle (Hippodamia variegata), another introduced species, pictured above and below.Same species, different individual:Three species of lady beetles noted in Brooklyn Bridge Park on the same day, all originally introduced species. In fact, I’m hard pressed to find any native species of lady bugs locally, and I’m not the only one. For instance, New York State’s state insect, the 9-Spotted Lady Beetle (Coccinella novemnotata), is extremely rare now — it was thought absent from the state until one was found last year on Long Island. Check out the Lost Lady Bug Project for more details.

What is the connection between the introduction and spreading of non-native to dwindling numbers of native species? Unknown. Habitat destruction — native insects have spent millions of years developing relationships with native plants — and poisons may be the reason, or some combination of all these things.

mthew

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11 responses to “Ladybugs: Aphid-Eaters”

  1. trail-hike-life

    Very cool. Can you help me identify my beetle?

    Reply
    1. mthew

      I usually submit to Bugguide.net for things that aren’t in my books, so you may want to try them for more detail. Your beetle, however, does look like the picture of a genus Pterostichus species “ground beetle” (they seem to have run out of common names for these guys) in Evans’s Field Guide to Insects and Spiders of North America… http://trail-hike.com/2012/06/24/beetle-juice-beetle-juice-beetle-juice/

      Reply
      1. trail-hike-life

        Thank you for the information!

  2. Beth

    I just read this article at DNA.com. I wasn’t quite sure which type of beetle they released. I’m just hoping that since Cornell supplied them with the insects they’re actually a native species.

    Reply
    1. mthew

      You don’t happen to have a link to that article?

      There are also West Coast US native lady beetles that have been introduced on this side of the Rockies. But the problem with all these lady bug introductions, as people who’ve ordered lady bugs through the mail will attest to, is that lady bugs can fly. And there’s nothing to stop them from flying away from your garden or farm.

      The bigger problem with such introductions, intentional or accidental, is that nobody has any idea what the long-term effects are. Often they have been disastrous. Kudzu, Zebra mussels, etc. Australia is the test (if not basket) case for repeated introductions of species that have blown up in their faces, like cane toads.

      Reply
      1. Beth

        I’m sorry, I intended to past the link to the article and must have forgotten. http://www.dnainfo.com/new-york/20120625/lower-east-side/lower-east-side-garden-new-home-for-140000-ladybugs?cluster_id=100105&index=1&group_hood_id=25182

        Agreed about the introduction. I’m not convinced these are the right type of insect for this garden. I just hope Cornell knew what they were doing.

      2. mthew

        Thanks, Beth!

  3. Paul

    Mostly off topic: I saw a beaver in Fort Tryon Park at the north end of Manhattan last week. (It was more satisfying to me than the Cloisters.)

    Reply
    1. mthew

      ! Paul, that’s amazing. You didn’t get a picture of it by any chance, did you? You could probably sell it to the papers, or whatever paying media still exists.

      I don’t think beavers have been seen on Manhattan Island for quite some time. They used to be found here, and by used to I mean three hundred years ago, when Manhattan was more or less attached to the rest of North America, at least at low tide. The Bronx saw a beaver show up in 2007, after who knows how long, and then another in 2010.

      Reply
      1. Paul Lamb

        Sorry, I didn’t get a photo, but there were two elderly people who were watching it as well. It was just down from that lovely overlook, foraging in the grass.

  4. Two-Spotted in Brooklyn « Backyard and Beyond

    […] the pronotum has a similar M/W mark as the Multi-colored Asian lady beetle (Harmonia axyridis) (see some examples here), but these bipunctata are not as large or round as that more common and invasive […]

    Reply

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