Holy cow! Wow! Just... wow. When I first heard about this phenomena happening in the Sierra Nevada during my first entomology class 20 years ago, I mentally placed it on my bucket list of things I wanted to witness firsthand. In my mind's eye, I had pictured maybe a gallon's worth of beetles at the base of a large tree. Actually seeing this exceeded all my long-held expectations... by a long shot. Wow.
During my museum stint in Cleveland, I fielded calls about aggregating ladybugs around Halloween, but instead of doing their thing out on the forest floor like shown above, the introduced multicolored Asian lady beetles (Harmonia axyridis) preferred the warmth in or on human structures. I don't blame them, it's gets awfully cold in Ohio. Imagine having a horde of ladybugs on the wall of your living room? Interesting, but not pleasant to live with. They make such a mess and are not good house guests. My advice to folks who called was to use a vacuum cleaner, as this Ohio State Extension Fact Sheet clearly explains.
There are lots of different kinds of lady beetles and many of them look very similar. According to Powell and Hogue, there are more than 125 spp. in CA alone. I couldn't find any information on whether all lady beetles gather in some capacity for the winter or not, or even if they move their gathering spot around. I believe the recent, decent rains helped create this massive and extensive aggregation. By the next day, Randy @ Way Points discovered there were much fewer here, but his pictures are still impressive. I've heard the term hibernate thrown around when referencing lady beetles, but I don't think that's an accurate use of the word. Does anyone have a better descriptor for what lady beetles do in the winter? Diapause?
Sigh... now, this was one of several of our day's findings which prompted some discussion about, as Cindy put it, the "delicate process of protecting natural resources on public land." I have to admit, that's one thing I do not miss about being affiliated with an institution, organization, or governmental body - that kind of public tiptoeing over my own sheer joy of nature. For my own blog, I've laid out some basic, good-sense ground rules and generally don't worry about what other people will do with the limited information I choose to share. However, this time I'm trying to be especially respectful of other people's concerns. So, in the interest of sharing the wonder of nature, I've been given the green light to post about this very cool lady beetle phenomena... despite the fact there are people who could profit from such a find. Indeed, most of those garden centers that sell ladybugs? Well, where do you think they get them? Eh-hem. My advice? As a rule of thumb, do not purchase lady beetles, even if it superficially appears to be the "green" thing to do for your garden.
ps 08/22/14 - Cat Ferguson from the Awl asked for permission to use my photos to illustrate ladybugs harvested in the Sierra Nevada. I initially declined, "Thank you for your permissions request and compliments on my photos. Unfortunately, I am denying your use of my photos to illustrate Sierra Nevada lady beetle congregations, because my photos were taken in the Santa Cruz Mountains - totally different habitat with different trees. To the trained eye, it is not factually correct. Isn't the Awl motto Be Less Stupid? And, for the record, I am against wild-collecting ladybugs for sale as natural pest control. Due to their documented seasonal pattern of winter congregation and then obligate flight dispersal before chowing down on aphids, they are not effective as directed pest control. All collecting achieves is quick money for the sellers and a disruption of natural processes, which could potentially have a negative impact on our native beetle populations." After assuring me her article would be about general Northern CA ladybug populations, not just Sierra Nevada, and about the ineffectiveness and problems with wild collection, I finally agreed for a fee. Eh, my photos ended up not being used, and that's fine by me. Cat's "The Flight of the Ladybugs" contains an interesting tidbit from a 1919 California State Commission of Horticulture bulletin about dispersal of the ladybugs. We've known for almost a hundred years that releasing ladybugs at a location doesn't work, and yet it remains a commercial enterprise? Too bad. I've got a bridge to sell you.
During my museum stint in Cleveland, I fielded calls about aggregating ladybugs around Halloween, but instead of doing their thing out on the forest floor like shown above, the introduced multicolored Asian lady beetles (Harmonia axyridis) preferred the warmth in or on human structures. I don't blame them, it's gets awfully cold in Ohio. Imagine having a horde of ladybugs on the wall of your living room? Interesting, but not pleasant to live with. They make such a mess and are not good house guests. My advice to folks who called was to use a vacuum cleaner, as this Ohio State Extension Fact Sheet clearly explains.
There are lots of different kinds of lady beetles and many of them look very similar. According to Powell and Hogue, there are more than 125 spp. in CA alone. I couldn't find any information on whether all lady beetles gather in some capacity for the winter or not, or even if they move their gathering spot around. I believe the recent, decent rains helped create this massive and extensive aggregation. By the next day, Randy @ Way Points discovered there were much fewer here, but his pictures are still impressive. I've heard the term hibernate thrown around when referencing lady beetles, but I don't think that's an accurate use of the word. Does anyone have a better descriptor for what lady beetles do in the winter? Diapause?
Sigh... now, this was one of several of our day's findings which prompted some discussion about, as Cindy put it, the "delicate process of protecting natural resources on public land." I have to admit, that's one thing I do not miss about being affiliated with an institution, organization, or governmental body - that kind of public tiptoeing over my own sheer joy of nature. For my own blog, I've laid out some basic, good-sense ground rules and generally don't worry about what other people will do with the limited information I choose to share. However, this time I'm trying to be especially respectful of other people's concerns. So, in the interest of sharing the wonder of nature, I've been given the green light to post about this very cool lady beetle phenomena... despite the fact there are people who could profit from such a find. Indeed, most of those garden centers that sell ladybugs? Well, where do you think they get them? Eh-hem. My advice? As a rule of thumb, do not purchase lady beetles, even if it superficially appears to be the "green" thing to do for your garden.
ps 08/22/14 - Cat Ferguson from the Awl asked for permission to use my photos to illustrate ladybugs harvested in the Sierra Nevada. I initially declined, "Thank you for your permissions request and compliments on my photos. Unfortunately, I am denying your use of my photos to illustrate Sierra Nevada lady beetle congregations, because my photos were taken in the Santa Cruz Mountains - totally different habitat with different trees. To the trained eye, it is not factually correct. Isn't the Awl motto Be Less Stupid? And, for the record, I am against wild-collecting ladybugs for sale as natural pest control. Due to their documented seasonal pattern of winter congregation and then obligate flight dispersal before chowing down on aphids, they are not effective as directed pest control. All collecting achieves is quick money for the sellers and a disruption of natural processes, which could potentially have a negative impact on our native beetle populations." After assuring me her article would be about general Northern CA ladybug populations, not just Sierra Nevada, and about the ineffectiveness and problems with wild collection, I finally agreed for a fee. Eh, my photos ended up not being used, and that's fine by me. Cat's "The Flight of the Ladybugs" contains an interesting tidbit from a 1919 California State Commission of Horticulture bulletin about dispersal of the ladybugs. We've known for almost a hundred years that releasing ladybugs at a location doesn't work, and yet it remains a commercial enterprise? Too bad. I've got a bridge to sell you.
