October 31, 2014<\/p>\n
Multicolored Asian<\/p>\n
Lady Beetles<\/p>\n
The multicolored Asian lady<\/p>\n
beetle is distinguished from native<\/p>\n
species by its great numbers, its<\/p>\n
highly variable coloration, and a<\/p>\n
convenient marking\u2014a dark “M<\/p>\n
on the light-colored pronotum,<\/p>\n
or shield, that covers the insect’s<\/p>\n
head.<\/p>\n
Just in case you hadn’t noticed\u2026 The bugs are back in town.<\/p>\n
Make that the ladybugs. Or, to be more correct, the multicolored Asian lady<\/p>\n
beetles, Harmonia axyridis. Pretty from a distance, yet teeming in numbers,<\/p>\n
stinky when disturbed and sometimes bitey, these imported insects ain’t no<\/p>\n
ladies. Or are they?<\/p>\n
Perhaps ill-mannered by our human standards, the multicolored Asian lady<\/p>\n
beetle’s habits actually do make sense when taken in context. Their peculiar<\/p>\n
smell is related to a defense behavior called reflex bleeding; they release a<\/p>\n
small amount of stinky fluid (toxic alkaloids) to deter predators. And their<\/p>\n
“bites” aren’t meant to be aggressive; they’re simply one way an MALB<\/p>\n
explores its environment. Lastly, their great numbers can be attributed to<\/p>\n
their reputation as a beneficial insect; in both their larval and adult stages,<\/p>\n
these insects consume large quantities of garden and crop pests.<\/p>\n
Although various isolated introductions occurred in the late 1800s, the<\/p>\n
imported insect’s “official” history here in the United States dates to 1916,<\/p>\n
when the federal government released a shipment of beetles in California<\/p>\n
as part of an effort to control aphids and scale insects on nut trees.<\/p>\n
Subsequent releases around the country, combined with assorted accidental<\/p>\n
introductions, have led to one undeniable fact: MALBs are here to stay.<\/p>\n
If you’re reading this near a sunny window ledge, you probably don’t need<\/p>\n
me to tell you that.<\/p>\n
According to Asian entomologists, MALBs are programmed to migrate<\/p>\n
toward “prominent, isolated objects on the horizon” as temperatures cool in<\/p>\n
the fall. (Our native species head for the safety of loose bark and leaf litter.)<\/p>\n
In the MALB’s homeland, those “prominent, isolated objects” typically are<\/p>\n
mountains and cliffs lined with cracks and crevices \u2013 excellent places to<\/p>\n
crawl in and take a long winter’s nap. But here, our “prominent, isolated<\/p>\n
objects” are houses, apartments and offices buildings. And, unless you’re<\/p>\n
really good with a caulk gun, your “object” probably has at least a few cracks<\/p>\n
and crevices, especially around doors and windows. You may have found you<\/p>\n
have more than a few multicolored visitors on your windows, curtains and<\/p>\n
walls.<\/p>\n
Why have so many shown up this week? According to research conducted<\/p>\n
in Ohio, MALB migration as a rule begins the first day temperatures surpass<\/p>\n
64F after a period of cooler, near-freezing temps. Last week’s overnight lows<\/p>\n
were in the 30s, with daytime highs in the 60s. Then, last Monday, we hit<\/p>\n
77F\u2014a temp the ladies found irresistible. At Hickory Knolls, we had MALBs<\/p>\n
finding their way inside in droves.<\/p>\n
Curiously, they seem to like to congregate beneath a light fixture in the<\/p>\n
basement stairwell. Lights on, lights off\u2014it doesn’t seem to matter to these<\/p>\n
guys, and gals. Apparently that wall is the perfect “prominent, isolated object”<\/p>\n
they’ve been seeking, and their numbers have increased steadily as the week<\/p>\n
has gone on.<\/p>\n
Their presence has given us a great chance to explore the species in great depth. Here’s what we’ve been able to<\/p>\n
glean over the past few days:<\/p>\n
\u2022 Multicolored Asian lady beetles really do come in a multitude of colors. We have yellow ones, orange ones, red<\/p>\n
ones; some with many spots, some with none at all.<\/p>\n
\u2022 The one trait they do share is the marking on the pronotum\u2014the small shield-like structure that partially covers<\/p>\n
the head and thorax. It’s conveniently marked with an “M,” which makes for a great way to distinguish MALBs<\/p>\n
from some of our native ladies. (Note: The two-spotted lady beetle, Adalia bipunctata, has a similar, M-shaped<\/p>\n
marking, but the center of its “face” is black, while the MALB’s is white.) (Oh, and while you’d think two-spotted<\/p>\n
ladybugs would only have two spots, that number can range from zero to 10.)(But I digress\u2026)<\/p>\n
\u2022 Grass spiders are not interested in eating them.<\/p>\n
This last observation came on Thursday, when I thought I’d see if a male grass spider, who’s taken up residence inside<\/p>\n
an unused plastic dish in our workroom, might be interested in a lady beetle meal. I dropped the insect into the<\/p>\n
spider’s web, and waited. Spider Man (yes, we checked; he’s clearly a male) scuttled out of his lair and headed toward<\/p>\n
the ladybug (which may or may not be female, since we aren’t sure how to tell). But then, a few millimeters away from<\/p>\n
his quarry, the spider stopped. After a moment or two, he turned around and headed back to his hideout. The MALB,<\/p>\n
meanwhile, walked across the non-sticky web and onto the floor; presumably s\/he is back on the stairwell wall by<\/p>\n
now.<\/p>\n
So, spiders-as-agents-of-MALB-control might not be a sound plan. Vacuums, however, are. If you find yourself with<\/p>\n
more beetles than you know what to do with, try sucking them up. But be prepared to dispose of the bag, or empty<\/p>\n
the receptacle, promptly, since the MALB’s chemical defense can be quite odiferous. Also be careful not to squish<\/p>\n
them as you’re cleaning, to avoid releasing the stink, and stain, on your walls and windowsills.<\/p>\n
Are you, like me, wondering what MALB’s effects on native ladybug species have been? It would appear that the<\/p>\n
diversity among our natives is decreasing. But research is ongoing, since it takes time to identify long-term trends.<\/p>\n
One worthy effort is Cornell University’s Lost Ladybug Project, which relies on data submitted by citizen scientists<\/p>\n
around the country to track and monitor populations of native ladybug species.<\/p>\n
Do you think this program sounds like fun? Get involved! Visit their site, www.lostladybug.org, for more info. Come<\/p>\n
next spring, you can let them know when the bugs\u2014the native ones, that is\u2014are back in town.<\/p>\n
Pam Otto is the manager of nature programs and interpretive services for the St. Charles Park District. She can be<\/p>\n
reached at potto@st-charlesparks.org or 630-513-4346.<\/p>\n","protected":false},"excerpt":{"rendered":"
October 31, 2014 Multicolored Asian Lady Beetles The multicolored Asian lady beetle is distinguished from native species by its great numbers, its highly variable coloration, and a convenient marking\u2014a dark “M on the light-colored pronotum, or shield, that covers the insect’s head. Just in case you hadn’t noticed\u2026 The bugs are back in town. Make<\/p>\n","protected":false},"author":101031,"featured_media":46631,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"categories":[105],"tags":[310,111,477],"class_list":["post-45284","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-good-natured","tag-bugs","tag-insect","tag-ladybugs"],"_links":{"self":[{"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/posts\/45284","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/users\/101031"}],"replies":[{"embeddable":true,"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/comments?post=45284"}],"version-history":[{"count":2,"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/posts\/45284\/revisions"}],"predecessor-version":[{"id":46630,"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/posts\/45284\/revisions\/46630"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/media\/46631"}],"wp:attachment":[{"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/media?parent=45284"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/categories?post=45284"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.stcnature.org\/good-natured\/wp-json\/wp\/v2\/tags?post=45284"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}