Tuesday, November 14, 2006

Prepare for the lady bugs

Sitting in my living room I hear “tink... tink...” above me. In the ceiling lamp is a small spot bumping and crawling around inside the globe. I quickly discern it to be a lady bug- or, more properly, a lady beetle. As I look closer I can see that it is not alone- one or two others are crawling and bumping around attempting to fly out of their prison and still others have succumbed, no longer moving in the bottom of the globe.

In fact, these insects are Asian lady beetles (harmonia axyridis) and they have taken center stage for scenes like this every fall for the past several years. Introduced by USDA Agricultural Research scientists in the late 1970's and early 1980's as a biological control agent for pear psylla and other soft bodied insects, the Asian lady beetles have become a common sight in the US. In their native habitat, they often overwinter in cliffs so the next best thing here in the US is often houses or buildings where they can find cracks and crevices. Here on the Ball State campus, one of the most prominent places they swarm is on the southwest corner doors of the Teachers College building- beginning in mid to late November they can be seen in great numbers carpeting the side of the entrance there.

They can pinch if they become trapped in your clothing and can emit a foul odor. The odor is caused by the beetles exuding a yellow colored liquid (that is actually their blood) and it can stain and even cause allergic reactions in some. What they do not do is chew wood, bore into walls, or lay eggs in houses.

How do you tell if you have found an Asian or a common lady beetle? Asian lady beetles, often called multicolored, range in color from yellow to pumpkin orange to red (but never quite as bright as the common lady beetle). Asian beetles also have a black mark on their middle thorax between their head and the big shell shaped like an M. That area on common lady beetles tends to be all black or more of a stylized figure 8 or black with 2 white splotches similar to eye-spots. (Asian lady beetles on the left; common lady beetle on the right)

Find out more at the SHSL and on the internet:

Resources in the SHSL (click on the hyperlink to view the CardCat record)

American Beetles, (2 vols.)
Sci QL581 .A43 2001

American Insects
Sci QL474 .A76 2000

Encyclopedia of Entomology
Sci Ref QL462.3 .E47 2004

Encyclopedia of Insects
Sci Ref 462.3 .E485 2003

General Information






Identification and More Information


http://ohioline.osu.edu/hse-fact/1030.html (Asian lady beetle)

http://ohioline.osu.edu/hyg-fact/2000/2002.html (common lady beetle)