Thursday, August 11, 2011

Lost Ladybugs

Dave over at Little Heelers recently directed me to an interesting article on ladybugs from the CBC, or ladybirds as they say in many other countries. They are also called lady beetles.

Nine-spotted ladybug (Coccinella novemnotata). They have a "milk mustache" above their head not in other species.

The article is concerned with the fate of the nine-spotted ladybug, a species that was once incredibly common across much of North America. It has since become exceedingly rare after several other species of beetle were introduced (including the seven-spotted ladybug, Coccinella septempunctata), even though nearly all of the different species have different habitats and diets. In fact, there were no sightings in the Eastern United States in fourteen years. Since the species are not competing, what could possibly be causing the decline? Well, we don't know yet. There are multiple possible causes, including introduction of parasites, parasitoids, or competition from the seven-spotted ladybug. However, little data was recorded after the introduction of the new species, so it is not known what, if any direct affect the seven-spotted ladybugs have had on the nine-spotted ladybugs. There is now a Lost Ladybug Project which is concentrated on collecting more data on the density of the now rare species, including the nine-spotted ladybug. If you see a ladybug, take a picture and join in. It might be a rare lady beetle.

Seven-spotted ladybug for contrast
It's always unfortunate when a species goes extinct, and I'm sure many people following this blog remember catching ladybugs in their childhood, me included. Most people would say, "So? It's just an insect. There's so many of them, what will the loss of one species do?" Well, the problem is we don't know. This is true in all cases where a species is going extinct. The introduced species may eat so voraciously that they negatively affects numerous other species. The native species may have been keeping a prey species in check that could potentially cause major damage when its predator is removed. I can't answer that, and since it's unlikely the species will recover to its previous numbers, we may find out soon enough.

Going against my usual methods, the main image is directly from the article. It is originally from Cornell University.
The seven-spotted ladybug is from Wikimedia Commons under a creative commons license

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