Saturday, November 10, 2007

Vampire Moths!?!?

Maybe you folks don't find insects as inherently interesting as I do, but I'll share my findings from a recent article published in Insect Behavior anyway, because I think it's pretty cool.

The existence of blood-feeding moths was unknown to me until reading this highly informative paper (Zaspel et al., 2007), despite the existence and behaviors of this genus (Calyptra) having been known since at least 1983. This article describes a species of vampire moth that has been found in Russia, whereas previously species with blood-feeding species had only been reported from southern Europe and Asia and eastern Africa.

The vast majority of Lepidopterans (moths and butterflies) do not even have the ability to digest protein (they lack proteinases), and while no analysis of the digestive capabilities has been completed, it seems as if this group must have evolved this trait.

This study only determined that this species (C. thalictri) will feed on blood under experimental conditions, although other members of the genus have been documented feeding on ungulates and even humans under natural conditions. The flesh-piercing, blood-sucking traits seem to have been derived from fruit-piercing behaviors. It was also observed by this study that only the males can be induced to feed on blood. This is unusual in insects because it is normally the female who is a obligate blood-feeder because the protein is required for the development of offspring (mosquitoes and other Dipterans). Other moths of this genus are not obligate blood-feeders, but rather only facultatively or opportunistically feed on blood when other substrates (fruit or nectar) are not available. It should be noted however, that these moths have the morphology to pierce fruit and even skin, because the proboscis is more heavily sclerotized than Lepidopterans that only feed on nectar. The proboscis of C. thalictri is even equipped with "tearing" barbed hooks, a feature most moths and butterflies lack.

One of the best features of this article was all of the color graphics that were included. If you are in this class then chanced are you are UMass student and therefore have access to this article through E-journals. You really should check out the eerie pictures of moths feeding on peoples' hands and the coiled mouthparts dripping with blood. There is even a neat picture of the barbed proboscis.

I'm not sure I would have liked to have participated in this study however, because some people agreed to let these moths feed on their blood despite the possibility of the moths being a vector for some vertebrate disease. These people were not even identified in the acknowledgments.

posted by: Morkeski (7)


At 9:44 PM, Blogger PWH said...

This is a great blog entry and it sounds like the article it was based on was really interesting. I'm glad these moths live in Russia and not here... It's also really interesting that they think this behavior is evolutionarily linked to fruit piercing behavior. Great job!

Christina Breed (7)

At 10:30 PM, Blogger PWH said...

I thought you did a great job covering the article. I had no clue of such things amongs moths. I also thought it was interesting the connection to evolution leading to this behavior.
By the way it was pretty cool how you started your entry. Although I'm not really an expert in insets and have not read much about them I thought your entry was interesting.

Bruno Karam (7)

At 1:34 AM, Blogger Stormslegacy said...

Wow, that sounds really interesting. I wonder if it is a good analogy for bat evolution? The questions I might ask of the study are: Do the chemicals used to breakdown fruit protien prelude those that break down blood? Is it an easy step from fruit to blood? What scenerios could trigger a change in feeding habits from one to the other?

~Michelle Vigeant


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