Answering The Alarm

Lady Beetles

Lady Beetles Feeding on Tree Sap

Adult Seven-Spot Lady Beetles, Coccinella septempunctata, spend much of the time in search for aphid prey. Cues such as aphid honeydew can elicit intense searching by the beetle. The beetles are also capable of detecting and following aphid alarm pheromone. When an aphid is attacked by a predator, it may release and alarm pheromone that causes nearby aphid clones to stop feeding a drop from the plant. This escape behavior can help avoid the lady beetle.

Al Abassi and colleagues* have shown that the Seven-Spot lady beetle has receptors on the antennae that are responsive to biologically significant concentrations of aphid alarm pheromone. When given a choice between an airstream containing aphid alarm pheromone and no odor, the beetles follow the aphid alarm pheromone two thirds of the time. Alarm pheromones may be useful signals for lady beetles to find aphids in a complex environment.

*Al Abassi S, Birkett MA, Petterson J, Pickett JA, Wadhams LJ, Woodcock CM (2000) Response of the seven-spot ladybird to an alarm pheromone and an alarm pheromone inhibitor is mediated by paired olfactory cells. J Chem Ecol 26:1765–1771

About jjneal

Jonathan Neal is an Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
This entry was posted in behavior, by jjneal, Environment. Bookmark the permalink.

4 Responses to Answering The Alarm

  1. S. Carter says:

    Are these the infamous Asian beetles? And do they come in houses and crawl around on houses because they are used to wintering on cliffs?

  2. jjneal says:

    Yes. The pic is of Asian Lady Beetles, with the distinctive “M” on the pronotum.

    • S. Carter says:

      Ah, now I see it. “M” for manage. I believe that they can be vaccumed up if you put a filter, like a piece of cheesecloth in the hose. Don’t want them sucked into the canister. Also, don’t smoosh them because they will stink and they will stain the surface. What else can we do to get rid of the blasted things?

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