Friday, August 28, 2009

Ladybug Lifecycle

The ladybugs are abundant in our vegetable garden, thanks in large part to all those aphids. I have discovered dozens of mating couples over the last few weeks, and am happy to report that our ladybugs are quite fertile. We have eggs, nymphs (sometimes compared to miniature crocodiles), and mature ladybugs on our bronze fennel. There are at least 25 pupa on the plant as well. The pupa look like dry, shriveled ladybugs that are clinging to the fennel stems. The ladybugs are co-existing happily in all stages of their life cycle.

On the same fennel plant there are many mealybug destroyers. This is a beneficial insect that is a member of the lady bug family, although you wouldn't guess it after looking at both together. The latin name of the mealybug destroyer is Cryptolaemus montrouzieri, and like ladybugs, mealybug destroyers are useful predators when they are nymphs as well as adults. They eat aphids when their first choice (mealybugs) is not available. The nymphs pop out with their bright white color and unusual bodies, their floppy white shape often compared to a mop head. The nymphs look quite similar to their favorite prey, mealybugs, so it's important to determine if you have a beneficial insect or a pest before taking any action.

It looks like the ladybugs are collaborating with their cousins the mealybug destroyers to eliminate our aphid population. Now if I can just figure out a way to get them all to relocate from the fennel to the cowpeas where they will find a limitless supply of those tasty aphids.

1 comment:

  1. The photos are great. I am studying ladybugs with my students and it's nice to see the real things rather than drawings.


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