Monthly Archives: June 2013

Caterpillars on my crucifers: friends or foes?

A high glucosinolate (putatively anti-cancer) broccoli variety is now on the market.  Jeanne wonders if caterpillar herbivory-induced increases in glucosinolates can match it.  The answer is unsatisfyingly complicated. 

Cabbage butterfly pupa on the tile above my sink. A survivor from washing crucifers from the garden.

Cabbage butterfly pupa on the tile above my sink. A survivor from washing crucifers from the garden.

There are three primary reasons why I haven’t launched aggressive war on the cabbage butterfly (Pieris rapae) caterpillars munching on the cruciferous veggies in my garden, even though I don’t like them:  (1) garden neglect; (2) hostility towards most pesticides; and (3) bonhomie toward caterpillars by my toddler.  There is also a fourth reason.  I know that in general most plants increase production of chemical defense compounds when they detect that they’re being attacked by pathogens or herbivores (Textor and Gershenzon 2009).  Some of these defense compounds have been shown to be beneficial for human health, including those in crucifers.  I’ve been wondering for a while if those caterpillars were actually enhancing the value of the tissue they didn’t consume.  A recent report about a high-defense-compound laden variety of broccoli prompted me to do some research into the issue.  I’m left with more questions than answers. Continue reading

Aching for strawberries

If you have ever doubted the practical side of  plant anatomy, keep reading, as Katherine explains what you can learn about flowers by cutting up a strawberry.  As it turns out, this enigmatic little gem is packed with coincidences and apocrypha along with its citric acid and anthocyanins.  Could it turn out to be true that a strawberry is a berry after all?

Welcome to early June, when strawberry season is finally well underway across the US, as far north as the upper Midwest and New England.  Here in the promised land where little green plastic baskets are never empty (coastal northern California), there is still a peak season for strawberries, since the popular varieties don’t reach their full potential until mid-May.

With so many strawberries in so many kitchens this month, now is the perfect time to merge botany lab and breakfast preparation by working through the many parts of a strawberry.  Once you have mastered berry dissection, I promise you will find it a surprisingly versatile skill.  Having the confidence to steer a conversation towards strawberry anatomy can help you recover from one of the more awkward inevitabilities of summer – biting gracelessly through an enormous chocolate-covered strawberry just as you are introduced to the mother of the bride.  After you have pointed out the veins and ovaries and have explained the developmental origin of the epicalyx, she won’t remember the red juice and bits of chocolate shell you have just dribbled down your frontside.  Or so has been my experience. Continue reading