California’s Butterflies

Nectaring

Butterflies feed through a structure called the proboscis.  The proboscis acts like a straw through which a butterfly draws in its liquid diet, often from flowers.  The solution taken from flowers is called nectar, which is why feeding from flowers is often called nectaring.  Flower nectar contains sugars and amino acids, which in turn can be used to provide energy for the butterfly and nutrition to develop eggs.  Studies from honey production in bees have shown that nutrition in flowers differ with different plant species.  This may explain why female butterflies can be more selective in the species of plant they nectar upon, compared to males.  Because females produce eggs, they have different nutritional needs from males.

 

Butterflies also feed on a number of nutritional sources other than flowers.  Some species such as red admirals, anglewings, morning cloaks, and tortoiseshells feed upon sap.  Sap exudes from open wounds in trees, such as willows and oaks.  Many Nymphalids including red admirals, anglewings, and tortoiseshells will also feed upon carrion and feces.  Aphid and other heteropteran honeydew can be used by some butterflies.

 

 

 

 

At Right: An adult Lupine Blue butterfly nectaring on a yellow flower.