Missouri Master Naturalists- Springfield Plateau Chapter

Wednesday, March 4, 2020

Life in an Empty Walnut

Late winter is the season for Nature Mobiles at the WOLF School.  The students hang various found items from nature on threads and hang them from a stick to balance them. They then relate these elements to their role in nature, all of them signs of life.

Sweetgum balls and other seed pods can represent the source of new life, unlike on our lawn where they are @#$% to our bare feet and rakes.  Small found rocks with holes can be the remains of crinoid fossils, a sign of life millions of years ago when Missouri was covered by oceans.  Feathers can represent birds soaring for food and love while buckeyes are said to bring good luck.

 “Into every empty corner, into all forgotten things and nooks, Nature struggles to pour life, pouring life into the dead, life into life itself.” - Henry Beston

Pyralidae moth in the lower cavity
Last summer we collected walnut half-shells to be incorporated into nature mobiles this winter. They were already split open, dried and apparently empty when we put them in a ziplock bag. Now opening them we found brown grains and silk webbing filling the cavities.  As we stood over the kitchen sink picking out the detritis we found further unexpected evidence of life.


Under magnification the most common find was these 6mm (1/4") Pyralidae moths.  According to Bug Lady "Pyralidae (snout moths), is one of the largest moth families in the order Lepidoptera with 1,100 mainly plant-loving species in North America north of the Rio Grande."  Many species in the family that are familiar guests in our homes are called meal moths, found in our kitchens as we discussed in this blog.




Empty pupa case

In addition to lots of dead and dried moths there were the silk wrapped pupa cases from which they had emerged.  These were dusted with frass from the larvae before their pupation.  As we stood together happily cleaning the shells out at the kitchen sink, I knew I had married the perfect woman.  On the other hand we now have friends reading this who will never again come to dinner at our house.

Dermestid beetle larva -4mm

One final find was this little dermestid beetle larva.  Although I tend to associate them with the flesh consuming varieties that clean skulls for us, many species will eat their (dead) veggies including grain and even nuts.

All of this serves to remind me that there is a lot more life around us daily than we know or even care to think about.  Meal worms living in our flour and cereal were here long before we emerged from caves to create kitchens.

These little creatures live in a world of even smaller creatures, long before we get to bacteria.  These thoughts led me back to viewing the Chaos of Delight photographs of 0.1mm to 2mm mesofauna that live in the soil, a colorful subterranean safari for a cold dark winter day.