Friday, July 4, 2014

Yarden Mud Pots In July

Eumeninae nest on Solanum melongena leaf
Eumeninae nest on Solanum melongena leaf

Little Mud Pots


Here it is July again, and the potter wasps are back.  This is evidenced by the little mud urn-shaped pots left on the plants.  So far, I found one little mud pot fastened very securely on the top of a black beauty eggplant leaf.

Based on the style, position and singularity of the little mud pot, there are a few clues about the maker. First, since the mud pot is solo, it is probably created by a larger species of the potter wasp.  Second, since the top of the pot is still open, and the form is basically constructed, it's safe to assume the wasp is hunting down morsels to stuff into the pot.

How Are They Constructed?
Potter wasp (by Natasha Mhatre on Flickr)
Potter wasp (by Natasha Mhatre on Flickr)


Potter wasps typically construct their nests from mud and regurgitated water.  Others may use only plant material.  The nest we found appears to be of mud construction.  It takes some time for the wasps to gather up the mud balls little by little and complete the form of the nest.

Eumenes fraternus nest provisioned
Eumenes fraternus nest provisioned
BugGuide.net

What Are They Used For?


The potter wasps build these nests to provision insects for a single egg per pot.  Once the nest is constructed, the wasps gather insects and stuff them inside.

This is the part of the lifecycle that makes the Potter Wasps beneficial for the garden.  They'll take all the juicy caterpillars, immobilize them and put them away.  Because
Potter wasp with capped nest by Mary Holland
Potter wasp with capped nest
by Mary Holland
of this, Potter Wasps are welcome in my yarden.

Once the nest is provisioned and an egg is laid, the nests are usually capped.  This leaves the paralyzed caterpillar trapped with the wasp larvae for leisurely dining spanning approximately 2 or 3 weeks up to a year. The larvae eats, grows and then pupates into an adult Potter Wasp.  Upon final pupation, the adult wasp emerges and feeds on our yarden nectar.  This is a double benefit for the yarden, because we have another insect pollinator helping us out.

Potter wasp - Eumenes bollii
Potter wasp - Eumenes bollii

Identifying Adults

Last year, we were able to snap a picture of an adult Potter Wasp.  It was quite striking looking.  According to Wikipedia, here are the visual ques:

They are particularly recognized by the following combination of characteristics: 1) a posterolateral projection known as a parategula on both sides of the mesoscutum; 2) tarsal claws cleft; 3) hind coxae with a longitudinal dorsal carina or folding, often developed into a lobe or tooth; and 4) fore wings with three submarginal cells. ~ Wikipedia
In plain speak, they have bumps on the inner side of two wing joints at either side of the large body segment after head; An appearance of what looks like spurs on their toes; A folded looking dent or crease in the first segments of the hind legs; And three cells aligned to the rear of the main wing cell.

We aren't sure which type of wasp set up the mud pot, but hopefully if we keep our eye on it we'll know eventually.