Silphium Gall-Wasp Emergence Patterns in a Restored Prairie

College of General Studies / Math and Natural Sciences


The objectives of this study are to document the emergence patterns of Silphium gall-wasps of the genus Antistrophus (Hymenoptera: Cynipidae) from four different species of Silphium plants: compass plant, Silphium laciniatum, cup plant Silphium perfoliatum, prairie dock, Silphium terebinthinaceum, and rosinweed, Silphium integrifolium. Very little is known about the Antisrophus wasps, as they are tiny and difficult to catch and identify in the field. The first step is document emergence patterns. We have collected stems of the 4 Silphium plants during late fall or early spring for the last three years (2016, 2017, 2018) in the Marlin Johnson Prairie, a restored prairie at the UWM at Waukesha Field Station. We stored the stems in plastic bags and collected the wasps as they have emerged, keeping track of their emergence dates. During the spring semester, we plan to finish counting the emerged wasps, compiling the collected data and analyzing it to compare emergence across years, plant type, and prairie treatment type (burned the previous year or not). As time allows, we will also start identifying the emerged wasps and separate them into eco-species. We then can compare the emergence of the different groups of wasps.

Tasks and Responsibilities

The first task the student will be responsible for is to finish counting the wasps that emerged during the last 3 years, and entering the data into spread sheets. The student then will help analyze and compile the collected data. We will be looking at emergence patterns across years, across the 4 plant species, and also across treatments (burned the previous year or not). The student will also help collect stems in spring for the following summer. We will collect from a remnant prairie, so that we can compare emergence patterns from a restored prairie vs. a remnant prairie. As time allows, in addition to straight counts of emerged wasps, the student will start sorting the collected wasps into eco-species groups; this will require the use of a microscope to identify the wasps. The student will also participate in prairie management at the Field Station, especially with planning, prepping, and prairie burning.

Desired Qualifications

Student should be able to commute to the UWM at Waukesha Field Station