Silphium Gall-Wasp Emergence Patterns in a Restored Prairie

College of General Studies / Math and Natural Sciences


We will be doing two ecology-based projects at the UWM at Waukesha Field Station—emergence patterns of Silphium wasps and alternate control methods of invasive buckthorn. The objective of the wasp study is to document the emergence patterns of Silphium gall-wasps of the largely unstudied genus Antistrophus (Hymenoptera: Cynipidae) from four different species of Silphium plants. We will be continuing a multi-year project examining emergence patterns from the flower stems from a restored and a remnant prairie. This is the 4th year of emergence data from the restored prairie, and the first year of data from a remnant population. The objective of the buckthorn study is to compare the effectiveness two methods of control of the invasive common (Rhamnus cathartica) and glossy (Frangula alnus) buckthorn. Previously, 2 acres of wooded area has been cleared of a large buckthorn population. When the buckthorn was cleared, latent seeds sprouted forming a dense mat of new buckthorn shoots. We will take a census of plant populations before treatment, apply two different treatment methods to the sprouts—black plastic covering, and burning the seedlings with a torch, and then census plant populations afterward.

Tasks and Responsibilities

Silphium flower stems are collected in the dormant season and stored in zippered plastic bags. Adults emerge from the stems in May-July. The student will be responsible for collecting and counting the wasps from the both the restored and remnant prairie populations as they emerge, as well as entering the data into spreadsheets. They 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, restored vs. 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. For the buckthorn project, the student will help with pre- and post-treatment censuses, as well as for assisting with application of the treatment. The student will also help with data processing and analysis.

Desired Qualifications

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