Parasitoid wasps are a larger group (~100,000 – 500,000 species) of free-living insects that inject venom into and then lay their eggs in or on other insects, eventually killing the hosts.  Parasitoids vary in hosts they utilize (flies, beetles, butterflies, etc), the life stage they parasitize (eggs, larvae, pupae), and whether their eggs are laid and develop within or outside the host.  Due to this diversity, parasitoid venoms have evolved different mechanisms for manipulating host immunity, physiology and behavior in ways that enhance development of the parasitoid young.  Among their effects, venoms can induce temporary or permanent paralysis, selective apoptosis, alterations in lipid uptake, and host immune suppression. Yet virtually nothing is known about the diversity of their venom proteins.  Given the incredible number of parasitoids  and host associations, their venoms also represent an impressive untapped pharmacopoeia of potential great utility.  One challenge is to efficiently assess this potential and to determine whether short peptides with bioactivity relevant to medicine and research can be among this large potential pharmacopeia.

The recently sequenced genome of the parasitoid Nasonia, along with development of RNAi methodology for Nasonia, provides us with a springboard for studying diverse venom proteins of parasitoids and their effects. Nasonia has at least 79 different venom genes, of which 24 have no sequence similarity to other known proteins or known conserved domains (Degraaf et al. 2010).

We are now embarking on a research program to explore the function, diversity and evolution of parasitoid venoms using a combination of genomic, transcriptomic and genetic approaches.  We are also investigating potential pharmacological  applications of small peptides discovered in these venoms.   This research program affords many opportunities for exciting research and training opportunities for graduate students and postdoctoral researchers interested in genetics, evolution, genomics, entomology and molecular biology.  Below are some recent papers.  If you would like to learn more,  please feel free to contact Jack Werren at


  1. Martinson, EO, D Wheeler, J Wright, Mrinalini, AL Siebert, & JH Werren 2014.  Nasonia venom causes targeted gene expression changes in its fly host.  Molecular Ecology 23:5918-5930.
  2. Mrinalini, AL Siebert, J Wright, E Martinson, D Wheeler, and JH Werren. 2015.  Parasitoid venom induces metabolic cascades in fly hosts. Metabolomics 1-17. Doi:10.1007/s11206-014-0697-z
  3. Siebert, AL, D Wheeler, and JH Werren.  2015.  A new approach for investigating venom function applied to venom calreticulin in a parasitoid wasp.   Toxicon (Special Issue of Genomic Approaches in Venom Research) doi:10.1016/j.toxicon.2015.08.012.
  4. Martinson, EO, VG Martinson, RE Edwards, Mrinalini, and JH Werren. 2015  Laterally transferred gene recruited as a venom in parasitoid wasps.   Mol. Biol. Evolution doi: 10.1093/molbev/msv348.