First instar Manduca sexta larvae feeding on Solanum	5th Instar Manduca	Adult Podisus maculiventris spearing a Colorado Potato beetle larva.	Experimental enclosure containing Solanum ptycanthum	Me

STUDY ORGANISMS

Manduca sexta (tobacco hornworm), Podisus maculiventris (stink-bug), Solanum ptycanthum (black nightshade) and Lycopersicon esculentum (Tomato)

RESEARCH INTERESTS

1) Indirect effects of carnivores on host plant quality.

• Is the feeding behaviour of Manduca sexta  altered by the presence of a generalist predator (Podisus maculiventris)? 
• If so, what are these behavioural changes, and how do these changes in herbivore feeding behaviour affect host plant quality?
• How do these changes in host-plant quality influence resulting insect herbivore and carnivore communities? In particular, how is oviposition preference of Manduca affected by changes in host-plant quality?

2) Direct effects of carnivores on host plant quality.

BACKGROUND

     Manduca sexta  is well known and well studied herbivore of Solanaceous plants.  Manduca, Latin for glutton, is a name that well suits these caterpillars.  A single Manduca larva can consume up to 60,000 mg of leaf material, and can weigh up to 13g (that is 3g more than an adult chickadee).  Manduca sexta can be found throughout most of the United States and into Southern Ontario and are especially abundant on important agricultural crops, including tobacco, tomato, and eggplant. 

    Manduca sexta has a number of natural enemies, including a specialist parasitoid wasp, Cotesia congregata ,and a generalist predator, Podisus maculiventris.  Although there is a growing literature on the interactions between Manduca and its natural enemies, little research has documented how these interactions influence the host-plants, especially host-plant quality (i.e., plant defences and nutritional composition).  Understanding how host-plant quality is influenced by direct and indirect effects of carnivores has potentially large implications for understanding the ecology and evolution of plant-insect interactions, such as effects on insect community composition and structure.  Furthermore, understanding the biology behind plants and carnivores is of critical importance for agriculture.

PUBLICATIONS

Muis, C. A. and C. G. Eckert. 2002.  Biparental inbreeding in a highly selfing plant, Aquilegia canadensis.  In submission to Evolution.