Influence of Host Plants - Specific Projects

• Disentangling the importance of prezygotic isolation barriers
  between the two host strains of Spodoptera frugiperda

PhD project Sabine Hänniger (Funded partly by DFG)

The polyphagous moth Spodoptera frugiperda (Noctuidae) is a pest species occurring in the US and South America. Despite its polyphagous nature, two host strains have been identified: 80% of the larvae collected from corn fields are so-called "corn strain" individuals, while 95% of the larvae collected from pasture and forage grasses belong to the "rice strain", based on several genetic markers. This host plant differentiation most likely resulted in habitat isolation between the two strains. more >>>

Collaborators: Manfred Ayasse, Carlos Blanco, David Jenkins, María Laura Juárez, Juan Lopez, Jeremy McNeil, Rob Meagher, Andreas Reinecke, Silvia Schmidt, Gerhard Schöfl, Sybille Unsicker

• Level and importance of postzygotic isolation
  in the two host strains of Spodoptera frugiperda

Postdoc project Silvia Schmidt

Speciation is caused by the evolution of reproductive isolation barriers that reduce or prevent gene flow between diverging populations. Such barriers are commonly divided into those that act before mating (premating isolation) and those that act afterwards (postmating isolation). In contrast to premating isolation mechanisms, postmating isolation mechanisms do not act directly on the members of the diverging populations but on the resulting hybrids and thus come into play when premating isolation is incomplete or absent.
more >>>

Collaborators: Gerhard Schöfl, Sabine Hänniger, Melanie Marr

• Identifying the level of host specialization
  in two laboratory strains of the generalist Heliothis virescens,
  and its impact on sexual communication differentiation

Diploma (~MSc) project Anne Karpinski

Heliothis virescens (Hv) is a major pest throughout the world, feeding on many different plant species. However, populations of Hv are hypothesized to be regional ‘specialists’. We are investigating the level of host plant specialization in two laboratory strains that seem to be adapted to either cotton or chickpea. more >>>

Collaborators: Carlos Blanco, Fred Gould

• Host plant adaptation
  of the crucifer-specialized moth Plutella xylostella to pea plants

PhD project Kathrin Henniges-Janssen

The diamondback moth (DBM), >Plutella xylostella (Lepidoptera: Plutellidae), is a specialist pest feeding exclusively on brassicaceous plants, a plant family characterized by the glucosinolate-myrosinase defence system against herbivore attack. DBM has the ability to deactivate this defence system using a highly active glucosinolate-sulfatase and, thus, is specifically adapted to brassicaceous plants. Therefore, it was surprising to find DBM larvae feeding on sugar snap peas (Fabaceae) in Kenya in 1999. more >>>

Collaborators: Lisa Knolhoff, Annette Reineke

• Geographic and genetic variation in aggregation pheromone
  of the agave weevil

PhD project Ausencio Azuara Domínguez, Campus Montecillo, Mexico

Main Supervisor: Dr. Juan Cibrian Tovar

Collaborators: Dra. Obdulia Segur León, Dr. Antonio P. Teran Vargas, Dr. Carlos A. Blanco, Dr. Astrid T. Groot, Dra. Angélica Cibrián Jaramillo