Tri-trophic effect on predator feeding: consumption by the carabid Harpalus affinis of Heliothis armigera caterpillars fed on proteinase inhibitor-containing diet

Research output: Contribution to journalArticle


During the breeding of our major crop plants for high
yield and edibility, several desirable traits, including
resistance to pest insects, have been lost (Gatehouse
et al., 1991). Genetic engineering is now vigorously
seeking to reinsert such genes into crop plants, making
them toxic or less palatable for herbivorous pests. One
class of inhibitors under study are protease/proteinase
inhibitors. The major digestive proteolytic enzymes in
many insects are serine proteinases such as trypsin and
chymotrypsin (Broadway & Duffey, 1986; Terra et al.,
1996), therefore numerous trypsin and chymotrypsin
inhibitors have been investigated. The effects on different
herbivores of both genetically engineered plant
material (Johnson et al., 1989; Gatehouse et al., 1991;
McManus et al., 1994) and artificial diets containing
the inhibitors (Burgess et al., 1991, 1994) have been
studied. The effects are species- and inhibitor-specific
but generally the negative effect on the growth and
survival of the herbivores is significant.
However, as the experience with pesticides indicates
very well, it is short-sighted to look at the
pest damage problem in isolation. Agricultural fields,
even if often impoverished with respect to ‘natural’
habitats, contain many species participating in ecological
interactions that are vital for the productive
functioning of these systems (Thomas&Waage, 1996;
Gould, 1998). Pest control provided by naturally occurring
predatory arthropods is one of those important
Biological control by predatory arthropods and
control by gene manipulation can interfere with each
other. As a first step to study the existence and significance
of such interactions, we examined whether
a specific proteinase inhibitor in the food of a herbivore
can affect the consumption of this herbivore by
a polyphagous predator. We also studied if this effect
lasts longer in the predator than the actual exposure to
the proteinase inhibitor fed prey.


External organisations
  • External Organization - Unknown
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Ecology


  • predators, herbivores, feeding, tritrophic interactions, proteinase inhibitor, genetic manipulations
Original languageEnglish
Pages (from-to)113-116
JournalEntomologia Experimentalis et Applicata
Issue number1
Publication statusPublished - 1999
Publication categoryResearch