The aphid parasitoid Aphidius ervi was collected and subsequently reared on Sitobion avenae on wheat or Acyrthosiphon pisum on alfalfa. Parasitoids from both origins were exposed in an olfactometer to alfalfa or wheat volatiles after plant experience (wheat or alfalfa) or after oviposition experience (S. avenae on wheat or A. pisum on alfalfa). The results showed the importance of adult experience, conditioning and innate preferences on the responses of A. ervi toward volatiles and provided a mechanistic explanation to the high prevalence of A. ervi on aphids on cereals and legumes in central Chile.
Dactylopius coccus is a sessile scale insect living on cladodes of Opuntia ficus indica which has commercial importance as a source of carminic acid. We herein present behavioural evidence of the existence of a sex pheromone in D. coccus, based on olfactometric experiments using both biological sources of odours and collected chemical extracts.