Pheromone release behaviour in females of Phyllonorycter strigulatella (Lien. & Z.) and Ph. sorbi (Frr.) (Lepidoptera, Gracillariidae) under cycling temperature

• The pheromone release postures of virgin Phyllonorycter strigulatella andPh. sorbi females were very similar to those of other species of the samegenus with antennae held close to the wings, which were slightly spread andlowered, the abdominal tip dorsally curved and the distal segments extended.In both species with equal sex ratios, one peak of signalling activity wasregistered 0.5 h after the light had been put on and when 84% of Ph. strigulatellaand 90% of Ph. sorbi individuals were active. The high pheromonerelease behaviour with 50% active females lasted for two hours. The callingactivity of the group of females was about 6 h/day for both species. The totalperiod of calling activity of an individual female lasted for 131 ± 62 min(mean ± SD) and 145 ± 73 min a day for Ph. strigulatella and Ph. sorbirespectively. The occurrence of one signalling peak per day in the specieswith equal sex ratios as found in Ph. strigulatella and Ph. sorbi, supportedthe hypothesis that pheromone release activity with a clear presence of twoactivity peaks during a photophase could be adaptive for species with a sexratio strongly shifted towards females, as in Ph. junoniella.

Subject headings

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

Keyword

Leaf-miner

diurnal rhythm

calling

communication

behaviour

Publication and Content Type

vet (subject category)

art (subject category)