Abstract
Many species of insect have pheromones which include a (Z)-alkene in their structure. The aim of this project was to establish for a number of different pheromones of this type that the replacement of the (Z)-alkene by a 1, 2-disubstituted cyclopropene would lead to a molecule that would interfere with the mating behaviour of the particular species studied.In the first section of this thesis, the effects of insect pheromones and their cyclopropene analogues on the mating behaviour of housefly, diamondback moth and warehouse moth are compared . All the cyclopropenes were tested toxicologically on houseflies and found to be non-toxic. Electroantennograms were performed on diamondback moth and warehouse moth and showed that the corresponding analogue promoted a response, although somewhat smaller than at the same dose level with the pheromone. All cyclopropenes were tested
behaviourally in olfactometers and were shown to reduce mating activity. In the case of the housefly, this effect was long-lived in relation to the lifetime of the fly; in the cases of the diamondback and warehouse moths, mating behaviour did not return to normal on subsequent treatment with the natural pheromone. Field trials indicated that for the diamondback moth the attractiveness of the natural pheromone was reduced in the presence of the cyclopropene analogue.
In the second section of the thesis, the effects of a green leaf volatile and its
cyclopropene analogue on the behaviour of the black bean aphid were tested. The cyclopropene was again found to be non-toxic to houseflies. Electroantennograms were performed on the black bean aphid and the bark (pine shoot) beetle, Tomicus minor. In the first case, the cyclopropene analogue elicited a greater response than that for the natural plant volatile; in the second case, a lower response was observed with the analogue than with the plant volatile. The cyclopropene was also tested behaviourally using a linear track
olfactometer and caused the insects to be repelled rather than attracted. When a mixture of the cyclopropene and an extract of the plant was used, no attraction of the insects was observed.
| Date of Award | 1998 |
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| Original language | English |
| Awarding Institution |
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| Sponsors | Consortium Project for Norske Conoco, Norsk Hydro and TotalFinaElf |
| Supervisor | Mark Baird (Supervisor) |