Floral derived compounds as attractants for agricultural pests in the family Noctuidae

• Main Author: Whitfield, E. Charles
• Format: Dissertation
• Language: English
• Published: University of Greenwich 2014
• Subjects: S Agriculture (General)

Many species of moths within the family Noctuidae are significant agricultural pests. Specific floral volatiles are attractive to both male and female Noctuidae and may be used to as attractants in crop protection. For the first time the following research compares two types of floral volatile blends - those that mimic natural floral odours and those that are artifical odour blends ('super-blends'). In wind tunnel bioassays and field trials in two diverse geographic locations (Argentina and the United Kingdom) a range of noctuid moth species that are considered crop pests were found to be attracted to both types of the floral odour blends. However, a 'super-blend' containing phenylacetaldehyde, salicylaldehyde, methyl 2-methoxybenzoate, linalool, and limonene (in a 10 : 4 : 2 : 2 : 1 ratio) was found to be the most effective general attractant across the following species: Helicoverpa armigera and gelotopoeon, Heliothis zea, Spodoptera frugiperda, and Autographa gamma suggesting that these compounds are universal cues to this family of moths when searching for flowers. Further behavioural bioassays found that the physiological state of the insect had an important effect on its behavioural response to the floral odour super-blend. Bioassays carried out on H. armigera revealed that gravid insects were significantly less likely compared to virgin insects to make contact with an odour blend baited lure. In addition, insects provided with sucrose solution were significantly less likely to make contact with the odour source compared to starved insects or insects only provided with water. This is the first time this affect has been seen in this species and may have important implications for using these types of floral odours for crop protection. Investigations into the most effective trap for capturing Noctuidae found that a homemade bucket and water trap or funnel and sleeve traps were significantly more effective than UniTraps or sticky traps. During the field trials large numbers of nontarget insects were also captured, including beneficial insects and pest species. By using green coloured traps captures of beneficial hymenoptera (Syrphidae and Apoidea) were significantly reduced. Taken together, the current findings provide insights into how Noctuid moths interact with host odour cues and how they may be used in developing pest management techniques.