Leptoglossus occidentalis occidentalis: : Leptoglossus - PowerPoint PPT Presentation

Leptoglossus occidentalis occidentalis: : Leptoglossus Communication signals & foraging cues Stephen Tak Taká ács cs, Hannah , Hannah Bottomley Bottomley, , Stephen Iisak Andreller Andreller, Karl Hardin, Ward Strong, , Karl Hardin, Ward Strong, Iisak Robb Bennett & Gerhard Gries Robb Bennett & Gerhard Gries

Other Research …..

Pheromone of Contarinia oregonensis

Pheromone of Contarinia oregonensis Captures of male midges in pheromone-baited traps are predictive of crop damage (monitoring tool)

Pheromone of Contarinia oregonensis Captures of male midges in pheromone-baited traps are predictive of crop damage (monitoring tool) Pheromone-based control of populations ?

Pheromone of Mayetiola thujae

Pheromone of Mayetiola thujae � Development of the pheromone as a tool for monitoring and possibly control is still be done

Leptoglossus occidentalis occidentalis Leptoglossus Communication signals: Pheromone and sound Foraging cues: Infrared radiation Visible light wavelengths Cone size Semiochemicals

Pheromones

Sound

Recording substrate-borne sound

Sound analyses

Results

Bioassay Played-back signal Computer-regenerated signal

Results

Results

Substrate-borne sound

Airborne sound Substrate-borne sound

Results

Airborne sound Reviewer’s argued: No evidence for..

Pentatomomorpha The flat bugs, seed bugs, leaf-footed bugs, and stink bugs are some of the most distinctive groups within the Pentatomomorpha. All members except… …possess 2 or more trichobothria on several abdominal segments

Trichobothria …. shown to be receptors of airborne sound

Trichobothria …. also present on abdomen of Leptoglossus Leptoglossus occidentalis occidentalis

Foraging cues

Infrared (IR) radiation? Prediction: cones emit more IR radiation than surrounding foliage, providing a foraging cue for L. occidentalis

Electromagnetic Spectrum Electromagnetic Spectrum

Supporting Evidence Supporting Evidence � Differential IR radiation emission by cones � Differential IR radiation emission by cones � L. occidentalis occidentalis possess IR receptors possess IR receptors � L. � L. occidentalis occidentalis is attracted to IR stimuli is attracted to IR stimuli � L. � Occluded specimens no longer respond to � Occluded specimens no longer respond to IR stimuli IR stimuli

Supporting Evidence Supporting Evidence � Differential IR radiation emission by cones � Differential IR radiation emission by cones � L. occidentalis occidentalis possess IR receptors possess IR receptors � L. � L. occidentalis occidentalis is attracted to IR stimuli is attracted to IR stimuli � L. � Occluded specimens no longer respond to � Occluded specimens no longer respond to IR stimuli IR stimuli

Supporting Evidence Supporting Evidence � Differential IR radiation emission by cones � Differential IR radiation emission by cones � L. occidentalis occidentalis possess IR receptors possess IR receptors � L. � L. occidentalis occidentalis is attracted to IR stimuli is attracted to IR stimuli � L. � Occluded specimens no longer respond to � Occluded specimens no longer respond to IR stimuli IR stimuli

Scanning Electron Micrograph Scanning Electron Micrograph 1 cm L. occidentalis Merimna atrata Australian “fire-beetle” Schmitz H. et al. 2000

Scanning Electron Micrograph Scanning Electron Micrograph 200 µm L. occidentalis Merimna atrata Australian “fire-beetle” Schmitz H. et al . 2000

Method for IR-Receptograms Indifferent electrode IR Source Glass Tube First Face Mirror Recording electrode

Results for IR- -Receptograms Receptograms Results for IR

Supporting Evidence Supporting Evidence � Differential IR radiation emission by cones � Differential IR radiation emission by cones � L. occidentalis occidentalis possess IR receptors possess IR receptors � L. � L. occidentalis occidentalis is attracted to IR stimuli is attracted to IR stimuli � L. � Occluded specimens no longer respond to � Occluded specimens no longer respond to IR stimuli IR stimuli

Bioassay Set-up 1 m Red light

Bioassay Criteria

Bioassay Criteria

30 20 10 38.0°C 6.0°C Bioassay Set-up

Reflection of IR Radiation Reflection of IR Radiation 27.9°C 25 20 15 10 5 27.9°C 0.6°C 25 20 15 10 5 0.6°C

Response of L. L. occidentalis occidentalis to to Response of IR Radiation IR Radiation

Field Study Field Study

Field Study Field Study 33.6°C 30 25 20 15 empty ice water 12.7°C

Field Response of Field Response of L. occidentalis occidentalis to IR Radiation to IR Radiation L.

Supporting Evidence Supporting Evidence � Differential IR radiation emission by cones � Differential IR radiation emission by cones � L. occidentalis occidentalis possess IR receptors possess IR receptors � L. � L. occidentalis occidentalis is attracted to IR stimuli is attracted to IR stimuli � L. � Occluded specimens no longer respond to � Occluded specimens no longer respond to IR stimuli IR stimuli

Occlusion Experiments Occlusion Experiments � silica/acrylic silica/acrylic – – opaque to IR opaque to IR �

Occlusion Experiments Occlusion Experiments � Occluded Occluded � Control Control � �

Occlusion Bioassay Set-up 1 m Red light

Results Results Control 17 Insects Non-responding Occluded 35 Insects Non-responding

Concluding Summary Concluding Summary � Differential IR radiation emission by cones � Differential IR radiation emission by cones � L. occidentalis occidentalis possess IR receptors possess IR receptors � L. � L. occidentalis occidentalis is attracted to IR stimuli is attracted to IR stimuli � L. � Occluded specimens no longer respond to � Occluded specimens no longer respond to IR stimuli IR stimuli

Wavelengths of visible light? Prediction: cones emit specific wavelengths of visible light that provide a foraging cue for L. occidentalis

Wavelengths of visible light? Prediction: cones emit specific wavelengths of visible light that provide a foraging cue for L. occidentalis

Wavelength reflection profiles

Trap color Sechelt May 25, 2007 12:45 Ambient = 17 °C

Trapping results

Green = Green?

Attraction of Indian meal moth ( Plodia interpunctella ) to specific wavelengths of light Tom Cowan

Experiment 1: Bioassay Setup Approx. 1.5m Release Stand Approx. 1.5m Delta Trap

Results of Experiments 1-3 Proportion IMM response to 4 spectra at the same intensity ♂ V ♀ G ♀ 0 5 10 15 20 25 30 35 n = 10 % Response

Spectral Power Distribution of Blue LEDs 435nm 405nm 470nm 450nm

Results: Experiment 4 Proportion of gravid females responding to blue LEDs emitting at the same intensity b 470nm b 450nm b 435nm 405nm a 0 10 20 30 40 50 60 70 n = 10 % response

LED Trap in Action

L. occidentalis occidentalis L. � Does a specific wavelength of green provide an optimal foraging cue? � Is there an interaction between a specific wavelength and IR radiation?

Sechelt May 25, 2007 12:45 Ambient = 17 °C

Kalamalka June 20, 2007 1:20 Ambient = 25 °C

Cone size? Prediction: cone/trap size matters as a foraging cue

Trap size

Semiochemicals? Prediction: semiochemicals contribute to the complex of foraging cues. However…..

…when traps are suspended from trees, synthetic cone semiochemicals may not be needed.

Semiochemicals � Are some cone volatile blends more attractive than others? � Bait traps in seed orchards of Douglas-fir, lodgepole pine, or spruce with e.g. volatiles from western white pine cones?

Management � IR radiation Trap design:

Management Trap design: � IR radiation � Specific wavelength of visible light

Management Trap design: � IR radiation � Specific wavelength of visible light � Proper size

Management Trap design: � IR radiation � Specific wavelength of visible light � Proper size � Semiochemical bait?

Management Trap design: � IR radiation � Specific wavelength of visible light � Proper size � Semiochemical bait? � Airborne sound?

Management Trap design: � IR radiation !!! � Specific wavelength of visible light !!! � Proper size !!! � Semiochemical bait? � Airborne sound?

Management � Timing of trap placement: Early in the spring when trap-derived cues outcompete cues from natural cones

Management � Removal of cones in the fall