Arthropod-Plant Interactions (2018) 12, 715-723

Carlos Francisco Sánchez Barahona, Betty S. Threlkeld, Pasco B. Avery, Antonio W. Francis and Ronald D. Cave (2018)
Compatibility and efficacy of the lady beetle Thalassa montezumae and the entomopathogenic fungus Isaria fumosorosea for biological control of the green croton scale: laboratory and greenhouse investigations
Arthropod-Plant Interactions 12 (5), 715-723
Abstract: The lady beetle Thalassa montezumae and the entomopathogenic fungus Isaria fumosorosea (Ifr) were assessed alone and in combination to suppress green croton scale, Phalacrococcus howertoni, populations on croton plants using laboratory bioassays and greenhouse cage studies. The acquisition of Ifr blastospores by beetle larvae (3rd instar) and adults during contamination in well plates was used to simulate exposure to direct spraying and subsequent possible fungal infection was assessed. Spore dispersal by the insects was determined after the blastospore-contaminated T. montezumae life stages roamed on agar plates for 24 h by counting the number of colony-forming units (CFUs) produced in the plates. There were no significant differences in survival times at 14 days post-treatment between beetle larvae and adults exposed to Ifr and those exposed to water only. Mean survival time of larvae exposed to Ifr was 14 days and water 12 days, whereas for adults it was 13 days compared to 13 days, respectively. Plates with Ifr blastospore-contaminated T. montezumae adults roaming on the agar surface displayed significantly more fungal trails as CFUs compared to plates with larvae. In greenhouse cage studies, the mean mortality rates of the scale exposed to beetle larvae, either alone (80.8%) or in combination with Ifr (89.1%), were not significantly different. Scale mortality rates in the fungus-only (60.5%) and beetle larvae-only treatments were statistically similar. The treatment with both biocontrol agents had a significantly higher scale mortality rate compared to the treatment with Ifr only. Therefore, spraying Ifr prior to releasing T. montezumae is an effective and compatible biological control strategy for management of the green croton scale on croton plants.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Pasco B. Avery

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection
environment/habitat manipulation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phalacrococcus howertoni	Croton (crop)
Cordyceps fumosorosea (entomopathogen)	Phalacrococcus howertoni	Croton (crop)
Thalassa montezumae (predator)	Phalacrococcus howertoni