Submitted to: Journal of Experimental and Applied Acarology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2005
Publication Date: 6/1/2005
Citation: Beach, L.R. 2005. Continental comparisons of the interaction between climate and the herbivorous mite, Floracarus perrepae (Acari: Eriophyidae). Journal of Experimental and Applied Acarology. 88(2):129-134
Interpretive Summary: The Old World climbing fern, Lygodium microphyllum, is an invasive weed fern in the Florida Everglades and the leaf roll galling mite, Floracarus perrepae, is a proposed biological control agent. This agent was studied in its native range in Australia, Oceania, and Asia to determine the effect of weather and climate on its population levels. It was determined that high rainfall over several days and temperatures above 82 degrees F had a damaging effect on mite populations. We compared the climate in the native range to the climate in the proposed new environment in Florida, and concluded that the climate in South Florida would not preclude the establishment of this biological control agent. This research was done collaboratively between USDA-ARS scientists in Australia, India, New Caledonia and the USA.
Technical Abstract: The Old World climbing fern, Lygodium microphyllum, is an invasive weed in the Florida Everglades and the leaf roll galling mite, Floracarus perrepae, is a proposed biological control agent. Field studies were conducted for one to two years at sites in its native range in Australia, New Caledonia, and India to evaluate the effect of climate on F. perrepae. Monthly counts of the proportion of L. microphyllum subpinnae (leaflets) with leaf roll galls were used to measure the incidence of damage caused by F. perrepae. Between sites the most significant weather variable was rainfall 14 to 28 days prior to sampling, with higher levels having a depressive effect on the incidence of leaf rolls. Within sites the mean maximum temperature was the only significant weather variable, showing a decrease in the incidence of leaf rolls above 27 ºC, and it was predicted that no leaf rolls would form above 35 ºC. The weather parameters in Homestead, Florida for 2002 were within the range of those evaluated in the eight native range field sites, therefore, we do not predict that climate will prevent the establishment of this biological control agent for L. microphyllum in southern Florida.