Cost Effectiveness of Biological Control: Invasive Mole Crickets in Florida Pastures

The mole cricket biological control program (MCBCP) has become a classic example of successfully managing alien invasive pests that warranted formal analysis and documentation of its effectiveness and benefits relative to costs for cattlemen in the southeastern U.S.  Three biological control agents that parasitize Neoscapteriscus spp. mole crickets were imported, tested for non-target affects, and distributed widely in Florida.  Larra bicolor F. (Hymenoptera: Crabronidae), a parasitoid of large nymph and adult mole crickets, was collected in Bolivia and established in Florida, Georgia, Alabama and Mississippi during 1988-89.  Another parasitoid of large mole crickets, Ormia depleta (Wiedemann) (Diptera: Tachinidae), was introduced several times from Brazil during the early 1980s and released extensively.  An entomopathogenic nematode discovered in Uruguay, Steinernema scapterisci (Nematoda: Rhabditida: Steinernematidae) reproduces within adult mole crickets, building up large populations that infect additional mole crickets and ultimately create an epidemic.  This very effective biological control agent was applied to pastures, turf farms, golf courses, athletic fields, and other mole cricket habitats across Florida after in vitro culture was developed and a commercial product became available, Nematac^® S.  About $8.7 million and 30 plus years were spent on the MCBCP and the overall annual savings were $4,209,979; $7,385,592 and $2,041,129 for North, Central and South Florida, respectively.  Applying a 3% perpetual benefit, the MCBCP will save cattle producers $453 million, a benefit:cost ratio of 52:1.