Progress 10/01/99 to 09/30/04
Outputs
The project commenced with objectives to further biological control of pest mole crickets as the main component of integrated pest management for these pests. Much work had been done in predecessors of this project on the beneficial nematode Steinernema scapterisci. However, that nematode was no longer being produced commercially in 1999. For those two reasons, the intent was to emphasize three other biological control agents: Larra bicolor (Sphecidae), Ormia depleta (Tachinidae), and Pheropsophus aequinoctialis (Carabidae). However, it became hard to maintain this emphasis when the nematode was once more produced and marketed commercially: because ranchers and growers wanted more information about it -- they displayed minimal interest in the other three agents. Their attitude presumably came about because the nematode was marketed as a biopesticide, which fit the familiar concept of using a pesticide with instantaneous effect against pest insects. In fact, the
nematode and the others all serve as classical biological control agents. Permanent control of pest mole crickets may best be achieved by establishing populations of all four agents and managing those populations. Ormia depleta and Larra bicolor were released in the late 1980s and are established in Florida. Methods for management of their populations are needed. Pheropsophus aequinoctialis never has been released and still awaits satisfactory demonstration of its safety to non-target organisms. Students worked on aspects of the biology of all three of the insect biocontrol agents although without thorough resolution of any of the questions about management. Populations of Larra bicolor have continued to spread in Florida, partly with assistance and partly naturally. The level of biological control achieved in the Gainesville, FL area is now better than 95% as measured by long-term monitoring traps. This control is attributed to effects of Larra bicolor and Steinernema scapterisci.
Farther South in Florida, Ormia depleta must add to the level of control achieved. As Larra bicolor spreads to still more counties, and as Steinernema scapterisci is applied in additional areas, area-wide control should be achieved in more and more of Florida.
Impacts
Biological control of pest mole crickets in the Gainesville, Florida area has been achieved by introduction, release and establishment of two classical biological control agents acting together: the wasp Larra bicolor and the nematode Steinernema scapterisci. In 2002/2003 the level of control exceeded 95% for southern mole crickets and 99.5% for tawny mole crickets as contrasted with the average for nine years before these biocontrol agents were released. The future of the project is to extend this level of biological control throughout Florida. A still higher level of control is being sought by management of populations of some of the biocontrol agents.
Publications
- Parkman, J.P., Frank, J.H. 2002. Interactions between Ormia depleta (Diptera: Tachinidae) and Steinernema scapterisci (Nematoda: Steinernematidae), natural enemies of pest mole crickets (Orthoptera: Gryllotalpidae). Environ. Ent. 31: 1226-1230.
- Welch, H.C. 2000. Determination of carbohydrate sources of Ormia depleta through gas chromatographic analysis of crop sugars. MS thesis, Univ. Florida, 36 p.
- Welch, C.H. 2004. Ormia depleta: laboratory maintenance, strain identification, and evaluation of Aphis nerii as a banker species. PhD dissertation, Univ. Florida, ix + 77 p.
- Welch, H.C., Frank, J.H. 2000. The strange diet of Ormia depleta. Florida Turf Digest 17(2): 22-24.
- Cabrera Mireles, H. 2002. Relationship between temperature and development of the ectoparasitoid Larra bicolor (Hymenoptera: Sphecidae) and the endoparasitoid Ormia depleta (Diptera: Tachinidae). PhD dissertation, Univ. Florida, 175 p.
- Frank, J.H. 2000. A parasitic fly that kills mole crickets: Its use in states north of Florida, US Golf Assoc., 1999 Turfgrass and Environmental Research Summary: 18-20.
- Frank, J.H. 2001. Statewide controls for mole crickets? Florida Turf Digest 18(4): 44-45.
- Frank, J.H. 2002. A parasitic fly that kills mole crickets. USGA Green Section Record 40(5): 9-11.
- Frank, J.H. 2002. Biological control agents for mole crickets. p. 17 in Nus, J.L., Kenna, M.P. (eds). 2001 USGA Turfgrass and Environmental Research Summary. USGA Green Section, Far Hills, NJ.
- Frank, J.H. 2002. Biological control agents for mole crickets. p. 6 in Nus, J.L. (ed.) USGA Turfgrass and Environmental Research Executive Summary. NS 1651. USGA Green Section, Far Hills, NJ.
- Frank, J.H. 2002. A parasitic fly that kills mole crickets. Turf and Environmental Research Online 1(9): 1-5. (http://turflib.msu.edu/tero/v01/n09.pdf)
- Frank, J.H., Buss, E.A., Barbara, K. 2002. Beneficial nematodes in turf: Good for how many years against pest mole crickets? Florida Turf Digest 19(4): 48-50.
- Frank, J.H., Fasulo, T.R., Short, D.E., Weeds, A.S. 2002. MCricket: Alternative methods of mole cricket control. (http://Molecrickets.ifas.ufl.edu).
- Frank, J.H., Leppla, N.C., Vicente, N. 2004. Mole crickets to the South. Florida Turf Digest 21(4): 20-22, reprinted 21(6): 16-17.
- Frank, J.H., Parkman, J.P. 1999. Integrated pest management of pest mole crickets with emphasis on the southeastern USA. Integrated Pest Management Reviews 4: 39-52.
- Frank, J.H., Sourakov, A. 2002. Larra wasps. Featured Creatures, EENY-268. (http://Creatures.ifas.ufl.edu/beneficial/Larra_wasps.htm).
- Frank, J.H., Walker, T.J. 2003. Mole crickets (Orthoptera: Gryllotalpidae) in Jamaica. Florida Ent. 86: 484-485.
- Frank, J.H., Woodruff, R.E., Thomas, M.C. 2002. Mole crickets (Orthoptera: Gryllotalpidae) in Grenada, West Indies. Entomotropica 17: 207-212.
- Lake, P.C. 2000. Behaviors of Pheropsophus aequinoctialis (Coleoptera: Carabidae) affecting its ability to locate its larval food, eggs of Scapteriscus spp (Orthoptera: Gryllotalpidae); and the effect of moisture on oviposition depth in Scapteriscus abbreviatus. MS thesis, Univ. Florida, 52 p.
- Lombardo, J., Weldon, R.N., Frank, J.H. 1999. Quantification of risk for integrated pest management strategies as a decision making aid with applications for turfgrass in the Southeast. Univ. Florida, Food & Resource Economics Dept., Staff Paper SP 99-1.
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Progress 10/01/02 to 10/01/03
Outputs
The beneficial wasp Larra bicolor has now been detected in 15 counties in north and central Florida. From its initial release in 1988 in Alachua County, its population has spread naturally to most of the others, having been assisted to spread only to Brevard and Charlotte counties. Its detection in other counties was either fortuitous, or collaborators maintained plots of the wildflower Spermacoce verticillata and checked these plots occasionally for presence of adult wasps. It is hoped to find collaborators in many other counties willing to maintain such wildflower plots. It is also hoped to establish wildflower plots in distant counties, where the wasp is unlikely to be present, and redistribute wasps from Alachua County to them. Spermacoce verticillata contains low levels of an alkaloid, but the alkaloid has not prevented its use as a forage for cattle. Its nectar is high in sucrose, and its flowers are highly attractive to Larra bicolor, much more so than are five
other wildflowers tested by us. It is widespread in southern Florida, was mentioned in a botanical work published in 1860 as being present in the Florida Keys, and thus is arguably native to Florida. Outside Florida, it is believed to be native in the Greater Antilles and to a wider area of the Neotropics. It occupies southern areas of some Gulf Coast states. At present, it is the most promising candidate for use in wasp-gardening (like butterfly-gardening) where the services of Larra bicolor would be useful to suppress populations of pest mole crickets. Traps baited with synthetic mole cricket sound have now been operated at two sites near Gainesville for 24 years. They catch adult tawny and southern mole crickets and act as population monitoring devices, showing changes from year to year. As measured by these traps, populations began to decline about 1992, a few years after Larra bicolor and the nematode Steinernema scapterisci had reached the trap locations after release elsewhere.
The latest data (for the year 2002-2003) show that tawny mole cricket populations have fallen to less than half of 1% of what they were on average before biocontrol agents were released.
Impacts
Biological control of pest mole crickets in the Gainesville, Florida area has been achieved by introduction, release and establishment of two classical biological control agents acting together: the wasp Larra bicolor and the nematode Steinernema scapterisci. In 2002/2003 the level of control exceeded 95% for southern mole crickets and 99.5% for tawny mole crickets as contrasted with the average for nine years before these biocontrol agents were released. The future of the project is to extend this level of biological control throughout Florida. A still higher level of control is being sought by management of populations of some of the biocontrol agents.
Publications
- Frank, J.H., Arevalo, A., Barbara, K.A. 2003. The little wasp that really can. Florida Turf Digest 20(4): 18, 20-21, 24.
- Barbara, K.A., Buss, E.A. 2003. Interactions between mole crickets and insect-parasitic nematodes (Steinernema scapterisci, Nematac S). The Florida Green, spring 2003: 56
- Weed, A.S. 2003. The reproductive strategy of Pheropsophus aequinoctialis L.: Strategies describing the fecundity, fertility, oviposition behavior, and the influence of mole cricket egg chamber depth on larval survival. M.S. thesis, Univ. Florida, xi + 60 p.
- Adjei, M.B., Frank, J.H., Gardner, C.S. 2003. Survey of pest mole crickets (Orthoptera: Gryllotalpidae) activity on pastures in south-central Florida. Florida Entomologist 86: 199-205.
- Arevalo-Rodriguez, H.A. 2003. Recognition and selection of various species of plants that can be used as food resources for adults of Larra bicolor F. (Hymenoptera: Sphecidae) in Florida. M.S. thesis, Univ. Florida, xii + 61 p.
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Progress 10/01/01 to 10/01/02
Outputs
Applications of the beneficial nematode Steinernema scapterisci were made in turf and pastures in several additional Florida counties. Populations of this nematode established in 1988/1989 on two golf courses in the Gainesville area were still present 12+ years later, and still infecting pest mole crickets. Beneficial wasps of the species Larra bicolor spread of their own accord to additional counties in northern Florida, and were released and established in one county in central Florida.
Impacts
Natural and assisted spread of Steinernema scapterisci and Larra bicolor to additional areas should reduce pest mole cricket populations. Repeated demonstration of such reduction should persuade ranchers and turf managers to use biological control.
Publications
- Frank, J.H. 2002. A parasitic fly that kills mole crickets. USGA Green Section Record 40(5): 9-11.
- Frank, J.H., Buss, E.A.Barbara, K. 2002. Beneficial nematodes in turf: Good for how many years against pest mole crickets? Florida Turf Digest 19(4): 48-50.
- Leppla, N.C. 2002. Mole cricket state program update - mole cricket campaign moves to phase II: statewide. Florida Turf Digest 19(2): 40, 42.
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Progress 10/01/00 to 10/01/01
Outputs
Traps were operated nightly for flying adult mole crickets at 2 Gainesville locations (Green Acres Farm, & Pinetops Farm) since the UF/IFAS mole cricket program began in 1978. Green Acres Farm was sold by UF so a summation of trapping results is timely. The traps monitor annual changes in numbers of mole crickets and have no control effect of their own. For the first 8 years of records, there was no trend in total numbers of mole crickets trapped. In 1985 the nematode Steinernema scapterisci, and in 1988 the wasp Larra bicolor, introduced from South America, were released elsewhere in Alachua County. Their populations spread and they appeared at the 2 farms and began to reduce mole cricket numbers by 1992. Since then, annual numbers of southern and tawny mole crickets trapped there have been reduced by 95%. It appears that the effect of these two biocontrol agents, acting together, is highly successful. In view of this success, efforts to further disperse these two
bicontrol agents have been emphasized. Larra bicolor: In July 2000, 60 Spermacoce verticillata plants (a favorite nectar source of the adult wasps), were carried from Gainesville, FL, to Tifton, GA, and distributed in 3 plots located not less than 10 miles apart. In september 2000, 180 L. bicolor adults were harvested at a prepared site near Gainesville, carried to Tifton, and distributed among the 3 plots in ratio 30:60:90. This was to give an indication of the number of wasps needed to establish a population. Over half of the wasps released were females. Visits to the 3 plots in summer and fall 2001 showed establishment of wasps at all 3 plots. The ability of this wasp to overwinter north of Florida had not been known. Steinernema scapterisci: About 50 billion mole cricket nematodes, S. scapterisci, were produced by MicroBio, UK under exclusive license from the University of Florida Foundation. They were supplied by Becker Underwood, Ames, Iowa, and applied to pastures, golf
courses, sod farms, and urban landscapes throughout central Florida. Pastures in Desoto, Hardee, Highlands, Hillsborough, Manatee, Orange, Osceola, Pasco, and Polk counties received 26.5 billion nematodes. A total of 5 billion nematodes was used to treat 5 sod farms in Polk and Osceola counties. Nearly 20 golf courses from Jacksonville to Naples were given about 25 billion nematodes. Urban landscapes received 4 billion nematodes, mostly applied to athletic fields. Research included application rates & patterns in different situations, baseline application parameters for equipment modification, nematode establishment & impact evaluation, correlation of mole cricket trap capture with damage, monitoring techniques to demonstrate mole cricket death (sound and pitfall traps), and rate of dispersal of infected mole crickets. Extension & education workshops and field days were conducted. Fundamental research was conducted in the laboratory to determine the effects of soap flushes for mole
crickets on the identification of nematode infections, rapid identification of S. scapterisci versus other nematodes encountered on mole cricekt samples, quality control of the shipped nematodes, and mole cricket sampling methods.
Impacts
The apparent ability of Larra bicolor and Steinernema scapterisci together to reduce mole cricket popultaions by 95% is very encouraging. We now know that both these biocontrol agents can persist in southern Georgia. This suggests that no climatic region of Florida is too severe for habitation by them, and that it should be possible to reduce mole cricket populations throughout Florida by 95% by spreading these biocontrol agents.
Publications
- Buss, E.A., and Short, D. 2001. Mole crickets in Florida. University of Florida, IFAS, LH-039.
- Frank, J.H. 2001. Statewide controls for mole crickets? Florida Turf Digest 18(4):44-45.
- Reinert, J. A., and Busey, P. 2001. Host resistance to tawny mole cricket, Scapteriscus vicinus, in bermudagrass, Cynodon spp. International Turfgrass Society Research Journal 9:793-797.
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Progress 10/01/99 to 09/30/00
Outputs
The main energy source of field-trapped adult Ormia depleta in Florida has been found to be the sugar melezitose. This sugar is not a usual component of plant nectars, but is a principal component of homopteran honeydew. This has obvious implications for management of O. depleta populations in the field to suppress populations of pest mole crickets. Adults of Pheropsophus aequinoctialis do not seem to use chemical sensory clues to detect mole cricket eggs. They lay 90% of their eggs at 0-15 cm from the soil surface, at least in the absence of mole cricket eggs. Their neonate larvae are not phoretic on adult female Scapteriscus abbreviatus mole crickets. The laboratory (quarantine) colony of P. aequinoctialis studied was found to be infected with a bacterium of the genus Wolbachia. Adult female Scapteriscus abbreviatus prefer to lay their eggs at a soil moisture of 12-20%, and in the laboratory some laid eggs as deep as 75 cm below the soil surface.
Impacts
Establish basis of enhancing populations of Ormia depleta in the field. Warning that the Wolbachia bacterium of Pheropsophus aequinoctialis should be investigated before stock is released.
Publications
- Frank, J.H. 2000. A parasitic fly that kills mole crickets: Its use in states north of Florida. US Golf Assoc., 1999 Turfgrass and Environmental Research Summary: 18-20.
- Lake, P.C. 2000. Behaviors of Pheropsophus aequinoctialis (Coleoptera: Carabidae) affecting its ability to locate its larval food, eggs of Scapteriscus spp. (Orthoptera: Gryllotalpidae); and the effect of moisture on oviposition depth in Scapteriscus abbreviatus. MS thesis, Univ. Florida, Gainesville. 52 p.
- Welch, H.C. 2000. Determination of carbohydrate sources of Ormia depleta through gas chromatographic analysis of crop sugars. MS thesis, Univ. Florida, Gainesville. 36 p.
- Welch, H.C., Frank, J.H. 2000. The strange diet of Ormia depleta. Florida Turf Digest 17 (2): 22-24.
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Progress 10/01/98 to 09/30/99
Outputs
No progress to report at this time
Impacts
(N/A)
Publications
- No publications reported this period
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