Long-term mole cricket control on horizon A nematode product patented for use by the University of Florida to provide long-term biological con- trol of turf-damaging mole crickets will be available next year from Becker Underwood. This product, known as Nematac S, will be cost-effective and highly beneficial for a wide range of consumers, from golf- course managers to ranchers. By Angela Brammer UF graduate student The parasitic nematode Stein- ernema scapterisci attacks only for- eign mole crickets — those that are most damaging to turfgrasses in the Southeast. The nematodes live in the soil and enter the mole cricket through openings in the body, such as the mouth or spiracles. Once in- side, they release bacteria that feed on the mole cricket, usually killing it within 48 hours. The nematodes feed on the bacteria and reproduce inside the mole cricket, and the next generation emerges to search for another host once it dies. Steinernema scapterisci spreads slowly on its own, mostly relying on University of Florida/Dr. K.B. Nguyen its host for dispersal. After infection, Steinernema scapterisci nematodes emerge from the body of a dead a mole cricket may fly up to a mile, tawny mole cricket. taking its parasitic nematodes along for the ride. Nematodes then emerge on insecticides to prevent such dam- Applying them just beneath the sur- into the new location once the host age. face provides some protection from cricket dies. Because of this, it may In the 1980s, University of Flor- desiccation and ultraviolet light. be possible to effectively cover an ida scientists imported the mole Surface distribution should be fol- area of mole cricket infestation by cricket nematode from South Amer- lowed by irrigation to help the applying the nematodes to the “hot ica. The species was formally de- nematodes into the soil. It may be spots,” those places with the highest scribed in 1990 by UF nematologists possible to apply the nematodes concentrations of mole crickets. The Dr. Grover Smart and Dr. K.B. through existing irrigation systems mole crickets themselves do the Nguyen. Experiments showed that as well. work of spreading the later genera- the nematode killed 100 percent of Golf courses may require higher tions of nematodes throughout the tawny and southern mole crickets concentrations per acre, but in pas- site. and at least 75 percent of short- tures, fields or areas with large Of the three species of Scapteris- winged mole crickets without ad- numbers of mole cricket popula- cus spp. mole crickets that immi- versely affecting other insects. It is tions, the cost per acre can be re- grated here from their native South an effective, permanent method of duced by applying the nematodes in America about 100 years ago, the controlling all three Scapteriscus strips. UF research has shown that a tawny and southern mole crickets spp. mole crickets. swath of nematodes as small as 1/8 cause the most damage in Florida. acre, given time, can control an With no native natural enemies in Ease of Use acre’s worth of mole crickets. In an the U.S., they multiplied and experiment on 24 acres of ranchland thrived. Now, the two species cause Application of the nematodes is in Polk County, nematodes applied millions of dollars of damage each simple. Mixed with water, they can in proportions varying from none to year to Bahia, Bermuda, Centipede be sprayed on the surface or injected half of the treated area appeared to and St. Augustine grasses. Addi- into the sod under low pressure. spread throughout the 24-acre site in tional millions are spent each year less than a year. The nematodes naturally have teriscus. Even native mole crickets acre strip, etc. This brings the cost greater effect on large nymphs and are not at risk. With chemical pesti- for those who treat their pastures in adult mole crickets, as it is easier for cide use, not only are other, poten- 1/8-acre strips down to about them to find their way into the tially beneficial, insects at risk, but $25/acre for the product, plus $5- mouths and spiracles of the larger so are humans, pets and wildlife. $10 for application. insects. Thus, it makes sense that This is not the case with nematodes. they would be most effective in the With nematode applications, golf Demonstration early fall or late spring just before courses do not have to keep the pub- and Research Sites adult mole cricket populations reach lic away for a time as they do with their peak. pesticides. The Florida Legislature awarded Nematodes are environmentally $300,000 in state funds to the mole Benefits of Biological Control friendly as well. There is no danger cricket nematode program this year. of contamination of nearby water The money will enable the Mole Chemical control of insect pests sources or other negative environ- Cricket Task Force to establish re- is costly. Insecticides are immedi- mental impacts, which means there search and demonstration sites ately effective but must be reapplied won’t be any cleanup bills. In addi- around the state to test the effective- often — at considerable cost —to tion, the public looks kindly upon ness of the nematode product on maintain control of a mole cricket biological controls. The use of harsh various types of land with different population over time. Mole cricket pesticides is a growing public con- amounts and methods of application. nematodes, on the other hand, have cern, and minimizing their use when The Mole Cricket Task Force a residual effect on mole cricket alternatives are available can con- includes University of Florida and populations that lasts long after the tribute to a positive public image. Florida Department of Agriculture initial application. The nematodes and Consumer Services, Division of reproduce inside the mole crickets. Cost and Availability Plant Industry researchers; county Each infested mole cricket can har- extension agents; product develop- bor as many as 50,000 new nema- The University of Florida has ment specialists from MicroBio; and todes. Those 50,000 will emerge issued an exclusive license to pro- members of the affected industries. once the mole cricket dies to seek duce the nematodes to the U.K. The nematodes will be applied new host mole crickets. This reduces company MicroBio, owned by during September and October, at the need for further application. Be- Becker Underwood of Ames, Iowa. various sites around the state, in- cause of this, controlling mole MicroBio will sell the product under cluding golf courses, pastures, crickets with these nematodes costs the name Nematac S. It will be ranchland, sod farms, and city parks less than using pesticides. available in units of 500 million for and playgrounds. Different methods Nematodes should be used as a about $100 a unit. The total cost per of application (slit injection, liquid preferred tactic in the integrated pest acre will vary with the type of land injection and spraying) will be management of Scapteriscus spp. and need for fast results. A higher tested and demonstrated. The results mole crickets. Chemical insecticides initial concentration of nematodes of this work will be presented at can be effective in controlling out- will eliminate mole crickets more field days or workshops in areas of breaks and reducing heavy infesta- quickly and may be the best solution the state that are heavily infested tions of mole crickets; however, in a situation where speed is key. with mole crickets. most situations call for prevention or A general recommendation is to suppression through turf manage- use 800 million to 1 billion nema- For more information about the ment, biological control, use of re- todes per acre. Partial-acre treat- Mole Cricket State Program, please sistant turf and other more sustain- ments should use a proportional contact Dr. Norm Leppla, UF, co- able tactics. Steinernema scapterisci amount of nematodes: 400 million chair of the Mole Cricket Task parasitizes only the three South to 500 million for a ½-acre strip, Force, at 352-391-1901, ext . 120, or American species in the genus Scap- 200 million to 250 million for a ¼- [email protected]. For more details, please visit Tom Fasulo at the University of Florida Entomology and Nematology trade show booth or Tom Hinks at the Becker Underwood booth. For information on how to become a distributor for Nematac S, please contact Tom Hinks, MicroBio, at 519-767-3188 or [email protected]. UF entomology graduate student Angela Brammer compiled this report. Her e-mail address is [email protected]. .