Fungi. Beaureria bassiana |Naturaiis-Oi is the most 

 commonly used fungus in ornamentals. Although in- 

 sects are susceptible to fungi, high humidit>' is often 

 required to make the fungus grow. This same humid- 

 ity may encourage plant pathogenic fungi to develop. 

 Naturalis cant be tank-mixed with fungicides or used 

 in a tank with fungicide residue. The use of fungi- 

 cides may decrease its effectiveness. 



Vlmses. There are no commercially available viruses 

 primarily because viruses rapidly degrade in light 

 and are very species-specific. (Narrow host range 

 equals a small market, i 



BIORATIONAL PESTICIDES 



These pesticides are chemicals from living organisms 

 and have modes of action which are non-toxic to 

 mammals. Spinosad is a new product that has not yet 

 reached the ornamental market. We are looking at it 

 in turf. Spinosad is a chemical extract of an actino- 

 mycete bacteria that kills some species of insects but 

 has very low toxicity to mammals. Azadirachtin is a 

 chemical extract from the neem seed, .\pparently. 

 this tree has developed its own insecticide against 

 insects feeding on it. .Azadirachtin acts as an insect 

 growth regulator, has low persistence, and requires 

 repeat applications. The trade names of this product 

 are Triact. .\zarin. and Neemazad 



LOW-RISK CONVENTIONAL PESTICIDES. 

 The ornamental and turf industry desires low-risk, yet 

 reliable, convenient (user-friendly), and effective pes- 

 ticides that can be applied with conventional equip- 

 ment. The industry has found that growers are willing 

 to pay more for such products because ornamentals 

 and turf are high-value crops. .An industry representa- 

 tive told me that European chemical company execu- 

 tives could not believe the money Americans are 

 willing to spend to maintain a quality golf course. 

 The best example of this new low-risk chemistry is 

 imidacloprid. Imidacloprid is sold by Olympic as 

 Marathon for ornamentals and bv Baver as .Merit for 



turf. Imidacloprid has very low toxicity to mammals, 

 is extremely effective, and can control insects for 

 eight to ten weeks in ornamentals. .Merit will control 

 Japanese Beetle lar^a for a full season. Merit is sold 

 under the Scott's label as GrubEx. Another product 

 which is just got registered in turf market is 

 halofenozide iMach 2) by American Cyanimid and 

 Rohm and Haas. Mach 2 acts as an insect growth 

 regulator and has excellent persistence As with 

 .Merit, it will give full-season control of grubs and is 

 so low risk that EPA put it on a fast track for registra- 

 tion. 



There is unfortunately a negative aspect to the de- 

 velopment of these new low-risk conventional pes- 

 ticides. Why would a greenhouse grower bother to leam 

 how to use Encarsia wasps for the control of whiteflies 

 when Marathon will do it ver>' effectively and much 

 more conveniently? Why bother scouting as part of an 

 IPM program if control is possible for so long? In other 

 words, there will be less grower interest in biologicals 

 and possibly IPM. Consequently, there will be less will- 

 ingness for companies to spend money developing 

 biopesticides which are often more inconvenient, often 

 less effective, and more expensive. The market is ruth- 

 less. Over the last couple years, there has been bank- 

 ruptcy and downsizing of companies which specialize in 

 the biopesticides. For the near future, biopesticides 

 and biorationals will occupy a niche market until there 

 is a change in attitude forced by government regulation 

 or severe insect resistance to conventional pesticides. 

 On a positive note, the ornamentals industry can expert 

 to see some new chemistry with low toxicit>- that gives 

 growers what they want: convenience and performance 

 at a reasonable price. This is great for the industry and 

 the environment. I just hope that we don't regress and 

 overly rely on these new pesticides while forgetting the 

 basic principles of IPM. 



Dr. Svier is Extension SpecialislEntomology. Department 

 of Plant Biology. UNH. Durham. He can be reached at 

 603-862-1733. 



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