Vol.12_No.2 - Pesticide Alternatives Lab - Michigan State University

Spring 2003 Resistant Pest Management Newsletter Vol. 12, No.235%. The efficacy of the 4 IGRs did not differ greatlyand ranged from 90 to 95% (Fig.3).Chlorpyriphos: It is used in Emilia-Romagna andTrentino for pest-control in orchards affected by a highCM density and where resistance to either azinphos-mor diflubenzuron was detected. The choice was madeaccording to the results that demonstrated no crossresistancewith azinphos methyl. As a matter of fact,the attracticide susceptibility test carried out on malemoths showed that there was not a reduction inmortality when applied on the azinphos-resistant strainof codling moth (Fig. 4).beneficial organisms, new strategies have beenevaluated based on less toxic control measures with aview to replacing chlorpyrifos in the IRM.In Emilia-Romagna, field trials were conducted ina pear orchard where the previous year's harvest fruitdamage had been 85%, in spite of the application of asmany as 12 treatments. The efficacy of differentinsecticides was assessed against the first generation ofcarpocapsa (Boselli et al, 2001). All the treatmentswere based on one application of flufenoxuron, at thestart of egg-laying, followed by two larvacidetreatments with different active ingredients(carpovirusine, chlorpyriphos, chlorfenapyr,methoxyfenozide, indoxacarb, tebufenozide, andspinosad) against the new-born larvae. The results atthe end of the first generation show that there were nosignificant differences between six of the seveninsecticides compared. In this case there is a suspicionthat the flufenoxuron applied at the start of the seasonhad actually contributed to significantly limiting thefinal damage in all the experimental regimes, thusreducing the differences between the various productsbeing tested (Fig. 5). Only the fruit damage in thechlorfenapyr plots resulted significantly higher than theIn Emilia-Romagna field tests were again carriedout on the first generation. Such tests comprised thetwo applications of chlorpyriphos targeted to the newbornlarvae, preceded by an action with different IGRs(diflubenzuron, flufenoxuron, esaflumuronteflubenzuron, methoxyfenozide, triflumuron,lufenuron) applied at the beginning of the egg-layingperiod. As a further treatment two applications ofchlorpyriphos were applied. All the treatments werestatistically differentiated from the untreated plot, butnot among themselves. Indeed, just two applications ofchlorpyrifos provided the same efficacy as thosestrategies where an IGR was applied at the beginningof the season.The EVALUATION of NEW STRATEGIES BASED on LESSTOXIC CONTROL ACTIONS As chlorpyriphos does nothave a good profile in terms of toxicity for humans andothers.New field trials were organised in orchards wherethe presence of resistant CM populations had beendemonstrated, in order to evaluate the efficacy of theinsecticides when used alone, with no IGR as the initialtreatment. The products used were the granulosis virusand new products like indoxacarb, spinosad, andthiacloprid; azinphos-methyl was used as a standard ofreference. The treatments were applied at the start ofegg hatching and repeated eight days later (Boselli etal, 2001).67