02459naa a2200313 a 450000100080000000500110000800800410001910000160006024501810007626000090025752015220026665000110178865000260179965000160182565000110184165300110185265300080186365300110187165300310188265300240191365300250193765300080196265300320197070000170200270000160201970000230203570000190205877300680207714447852024-03-20       1996    bl uuuu     u00u1 u    #d1 aABOT, A. R.  aDevelopment of resistance by Anticarsia gemmatalis from Brazil and the United States to a nuclear polyhedrosis virus under laboratory selection pressure.h[electronic resource]  c1996  aColonies of velvetbean caterpillar, Anticarsia gemmatalis, collected in Brazil (Dourados, State of Mato Grosso do Sul; and Sertanopolis, State of Parana) and in the United States (Louisiana) were established in the laboratory, in each respective country, with the objective of evaluating the potential of this insect for developing resistance to the A. gemmatalis nuclear polyhedrosis virus (AgMNPV). Larvae of the three colonies were exposed to a selection pressure of ca. 80% mortality by AgMNPV in each generation, while a portion of the population was left unchallenged (control). Larvae of selected and control populations were bioassayed with AgMNPV isolate LD-79. Log-dose-probit regression lines and associated parameters were used to compare the selected andcontrol insects in each generation. All three insect populations developed a significant level of resistance within 3-4 generations of exposure to AgMNPV, based on comparison of LC50s between AgMNPV-exposed and control insects and non-overlap of 95% CL. The two populations from Brazil developed resistance ratios&gt 1000X within 13-15 generations of exposure to virus, whereas the resistance ratio in the United States leveled at approximately 5X after 4 generations. Thus, A. gemmatalis has a high potential of developing resistance in Brazil, where the virus occurs naturally and is extensively employed as a microbial pesticide. In the United States, the potential for resistance interfering with a microbial insecticide based on AgMNPV is lower.  aBrazil  aAnticarsia Gemmatalis  aBaculovirus  aInseto  aBrasil  aEUA  aInsect  aNuclear polyhedrosis virus  aResistance to virus  aResistancia ao virus  aUSA  aVirus da poliedrose nuclear1 aMOSCARDI, F.1 aFUXA, J. R.1 aSÓSA-GOMEZ, D. R.1 aRICHTER, A. R.  tBiological Control, Orlandogv. 7, n. 1, p. 126-130, Aug. 1996.