Life Table Characteristics of the Two Spotted Spider Mite Tetranychus urticae Koch treated with Certain Acaricides

Life Table Characteristics of the Two Spotted Spider Mite Tetranychus urticae Koch treated with Certain Acaricides The experiment was carried out to  estimate the  sustainable effect of the acaricides,  profenofos, hexythiazox and spiinomesifen on offspring of the two spotted spider mite Tetranychus urticae Koch. TI1e estimation was determined using a combination of conventional bioassay of the tested acaricides and life table procedures of the two spotted spider mite.  LC25. LC50 and LC90 of profenofos recorded 3.64 , 9.90 and 66.82 ppm, respectively and 6.9, 20.68 and :67.2 ppm, respectively for hexythiazox; whereas they were 10.46, 57.5 and 455.8 ppm,respectively for spinomesifen. The  biological aspects, developmental time  of mites treated  with LC50  of the  tested  acaricides, were followed up. Results show that the tested acaricides affected the developmental time of immature stages. Developmental time 2f untreated mites was achieved throughout 6.16 days; whereas it  was 7.12, 7.36 and 8.88 days for mites treated with,  profenofos,  hexythiazox  and  spinomesifen,  respectively.  The tested acaricides  showed  slight  effect  on preoviposition period. Survivorship (Lx) varied in their chances to reach adulthood according to the tested acaricide. Fecundity (Mx), the  gross reproductive rate (GRR) and net reproductive rate (Ro) were markedly affected by the acaricides. There were no significant differences on the hatchability percentages of laid eggs by treated and untreated females and among eggs that were laid at different time throughout the laying period. Data revealed that there were no significant differences among generation time (T) of treated and untreated females.  Data showed that untreated mite have the highest intrinsic rate of increase (rm) 0.46 per individual per day; whereas the tested acaricides, profenofos, hexythiazox and spiromesifen enhanced negative intrinsic rate of increase -0.67, -0.74 and-0.7 per individual per day, respectively. Data also showed that the population of the untreated mite, as finite rate of increase (A.), increased daily by 1.58; whereas it  was 0.51,  0.48 and  0.5 times  for  treated  mite with profenofos,  hexythiazox or spiromesifen respectively.