Effect of two compounds,tracer and nomolt, on the activity and reproduction of certain Cotton pests natural enemies

Laboratory bioassay were carried out to evaluate the toxicity of the ýbioinsecticide, Tracer 24% SC and the chitin synthesis inhibitor, ýNomolt 15% SC. Direct and indirect toxicity affects on the green ýlacewing, Chrysoperla carnea larvae and the ladybird, Coccinella ýundecimpunctata larvae, the egg parasitoid Trichogramma evanescens ýand the larval parasitoid Bracon brevicornis: The two predators were - ýinvestigated after feeding on treated egg masses, 2nd and 3rd larvae ýinstars of the cotton leafworm, Spodoptera littoralis (Boisd.). Results ýindicated a dose response relationship in which the mortality increased ýwith high concentrations especially the early larval stages. The LC50 ýeffects on treated larvae were with significantly different deformations. ýHigher toxic effects on treated 2nd larval instars of the cotton ýleafworm with Tracer was observed using contact method rather than ýdipped method. In general, treatments either by Tracer or Nomolt ýprolonged larval duration, reduced pupal period and weight that caused ýa reduction in adult longevity. Pupal duration and adult longevity were ýdecreased and average numbers of hatched deposited eggs/female were ýreduced significantly. High reduction in pupation and adults emergence ýresulted from treated larvae. No effects were observed on 2nd larval ýinstars of the two predators. Other effects on the egg parasitoid ýTrichogramma evanescens adults, immature stages and adults ýemergence after treated the Ephestia kuehniella eggs by Tracer and ýNomolt with spray method for 1st , 4th and 7th days of parasitism . ýWhile for the larval parasitoid Bracon brevicornis by treated after 1st ýý,3rd and 5th days of parasitism for indirect toxicity effects on the adults, ýimmature stages and adults emergence after treated the 2nd larval ýinstars of spodoptera littorlis by Tracer and Nomolt with contact ýmethod that were under laboratory conditions.ý