GC-Mite™
Apple
Spider Mite: Tetranychus urticae Koch
   
Plant Protection Res. Institute, ARC. Giza Egypt
 

The tetranychid mites are plant feeders of considerable economic importance, attacking fruit and vegetable crops. They usually feed on the leaves injuring the epidermis and resulting in blotching stippling or bronzing and sometimes accompanied by leaf fall. Some of the species are most specific but the majority of it is polyphagous and has a wide range of hosts. Severe mites feeding result in economic reduction in the quality and quantity of crop production.

 
A complete randomized block design with four replicates (six trees/replicate) was used. Two concentrations, 1000 cc (1%) and 2000 cc (2%) per 100 liter of water, from the product, GC-Mite 20% EC were tested in each of the four experiments. Sample size was 80 leaves from each treatment (20 leaves per replicate). Weekly sampling was collected randomly after spraying. A pre-count was taken just before spraying at each replicate. Lower surface of the leaves was examined carefully; living mites were counted and recorded. All sprays were applied by using a motor sprayer of 600 liters capacity. Percentage of reduction in all motile stages was estimated according to the equation of Henderson and Tilton (1955).
 
Results and Discussion:
Efficiency of the natural product, GC-Mite 20% EC, at the recommended concentrations 1% and 2%, on the motile stages of the spider mites, Tetranychus urticae infesting apple was evaluated under the Egyptian environment.
 
Data in Table 1 and Figure 1 indicated that the GC-Mite, at the concentrations of 1 and 2%, gave 84.3 and 91.8% reduction, respectively in the population of T. urticae on apple trees.
 
Table 1. The Evaluation of Different Concentrations of GC-Mite 20% on Motile Stages of the Spider Mite, Tetranychus urticae Koch on Apple Trees in Egypt.
Treatment
Rate of Application %
Pre-count/ 80 Leaves
No. of Motile Stages/80 Leaves and % Reduction after Treatments

Average of Reduction %

One Week
Two Weeks
Three Weeks
Four Weeks
No.
%
No.
%
No.
%
No.
%
T1
1
896
143
85.55
152
85.04
191
83.94
221
82.73
84.31
T2
2
923
71
93.03
83
92.07
104
91.51
126
90.44
91.76
Control
-
784
866
-
889
-
1041
-
1120
-