Saturday, February 23, 2008

My First Experiment Journey

In my used to know, Fluctuating Asymmetry (FA) is right and left size differences of organism. Lens (1999) was studied that measurements of FA can provide a sensitive early warning system for monitoring stress effects in highly threatened ecosystems.
I have been done some work for my experiment discussed about FA wing size of Eriborus argenteopilosus Cameron (Hymenoptera: Ichneumonidae) from cabbage field and reared from caterpillar Crocidolomia pavonana (Lepidoptera: Pyralidae).
Eriborus argenteopilosus is one of parasitoids usually parasitizes effectivelly some of cabbage and corn caterpillar such C. pavonana, Spodoptera litura, and Helicoverpa armigera
in the field.
I used TPSdig 2 ( Rohlf 2004) program to measure wing size and FA of parasitoid.
I digitized landmark in each dot wing venation BY TPSdig 2 program.

To get the finally FA size, I used formula :

Centroid x = ∑ (x1-xn) / 13 ; Centroid y = ∑ (y1-yn) / 13

Explanation :

x1 = first size dot from X.
xn = n size dot from X.
y1 = first size dot from Y.
yn = Nn size dot from Y.
n = number all of dot.

Distance n = SQRT [ (xn - centroid x)2 + (yn-centroid y)2 ]

Explanation :

xn = size of n dot from X.

yn = size of n dot from Y.

Finally, we can get FA :

FA = │ wide of right wing-wide of left wing │

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