Abstract:
Development, reproduction and life table parameters
of
Tetranychus urticae
Koch were
determined on leaves of peach (G. H. Hale cultivar)
at different temperatures, ranging
from 13 to 33
°
C under laboratory conditions. No development was o
bserved at 13
°
C.
Egg-to-adult developmental time decreased gradually
from 17 to 27
°
C and increased at
higher temperatures (27 to 33
°
C). An average of 136.43 degree-days was required t
o
complete development above the lower threshold temp
erature (13.79
°
C). Mean total egg
productions per female were 40.09, 18.74, 8.03 and
21.33 at 25, 27, 30 and 33
°
C,
respectively. Mean longevities of the females were
12.91±1.65, 5.92±0.55, 3.56±0.54 and
6.53±0.56 days, respectively at the above mentioned
temperatures. The intrinsic rate of
increase (
r
m
) at different temperatures ranged from 0.108 to 0.
213 day
-1
, with the highest
value recorded at 27
°
C. The highest and the lowest values of the net rep
roductive rate
(
R
0
) were obtained at 25
°
C (16.87) and 30
°
C (4.18), respectively. Doubling time (
DT
)
varied significantly at different temperatures and
the shortest and longest values of this
period were obtained at 27 and 30
°
C, respectively. The results suggested that
T. urticae
was able to develop and reproduce within a wide ran
ge of temperatures, and that
temperatures from 27- 30°C are the most suitable con
ditions for the development,
survivorship and reproduction of the mite.
Keywords
: Development, Life table parameters, Peach, Temper
ature,
Tetranychus urticae
.
