The relationship between temperature : Tetranychus urticae and cucumber hybrids

Abstract EN

Three different temperature degrees (25, 30 and 35˚C) were used to study their effect on the biology of two spotted spider mite (Tetranychus urticae).

The results demonstrated that the longest developmental time was 9 days at 25˚C and the shortest developmental time was 6.8 days at 35˚C with R.H.65±5%.

The maximum period of adult longevity was 17 days at 25˚C, and minimum longevity was 13.8 days at 35˚C.

The pre- oviposition period was 1.5, 1.3, and 0.9 days at 25, 30 and 35˚C, respectively.

Oviposition period was 8, 7 and 6 days as above mentioned temperature.

The highest number of eggs (31.67) was laid at 25 ˚C after three days and minimum eggs (6.67) were deposed after five days at 35˚C.

The highest number of larvae which 43 larvae was observed at 35˚C after six days and the minimum number 1.17 was recorded at 25˚C after three days.

As well as, the highest number of nymphs (27.67) was noticed after seven days at 30˚C, whereas the lowest number of nymphs (1 nymph) found after four days at 25˚C.

The Unigene cucumber hybrid showed more resistant to T.

urticae with lowest mean numbers (267.89, 54.67 and 247.11) of eggs, adults and lesions respectively.

While, Saef hybrid was the most susceptible variety with (694.44, 315.89 and 1226.67) for the eggs, adults and lesions respectively.