Cydnoseius negevi (Swirski & Amitai, 1961)

Alatawi, Fahad J., Basahih, Jamal S. & Kamran, Muhammad, 2018, Suitability of date palm pollen as an alternative food source for the predatory mite Cydnoseius negevi (Swirski & Amitai) (Acari: Phytoseiidae) at a low relative humidity, Acarologia 58 (2), pp. 357-365 : 359-360

Biology of Cydnoseius negevi feeding on fresh date palm pollen under different humidity levels

Cydnoseius negevi successfully completed its development when fed on date palm pollen at both 35 % and 60 % RH levels and 30 °C. The immature developmental time, total life span, and longevity of male and female and different reproductive parameters of the female are shown in Tables 1 and 2 .

The total duration of the immature stage development of both C. negevi females and males were significantly lower at 60 % RH (3.30 and 4.45 days, respectively) than at 35 % RH

(5.33 and 6.01 days, respectively) (F 3.70 = 16.72; P <0.0001). At both 35 % and 60 % RH,

the duration of the developmental stage of C. negevi immature males was longer than that of

2 °C.

Development of immature stages (days)

Humidity % RH. Sex

Egg Larva Protonymph Deutonymph Total immature

♀ 1.89±0.12a 0.77±0.04a 1.23±0.09a 1.44±0.1a 5.33±0.3a

35

♂ 2.05±0.15a 1.13±0.13b 1.75±0.14b 1.13±0.13a 6.05±0.35a

♀ 0.81±0.05b 0.54±0.02c 0.74±0.06c 1.20±0.12a 3.30±0.14b

60

♂ 1.14±0.15b 0.73±0.08a 1.18±0.15a 1.41±0.22a 4.45±0.35c

Means followed by different letters within the same column are significantly different (ANOVA) followed by LSD test:

P<0.05).

Means followed by different letters within the same column are significantly different (ANOVA followed by LSD test: P<0.05)

females ( Table 1). The incubation period (F 3.70 = 24.11; P <0.0001), duration of the larval (F 3.70

= 11.12; P <0.0001) and protonymphal stages (F 3.70 = 10.32; P <0.0001) were significantly higher at 35 % RH than at 60 % RH. However, the developmental duration of the deutonymphs of both sexes was not influenced significantly at both RH levels ( Table 1).

Decreasing humidity levels from 60 % to 35 % had a significant effect on the mean total fecundity and longevity of C. negevi females ( Table 2 ). Cydnoseius negevi females deposited fewer eggs (14) at 35 % RH than at 60 % RH (20.3) (F 1.57 = 7.11; P <0.01), although the oviposition period and total life span of the females did not significantly differ 1.57 (F = 3.56;

P <0.06) at the two RH levels ( Table 2 ). The sex ratio of C. negevi progeny was female-biased and not affected by RH (71 % and 73 % of females, for 35 % and 60 % RH, respectively) ( Table 2 ).