Oligonychus afrasiaticus

Chaaban, Sameh Ben, Chermiti, Brahim & Kreiter, Serge, 2012, Effects Of Host Plants On Distribution, Abundance, Developmental Time And Life Table Parameters Of Oligonychus Afrasiaticus (Mcgregor) (Acari: Tetranychidae), Papéis Avulsos de Zoologia 52 (10), pp. 121-132 : 121-132

Estimation of O. afrasiaticus developmental time

Oligonychus afrasiaticus juvenile survival and developmental time of males and females were determined when feeding on fruits of Deglet Noor, Alig, Kentichi, Bessr, and Deglet Noor date palm varieties and on sorghum leaves and Deglet Noor pinnae. Dates and pinnae were collected during the period of Kimri stage.

All experiments were conducted in a climatecontrolled room at 27 ± 1°C, 60 ± 10% R.H., and a photoperiod of 16:8 h (L:D). Date Fruits and leaf disks (4 cm) were placed on water saturated foam mat in a plastic tray. Water saturated cotton wool was used to prevent mite escape and maintained leaf freshness. The cotton wool was maintained wet by adding distillate water when necessary.

A few days prior to the starting of the test, for each host plant, fifty Deutonymphal (2 nd nymph stage) females were randomly selected from the corresponding colony and were held separately on each date or leaf disc, after that 2 males were added and allowed to mate. After two days, ten mated females were placed together on each of five of date or leaf disc, to lay eggs. An hour later, all females are eliminated and eggs laid during this space of time are counted. This operation was repeated until the getting of 100 eggs. All these eggs have an age known at almost one hour near. After hatching, larvae were reared on fresh experimental units. Before hatching, eggs were observed at 6-h intervals. After the hatching of larvae, continuous daily observations were made at 6:00 AM and 6:00 PM until they reached maturity .