Keywords : yellow date fruits
ANBAR JOURNAL OF AGRICULTURAL SCIENCES,
2015, Volume 13, Issue 1, Pages 373-386
The date dust mite Oligonychus afrasiaticus (McGregor) is one of the main pest that infest date trees in Iraq and cause great quantity and quality losses in dates production if the pest is not controlled.The research delt with the studing of the population density of date dust mite during April – December of the year ( 2013) besides the biology of this mite in the field.
The study revealed that the appearing of this mite was in the begining of April (2013) when hibernated females ( deutogyne ) were appaered , then the population of this might start to increase gradually to reach its peak in middle August , this increasing was synchronized with the gradual temperature increase and with the decreasing of relative humidity , after that the population density of this might begin to decrease when the temperature start in decreasing to reach lowest level in the month December and developed to the females (deutogyne ) in January .
The biological study results on the date leaves, green date fruits (Alkhalal alakhther) and yellow date fruits (Alkhalal alasfar) revealed significant differences between instar grow means of females and males. Significant differences are also appeared between longevity of the females and males , which was longer in females compared with males on the green fruits and yellow fruits ( 14.7 , 11.75) day and (12.81, 11.5 ) day respectively. The results revealed also that is the fecundity of females which grew on green date fruits and yellow date fruits are ( 19 , 28.25 ) egg respectively during their longevity , the preoviposition period of females on the green date fruits and yellow date fruits were ( 1.54 . 0.65 ) day respectively.