STUDIES ON CITRUS LEAF MINERS PHYLLOCNISTIS CITRELLA STAINTON

Abstract

Th e present stud ies we re ca rri ed o ut on di fferen t c itrus o rc h a rds ( n ave l o ra n ge. sweet o ra nge. va l en cia o ra nge. ba l a di o ra n ge. ma ndar in. g ra pefr u i t a n d l e m on ) in Sh a rkia Governo ra te d u rin g two s uccessi ve seasons 1 997 I 1 998 an d 1 998 I 1 999. u nd er fi el d a nd labo ra to ry conditi ons. Th e o bta in ed res ults ca n be s u m ma rized as fo llows: The bi o l og-v of diffet:e n t stages of t h e cit rus l eaf mi n ers Phy!Locnistis cirre!La we re i nvest i gated und e r field co nd iti o ns o n ( n avel ora nge. m a n darin a n d lem on) w hil e it was onl y on th e m a nda rin seed l ings in l a bo rato ry co n d iti o ns. The res ults c l ea rl y indi ca ted t h a t th e tota l develop m e ntal period of im matu re stages ra n gebetween 1 4.7-1 7.7 days. A l so eco l og i ca l s t udies on (CLM) i nc l uded : a) Th e popul a ti o n de ns it y a nd seaso na l flu c tua ti o ns of C L M during 1 99711998 a n d 1 99811999 seaso ns. b) Th e host p refe rence of CL M. c) Assess m en t of eco n o mi c thresh ol d a nd inj ury level s o n certa in c itru s s peci es. d ) Th e effect of certai n c l i ma ti c factors o n the po pul ation de nsity of CLM.