The impact of Smicronyx cyaneus Gyll. and Phytomyza orobanchia Kalt. in some phenological parameters of Orobanche ramosa L. in tomato fields

The impact of larvae feeding of of the agromyzid fly (Phytomyza orobanchia Kalt., and curculionid weevil (Smicronyx cyaneus Gyll.), inside shoots and seed capsules of branched broomrape (Orobanche ramosa L.) which infested tomato, in some phenological parameters: shoot length, number capsules/shoot, wet and dry weight of shoot, were determined. The results indicate to the efficacy of larvae feeding in reduction of O. ramosa bio-mass, it caused significant reduction in the values of all studied parameters, of infested branched broomrape plants in comparison to healthy ones, While the mixed infestation of the both insects caused higher reduction in the values of these parameters, with high significant differences in: shoot length, number capsules/ shoot, and wet weight of infested shoot, in comparison with healthy ones. the reduction rate which resulted from mixed infestation reached to 55.5%, 58.8%, 76.7%, 57.2% for shoot length, number capsules/ shoot, wet weight and dry weigh respectively. The results indicate to the potential role of P. orobanchia and S. cyaneus in reduction the density of O. ramosa in tomato fields, at the Syrian coastal region.

A study of some biological parameters of Phytomyza orobanchia Kalt. under laboratory conditions

A biological study of Phytomyza orobanchia Kalt on branched broomrape (Orobanche ramosa L.) which infest tomato crop, in the coastal region of Syria, was conducted during 2011/2012 growing season. It included a study of some biological parameters: The preoviposition, oviposition, post oviposition, total number of eggs laid per female, and total developmental period, at 25 ± 1ºc, 30 ± 1ºc and 70±5% RH. The results showed that the fertilized females insert their eggs singly in the flowers (seed capsules) and sometimes in the shoots of O. ramosa. The average of the total number of eggs per female was 12.90 ± 5.41, 13.50 ± 7.53 at 25 ± 1ºc, 30 ± 1ºc, respectively, without significant differences. The preoviposition period was 3.60 ± 0.79 day at 25 ± 1ºc, and decreased to 1.90 ± 0.32 day at 30 ± 1ºc with significant differences. The average values of other biological parameters (oviposition, post oviposition) were higher at 25 ± 1ºc, without significant differences. This insect has three larval instars, and the larvae complete its development and pupate inside seed capsules. the developmental period of pupa for female was shorter than pupa for male, and the total developmental period of P. orobanchia occupied 18.5 ± 3.49, 17.75 ± 2.99 day for male, and 17.7 ± 2.93, 16.7± 2.6 day for female at 25 ±1ºc, 30±1ºc respectively.