Acanthiophilus helianthi Rossi (Diptera Tephritidae) on safflower in the Friuli region

Abstract

During the year 1990 a study was carried out in the Friuli region (North-East of Italy) to evaluate the damage incidence and infestation pattern of the grey safflower fly Acanthiophilus helianthi Rossi (Diptera Tephritidae) on six cultivars of safflower (Carthamus tinctorius L.). Four-hundred and eighty secondary flower heads were collected in the field at the beginning of August, about three weeks after the end of the crop flowering. They were dissected in the laboratory to verify the degree of infestation. The number of puparia in 240 flower heads, and the number of undamaged seeds in 120 heads were also counted. An average of 59% flower heads were infested; the average number of puparia per attacked head was 5.4; among the six safflower cultivars no significant differences were observed. The seed loss was evaluated by the equation of the regression line between the number of puparia in the heads and the number of undamaged seeds; the average loss of seeds was 21.8%. The number of puparia in each head fits the A type of Neyman's contagious distribution model with two parameters.