Abstract :
The safflower fly is one of the most important pests of safflower in Iran. Losses
caused by larval feeding leads to disrupted plant activities, reduction in flower buds, and, ultimately,
to decreased quality and quantity of crop. This study was conducted on Acanthiophilus helianthi
Rossi (Diptera: Tephritidae) at the Gachsaran Agricultural Research Station in Iran from November
2008 to July 2009. Sampling was performed weekly using a two-stage cluster sampling method.
For the life cycle studies, the infected flower heads were collected from an experimental field plot
and were developed in cages (160×160×100 cm) from egg to adult under laboratory
conditions(27±2°C; relative humidity, 60%; and 16/8 L:D).The results showed that the first adults
emerged gradually in mid April 2009. Female A.helianthi had a pre-oviposition period of 5.8 ± 1.0
days and the average fecundity was 27 ± 3.2 eggs. The Eggs were laid in the bracts of flower
heads singly or in clusters of 3-18. The Incubation period was 3.8 ± 0.6 days under field conditions
and 3.4 ± 0.6 days under cage conditions. The egg dimensions were 1.19 × 0.19 mm. Three larval
instars occurred, and the larval phase was 7-10 days. The mean body dimensions (L × W) of larvae
were 4.79 × 1.71mm. Pupa were coarctate and become sluggish before last molt. The pupal period
was 7.5 days (range,6-9 days). The mean pupal dimensions of male and female cocoons were 3.95
× 1.42 and 4.55 × 2.27 mm, respectively. The flies spent their entire lifespan from egg to adult
inside the flower heads of safflower plants. Males emerged earlier than females, but the longevity of
the adult females (12 ± 3.0) was significantly greater than that of males (8 ± 1.0).
