EGG DEPOSITION BEHAVIOR IN THE HAPLODIPLOID SAWFLY ATHALIA-ROSAE-RUFICORNIS JAKOVLEV (HYMENOPTERA, SYMPHYTA, TENTHREDINIDAE)

The egg deposition behavior of the turnip sawfly, Athalia rosae (Hymen optera; Symphyta), is described. Both unmated and mated females lay eg gs individually inside of fresh young leaves of cruciferous plants. Du ring an oviposition event, females exhibit a distinct pause in abdomin al contractions just before the actual egg deposition act. Unmated fem ales show a longer pause (11.31 s on average) than mated females (4.38 s on overall average). By employing an eye color mutation, the sex of the eggs laid by females was ascertained, Females mated once lav most ly fertilized (diploid female) eggs initially but begin to lay a consi derable number of unfertilized (haploid male) eggs later in life. The laying of an unfertilized egg is associated with a longer pause (6.98 s on average) than the laying of a fertilized egg (3.76 s on average). These results are in contrast to previous reports on apocritan Hymeno ptera, where the presence of a pause or a longer pause during oviposit ion was associated with the deposition of fertilized eggs rather than unfertilized eggs. The possibility that mated Athalia rosae females co ntrol fertilization and its implications for sex allocation strategies are discussed.