| Low temperature storage of Iranian population of predatory midge, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) |
| Paper ID : 1019-3IICE (R1) |
| Authors: |
|
Khadijeh Madahi *1, Ahad Sahragard1, Reza Hosseini1, Valiollah Baniameri2 1Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan Rasht. Iran. 2Agricultural Entomology Research Department, Iranian Research Institute of Plant Protection, Agricultural Research, Education and Organization (AREEO), Tehran, Iran. |
| Abstract: |
| The predatory midge, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae) is widely used for the biological control of aphids in many agricultural systems. This study was conducted to investigate the best temperature and storage time to maintain the larvae of Iranian population of A. aphidimyza for longer periods. First, the larvae of A. aphidimyza were collected from colonies of A. gossypii on rose mallow shrub, Hibiscus syriacus (L.) at the campus of the Faculty of Agricultural Sciences, University of Guilan and were reared for at least three generations on A. gossypii consumed on squash (Rajaei cultivar) in cages (1×1×1 m) in greenhouse conditions (24± 5 °C, 70± 10% RH and natural photoperiod). Then, final-day larvae were stored at 1, 2, 3, 4, 6, 8, 10, 12, 16, 20 and 22 weeks at 0, 5 and 10 °C in total darkness and at 70±5 % R.H., with a previous acclimation period and induction of diapause (3 days at 15 °C and 13:11h L:D). For each storage duration at each temperature, the experiment was replicated 10 times. Each replicate consisted of 20 diapause induced larvae in vermiculite in plastic containers (19×16×6 cm). One control group with 10 replicate, each consisted of 20 larvae of A. aphidimyza was maintain in laboratory conditions without any acclimation and cold storage (24± 1 °C, 70± 5% RH and 16:8h L:D). Differences between each treatment and control were compared using t-test by SAS 9.2. According to the obtained results, storage of predator at 5°C for 2 weeks had no effect on total adult emergence, however, longer storage time resulted in decrease of emergence. In all storage periods, total adult emergence of A. aphidimyza was significantly affected by storage at 0 and 10°C. Moreover, synchronous emergence of adults (the adult emergence percentage in first 4 days) was affected by predator storage at 0, 5, and 10°C for different periods. The storage of gall midges at 0, 5 and 10°C, respectively for 1, 2 and 1 week(s) had no effect on their fecundity. Longer storage time led to significant effects on fecundity of A. aphidimyza. On the other hand, according to IOBC standard for this predator (total adult emergence>70% and fecundity>40 eggs per female), it can be suggested that diapause induced larvae of A. aphidimyza kept at 0 or 10°C for 1 month or at 5 °C for 2 months could provide promising results. |
| Keywords: |
| Acclimation, Aphidoletes aphidimyza, Biological Control, Cold storage, Diapause |
| Status : Paper Accepted (Poster Presentation) |
