| Evaluation of the native egg and larval parasitoids for biological control of Cydalima perspectalis, hopes for neoclassical biological control |
| Paper ID : 1324-3IICE (R1) |
| Authors: |
|
Jalal Shirazi *1, Mohammadreza Attaran2, Zahra Mojib3, Mitra Moezipour4 1PO Box 1454-19858 2IRIPP 3Plnat Protection Dept 4Plant protection Dept |
| Abstract: |
| Hyrcanian Box Tree (HBT) moth, Cydalima perspectalis (Walker) (Lep.: Crambidae) is a new invasive pest in the coastal forests of northern provinces of Iran. The pest defoliates the HBT thoroughly and as season advances it may damage the barks. Therefore, a study was conducted to evaluate the impact of some promising native strains of egg and larval parasitoids towards biological control of C. perspectalis. We initially established a colony of the pest by collecting larval stages from infested HBT and rearing them on fresh HBT leaves using young twigs (~20 cm long with their ends placed in vials containing water) in small plastic boxes (30×20×20 cm) at 25±2 °C, 50±10 % RH and 16:8 h L:D. Eclosed male and female moths were confined in clear cylindrical containers (30×15 cm) and provided with similar HBT twigs. Eggs were collected with leaf pieces and used for experiments or colony recruitment. Simultaneously, 2 colonies of the egg parasitoids, Trichogramma brassicae (Behshar and Mashhad strains coded as BK1 and Tbr, respectively), were reared on Sitotroga cereallela eggs and one colony of Habrobracon hebetor was established on Ephestia kuehniella larvae at the mentioned conditions. In the first experiment, 45 mated T. brassicae female (< 24 h) of each strain (in 3 replicates) were exposed individually to ~20-30 fresh eggs of the HBT moth in glass tubes (10×2 cm). Wasps were removed after 24 h and eggs were incubated at above mentioned condition. Similarly, 30 pairs of newly emerged (< 24 h) H. hebetor were each exposed to a last instar larvae of C. perspectalis in a Petri dish (10 cm diameter) for 48 h. Paralyzed larvae along with the wasp eggs were reared at above mention conditions. Results showed that the Tbr stain accounts for 43 % C. perspectalis egg parasitism followed by 35 % by the BK1 strain. Both strains deposited up to 3 eggs in one pest egg and their progeny sex ratio was extremely female biased (87 %). Moreover, 90% of the pest larvae were paralyzed by H. hebetor. The wasp eggs were hatched and the larvae were fed up to 1st instar but they all died before molting into the next stage. Although our investigations show that the parasitoids have a potential in parasitizing the pest eggs, a comprehensive field trial will substantiate if they play a significant role in controlling the pest population. |
| Keywords: |
| Cydalima perspectalis, Hyrcanian box tree, Trichogramma brassicae, Habrobracon hebetor, Neoclassical biological control. |
| Status : Paper Accepted (Poster Presentation) |
