| Effect of temperature on biology and life table parameters of Dicrodiplopsis manihoti Harris, by feeding on Phenacoccus solenopsis Tinsley |
| Paper ID : 1099-3IICE (R1) |
| Authors: |
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Mojtaba Zilai1, Leila Ramezani1, Sara zarghami *2 1Department of Plant Protection, Faculty of Agriculture, Ramin Agriculture and Natural Resources University of Khuzestan, Iran 2Date Palm and Tropical Fruits Research Center Horticultural Science Research Institute Agricultural Research, Education and Organization (AREEO) |
| Abstract: |
| The Phenacoccus solenopsis Tinsley (Hem., Psedococcidae) is one of the most destructive pests of cotton and many other crops in the world. It has been recently reported from South and Southwest of Iran. The predatory gall midges, Dicrodiplopsis manihoti Harris (Dip., Cecidomyiidae) can be a good candidate for biological control of the pest. In this research, the effect of temperature on the biology and life table parameters of D. manihoti was evaluated at five constant temperatures (17, 22, 27, 32 and 37 ± 1 0C, 65 ± 5 % RH, and 14: 10 (L: D) using Hibiscus rosa-sinensis L. leaves as plant host. The data were analyzed using the age-stage, two-sex life table method. The results showed that D. manihoti is inactive at 17± 1 0C. Out of the cohort of 361, 178, 186 and 217 eggs at the beginning of each experient, 130, 164, 128 and 139 eggs hatched at 22, 27, 32 and 370C, respectivelly. The duration of total pre-adult stage decreased with the increase in temperature and was 36.12, 24.09, 14.96 and 12.68 days at 22, 27, 32 and 37 0C, respectively. The oviposition period was not affected significantly at all temperatures, however, females laid an average of 23.65, 11.14, 12.32, 8.57 eggs at these four temperatures, respectively. Female and male adult longevities were significantly longer at 22°C compared with those of other temperatures. As temperature elevated values of the intrinsic rate of increase (r) leveled up as 0.0247, 0.0291 and 0.0374 d-1 at 22, 27 and 32°C, respectively. At 37°C, however, there was a reduction in r ( 0.0103 d–1). There was no significant difference in the finite rate of increase (λ) at all temperatures. The net reproductive rate (R0) was not significantly different at 22, 27 and 32°C (2.62, 2.19 and 2.15 offspring) and then significantly decreased at 37°C (1.18 offspring). The longest mean generation time was recorded at 22°C (38.28 days) and the shortest at 37°C (14.88 days). According to these results, the optimal temperature for activity of this predator was 32°C. It can be concluded that D. manihoti successfully survives and reproduces at warm climatic conditions of Khuzestan province and is capable to playa useful role in the biological control of mealybugs specially P. solenopsis. Complementary studies are suggested on mass production methods of the predator. |
| Keywords: |
| Dicrodiplopsis manihoti, Phenacoccus solenopsis, Temperature, Two-sex life table, Biological control |
| Status : Paper Accepted (Poster Presentation) |
