| Sublethal effects of Metarhizium anisopliae (Asc.: Hypocreales) on biological parameters of Aphis gossypii (Hem.: Aphididae) |
| Paper ID : 1174-3IICE (R1) |
| Authors: |
|
zahra alizadeh *1, Amin Sedaratian-jahromi2 1Iran - Kohgiluyeh and Boyer Ahmad - Yasuj Street Student, Yasouj University 2Plant Protedtion Dept., Yasouj University |
| Abstract: |
| Aphis gossypii Glover is one of the most important pests of the Cucurbitaceae, causes severe damage to host plants either by direct feeding from plant sap or transmission of plant viruses. The common method for controlling this pest is chemical insecticides. However, since development of resistance to chemical pesticides in different populations of this pest as well as their undesirable effects, attentions have been changed toward the use of environmentally friendly compounds and biological agents. In this study, sublethal effects (LC10, LC20, LC30) of MYG-101 strain of entomopathogenic fungus Metarhizium anisopliae Sorokin were evaluated on biological parameters of A. gossypii females and their offspring under laboratory conditions at 25 ± 1 °C, 65 ± 5% RH and 16: 8 h L: D. In each treatment 100 individuals were studied. Distilled water together with Tween 80 (0.02%) was considered as control. Data analysis was performed using Age-stage two sex life table theory. Sublethal treatments significantly increased fecundity and longevity of treated females. The highest recorded values of female fecundity (70.66 nymph) and longevity (14.91 day) were recorded at LC30 treatment and the lowest recorded values obtained at LC10 (52.45 nymph and 11.41 day, respectively). According to the results obtained, biological parameters of offspring from treated females were also significantly affected by sublethal treatments. The highest and lowest estimated values of net reproductive rate (R0) were recorded at LC10 and LC20 (75.05 and 52.46 offspring, respectively). The highest value of intrinsic rate of increase (r) was recorded at LC30 (0.506 day-1) and the lowest value (0.485 day-1) was observed in control. The calculated values of finite rate of increase (λ) were also significantly affected by sublethal treatments and the highest and lowest values of this parameters were obtained at LC30 (1.66 day-1) and control (1.62 day-1), respectively. The maximum value of mean generation time (T) was recorded at LC10 (8.68 day). Our findings revealed that in management program of A. gossypii more attentions should be devoted to sublethal effects of M. anisopliae. |
| Keywords: |
| Entomopathogenic fungi, Biological parameters, Biological control, Integrate management |
| Status : Paper Accepted (Poster Presentation) |
