(Fron) Deighton, the cause of eye spot disease of cereals. Biocontrol Science Technology 3, 13-19.
Screening of selected fungi for antagonism towards Pseudocercosporella herpotrichoides (Fron) Deighton, the cause of eye spot
. , Ongena , M. , Halimi , B. , Lara , Y. , Brans , A. , Joris , B. and Fickers , P. ( 2009 ): Bacillus amyloliquefaciens GA1 as a source of potent antibiotics and other secondary metabolites for biocontrol of plant pathogens . Microb. Cell
): Oviposition behaviour of Bracon brevicornis Wesmael (Hymenoptera: Braconidae) . Agric. Res. J. Kerala , 18 , 239 – 241 .
Rukshana , K. and Majeed , P. P. ( 2014 ): The effectiveness of biocontrol of Opisina arenosella (Lepidoptera: Oecophoridae
Byeon, Y. W., Tudam, M., Kim, J. H. and Choi, M. Y. (2011): Functional responses of aphid parasitoids, Aphidius colemani (Hymenoptera: Braconidae) and Aphelinus asychis (Hymenoptera: Aphelinidae). Biocontrol Science and Technology 21, 57
A total of 36 UV-induced mutants with altered colony morphology were isolated from strain
T334, a potential biocontrol agent against plant pathogenic fungi with the ability to produce constitutively low levels of chitinases. The level of constitutive
-acetyl-glucosaminidase production in standing and shaken cultures under non-inductive conditions was tested in mutants and compared to that of the parental strain. About 30% of the mutants showed significantly increased levels of enzyme production, with strain T334 col26a being the best producer. This mutant and the parental strain were subjected to
confrontation assays with plant pathogenic
Fusarium culmorum, Pythium debaryanum
strains. The mutant derivative could be characterized by significantly higher biocontrol index values than the parental strain in each experiment, suggesting, that mutants with improved constitutive extracellular chitinase secretion could be applied for biocontrol purposes against fungal plant pathogens.
Chaetomium globosum Kunze Ex. Fries has been identified as a potential antagonist of Bipolaris sorokiniana and Ascochyta rabiei. Nine isolates of this biocontrol agent were characterized based on RAPD technique using 40 random primers of OPB and OPM series, out of which 24 primers gave a total of 356 amplification products, showing 91% polymorphism. RAPD analysis revealed that C. globosum isolates taken under study formed genetically two distinct clusters, with isolates Cg2, Cg3 and Cg4 in one cluster and the remaining isolates in another cluster, which in turn was grouped separately into two subclusters separating isolates Cg6 and Cg8 from Cg1, Cg5, Cg7 and Cg9. Similarity matrix indicated that Cg1 and Cg2 were genetically distinct as they showed only 29.4% similarity followed by Cg2 and Cg7 showing 31.1% similarity, while isolates Cg7 and Cg9 were found to be genetically similar with 68.9% similarity index.
Authors:M. Bayoumy, A. Abdel-Kareim and A. Abdel-Salam
Laboratory studies were conducted to assess 1) the ovipositional preference of Encarsia citrina for host’s age by exposing it to 5–20-day-old scales 2) the effect of temperature (17.5, 20, 25, and 28 °C) and parasitoid density (1, 2, 3, 4, and 5 females/30 2nd instar) on host foraging efficiency of E. citrina. E. citrina significantly preferred 10-day-old scales with the highest emergence rate. Temperature had significant effect on the searching efficiency of E. citrina over the range of 17.5–28 °C. The highest rate of search was obtained at 20 °C. Although the increase in parasitoid density at 20 °C reduced the progeny production in E. citrina, due to the increase of mutual interference, it was able to distribute its progenies among the hosts more regularly. The highest values of killing power (k-value) were also obtained at 20 °C and the ratio of 4 parasitoid females/30 hosts. The shortest and longest handling time (Th) was measured at 20 and 17.5 °C, respectively. Accordingly, 20 °C is suitable condition to Encarsia reproductive and activity. E. citrina seems to be a promise candidate to control U. euonymi from late spring to early summer as well as during autumn, where the temperature is frequently around 20 °C. Therefore, parasitoid releases within this period on the early 2nd instar (10 days old) with a ratio of 1 parasitoid: 7.5 hosts have to be considered in the future biocontrol program of U. euonymi.