Molecular identification of two entomopathogenic fungus Clonostachys rosea strains and their efficacy against two aphid species in Iraq

Abstract

Background The green peach aphid, Myzus persicae Sulzer, and the bean aphid, Aphis fabae Scopoli (both Hemiptera: Aphididae), are serious pests of greenhouse vegetable crops in Iraq and other regions of the globe. In this study, two morphological identical isolates (AA80 and AA82) of the entomopathogenic fungus Clonostachys rosea Schroers (Hypocreales: Bionectriaceae) from Iraq were isolated and characterized with phylogenetic analysis based on the internal transcribed spacer (ITS) region. The efficacy of C. rosea against M. persicae and A. fabae was previously unknown. Results In the laboratory bioassays, mortality of adult M. persicae and A. fabae caused by both C. rosea isolates varied according to conidial concentrations, with complete mortality occurring at 1 × 109 conidia ml−1 10 day post treatment. For M. persicae, LC50 values of AA80 and AA80 isolates were 3.6 × 106 and 3.8 × 106 conidia ml−1. For A. fabae, LC50 values of AA80 and AA80 isolates were 4.5 × 106 and 4.35 × 106 conidia ml−1. Infection by both fungal isolates at LC50 values reduced total fecundity of the treated aphids by 20% when compared to the untreated aphids. Conclusions The results from laboratory bioassays showed that C. rosea has potential as a biological control agent of M. persicae and A. fabae which is crucial for ecofriendly biopesticide development. However, further field and greenhouse studies are required for mass production.

Filtration effect of Cordyceps chanhua mycoderm on bacteria and its transport function on nitrogen

“…C. chanhua strain was inoculated on PDA medium and activated in a constant temperature incubator at 25°C, and 0.05% Tween 80 solution was used to prepare the target concentration of 5 × 10 7 conidia/mL. Pupae of Antheraea pernyi Guérin-Méneville, sourced from the Dandong City Artificial Sericulture Base (Liaoning, China), were selected as host insects (cultivation medium) for C. chanhua , referring to Zeng et al ( 3 ) method of surface disinfection of A. pernyi : wash the surface of A. pernyi with tap water, and dry it naturally; soak in 75% alcohol in the sterile super clean table, and scrub the insect surface with cotton for about 10 s; then rinse it with sterile water, clip it into a white porcelain plate covered with sterile paper towels, and dry the surface water; and suck 0.02 mL of prepared conidia suspension, and inject it into the third ring just behind the wing of the tussah pupa ( 63 ). The inoculated silkworm pupa is clamped into a sterile glass bottle and cultured in a dark place at 25°C.…”

Isolation and Identification of Fungal Species from the Insect Pest Callosobruchus maculatus (F.)

“…As there are clear differences in the molecular weight of fungi species by ITS5 and ITS4 primer were used, this agrees with most references that used ITS1-5.8S-ITS2 region of fungal rDNA by ITS5 and ITS4 primer 22 . While there are several references were used for ITS1 and ITS4 primer for ITS1-5.8S-ITS2 region of fungal rDNA to the identification of entomopathogenic fungi [5,18,4] were isolated twenty-one entomopathogenic fungi, the resulting from the electrophoresis of the PCR product using the universal primer for the amplification of ITS rRNA gene of bands with a size of 650 bp. Also, Gebremariam et al 9 used ITS1 and ITS4 primers to identify Beauveria bassiana and Metarhizium anisopliae with a band size of 545 bp.…”

Effect of Diatomaceous Earth (DE) Against the Stored Product Beetles, Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae) under Laboratory Conditions

“…Residual pesticides are stored grain's record commonly a protectant against stored-product insects. These pesticides are applied directly to the product and protect against stored-grain pests if the insecticidal effect persists [7,8] .However, [9] states that using these protectants stances numerous problems, as they usually leave residues in the product and are toxic to mammals; additionally, several insect species are unaffected by some residual protectants. This led many researchers to assess the possible practice of other control methods because of limitations, such as growth regulators of insects, botanicals, microbial methods, inert dust, and biological methods.…”