Laboratory and Semi Field Evaluation of Garlic Aqueous Extract as Acaricide Against Two Tetranychid Mites (Acari: Tetranychidae)

Abstract

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), and the carmine spider mite, Tetranychus cinnabarinus (Boisduval), are two of the most important mite pests of different host plants in Egypt. These mites are spreading rapidly because of their resistance to acaricides; therefore, it was necessary to develop a new biological control tactics for mite management. Plant extracts, such as garlic extract (Allium sativum Linn.), may represent easy, available and viable alternative, because they are considered to be minimum-risk pesticides. A series of laboratory and semi-field experiments were considered to determine the susceptibility of adult mite females to different concentrations of garlic aqueous extract (G.A.E.). Mortality was measured upon treatment with five concentrations ranging from 1 to 25% W/V. Female mortality increased with concentration, T. urticae was more tolerant than T. cinnabarinus through laboratory studies as maximum mortality values were 90% and 100% after 24 hours using concentration 25% W/V, respectively. The chemical composition of the Allium sativum aqueous extract was characterized by GC/MS analysis which revealed the occurrence of 33 compounds, of which the major compound was identified as 2-Furancarboxaldehyde,5-(hydroxymethyl). The efficacy of G.A.E. was evaluated against T. urticae and T. cinnabarinus under semi-field conditions. Highest reduction (89.75 %) in T. urticae population was recorded by using concentration 50% W/V one day after treatment (DAT). T. cinnabarinus was more tolerant under the semi-field conditions as the reduction was (80.14 %) using the same concentration. G.A.E. is effective in the control of both tetranychids. It is promising candidates for biological control of these two mite pests.

Toxicological Effects of Garlic Bulbs Aqueous Extract on Two Tetranychid Mites (Acari: Tetranychidae)

“…Whereas the calculated LC 50 after three days of treatment was 14.62(10 3 ) ppm with a toxicity index (Ti= 100) and 17.22(10 3 ) with a toxicity index (Ti= 84.92) for T. cinnabarinus and T. urticae, respectively. Our results are in agreement with Habashy et al (2016) who studied the effect of garlic aqueous extract against T. urticae and T. cinnabarinus and recorded that T. urticae was more tolerant than T. cinnabarinus, in the laboratory. They recorded mortality reached to 90 and 100% after 24 hours of treatment for mites mentioned before, respectively.…”

“…The effectiveness of garlic as a potential biopesticide was highlighted by Dodia et al, (2000) because of the presence of volatile oil which contained diallyl trisulphide, diallyl disulphide, diallyl sulphide, allyl methyl trisulphide, allyl methyl disulphide, and sulphoxides which are derived from allicin. Likewise, (Roy et al 2006;Attia et al 2011;Mohammed, 2013;Habashy et al 2016;Wang et al 2016) recorded the presence of the same organosulphur compounds. <0.0001*** Species X Treatment 0.0017** * showed significantly different (P<0.05) ** showed highly significantly different (P<0.01) *** showed highly significantly different (P<0.0001) ns not significantly different Panella et al (2005) and Isman (2008) recorded garlic extracts as safe because of its little risks to the environment.…”

Prospective of mycorrhiza and Beauvaria bassiana silica nanoparticles on Gossypium hirsutum L. plants as biocontrol agent against cotton leafworm, Spodoptera littoralis

“…AL-Mekhlafi [ 43 ] reported that Paecilomyces lilacinus methanolic extract caused 100% mortality against Aedes caspius after 1 day. Likewise, spores of Metarhizium anisopliae resulted in 98% mortality in spotted spider mite, Tetranychus urticae after 1 week [ 44 ]. As well, Elbanhawy et al [ 13 ] stated that the Purpureocillium lilacinum methanolic extracts from the spores and mycelia displayed insecticidal activity against Aphis gossypii .…”

Acaricidal activity of nishinda (Vitex negundo) leaf and garlic (Allium sativum) bulb extract against red spider mite, Oligonychus coffeae (Acari: Tetranychidae) in tea plantations of Darjeeling hill, West Bengal, India

“…It also consists of 17 amino acids (arginine and others), several enzymes (e.g., allinase, peroxidases, and myrosinase), and minerals (selenium, germanium, tellurium, and other trace minerals) (Newall et al 1996;Omar and Wabel 2010). A large amount of organosulfur substances is responsible for toxic effects of A. sativum (Attia et al 2011;Singh et al 2001;Virtanen 1965;Roy et al 2006;Mohammed 2013;Habashy et al 2016;Wang et al 2016). Binding of the garlic lectin to the glycosylated epithelial membrane of the insect gut is the predetermining factor for insecticidal activity, which has been revealed by the earlier reports (Bandyopadhyay et al 2001).…”