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Accueil du site → Doctorat → Pakistan → ENTOMOPATHOGENS AS POTENTIAL BIOCONTROL AGENTS AGAINST RED PALM WEEVIL, RHYNCHOPHORUS FERRUGINEUS (OLIVIER)

University of Agriculture, Faisalabad (2016)

ENTOMOPATHOGENS AS POTENTIAL BIOCONTROL AGENTS AGAINST RED PALM WEEVIL, RHYNCHOPHORUS FERRUGINEUS (OLIVIER)

YASIN, MUHAMMAD

Titre : ENTOMOPATHOGENS AS POTENTIAL BIOCONTROL AGENTS AGAINST RED PALM WEEVIL, RHYNCHOPHORUS FERRUGINEUS (OLIVIER)

Auteur : YASIN, MUHAMMAD

Université de soutenance : University of Agriculture, Faisalabad

Grade : Doctor of Philosophy (PhD) 2016

Résumé
The red palm weevil red palm weevil Rhynchophorus ferrugineus (Olivier) (Coleoptera : Curculionidae) is one of the voracious pest among invasive insect pests. Pakistani populations of R. ferrugineus distributed among different areas have been found genetically diverse. Four different haplotypes were recorded across Punjab and Khyber Pakhtunkhwa (KPK) provinces. Haplotype H1, H5, H51 were found from all collection sites while H52 was rare haplotype that was only present in populations of Layyah and Dera Ghazi Khan only. Study indicated the native range of R. ferrugineus instead of invaded from other parts of the world, since the weevil was recorded from Pakistan in 1913 and may have been present before that. The populations of R. ferrugineus have gained resistance to commonly used chemical insecticides and phosphine due to the excessive and unwise use of these chemical insecticides. Resistance against seven different populations of R. ferrugineus was determined from very low to low and moderate to high level of resistance against commonly used insecticides. Phosphine, cypermethrin and deltamethrin exhibited high resistance against almost all the populations. To overcome the insecticide resistance entomopathogens were evaluated against R. ferrugineus. Nineteen different isolates of Beauveria bassiana s.l. and Metarhizium anisopliae s.l. (Ascomycota : Hypocreales) were screened which exhibited varying level of susceptibility towards larvae and adult. Three isolates of B. bassiana (WG-41, WG-42 and WG-43) and two isolates of M. anisopliae (WG-44 and WG-45) exhibited highest larval and adult mortality after 12 days of application and the same isolates were tested for their virulence at different exposure intervals against larvae and adult which caused almost 100% mortality for certain isolates. B. bassiana are capable of colonizing endophytically in live date palm petioles even after 30 days of inoculation and can significantly reduce the weevil population when exposed to the endophytically colonized date palm petiole pieces. Moreover Bacillus thuringiensis var. kurstaki (Bt-k) is also an effective agent that can cause detrimental effects on R. ferrugineus survival alone and in combination with endophytically colonized date palm. Both agents exerted influence on developmental parameters such as larval duration, larval weight, pre-pula duration, pre-pupal weight, pupal duration, pupal weight, adult longevity (male and female) and adult weight (male and female) etc. Moreover, diet consumption, frass production and weight gain was affected by the treatments applied. Entomopathogenic fungi in integration with Heterorhabditis bacteriophora Poinar applied either simultaneously or in sequential manners exert detrimental effects on growth and development of R. ferrugineus larvae. Combined application of three agents i.e. B. bassiana, Bt-k and H. bacteriophora also suppress the larvae and adult population collected from 4 different areas of Punjab and KPK, Pakistan under laboratory conditions. Hence we can use microbial entomopathogens against this voracious pest which are safer to human beings and compatible to environment.

Présentation (Pakistan Research Repository)

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Page publiée le 10 mai 2019