Hacer Handan Altinok, Mahmut Alper Altinok, Abdurrahman Sami Koca
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Biological control, Fungi, Mycoinsecticide, Pest management
Commercial formulations of entomopathogenic fungi are successfully applied as an alternative to chemical agents in control of agricultural pests. One of the major properties of these species is building resting spores under unfavorable environmental conditions and having facultative or saprophytic properties. Mitosporic fungi such as Beauveria bassiana, Lecanicillium lecanii, Metarhizium anisopliae and Isaria fumosorosea are common species worldwide and capable of infect species from Lepidoptera, Hemiptera, Coleoptera and Diptera. Entomopathogenic fungi infests the host insects via digestion, respiration and through integument. In infestation from integument which is one of the most common infestation methods, fungi grows hyphae to penetrate epicuticle and progresses into hypodermis to achieve the infestation. Anamorphic fungi like B. bassiana and M. anisopliae primarily propagates as blastospores rather than hyphal development and these blastospores invade the vital organs by dispersing across the insect body via circulation of hemolymph within body cavity and eventually result in death of insect by clogging the circulatory system. The fungus moves to facultative feeding phase after death of host and initiates hyphal development outwards the integument, builds massive amount of spores. Conidiospores found on conidiophores are utilized to establish new infestations. Some entomopathogenic fungi are capable of killing the host even faster by excreting some mycotoxins (like beauvericin, cyclodepsipeptide, destruxin and desmethyldestruxin) at earlier stages of the infestations. Toxigenic fungi are able to kill the host earlier as compared to non-toxigenic species. In this study, information on the mechanisms used by entomopathogenic fungi for infestation of their hosts are presented.
