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Virulence of 11 native strains of entomopathogenic fungi; Metarhizium anisopliae (three strains), Beauveria bassiana (six strains) and Lecanicillium psalliotae (two strains) collected from different parts of Iran, were studied against different developmental stages of Rhipicephalus (Boophilus) annulatus. After the exposure of ticks to the fungal strains in different concentrations (i.e. 10(3), 10(5), 10(7) conidia/ml), various parameters such as mortality rate and reproductive efficiency of engorged females, mortality of unfed tick larvae and eclosion percentage of infected eggs were evaluated to determine the fungal virulence. Based on the obtained results, five strains including M. anisopliae (IRAN 437 C and DEMI 001), B. bassiana (IRAN 403 C) and L. psalliotae (IRAN 468 C and IRAN 518 C) were found to be virulent to various stages of tick developmental cycle. Mortality rate of engorged females was found to be dose-dependent with regard to the conidial concentration used. Total mortality rates of 90-100%, 70% and 56.6% were observed for M. anisopliae (IRAN 437 C and DEMI 001), B. bassiana (IRAN 403 C) and L. psalliotae (IRAN 468 C), 6-11 days post inoculation (PI) with 10(7) conidia/ml, respectively. Most strains were able to inhibit egg laying by females in the range of 0-26% in different conidial concentrations. The results indicated that the mean egg laying of treated engorged tick females exposed to M. anisopliae (IRAN 437 C) was less than the mean values of those treated with other fungal strains. Results revealed 89.1%, 35.5% and 56.3% decrease in egg hatchability and 88.69%, 78.15% and 59.74% reduction in reproductive efficiency of the ticks using 10(7) conidia/ml of M. anisopliae (IRAN 437 C), B. bassiana (IRAN 403 C) and L. psalliotae (IRAN 468 C), respectively. In general, the entomopathogenic effects of native M. anisopliae and B. bassiana against various developmental stages of R. (B.) annulatus were confirmed in the present work. Likewise, although L. psalliotae, which was introduced for the first time as an entomopathogenic fungus against tick had not more than 13.3% mortality effect against adult females, but its effect on egg hatchability and reproductive efficiency was remarkable.

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Commercial feedstuffs are an important component in a modern aquaculture industry. Mycotoxin contamination of fish feeds represents a hazard to aquatic animals and human health. This study aimed to determine the mycoflora, aflatoxigenic strains of Aspergillus section Flavi, and occurrence of aflatoxins in fish feed samples. A total of 86 fish feed samples consisting of pellet, extruder, and scramble samples were collected from feed processing industries and fish farms in Iran. Identification of fungi, in vitro production of aflatoxins by Aspergillus section Flavi strains, and analysis of aflatoxins were done according to standard and established methods. The mean total fungal counts ranged between 2.16 and 4.74 log cfu/g in samples; and 2 samples (2.33%) exceeded the hygienic quality limit, i.e. 4 log cfu/g. Aspergillus was the predominant detected genera followed by Penicillium and Fusarium. Among the Aspergillus species, Aspergillus flavus was the most prevalent species, followed by Aspergillus parasiticus, Aspergillus niger, and Aspergillus ochraceus. All the A. parasiticus isolates and 48.1% of the A. flavus isolates produced aflatoxins in vitro. Contamination with aflatoxins were detected in 58 feed samples (67.5%), ranging between 0.46 and 68.5 µg/kg. The results revealed that the frequency of contamination with aflatoxins and prevalence of aflatoxigenic fungi in such a level can be a potential hazard for the aquaculture industry and human health. Regular monitoring of mycotoxins specially aflatoxins in feed supply chain can improve the situation through reducing economic losses and minimizing hazards to the public health.

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