One such study, conducted by Karimi et al. (2010), surveyed the effect of
Heterorhabditis bacteriophora (isolate Iran3) (Rhabditida: Heterorhabditidae) and
M. anisopliae applied simultaneously on second instar larva of white grub,
Polyphylla adspersa (Coleoptera: Scarabaeidae). Results revealed that application
of both pathogens had an additive effect.
Another pest targeted for field trials with fungal entomopathogens was the
rosaceous longhorn beetle, Osphranteria coerulescens (Coleoptera: Cerambycidae).
Mohammadyani et al. (2016) found high mortality in various larval stages of the
beetle. Their results also implied a potential of fungi against the larvae within
galleries. The challenge remains an application method for field usage to maintain
the fungal viability in extreme environmental condition. Another work investigated
the immunological response of the larvae to B. bassiana (Fashand and Ir-k40
isolates) and Cordyceps (Isaria) farinosa (1872c isolate) (Ascomycota:
Hypocreales) (Ajamhassani 2019). There was a variable cellular and enzymatic
response of larvae to different isolates of fungi.
11.6.1 Date Palm Pest
Microcerotermes diversus (Isoptera: Termitidae) is considered as a major pest of
date palm (Phoenix dactylifera L.) trees, in Iran, Iraq and Saudi Arabia. This pest
attacks root, trunk, stem, petiole and cluster of palm. Because M. anisopliae is
considered to be a suitable agent for biological control of this pest Cheraghi et al.
(2012b) investigated whether social behavior of M. diversus, such as grooming, can
be effective in promoting epizootic outbreaks of M. anisopliae in a colony. The
highest mortality of recipient workers was observed after 14 days after being treated
with the concentration of 3.5 Â 10
8 conidia ml
À1 with a donor: recipient ratio of 1:1.
The mortality of recipient workers was less than 20% at all concentrations at a donor:
recipient ratio of 1:9.
Cheraghi et al. (2012a) performed a field experiment in order to evaluate the
efficiency of M. anisopliae (DEMI001) to control a M. diversus population. After
introduction of wooden blocks treated with M. anisopliae, mean density of termites
decreased from 1756 to 691 individuals compared to the control. Mean percentage of
feeding decreased from 59.75 to 27.81 g. They concluded that treatment of wooden
blocks with M. anisopliae is a suitable control method for M. diversus.
Proliferation and virulence of EPFs can be affected by exposure to pesticides.
Shaabani et al. (2015) tested the compatibility of M. anisopliae (DEMI 001) with
imidacloprid (IMI) for control of M. diversus under laboratory conditions. IMI had
no negative effect on conidial germination or mycelial growth. However, sporulation
was progressively reduced as IMI concentrations increased. According to these
results, IMI is reasonably compatible with isolate of DEMI001. In addition, mortality of M. diversus in combined treatments was significantly higher than
non-combination treatments, indicating possible synergistic effects. Dastbarjan
et al. (2016) assessed viability of M. anisopliae conidia in vegetable oil formulations
462
H. Askary et al.
Heterorhabditis bacteriophora (isolate Iran3) (Rhabditida: Heterorhabditidae) and
M. anisopliae applied simultaneously on second instar larva of white grub,
Polyphylla adspersa (Coleoptera: Scarabaeidae). Results revealed that application
of both pathogens had an additive effect.
Another pest targeted for field trials with fungal entomopathogens was the
rosaceous longhorn beetle, Osphranteria coerulescens (Coleoptera: Cerambycidae).
Mohammadyani et al. (2016) found high mortality in various larval stages of the
beetle. Their results also implied a potential of fungi against the larvae within
galleries. The challenge remains an application method for field usage to maintain
the fungal viability in extreme environmental condition. Another work investigated
the immunological response of the larvae to B. bassiana (Fashand and Ir-k40
isolates) and Cordyceps (Isaria) farinosa (1872c isolate) (Ascomycota:
Hypocreales) (Ajamhassani 2019). There was a variable cellular and enzymatic
response of larvae to different isolates of fungi.
11.6.1 Date Palm Pest
Microcerotermes diversus (Isoptera: Termitidae) is considered as a major pest of
date palm (Phoenix dactylifera L.) trees, in Iran, Iraq and Saudi Arabia. This pest
attacks root, trunk, stem, petiole and cluster of palm. Because M. anisopliae is
considered to be a suitable agent for biological control of this pest Cheraghi et al.
(2012b) investigated whether social behavior of M. diversus, such as grooming, can
be effective in promoting epizootic outbreaks of M. anisopliae in a colony. The
highest mortality of recipient workers was observed after 14 days after being treated
with the concentration of 3.5 Â 10
8 conidia ml
À1 with a donor: recipient ratio of 1:1.
The mortality of recipient workers was less than 20% at all concentrations at a donor:
recipient ratio of 1:9.
Cheraghi et al. (2012a) performed a field experiment in order to evaluate the
efficiency of M. anisopliae (DEMI001) to control a M. diversus population. After
introduction of wooden blocks treated with M. anisopliae, mean density of termites
decreased from 1756 to 691 individuals compared to the control. Mean percentage of
feeding decreased from 59.75 to 27.81 g. They concluded that treatment of wooden
blocks with M. anisopliae is a suitable control method for M. diversus.
Proliferation and virulence of EPFs can be affected by exposure to pesticides.
Shaabani et al. (2015) tested the compatibility of M. anisopliae (DEMI 001) with
imidacloprid (IMI) for control of M. diversus under laboratory conditions. IMI had
no negative effect on conidial germination or mycelial growth. However, sporulation
was progressively reduced as IMI concentrations increased. According to these
results, IMI is reasonably compatible with isolate of DEMI001. In addition, mortality of M. diversus in combined treatments was significantly higher than
non-combination treatments, indicating possible synergistic effects. Dastbarjan
et al. (2016) assessed viability of M. anisopliae conidia in vegetable oil formulations
462
H. Askary et al.