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Abstract
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White grubs and Elm leaf beetle are two economically important major pests of
landscapes and parks in the most cities of Iran. These pests detrimentally affect wide range of
trees. Ecologists believe that establishing landscape and parks can be of advantage to the
environment and provide conditions for healthier life. In such places chemical based control
of pests is severely prohibited not only for environmental pollutions but also due to higher
hazards and risks to human. Therefore replacing the pesticides with efficient environmentally
friendly approaches has critical importance. White grubs are among the most destructive
pests of landscapes and parks. Immature stages chew off the roots of plants. Depends on the
host, white grub damage typically appears as stunted, wilted, discolored and death of plant. In
the current study, two year old Polyphylla olivieri larvae were exposed to native isolate of an
entomopathogenic nematode, Heterorhabditis bacteriophora in filter paper assay by which
individual larva was subjected to 1 ml of two concentrations of infective juveniles (IJs)
including 500 and 1000 IJs/ml. The experiment was run twice with four replications. Each
replication included 10 individuals of white grub larvae. Mortality was recorded after 48 h at
one day intervals for four days. Results revealed that larval mortality was non-significant
between IJs concentrations. In filter paper assays recording mortalities at successive days
were 40, 80, 80 and 100%, respectively. In another experiment, the elm leaf beetle,
Xanthogaleruca luteola, was used in the experiments. Six day old larvae of elm leaf beetle
were involved in leaf assay. Twenty four-well plates lined with 2 layers of filter paper were
loaded with concentrations of 32.5, 65, 130, 260, 520 and 1040 IJs/L. Then individual larva
were added to each well. One 24-well plate was considered as a replication. The LC50-values
were calculated using probit analysis at 36, 48 and 72 hours of larval exposure to t
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