Termites are eusocial insects that are found on all
continents except Antarctica. Termites have serious destructive
impact, damaging local huts and crops of poor subsistence. The
annual cost of termite damage and its control is determined in the
billions globally. In Egypt, most of these damages are due to the
subterranean termite species especially the sand termite, P.
hypostoma. Pyrethroids became the primary weapon for subterranean
termite control, after the use of chlorpyrifos as a soil termiticide was
banned. Despite the important role of pyrethroids in termite control,
its extensive use in pest control led to the eventual rise of insecticide
resistance which may make many of the pyrethroids ineffective. The
ability to diagnose the precise mechanism of pyrethroid resistance in
any insect species would be the key component of its management at
specified location for a specific population. In the present study,
detailed toxicological and biochemical studies was conducted on the
mechanism of pyrethroid resistance in P. hypostoma. The
susceptibility of field populations of P. hypostoma against
deltamethrin, α-cypermethrin and ƛ-cyhalothrin was evaluated. The
obtained results revealed that the workers of P. hypostoma have
developed high resistance level against the tested pyrethroids. Studies
carried out through estimation of detoxification enzyme activity
indicated that enhanced esterase and cytochrome P450 activities were
probably important mechanisms for pyrethroid resistance in field
populations. Elevated esterase activity and also additional esterase
isozyme were observed in the pyrethroid-resistant populations
compared to the susceptible populations. Strong positive correlation
between cytochrome P450 activity and pyrethroid resistance was also
reported. |Deltamethrin could be recommended as a resistancebreaking
pyrethroid that is active against resistant populations of P.
hypostoma.