Two more motorcyclists were killed on WA's roads, on Sunday, adding to the state's grim record-high death rate for motorbike riders for the year.
Police believe a 29-year-old man from Mundijong who crashed in Forrestdale may have been affected by a bee sting he received earlier.
His Suzuki motorcycle was travelling on Armadale Road when it appeared to have struck the centre island, according to police.
Members of the public went to his aid, including an off-duty police officer who administered CPR.
He later died at Kelmscott Hospital.
In another incident, a 58-year-old man died after his Triumph motorcycle collided with a Nissan Patrol ute in Dardanup.
The number of motorcylcists who died on WA roads so far this year is 41.
At about 3.50pm on Sunday the rider, from Wellington Mill, was heading east on Ferguson Road when he entered a left-hand bend on the road just before the intersection at Hayward Street.
"At the same time a Nissan Patrol utility was travelling west on the same road and was also entering the same bend. It appears the vehicles made contact side-on," a police spokesman said.
"The impact caused the Nissan vehicle to slide out of control and the motorcycle rider to fall from the motorcycle."
Anyone with information regarding this crash, or who saw either of the vehicles involved prior to the crash, is asked to call Crime Stoppers on 1800 333 000.