Canarian Weekly
31-05-2013, 11:50
OCKROACHES must be the biggest bugbear for residents and holiday-makers alike in Tenerife.
But there is bad news for those people who believe they have these horrible – if harmless – bugs under control by trapping them with sugar.
.American scientists have discovered that cockroaches have somehow been able to define that the glucose used to coat poisoned bait as bitter rather than sweet.
A team from North CarolinaStateUniversity have tested their theory by giving cockroaches a choice of jam or peanut butter. They then analysed the insects’ taste receptors, which are similar to our taste buds.
Researchers from the same team first noticed 20 years ago that some pest-controllers were failing to eradicate cockroaches from properties, because the insects were simply refusing to eat the bait.
Believe it or not, there are about 4,600 species of cockroach and fewer than 30 of these are considered pests.
Dr Coby Schal told the Science journal that this new study revealed the “neural mechanism” behind this refusal.
Researchers in the first part of the experiment offered the hungry cockroaches a choice of two foods – peanut butter or glucose-rich jam.
“The jam contains lots of glucose, while the peanut butter has a much smaller amount,” said Dr Schal.
“You can see the mutant cockroaches tasting the jam and jumping back – they’re repulsed and they swarm over the peanut butter.”
In the second part of the experiment, the team discovered exactly why the cockroaches reacted that way,
The cockroaches were immobilised and the scientists used tiny electrodes to record the activity of taste receptors – cells which respond to flavours that are “housed” in microscopic hairs on the mouths of insects.
“The cells that normally respond to bitter compounds were responding to glucose in these cockroaches, so they were perceiving glucose to be a bitter compound,” said Dr Schal.
More... (http://www.canarianweekly.com/ugh-theres-sweet-dreaded-cockroaches/)
But there is bad news for those people who believe they have these horrible – if harmless – bugs under control by trapping them with sugar.
.American scientists have discovered that cockroaches have somehow been able to define that the glucose used to coat poisoned bait as bitter rather than sweet.
A team from North CarolinaStateUniversity have tested their theory by giving cockroaches a choice of jam or peanut butter. They then analysed the insects’ taste receptors, which are similar to our taste buds.
Researchers from the same team first noticed 20 years ago that some pest-controllers were failing to eradicate cockroaches from properties, because the insects were simply refusing to eat the bait.
Believe it or not, there are about 4,600 species of cockroach and fewer than 30 of these are considered pests.
Dr Coby Schal told the Science journal that this new study revealed the “neural mechanism” behind this refusal.
Researchers in the first part of the experiment offered the hungry cockroaches a choice of two foods – peanut butter or glucose-rich jam.
“The jam contains lots of glucose, while the peanut butter has a much smaller amount,” said Dr Schal.
“You can see the mutant cockroaches tasting the jam and jumping back – they’re repulsed and they swarm over the peanut butter.”
In the second part of the experiment, the team discovered exactly why the cockroaches reacted that way,
The cockroaches were immobilised and the scientists used tiny electrodes to record the activity of taste receptors – cells which respond to flavours that are “housed” in microscopic hairs on the mouths of insects.
“The cells that normally respond to bitter compounds were responding to glucose in these cockroaches, so they were perceiving glucose to be a bitter compound,” said Dr Schal.
More... (http://www.canarianweekly.com/ugh-theres-sweet-dreaded-cockroaches/)