4. INTRODUCTION
• A broad term for chemicals involved in animal
communication is semiochemical, from the Greek
‘semeion’ means ‘sign’ (Law and Regnier, 1971).
Semiochemicals are usually divided into two
subclasses: pheromones, used for communication
within the species(intraspecific signals), and
allelochemicals, used for communication between
species(interspecific signals).
5. PHEROMONES
• PHEROMONES were originally defined as 'substances
secreted to the outside by an individual and received by a
second individual of the same species in which they release
a specific reaction, for instance a definite behaviour or
developmental process.
• PHEROMONES are chemical substances secreted by an
animal’s exocrine glands that elicit a behavioral or
physiological response by another animal of the same
species.
6. ALLELOCHEMICALS
• Allelochemicals, the second subclass of
semiochemicals, deal with inter specific
communication.
• Allelochemicals benefit the originator but not the
receiver.
• For example, during egg laying moths and betteles
use certain allelochemicals to repel insects of other
species, thereby protecting their progeny.
7. CHEMICAL ATTRACTION IN HONEYBEES
• Pheromones are involved in almost
every aspect of the honey bee colony
life.
• Pheromones allow communication
among all the honey bee castes: queen–
workers, workers–workers, queen–
drones, and between adult bees and
brood.
8. TYPES OF PHEROMONES
• Releaser pheromones cause rapid changes in
behavior. For example, alarm pheromone quickly
engages other bees to help defend the nest.
• Primer pheromones cause long-term changes in both
physiology and behavior. Brood pheromone, for
example, suppresses worker ovary development.
9. CHEMICAL ATTRACTION IN HONEYBEES
1. ALARM PHEROMONE, produced by workers, that
calls nest mates to help defend the colony from
intruders. A sting, which also releases alarm
pheromone, causes other bees to sting as well.
• Guard Bees: Patrol the entrance, release alarm
scent, recognize hive mates by rubbing antennae.
• Defender Bees: respond to danger by flying out of
the hive, stinging , and sometimes pursuing
intruders. Raise their abdomen to expose the sting
chamber
10. CHEMICAL ATTRACTION IN HONEYBEES
2. FOOTPRINT PHEROMONE, also known
as trail pheromone, is found in many social
insects. Worker honey bees secrete the
pheromone from their feet as they go about
their daily business, and the odor is attractive
to other honey bees. In theory, footprint
pheromone is used for orientation and may
aid the workers in finding the hive entrance
or in locating a good food source.
11. CHEMICAL ATTRACTION IN HONEYBEES
3. QUEEN
PHEROMONE, entices
worker bees to
groom and feed the
queen, and causes a
circle of attendants
to surround and
care for her.
12. CHEMICAL ATTRACTION IN HONEYBEES
4. BROOD ESTER PHEROMONE,
produced by larvae, is a primer
pheromone that, among other things,
inhibits ovarian development in
worker bees.
5. QUEEN MENDIBULAR
PHEROMONE, plays a role in the
suppression of egg laying by worker
bees, and in attracting drones when
mating.
13. CHEMICAL ATTRACTION IN MOTHS
• The pheromones of moths have been
particularly well studied as a source to
find a mate.
• Female silkworm moths (Bombyx mori)
attract male mates with the pheromone
bombykol, a volatile 16-carbon alcohol. In
the male moth's antennae, a pheromone-
binding protein conveys bombykol to a
membrane-bound receptor on a nerve cell.
14. CHEMICAL ATTRACTION IN
MOTHS
• When a female moth releases her volatile sex
pheromone into the night air, it is carried by the
wind like an invisible smoke plume from a
chimney. The wind shears it into pockets of air
with pheromone hits the antennae of a male
searching on the wing, he responds by flying
upwind for a fraction of a second. If he hits
another pocket of pheromone, he flies upwind
again. If he doesn’t hit more pheromone, he flies
from side to side until he hits pheromone again.