Hyssopus pallidus is Parasitoid Wasp feed on codling moth that is pest of apple fruit. in this topic learning behavior is discussed. Contact Email: mzeeshan_93@yahoo.com

2. Muhammad Faisal Riaz 24
Nimra Altaf
Faizan Iqbal
Faiz ullah Faiz 04
Muhammad Zeeshan Nazar 01
Jafar Ali Naqi Khan

3. Learning in the Parasitoid Wasp
(Hyssopus pallidus)

5. Before discuss this case study We should know,
A parasitoid’s host-searching ability depends on,
i. Responses to chemical cues.
ii. These responses have both genetic and learned components.
 Any critical phase at which a parasitoid is more likely to learned?
 Does learning carry through from one life stage to another?
Questions arise in this topic are

6.  Cydia pomonella is the major pest of apple fruits.
Hatched parasitoid larvae disperse
throughout the orchard to find new host.
 Hyssopus pallidus (parasitoid) used as biocontrol.

7. Q. Either wasp depends on the traces of (Moth’s) frass
in the channels of infested fruit or not???
Moth’s caterpillar feed on
Artificial diet
Strong decline of the response to frass of moths that
fed on artificial diet while other group showed opposite result.
Apple cues

8. • Host derived frass were recognized innately
• But learning was required before wasp recognized fruit derived
components.
Q. Did parasitoid need to learn fruit related chemicals from
caterpillars and their feces or exposure to fruit itself was sufficient?
After perceiving the existence of
learning behavior, the question arise

9. Moth Caterpillars
(1st instar moth)
Apple
Feed
Extract Worm
Waited for
5th instar
Worm
Filter paper
with extract
Apple pieceApple
Extract
Feed on
wheat germ
Introduced mated female in each group
New cage without
apple cues
New
Generation

10. New Generation
4 days old
Filter paper on top treating with apple extract
Hyssopus larva fed with apple diet showed significantly greater
response to host frass than reared without apple cues.

11. Q. Did a high response to host frass require exposure to both
the taste and smell of apple?
Apple supplement Odor of apple extract
Both treatments enhanced female response but their response towards
olfaction was more effective as taste and smell together.
Parasitoids
reared on
caterpillars
Parasitoids
reared on
caterpillars

12. Q. Was their a sensitive stage in parasitoid’s life history
for learning the relevant stimuli?
Wasps exposed to apple clues at different developmental stags.
Never exposed
to apple at all
Group 1 Showed greater response as adult to natural frass.
Exposed to apple
throughout its life
Group 1 Group 2

13. Stage exposed to odour
of apple fruit extract
Adult response to frass extract from apple-fed host caterpillars
Total development
Egg-young larva
Old larva-pupa
Pupa emergence
Adult
No Exposure (Control)
(0)
0 5 10 15 20 20 40 60 80 100 120 140 160 180
Response(s)Days from oviposition

14. Parasitoids are more
responsive to the
control than menthol
Control Group
Parasitoid used
only solvent
Egg to Larvae
Experimental
Group Parasitoid
used Menthol
Q. Was pre-imaginal learning confined to fruit cues,
or was it a more general phenomenon?

15. Parasitic wasp Hyssopus pallidus learns to locate its hidden
host by its frass and this recognition is two stage process.
 Host-derived chemicals in frass innately.
 Apple derived chemicals learned only through exposure in
early life cycle;
not early adulthood, but from egg to larva