Alarm Pheromone
By Alan
Aphid has capability to produce alarm pheromone. Sesquiterpene, (E)-β-farnesene is the primary
component of it. It is released in response to physical stress including attack by natural enemies (Al
mohamad et. all,.2008; Minks and Harrewijn, 1987). This pheromone act to warn related individuals of
predation (Byers, 2005). But also could be acts as a kairomonal cue for aphid natural enemies (Al
mohamad et. all,.2008)
The releasing of alarm pheromone make the aphid behave different than the normal aphid (Minks
and Harrewijn, 1987), especially it will causes aphids to cease feeding and disperse (Al Mohamad et.
all,.2008)
The alarm pheromone presents in all life stages of aphid. The quantities of alarm pheromone
increase in relation to increasing body weight, however the concentration declined exponentially with
increasing body weight. this suggest that young aphid need to balance costs of growth and maturation
with costs of producing the alarm pheromone (Byers, 2005).
Reference
Almohamad, R. ; F. J. Verheggen; F. Francis; G. Lognay & E. Haubruge.2008. Emission of alarm
pheromone by non-preyed aphid colonies. J. Appl. Entomol. 132 (2008) 601–604 p
Byers, John A. 2005. A cost of alarm pheromone production in cotton aphids, Aphis gossypii.
Naturwissenschaften (2005) 92:69-72
Minks, A.K.; P. Harrewijn. 1987. Aphid:their biology, natural enemy and control. Elsevier.
Amsterdam.450p
Siphunculi and its function
By Arya
Siphunculi is a special character in aphids. In the most cases, it is located at the posteromarginal end of
the 5th abdominal segments. Through the siphunculi, waxy exudates are secreted. When exuded, the
droplet rapidly solidifies in the air and may play a defensive role by gumming up the cephalic parts of
predators, or by reducing their feeding activity. It is also known that the liquid contains volatile
substances which act as alarm pheromone (Miyazaki, 1987). Alarm pheromone is released when aphids
are attacked by its predator such as ladybird or lacewing larvae. Exposure to alarm pheromone also
induce aphids to give birth to winged dispersal morph (Kunert et al. 2005)
When alarm pheromone is secreted, other aphids may stop feeding , walk from their feeding site to
avoid predation. A common component of alarm pheromone that is found in over 19 genera of aphids,
including the pea aphids, Acyrthosiphon pisum, is (E)-b-farnesene or also known as (E)-7,11-dimethyl3-methylene-1,6,10-dodecatriene (Mondor et al. 2000). Alarm pheromone may be found in the first
instar and increase significantly in the second instar. The number of alarm pheromone is steady in the
third and fourth instar, but decrease significantly in the adult (Mondor et al. 2000). Colony structure
and level of predation may influence the number of the alarm pheromone (Mondor et al. 2000).
A wild potato Soltium berthaultii able to release (E)-b-farnesene from glandular hairs in the foliage.
Because of that the aphid Myzus persicae is repelled, at a distance of 1-3 mm from the leaves. If the
ability of the wild potato in producing the pheromone could be introduced into cultivated potatoes. It
might be provide some protection against aphids and hence aphid-borne viruses (Gibson & Pickett,
1983).
References
Kunert, G., S. Otto, U.S.R. Rose, J. Gershenzon, and W. Weisser. 2005. Alarm pheromone mediates
production of winged dispersal morph in aphids (Abstract). Ecology letters 8: 596-603
Gibson, R.W. and J.A. Pickett. 1983. Wild potatoes repels aphids by release of aphids alarm
pheromone. Nature 302: 608-609.
Mondor, E.B., D.C. Baird, K.N. Slessor, and B.D. Roitberg. 2000. Ontogeny of alarm pheromone
secretion in pea aphids, Acrithosophon pisum. Journal of Chemical Ecology 26: 2857-2882.
Miyazaki, M. 1987. Morphology of aphids. In: Aphids their biology, natural enemies, and control.
Volume 2A. Minks, A.K., P. Harrewijn, and C.W. Helle. eds. pp. 2-25. Elsevier, Amsterdam
Pheromone Alarm Produced by Aphids
Boy Valenza Damiri
428 121 672
Homework 6d
Cornicle or siphunculus are one of important bodyparts on Aphids. It has glandular cells located
at the base of the siphunculus. A droplet of waxy exudate contain triglycerides can be secreted from the
glandular base resulted from contraction of the muscle in the siphunculus. This droplet will rapidly
solidifies in the air and may play a defensive role by gumming up the cephalic parts of predator, or by
reducing their feeding or oviposition (Dixon and Steward, 1975 in Nishino et al., 1976 ; Minks and
Harrewijn, 1987; Beale et al.; 2006). Aphids respond to the alarm pheromones at a distance of 1-3 cm
from freshly secreted droplets and repellent activity is retained up to 60 minutes after secretion.
(Nault et al., 1973). Alarm pheromones are perceived by primary and secondary sensoria (rhinaria)
located on the aphids antennae (Nault et al., 1973 ; Park and Hardie, 1998)
Cornicle droplets also contain alarm pheromones. The sesquiterpene (E)-b-farnesene (EBF) is
the primary component of the alarm pheromone of most aphid species. It is released in response to
physical stress including attack by natural enemies and causes other nearby aphids to cease feeding and
disperse (Almohamad, 2008) or walking or dropping off the host plant (Kunert et al., 2005). Alarm
pheromone also induces aphids to give birth to winged dispersal morphs that leave their host plant
when mature. It was suggested that EBF leads to a 'pseudo crowding' effect that induce groups of
aphids to produce a higher proportion of winged dispersal morphs among their offspring (Kunert et al.,
2005). Kunert et al (2005) also found that aphids react more strongly to the frequency of pheromone
release than the amount of pheromone delivered for producing winged dispersal morphs. Alarm
pheromone also can act as a kairomonal cue for aphid natural enemies including ladybeetles, hoverflies
and parasitic hymenoptera (Verheggen et al., 2008 in Almohamad, 2008).
The response of aphids to the alarm pheromone can be influenced by environmental factor such
as temperature. At higher temperatures, aphids have become less responsive to the aphid alarm
pheromone (by dropping, running, or backing up) which is released when under attack by insect
predators and parasitoids (Bayaa, 2008). Another factor that can influence aphid response to alarm
pheromone is aphids-life stage. It was found that, in pea aphids, adult and fourth-instar pea aphids have
good responses to alarm pheromone (by either dropping, running, or backing up) whereas younger
instars showed almost no response to alarm pheromone. It was suggested that younger instars respond
conservatively to alarm pheromone because they are less active on the ground and are more likely to
die there before finding a suitable food plant. (Roitberg and Meyers, 1978).
REFERENCES
Almohamad, R.; Verheggen, F. J.; Francis, F.;Lognay, G.; and Haubruge, E. 2008. Emission of Alarm
Pheromone by Non-Preyed Aphid Colonies. J. Appl. Entomol. 132 (2008) pp.601–604.
Blackwell Verlag: Berlin. Δ
Bayaa, B. 2008. Climate Changes and Plant Protection: A Challenge We Have to Face!. Editorial page.
Tunisian Journal of Plant Protection. Vol.3, No. 1, Juni 2008. Tunisia Δ
Beale, M. H.; Birkett, M. A.; Bruce, T. J. A.; Chamberlain, K.; Field, L. M.; Huttly, A. K.; Martin, J. L.;
Parker, R.; Phillips, A. L.; Pickett, J. A.; Prosser, I. M.; Shewry, P. R.; Smart, L. E.; Wadhams,
L. J.; Woodcock, C. M.; and Zhang, Y. 2006. Aphid Alarm Pheromone Produced by Transgenic
Plants Affects Aphid and Parasitoid Behavior. PNAS Journals. July 5, 2006 vol. 103 no. 27. Δ
Kunert, G.; Otto, S.; Röse, S. R.; Gershenzon, J.; and Weisser, W. W. 2005. Alarm Pheromone Mediates
Production of Winged Dispersal Morphs in Aphids. Ecology Letters (2005, May 19). Blackwell
Publishing Ltd. o
Minks, A. K. and Harrewijn, P. 1987. Aphids. Their Biology, Natural Enemies, and Control. Volume A.
Elsevier: Amsterdam.□
Nault, L. R., Edwards, L. J.; and Styer, W. E. 1973. Aphid Alarm Pheromones: Secretion and Reception
Environmental Entomology, Volume 2, Number 1, February 1973 , pp. 101-105(5).
Entomological Society of America. Δ
Nishino, C.; Bowers, W. S.; Montgomery, M .E.; Nault, L. R.; Nielson, M. W. 1976. Alarm Pheromone
of the Spotted Alfalfa Aphid Therioaphis maculata Buckton (Homoptera: Aphididae). Journal
of Chemical Ecology, Vol 3. No. 3. pp 349-357. Springer Netherlands. Δ
Park, K. C and Hardie, J. 1998. An Improved Aphid Electroantennogram. Journal of Insect Physiology
Volume 44, Issue 10, October 1998, Pages 919-928. Elsevier Science Ltd. Δ
Roitberg, B. D and Meyers, J. H. 1978. Adaptation of alarm pheromone responses of the pea aphid
Acyrthosiphon pisum (Harris). Can. J. Zool. 56(1): 103–108 (1978). NRC Canada. Δ
Alarm pheromones in aphids
By Haris Setyaningrum
Aphids as colony insect have unique system to give “ sign danger “ condition to colony its self.
Common called alarm pheromone, it’s secreted from cornicle in the hind body of aphids. When an
aphids is attacked by predator, droplets are secreted from its cornicles. These droplets contain an alarm
pheromones that signal nearby aphids which respond by dispersing the area. The alarm pheromones in
several economically important species in the subfamily Aphididae has been isolated and identified as
the sesquiterpene, (E) –β- farnesene (I) ( Nishino, et.al. 1976). (E)-b-Farnesene (EbF), the main
component of the aphid alarm pheromone, was identified in 16 aphid species, alone or associated with
other molecules. The species that had been reported advance are Myzus persicae and Megoura viciae
(Almohamad, 2008).
The aphid alarm pheromone (E)-b-farnesene (EBF) is the major example of defence communication in
the insect world. Released when aphids are attacked by predators such as ladybirds or lacewing larvae,
aphid alarm pheromone causes behavioural reactions such as walking or dropping off the host plant. the
exposure to alarm pheromone also induces aphids to give birth to winged dispersal morphs that leave
their host plants ( Kunert, et.al, 2005). Another function alarm surely as communication media.
Communication via an alarm appears to confer fitness benefits on their recipients and production of
alarm pheromones is likely to entail costs the emitting aphids , it might be adaptive for aphids to
regulate E- βf in response to the social environment ( Verheggen, anon.)
References:
Δ-Nishino, Chikao. 1976. Aphid alarm pheromones mimics: the nor-farnesenses. Appl. Ent. Zool. II.
(4): 340-343 (1976.
Δ-Almohamad, R.et.al. 2008. Emission of alarm pheromone by non-preyed aphid colonies. J. Appl.
Entomol. 132 (2008) 601–604. Blackwell Verlag, Berlin
Δ-Kunert, Grit. Et.al. 2005. Alarm pheromone mediates production of winged dispersal morphs in
aphids. Ecology Letters, (2005) 8: 596–603
Δ -Verheggen, Francois J. et.al. anon. aphids alarm pheromones production to presence or absence of
conspecifics.