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Beauveria brongniartii and M. anisopliae ,
whereas termites reared in groups are highly
resistant (Yanagawa et al ., 2008). Mutual
grooming is very effective in removing
conidia from the cuticle. Also termites held
in isolation have few conidia in the
alimentary tract (Yanagawa and Shimizu,
2007; Yanagawa et al. , 2012). Fungal
virulence seems to have a direct relationship
with fungal spore removal by grooming
(Yanagawa et al ., 2010).
Studies suggest that workers of C.
formosanus discriminate between fungi-
inoculated and uninoculated workers
(Yanagawa et al ., 2011). Electroantennograms
of C. formosanus workers indicate that
olfactory receptors detecting odours from
fungi and termites are able to differentiate
between fungi (Yanagawa et al. , 2009, 2010).
Pathogen-prevention behaviours such as
attack, cannibalism and burying behaviours
are also observed more frequently with
fungus-inoculated workers than uninocu-
lated workers. Although the fungal genera
and isolates greatly affect these behaviours,
fungal virulence does not affect any of these
disease-prevention behaviours. Apparently,
the factors that affect hygiene behaviour are
associated with morphological or genetic
characteristics and not virulence.
(3005) showed the highest activity against
B. thuringiensis (Hussain and Wen, 2012).
Infections stimulate a complex response
that may involve both the cellular and
humoral reactions, including phagocytosis
by macrophage-like blood cells, activation
of proteolytic cascades that leads to local-
ized melanization and coagulation, and
synthesis of a battery of potent antimicrobial
and antifungal peptides by the fat body. The
resultant molecules synergistically act to
destroy the invading microorganisms
(Hussain and Wen, 2012).
Alimentary tract
It has been shown that, even though
thousands of conidia were found in the
termite's alimentary system and conidia
had the chance to bind to the surface of the
cuticular lining of the gut, the conidia never
germinated (Chouvenc et al. , 2009b). When
termites were left for decomposition for
several days after death caused by an
external infection of M. anisopliae , the
hyphal growth was generalized in the body
cavity of the cadaver, but never in the lumen
of the gut. Conidia remained in the
alimentary tract for at least 72 h. Their study
suggests that fungistatic activity of the
termite gut was probably of multiple origin
and more than one biochemical was
involved.
Cellular encapsulation
Nodule formation at the point of entrance of
the fungal hyphae has been identifi ed as a
cellular encapsulation. The relative number
of haemocytes per termite increased 24 h
after fungal exposure and remained high in
the haemolymph for at least 3 days before
decreasing back to pre-exposure levels
(Chouvenc et al ., 2009a). Few conidia
penetrated the cuticular surface (average of
0.0002%) and cuticular melanization may
have played a role in sequestrating fungal
pathogens. Encapsulation was successful
and completed 4 to 9 days after exposure.
Within 12-18 h after infection with
M. anisopliae strain (2049), homogenates of
C. formosanus workers showed the highest
activity against Bacillus thuringiensis .
Homogenates of Beauveria bassiana strain
Necrophoresis and cannibalism
The removal of the dead is an important
sanitation function in colonies of social
insects (Sun and Zhou, 2013). Although
frequently observed in ants, it is less often
reported for termites because they lack
refuse piles. This behaviour appears to be
much more complex than previously
thought (Neoh et al. , 2012b). The reaction of
termites to dead nest mates varies depending
upon the species and the nature of the
carcass. Cadavers with sporulating M.
anisopliae only appear when the numbers
of dead are too large (>75% killed) for
surviving C. formosanus workers to dispose
 
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