Management of Drywood Termites: Past Practices, Present Situation and Future Prospects - Urban Insect Pests: Sustainable Management Strategies - page 132

et al. , 2007a,b; Inta et al. , 2007; Lewis,
2009a; Lewis et al. , 2013); galley systems
and maintenance (Springhetti and Sita,
1989; Grace et al. , 2009); life history and
biology (Harvey, 1934a,b; Light, 1934a,b,c;
Snyder, 1934; Gay, 1969; Weesner, 1970);
molecular genetics (Syren and Luykx, 1977;
Fuchs et al. , 2003; Indrayani et al. , 2006;
Inward et al ., 2007; Booth et al. , 2008, 2010;
Legendre et al ., 2008); reproductive strategies
(Lenz et al. , 1985; Lenz, 1987; Korb and
Lenz, 2004; Korb and Schmidinger, 2004;
Korb et al ., 2009); and tropisms to external
stimuli (Cabrera and Rust, 1996, 2000;
Chrysanti and Yoshimura, 2012). The biology
of the Kalotermitidae is typical of the lower
termites and characterized by incomplete
metamorphosis or hemimetabolous develop-
ment with the usual complement of castes:
immatures (larvae), 'workers', soldiers,
nymphs and reproductives (Fig. 9.1) (Miller,
1969; Roisin, 2000).
Description of the life stages is
complicated by the variety of terms used in
the literature (the instars above the third are
called workers, helpers or pseudergates by
different authors). Fortunately, experts
generally agree that the immature stages
display the ability to follow a variety of
developmental pathways (totipotency) and
this fl exibility is infl uenced by food avail-
ability with more dispersal forms being
produced in colonies that deplete the
available food (Korb and Hartfelder, 2008).
Immature stages comprise the majority of a
colony and the later instars (third and
above) have the ability to develop into
nymphs that progress to the imaginal (adult)
stage or can become neotenic reproductives
(sexually mature immature forms) (Roisin,

2000; Korb and Hartfelder, 2008). The
'workers' can also become neotenic
reproductives (Lenz et al ., 1985; Korb and
Hartfelder, 2008). The basic life history is
generally explained by establishment of
colonies through dispersal of winged
reproductives to another 'single' piece of
dead wood where the new colony exists
until natural mortality factors, such as
predation or depletion of that resource,
cause its demise (Korb and Lenz, 2004; Korb
and Schmidinger, 2004). The colony feeds
inside the food resource constructing a
gallery system that expands with time as the
population increases. The architecture of
the gallery system in structural lumber con-
sists of narrow passageways that connect a
number of larger feeding chambers (Grace et
al ., 2009). This architecture assists in
defending the colony because the narrow
passageways allow drywood termite sol-
diers to more easily block predator entry
into the system (Fig. 9.2). Colony fusion is
known to occur after two colonies of the
same species in the same resource encounter
each other, as is common in another family
of lower termites, the Termopsidae (Thorne
and Traniello, 2003; Johns et al. , 2009).
Therefore, colonies can contain a variety of
reproductive forms and 'familial' constructs
from monogyne to multiple neotenic repro-
ductives (Booth et al ., 2008; Lewis , 2009a).
Neoteny (expression of sexual maturity
during the larval stage) is commonly
encountered in fi eld and laboratory studies,
and this unique feature facilitates pest
status for numerous species within the
Kalotermitidae (Evans et al ., 2011). All of
the literature mentioned above involves a
few species that are considered pests.

Pre-soldier Soldier

Egg Larva Worker Nymph Alate

Neotenic

Fig. 9.1. Simplifi ed hemimetabolous developmental pathway typical of the Kalotermitidae.