termitas isopeteras

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Termite s
T
I ermites are mediurn-sized, cellulose-eating so-
cial insects comprising the order Isóptera, a rela-
tively small group of insects, consisting of approxi-
mately 1900 species worldwide. They live in highly
organized and integr¿ted societies, or colonies, with
the individuals differentiated morphologically into
distinct forms or castes-reproductives, workers,
and soldiers-which perform different biological
functions. The wings {present only in the reproduc-
tive caste) are four in number and membranous. The
front and hind wings are almost equal in size (Figure
l7-l l, hence the name Isóptera. The antennae are
moniliform or filiform. The mouthparts of the work-
ers and reproductives are of the chewing type. The
metamorphosis is simple. The nymphs have the po-
tential to develop into any one of the castes. Experi-
ments have shown that hormones and inhibitory
pheromones secreted by the reproductives and sol-
diers regrrlate caste differe¡rtiation.
Thclugh termites are popularly referred to as
"white antsr" they are not ants, nor are they closely
related to ants, which are groupeC with bees and
wasps in the Hymerióptera, whose social system has
evolved independently of that in the Isóptera. Ter-
mites are most closely related to the cockroaches,
rIsóptera: iso, equal; ptera, wings. This chaprer was written,'¿á{l with minor editorial changes by thc aurhors, by Kumar Krishna.
both having probably evolved from a primitive cock-
roachlike ancestor. The primitive living species
Mastotérmes darwiniénsis Froggatt from Australia
has affinities with some cockroaches, such as the
folded anal lobe in the hind wing and an egg mass
resembling the ootheca of cockroaches. This and
other evidence of relationship to primitive Blattlria
suggest that termites evolved in the late Permian,
approximately 200 million years ago (though the
known fossil termites date only from the Creta-
ceous, about 120 million years ago). The termite
society is therefore the oldest.
There are many important differences between
termi¡es and ants. Termites are soft-bodied and usu-
ally light-colored, while ants are hard-bodied and
usually dark. The antennae in termites are not el-
bowed as in ants. The front and hind wings of ter-
mites are nearly equal in size and are held flat over
ttre abdomen at rest, while in ants the hind wings
are smaller than the fore wings and the wings at rest
are usually held above the body. In termites, the
wings, when shed, break along a suture, leaving only
the wing base, or "scale," attached to the thorax.
The abdomen in termites is broadly joined to the
thorax, whereas in ants it is constricted at thre base,
forming the characteristic hymenopteran petiole, or
"waist." The sterile castes {workers and soldiers} in
termites are made up of both sexes/ and reproduc-
tives and sterile castes develop from fertilized eggs.

2. F¡gUfe 17-1. A rvrngcd termite. {Courresy oi USDA.)
In ants, the sterile castes are made up of females only
and all fernáles, sterile and reproductive, develop
from fertilized eggs, while the reproductive males
develop frorn unfertilized eggs.
Ternrite Castes
The reproductive function in the termite society is
carried out by the primary reproductives, the king
ancl queen-most commonly one pair to a coiony-
',vhich develop from fully winged (macropterous)
adults (Figure l7--2A1. They are heavily sclerotized
and have compound eyes. The king is generally
small, but in many species the queen develops an
enlarged abdomen as a result of her increasing egg-
laying capacity, and in some tropical species she óan
reach a size as great as ll cm (compared with 1-2
cm for the king). The winged reproductives from
which the king and queen devélop are produced in
large numbers seasonally. They leave the colony in a
swarming or colonizing flight, shed their wings
along a suture, and, as inciividual pairs, seek a nest-
ing site, mate, and establish new colonies. In some
species one emergence a year occurs; in others,
many. In the most comrnon eastern species, Reticu-
litfumes fLávipes, it occurs in the sprirrg; in many
western species, it occurs in late sumíner.
In the initial stages of colony foundation, the
reproduc.tives feed the young and tend to the nesr,
but these household duties are soon taken over bv
young nymphs and workers.
If it happens that the king and queen die or
part of the colony is separated from the parent col-
ony, supplementary reproductives clevelop within
the nest and take over the function of the king
and queen. fhe supplementary reproductives are
slightly.sclerotized and pigmented. with short wing
pirds {brachypterous} or no wing pads (aprerous} and
reduced compound eyes. They ilevelop from nymphs
Habits of ]'ermlles ?3s
and achic.,¡c ste;<tral rrraturity r..vitirout reaching the
fully u'ingccl aclult 5;t¿rgcs a¡rd ',vithout leaving tfre
nest.
The rvorl<cr ancl solclier castes, macle up of troth
sexes, are sierile, lvingless, in mosl species blinci,
and in sorrle species polymorphic, that is, of two
distinct sizes {Figurc 17-2C,Dl.
The workers are usually the most numerous in-
dividuals in a colony. They are pale and soft-bodied,
with mouthparts aciapted for chewing. They perform
most of the rvork of the colony: nest building and
repair, foraging, ancl feeding and grooming the other
members of the colony. Because of its feeding func-
tion, the worker caste causes the widespread destruc-
tion for which termites are no'üorious. In the primi-
tive families a true .¡¡orker caste is absent, and its
functions are carried out by wingless nyrnphs called
pseudergates, which may molt from time to time
without change irr size.
The soldier has a large, dark, elongated, highly
sclerotized head, aclapted in various ways for defense.
In the soldiers of nrost species, the mandibles are
long, powerful, hooked, and modified to operate with
a scissorslike actinn to behead, dismember, or l¿c-
erate enemies or predators (usually ants). In the sol-
diers of some genera, such as Cryptotérmes, the head'
is short ancl truncated in front anit is used in defense
to plug entrance holes in the nest.
The mechanical means of defense are sometimes
supplemented or displaced by chemical mean.s, in
which a sticky and toxic fluid is secreted by the .
frontal gland and ejected through an opening onto
the enemy. In Coptotérmes and Rhinotérmes, the
gland occupies a large portion of the head. In the
subfamily Nasutitermitinae, the mechanism of de-
fense is exclusively chemical: the mandibles are re-
duced, the frontal gland is greatly enlarged, and the
head has developed a snout, or nasus {Figure l7-ZBl,
through which a sticky repellent secretion is
squirted at the enemy.
' In afew genera, such as Anoplcttérmes, the soldier
caste is absent, and the nyrnphs and workers defend
the colony.
Habits of Terrnites
Termites frequently groom each other with their
mouthparts, probably as a result of the attraction of
secretions that are usually available on the body. The
food of termites is composed of the cast skins and
feces of other individuals, dead individuals, and
plarrt materials such as rvood and lvood products.
Some termites live in moist subterranean habi-
tats and others live in dry habitats abovegrouncl. The

3. 258 Chapier 17 Orrler lsÓPtera
Figurg 17-2. Castes of termites.
A, sexual rvinged adult, Amitérmes
tttbifórmans (Buckleyl, l0 x
(-fermítidae); B, nasute soldier of
Tenui r o stri t ér me s tenui¡ós tris
(Desneux|, 15 x (Termítidael; C,
worker, and D, soldier of
Prorhinotérmes símplex {Hagen), l0 x
(RhinotermÍtidae). (Courtesy of Banks
and Srryder and the U.S. National
Museum.l
subterranean forms normally li're in wood buried
beneath or in contact with the soil. They may enter .
wood remote from the soil, but must maintain a
passageway or connecting gallery to the soil, from
which they obtain moisture. Some species construct
earthen tubes between the soil and wood above-
ground. These tubes are made of dirt mixed with a
secretion from a pore on the front of the head (the
fontanelle; Figure l7-3, /on). The nests nray be en-
tirely subterranean, or they may protrude above the
surface: some tropical species have nests {terrnitaria}
9 meters high. The drywood termites, which live
aboveground (without contact with the ground-), live
in posts, $tumps, trees, and buildings constructed
of wood. Their chief source of moisture is metabolic
water (water resulting from the oxrdation of foocl).
The cellulose in a termite's footi is digested by
myriads of flagellated protists living in the termite's
digestive tract. A termite from which thcse flagel-
lates have been renoved will continue to feeci, but it
wil.l eventually starve to death because its [ood is
not digested. This association is an excellent cxam-
ple oí symbiosis, or mutualism. Some termites har-
bor bacteria rather than flagellates. Termites engage
in a unique form of anal liquid exchange (trophal-
laxis), and it is by this nreans- thar intestinal mi'
croorganisms are transmitted from one individual
to another.
Figurg 17-3. Head of Prorhinotétntes, do¡sal vierv,
showing fontanelle {/bn!. {Modifi.ed from Banks and
Snyder.I
I
ir

4. Key to the Families of lsÓPtera 237
Key to'the
I
_t-
I
olr'l1,1 | l.
z',.
3( i.').
a,
J.
Fam!lles of lsópt€ra (Minged Adrrlts)
Forrtanelle usually pfesent (Figure 17-3, /on); rvings lvith only 2 heavy veins in
anterior part of
.wing
beyond scale, R ustraiiy without ante rior branches
(FiguretT-4A) ...;.. """"'2
Fontarrelie absent; wings with 3 or more heayy veins iu anterior palt of wing
beyorrd scale, R with I clr more anterior branches (Figure 17-4Bl " " "3
Scale of front wing longer than pronotum; proflotLlm flat; cerci 2-segrnented;
wiCelyciistributed..- .-..Rfi¡notermítidae
Scaie of front wingshorter than pronotum; prt)ootum saddle-shaped; cerci l- or
2-segmented¡ southwestern United States " " "Termítidae
Ocelli pr€sent; shaft of tibiae without spines; antennae trsually with fewer
chan 2l segments; cerci short, 2-segmented; Florida and western United
States " 'Kalotermítidae
Ocelli absent; shaft of tibiae usually with spines; antennae usually with more
than 2l segmeflts; cerci long, 4'segmented¡ western United States and
southern British Columbia ...... " " 'Hodotermítidae
p.238
p.239
p. 238
p. 238
Key to the Fam¡lies of lsÓptera (soldiers)
t. Mandibles vestigial, the head producecl anteriorly into a long noselike
proiection (naiute soldiers; Fignt. l7-ZBl 'Terrnít¡dae
1'. Mandibles normal, head not as above " " ' '2
Figure 174. lvings of
teáites. A, Rhinotermítidae;
B, Kalotermitidae-
p.239

5. 231:J Cha'pter 17 ürcler lsópte¡^¿
2( 1 ',).
z',.
3(2)
al
o
4(3).
^,
5(4',).
5',.
6{5',).
6',.
I-Iead ionge r tiran broad (Figure 17-21)'1; nrantlibles n'ith o¡ withor-r¡ orcnritrcnt
margiriai teeth ... -.....3
FIead shcirt, hollt,'rve C outi rnanclibles without rriarginal tecttr; s,rr-rtf¡e rrt LII-rited
States {porvdi:riri¡st ternrite s) . . . .Kaloternrítitl;¡e
Ivlandiblcs rvith orre or nlorc prominent rnarginal teeth; sc;r,rthcrn ancl rvestcrn
United States .. ..4
Mandibles without marginal teeth IFigLrre t7-ZDl; wiclely clistributecl
. , Rhinote r'mítidae
I{anclibles with only I pronrincnt marginal tooth; head narrolvcci
anteriorly ....Terrnít¡clae
Mandibles with rnore than I prornincnr marginal tooth; head not narrc¡lved
anteriorly ........5
-fhircl. antennal segrnent modified; hind femora srvollen ...KalotÉi"r-r¡ÍtitJae
Thiid antennal segmenc not modified; hind femora variable .......6
Hin-d femora swollen; antennae with at least 23 segments; shalt of tibiae with
spines ..rllodoterrnit¡dae
Hind fernora not, or only slightly, swolleñ; aotenflae with fewer than 23
segments; shaft of tibiae rvithout spines ....Ka¡ot€rmítidae
p. 238
p. 238
p. 239
p.238
p. 238
p. 238
Family Kaloterñlítidae: This family is repre-
sented in the United States by 16 species and in-
cludes drywood, dampwood, and powderpost ter-
mites. These terrnites have no worker caste, and the
young of the other castes perform the rvo¡k of the
colony. The kalotermitids lack a fontanelle and do
not construct earthen tubes.
The drywood termites llncisitérmes, Ptero-
térrnes, and Marginitérmes) attack dry sounJ wood
and do not hdve a ground contact. Most infestations
are in buildings, but furniture, u-tility poles, and
piied lumber may also be attacked. Adults are cylin-
drical in shape and about 13 mm in length, and th.e
reproductives are pale brown in color. Incisit:ármes
minor {Hagen) and lvlarginitérmes húbbardi (Banks}
are important species in the southwe,stern states.
The dampwood termites in this family (Neo-
térmes and Paraneot&mesl attack moist dead lvood,
tree roots, and the like. They occur in Florida and
the western United States.
The powderpost cermites lCryptotérÍnes and Cal-
c.aritérmes) usually attack dry wocd {without a soil
contactf and reduce it to powder. They occur in the
southern United States. Cryptotérmes brévis
(V/alker) is an introduced species in the United
States. it occurs along the Gul{ Coast near Thmpa
and Nerv Orleans and has been found as far north as
Tennessee. It was probably introduced in furniture.
It attacks furniture, books, stationerli dry goods, and
building timbers and frequently does a great deal of
damage. It is found in buildings, neve.r oubdoors.
Where it is fourid, its coionies are numerous but
smali.
Fa m i I v HodotermítiCae-Da'm pwood Term ites : Th i s
group includes three species of Zootermópsis, which
occur along the Pacific Coast north to southern Brit-
ish Columbia. The adults are 13 mm or more in
length, are somewhat flattened, and lack a fonta-
neile. There is no worker caste. These termites at'
tack dead wood, and although they dc¡ not require a
grouñd contact, sorne moisture in the wood is re'
quired. They generaliy occur in dead, damp, rotting
Iogs, but frequently damage buildings, utility poles,
and lumber, particularly in coastal regir-rns where
there is considerable fog.
The most common species in this group are Z.
nevadénsis Banks andZ. angusticóliis {Hagenl. Zoot'
ermópsis nevadénsis is a little over 13 mm long and
Iives in relatively dry habitats {especiall;r dead tree
trunks). The wingless forms are pale with a <iarker
head, and the winged fornts ar¿ dark brorvn with the
head chestnut or orange. Zootermópsrs angr-rsticóllis
is larger (about 18 rnm long) and generally occurs in
damp dead logs, Adults are paie with a brown head.

6. Farnily Rhinr:lerniítielzie: This group is repre-
scnted in the lJnited States by rrine species (with
one spccies exten(ling northrvard into Canada) and
incltrcles thc subterranean termites {Reticulitérmes
ancl lleterotérmesl and the danrpwood termites in the
genus Prorhinotérmes {Figure l7-2C,D). The subter-
ranean terrnites are',nriclcly distributed, but the
damplvoocl ternrites occllr only in Florida. These
termites are small (adults are about 6-8 mm long).
Wingless fonns are very pale (soldiers have a pale
brown heacl), and rvinged forms are black. There is a
fontanelie on the front of the head {Figure 17-3, fonl.
The members of this group alrvays maintain contact
with the soil. They often construct earthen tubes to
wood not in contact with the soil. The eastern sub-
terranearr termite, Reticulitérmes flávipes (Kollar)
(Figure 17-5}, is probably the most destructive spe-
cies in the order and is the only termite occurring in
the Northea,st.
Coptotérmes formosrin¿¡s Shiraki, a native of
rnainland China and Thiwan and a serious pest, has
been introduced into Louisiana, Florida, and Texas.
The soldiers can be recognized by their oval heads
and a iarge fontanelle opening in the front margin of
the head. The nest is underground or in wood.
FamilV Termítldae: This group is represented in
the United States by la species in the Southwest. It
includes the soldierless termites lAnoplotérmes), the
desert termites (Amit&mes and Gnáthamitfumesl,
and the rlasutiform termites (Nasutitérmes and Tbn-
uiróstritérmesl. The soldierless termites burrow un-
der logs or cow chips and are not of economic im-
portance. The desert termites ere subterranean and
occasionally damage the wood of buildings, poies,
F¡gure 17-5. A group of eastern subterranean
termites, Reticulitérmes flávipes (Kollarl; note the
soldier in the right central position of the picture.
{Courte.sy oí Davidson.)
[cunomic lmocrt¿rnce oi ]'ermiies ?rí'j
and fence posts. The nasr-rtiforn: termites attacl<
tre es or oth.cr objects on tire ground and maintain a
gror-rnd contact.
fre nnornie lmport"lne € sfi T€rrniteg
'IL'rmites hold two positions from the economic point
of view. On the one hancl, they may be very destruc-
tive, since they feed upon and of ten clestroy variotls
Structures Lr materials that people use: .,vooden por-
tions of buildings, tcurniture, books, utility poles,
fence posts, many fabrics, and the iike (Figure 17-6i.
On the other hand, they are beneficial in that they
assist in the conversion of dead trees and other plant
proclucts to substances that can be used by plants.
ReticulitéÍmeli flávipes is the common termite
thrcrughout the eastern United States. This species
occurs in buried wood, fallen trees, and logs. It must
maintain a ground connection to obtain moisture. It
cannot initiate a new colony in the wood in a house;
the nest in the soil must be established first. Once
the soil nest is established, these termites may en-
ter buildings from the soil in one of five u'ays:
{1}through timbers that are in direct contact with
the soil, (2) throtrgh openings in rough stone foun-
dations, (3) through openings or c,racks in concrete-
block foundations, (4) through expansion ioints or
cracks in concrete floors, or (5) b;r means of earthen
tubes constructed over foundations or in hidclen
cracks and crevices in masonry.
Infestations of the subterranean termite in a
building may be recognized by the swarming of the
reproductives in the spring in or about the building,
by mud proiruding from cracks between boards or
beams or along basement ioists, by the earthen tubes
extending frr¡m the soil to the wood, or by the hol-
lowness of the wood in which the insects have been
.., tunneling. A knife blade can easily be pushed into a
timber hollowed out by termites, and such wood
readily breaks aparl.
Subterranean termites in buildings are con-
trolled by two general methods: by proper construc-
tion of the buildings to render them terrnite-proof,
and by the use of chemicals. The former involves
construction in which no wood is in contact with
the ground and in which the termites cannot reach
the wooden part of the builcling through outside
steps, through sills, or through the foundation. Con-
troi by chemicals involves their application to the
woocl or to the soil. Utility poles and fence posts,
which must be in contact with the ground, may be
rendered termite-proof by chemicai treatment.

7. 24fr Chaprter 17 Orijer lsó¡rtera
FigUfe 17-6. Termite damage. (Cotrrtesy of Davidson.)
The best method of eliminating drywood ter-
mites is by fumigation. For such termites in build-
ings, a large tent of plastic or other impervious ma-
terial is placed over the entire building. This is a
rather expensive procedure. Drywood termites. rnay
also be eliminared by drilling holes in infested tim-
bers, forcing a small amount of a poison dust into
the hoies, and then plugging up the holes. Terrnites
constantly groom one another, and once a few indi-
viduals get this dust on themsel'.'er, the other indi-
viduals of the colony will eventuaily obtain it and
be kiiled.
Collecting and Freservir¡g lsúptera
Termites can be found by turning over dead logs or
by digging into dead stumps. They may be coliected
with forceps or a moistened brush, or they may be
shaken out of inÍested timbers onto a paper. Termites
should be preserved in 70-BA% alcohol. Most indi-
viduals
^re
very soft-bodied and shrivel or become
di5torted if mounted on pins or points. It is often
necessery to mount these insects on microscope
slides for detailed studv.
References
Araujo, R. L. 1977. Carálogo dcs Is'.rlrrera do Novo Mondo.
Rio de |aneiro: Ac¿demi¿ Brasileira de Ciencias,gZpp.
Banks, N., and T E. Snyder. L92A. A revrsion cf the Nearctic
ternlites, with notes on their biology and distribution.
Btril. U.5. Natl. Mus. No. 108, 228 pp.; ilh:s.
Berger, B. C. I94Z Horv to recognize and control termites
in Iilinois. Ill. Nat. Hist. Surv. Circ. No. 4t.. 44 pp.;
illus.
Ebeling, W 19ó8. Termites: identification, biology and con-
trol of tcrmires attacking buildings. Calif. Agr. Expt.
Sta, Extension Se¡vice M¿nual No. 38, ó8 pp.
Ebcling, W 1925. Isoptera: rermires, pp. ll8, 13A-167, in
lJrban Entomolrgy. Berkeley: Univ. California Press.
Ernst, E., and R. L. A¡aujo. 1986. A Bibliograph;r of Termite
Literature, 1966-i978. Chichestcr, Engiand: lVi1e1;
903 pp.

8. Kofoid, C.A., S. E Light, A. C. Horner, M. Randall, W. B.
Herrns, anc! E. E. Borve, eds. 1934. Termites and Tireir
Control. Berkeley: Univ. Califo¡nia Press, 734 pp.t
ilir:s.
Krishna, K. 1961. A generic revision and phylogenetic sturly
of the fanrily Kaloternitidae {lsoptera}. tsull. Amer.
Mus. Nat. Hist. 122{4}:307-408; illus.
Krishna, K. 196(r. A kcy to eight termite genera. Coop.
Econ. Insect Rep. {USDAI 16{a7}:1091-1098.
Miller, E. M. 1949. A Handbook of Florida Termites. Coral
Gables, Fla.: Univ. Miami Press, 30 pp.
Skaife, S. H. 1961. Dwellers in Darkness. New York: Dou-
bletla¡¿ 180 pp,; illus.
Snyder, T. E. 1935. Our Enemy the Termite. Ithaca, N.Y:
Comstock, 196 pp.; illus.
Snyder, T E. 1949. Catalogue of the termites llsoptera) of
the world. Smithson. Misc. Coll. ll2(3953), 490 pp.
Snyder, T. E. '1954. Orcler Isoptera-The Termites of the
United States and Canada. New York: Natl. Pest Con-
trol Assoc ., 64 pp.¡ illus.
Snyder, T. E. 1956. Annotated subiect'heading bibliography
of tcrmites, 1350 B.c. to A.D. 1954. Smithson. Misc.
Coll. 130(a258), 305 pp.
References ?41
Snyder, T. E. 1961. Supplement io the annr:tated subject-
heading bibliography of terrnites, i955. to 1960. Smith-
son. Ir{isc. Coll. I43{3i, 137 PP'
Snyder, T E. 1968. Second supplement to the annota¡ed
subject-heading bibliography of ternrites, 1961-1965.
Smithson. Misc. Coll. i52, 188 PP.
Vickery, V R., and D. K. McE. Kevan. 1985. The grasshop-
pers, crickets, and related insects of Canada and adia-
cent regions: Ulonata: Dermaptera, Cheleutoptera, No-
toptera, Dictuoptera, Grylloptera, and Orthoptera. The
Insecrs and Arachnids of Canada, Part 14. Ottawa: Can.
Govt. Publ. Centre, 918 pp.; illus.
,Weesner, i.l ¡vI. 1960: Evoiution and biology of the termites.
Annu. Rev. Entomol. 5:153-170.
Weesner, F. M. i965. The Termites of the United States: A
Handbook. Elizabeth, N. I.: Natl. Pest Control Assoc.,
7t pp.
Weesner, F. M. 1987. Orde¡ Isoptera, pp. 132-139 in Imma-
ture lnsects, etl. F. W Stehr. Dubuque, Iowa: Kendall/
Hunt.