Helen R. Coles de Negret and Kent H. Redford.
The Biology of Nine Termite Species (Isoptera: Termitidae) from the Cerrado of Central Brazil.
Psyche 89(1-2):81-106, 1982.

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THE BIOLOGY OF NINE TERMITE SPECIES
(ISOPTERA: TERMITIDAE)
FROM THE CERRADO OF CENTRAL BRAZIL
BY HELEN R. COLES DE NEGRET' AND KENT H. REDFORD* The Neotropical region is second to the Ethiopian in numbers of described termite species (Araujo 1970). However, little is known of their biology. The literature on Brazilian termites is largely re- stricted to isolated taxonomic descriptions of species from the Amazon Basin and southern states of Brazil (Araujo 1961, 1969, 1977 and Fontes 1979). Exceptions to this include information re- lating termite species and their distribution to vegetation types in Mato Grosso State (Mathews 1977), the effect of deforestation on termites in the Amazon (Bandeira 1979) and data on the ecology and defense of termites in the cerrado vegetation of the Distrito Federal (Coles 1980).
The present study was done in conjunction with a study on mammalian termite predators, in particular the giant anteater, Myrmecophaga tridactyla (Coles 1980 and Redford in prep.). Six aspects of termite biology of importance in defense by termites against mammalian predators were studied for nine of the most common mound-building termite species in the Distrito Federal, Brazil. Reported here are individual weights, morphology of soldier castes, worker-soldier ratios, mound sizes and forms, mound hard- nesses and nest materials, distributions and abundances of nests and feeding habits for these nine species.
All species studied were from the family Termitidae (see Fig. 1 for comparison of soldier heads), subfamily Apicotermitinae, Grigioter- mes metoecus (Matthews); subfamily Nasutitermitinae, Armitermes 'Laboratoria de Zoologia e Ecologia Animal, Universidade de Brasilia, Brasilia D. F. 809 10, Brazil.
Museum of Comparative Zoology, Harvard University, Cambridge, MA 02138; and Department of Zoological Research, National Zoological Park, Smithsonian Institu- tion, Washington, D.C. 20008.
Manuscript received by the editor March 3, 1982. 8 1




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82 Psyche [vo~. 89
euamignathus (Silvestri), Cornitermes cumulans (Kollar), Cortariter- mes silvestri (Holmgren), Nasutitermes sp., Procornitermes araujoi (Emerson), Syntermes dirus (Burmeister), Velocitermes paucipilis (Mathews); subfamily Termitinae, Orthognathotermes gibberorum (Mathews).
This study was conducted primarily in the Distrito Federal, Brazil (15 47's 47 56'W) with supporting work done in Emas National Park, Goias State (18 19's 52 45'W). Both areas are located within the cerrado sensu latu vegetation type. Cerrado (sensu latu) is a semi-deciduous xeromorphic savanna vegetation found in the inter- mediate rainfall (750-2000mm/yr) area of Brazil. It is characterized by woody plants with thick bark and coreaceous leaves and a sea- sonal ground layer of grasses and herbs. Although geographically and floristically the cerrado vegetation zone is very uniform, physi- onomically it shows considerable variation (Eiten 1972). The types of cerrado sensu latu which were examined in this study are campo limpo (grassland), campo sujo (grassland with shrubs), cerrado sensu strictu (woodland) and cerradzo (dense, tall cerrado). Within the cerrado zone, gallery forest vegetation is found on the wet, more fertile soils along river courses; however this was excluded from the present study as it supports a termite fauna which differs greatly from that of the other vegetation types (Coles 1980). A. Comparative Morphology
Figure 1 depicts soldiers of the eight species of termites examined in this study, with a worker head of the soldierless species Grigio- termes provided for comparison, while Tables 1 and 2 provide information on the fresh weights and total body lengths. Table 2 also provides measurements of mandible length, nasus length, head length, head width and head depth for the soldiers (position of measurements depicted in Figure 2).
As can be seen from these data, the termite species in this study can be placed along a spectrum based on soldier and head shape. The two ends of this spectrum are 'well-developed nasus/vestigial mandibles' (such as Nasutitermes) and 'no nasuslverv well-devel-



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Negret & Redford -
n
Termite Species
Figure 1.
Soldier heads of eight of the species of termites studied; Grigioterme.~ metoecus worker included for comparison: a, Grigiotermes metoecus; b. Arn7iter- mes euamignathus; c, Cornitermes cumulans; d, Corfaritermes .si/\~e.stri; e, Pro- cornitermes araujoi; f, Nasutitermes sp.; g, S~wtermes dims; h, Velocitermes paucipilis; i, Orthognathotermes gibberorurn.



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84 Psyche K^
loped mandibles' (Orthognathotermes). Intermediate posit :Ìö o n: occupied by forms with 'slight nasus development / well-de v e 1 < mandibles' (such as Cornitermes) and 'well-developed nas u s / developed mandibles' (Armitermes). Grigiotermes, with no. s o caste, cannot be placed on this spectrum. These data also show that soldiers with very well- t- o T developed mandibles and poorly developed nasi are both h ez
and longer than soldiers with vestigial mandibles and well-dew ^^- lc nasi, Armitermes once again occupying an intermediate pos ^Ìö-c IS o Complete taxonomic descriptions for Grigiotermes mi e z -4 Arrnitermes euamignathus, Cortaritermes silvestri, Velo c- z-AF e l paucipilis, and Orthognathoterrnes gibberorum can be f o 'ÌàÌÔ n Mathews (1 977). Procornitermes aravjoi is fully described i n E I son (1952). Samples of Cornitermes cumulans collected du xi- nf- study in Brasilia were identified following Emerson ( 1 9 5 =>- though the general head and mandible forms were consist- n -C the published description, head length and width measu re :m were much lower than those previously described for this s pe However. Emerson indicated that there is considerable vari- 'B" Ac mean measurements between colonies from different localit C s -
samples from Brasilia were compared with various other s p e c i g the Museu Zoologia de Universidade de S5o Paulo (MZS F > - most closely related species was C. villosus which was clearly d i ent in that it had a greater number of setae and differently s *z mandibles. As a result of this divergence the best classiå£-i ^z^a appears to be C. cumulans. Specimens from Brasilia have=- I deposited in the MZSP and the Museum of Comparative Z o o la Harvard University.
Samples of Nasutitermes sp. collected from the Distrito F-d were compared extensively with material in the MZSP but c^i- Sf< from all species examined. N. coxipoensis most resembled th< md titermes we studied but differed in being smaller and in h-vir more oval shaped head. Further studies on these two for n s necessary to determine whether these differences are suffic 5 n warrant calling it a new species.
B. Weights
Fresh weights were measured on a Mettler balance. Fifty v^--" o r l and fifty soldiers from each of three different nests were w e % ~3 except for Syntermes for which only fifteen individuals of eat:: h c,



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19821 Negret & Redford - Termite Species 85 from the three nests were weighed and Nasutitermes for which five nests were sampled. The results are presented in Table 1 and are ordered from heaviest soldiers to lightest soldiers. Syntermes dirus has workers and soldiers much heavier than the next heaviest spe- cies, Cornitermes. The termite species with soldiers possessing strong or long mandibles are heavier than those termites whose soldiers have vestigial mandibles, and well developed nasi. These latter soldiers are also lighter than their workers, a relationship reversed in the other termite species.
Table 1.
Individual wet weights of termites (measurements expressed in micro- grams; mean with standard deviation in parentheses). Species Workers Soldiers
Syermes dirus
Cornitermes cumulans
Orthognathotermes gibberorum
Procornitermes araujoi
Grigiotermes metoecus
A rrnitermes euumignathus
Cortaritermes silvestri
Nasutitermes sp.
Velocitermes paucipilis
a Equal number of all three morphs weighed. b Only major soldiers weighed.
c Mixture of two worker types weighed.




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86 Psyche
C. Morphology of Soldiers
The positions of measurements taken on soldier heads are- indi-
cated in Figure 2 (adapted from Coles 1980). Total body lengt: Ai was measured from tip of mandible or nasus, whichever extended further, to the end of the abdomen. The figures presented in T a b l e 2 are the averages of 15 individual soldiers and are ordered from greatest to least mandible length. As can be seen, these five m o rpho- logical measurements are, on the whole, positively correlated- with each other, with total body length and with weight (Table 1 ^> - The major exception is Orthognathotermes, which has mandibles ^a-nd a nasus of a different shape than the other species. D. Worker-Soldier Ratios
Worker-soldier ratios were calculated by counting all o 3? the workers and soldiers in a piece of termite mound. The pieces- was rapidly removed from the surrounding mound so as to prev c n t a change in the normal worker-soldier ratio. For all species exce- pt P. araqjoi, A. euamignathus, S. dirus and C. silvestri, five pie= es of mound from at least three different mounds were counted - The
result obtained from a piece of mound was not used if the piece
contained less than 600 individuals. Because of the large variation obtained in the first five counts for P. araujoi, an additional "ailnree pieces were counted. The fifth count used for A. euamignathu-~t- was an average of 45 samples and was taken from Domingos ( 1 980). Only four counts were taken for C. silvestri. The large diffuse mounds inhabited by S. dirus and the r a p i d retreat of soldiers and workers made it impossible to obtain w o rker- soldier ratios from populations within the mound for this species. Instead, the value presented in Table 3 is an average of counts m a d e on eleven foraging parties. The method used (Coles 1980) w-^a-s to plug the exit at least one hour after foraging had begun. A f t e r spraying with pyrethrin aerosol insecticide all soldiers and wo r k e r s were collected and counted. Table 3 presents the data on wo rker- soldier ratios ordered from greatest to least percent soldiers. Those termite species with soldiers having chemical-based d e~ f en- sive systems have fewer workers per soldier than the other termite species. In fact, for these species, Velocitermes, Nasutitermes and Cortaritermes, there is little variation between species in this worker-soldier ratio. Similarly, Cornitermes and Procornitery-^res,



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19821
Negret & Redford - Termite Species
Figure 2. Positions of morphological measurements of soldier heads: lh= Lat- eral head length; In = nasus length; 1m = mandible length; Wh = maximu m head width; dh= head depth including postmentum.



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88 Psyche [VOI. 89
Table 2. Morphological measurements of soldiers (measurements expressed in millimeters; mean with standard deviation in parenthesis). Lateral
Length Maximum Total
Mandible Nasus of Head Head Body
Species Length Length Head Width Depth Length Orthogna thotermes
gibberorurn
fintermes
dirus
Corniiermes
cumulans
Procorniternies
araujoi
A rmit ermes
euamignathus
Nasut itermes
SP -
Velocitermes
pauc Ipiiis
Cortaritermes
silvestri
Note: Grigiotermes is excluded for it has no soldiers. two similar species have very similar workers-soldier ratios. Armi- termes occupies an intermediate position while Orthognathotermes has a large number of workers per soldier. A. Mound size and form
Table 4 presents data on mean heights, widths and lengths of ten mounds for each of the nine species of termites. Figure 3 (a-r) con- sists of two photographs of each species mound, one of an entire mound and the other of a mound in transverse cross-section. As can be seen from the data and the photographs, the shapes of these mounds range roughly from an inverted cone (Cornitermes) to a low dome (Orthognathotermes).




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19821 Negret & Redford - Termite Species 89 Table 3.
Proportion of workers in nests (mean with standard deviation in parentheses).
Species
Worker- %
Soldier
Soldiers
Velocitermes paucipilis
Nasutitermes sp.
Cortaritermes silvestri
finterms dirus*
Armitermes euamignathus
Procornitermes araujoi
Cornitermes cumulans
Orthognathotermes gibberorurn
*Figures derived from foraging parties. See text, Grigiotermes excluded as it has no soldiers.
The nature and form of individual mounds vary greatly and the characteristics listed below are generalized descriptions of mounds found in the Distrito Federal and Emas Park. Cornitermes cumulans (Fig. 3 a,b): The mound has a very hard outer shell of soil surrounding a soft inner core of carton (fecal material, communited plant material abd bits of soil) which often extends below ground as much as 40 cms. The galleries are large and unlined.
Nasutitermes sp. (Fig. 3 c,d): The mound is domed with the outer several centimeters softer than the inner core (as in arboreal Nasuti- termes and Constrictotermes) and often extends 25cms under- ground. The internal structure consists of thin-walled, convoluted,



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90 Psyche [Vol. 89
Table 4.
Dimensions of the epigeal portion of termite mounds (measurements expressed in centimeters; mean with standard deviation in parentheses). Species Height Length Width
Cornitermes cumulans
Nasutitermes sp.
Velocitermes paucipilis
Grigiotermes metoecus
Procornitermes araujoi 28.8 69.5 60.0
( 12.0) (33.9) (34.4)
A rmitermes euamignathus
Cortartiermes silvestri
Orthognathotermes gibberorurn 15.0 35.9 40.4 (3.0) (1 1.3) (13.6)
irregular galleries with a mottled black and soil-colored lining of fecal origin.
Syntermes dirus (Fig. 3 e,f): This species builds low-domed termi- taria, the major parts of which are below ground level (often to depth of 1.5 m.). The galleries are large and diffuse, often containing grass stores and are lined with regurgitated soil in which individual pellets are clearly visible.
Velocitermes paucipilis (Fig. 4 g,h): The mounds are pyramidal, very soft, crumbly and are generally built around a grass tussock. They often extend several centimeters underground in a series of very diffuse galleries which are lined with a discontinuous layer of black material of fecal origin. Large amounts of cut plant material are found inside the mound.




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19821 Negret & Redford - Termite Species 91 Figure 3.
Mounds of the termite species studied; external view and longitudinal section: a and b, Cornitermes cumuhs; c and d, Nasufirermes sp.; e =nd f, +nierrnes dims.




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92 Psyche [VOI. 89
Grigiotermes metoecus (Fig. 4 i,j): These medium-sized domed mounds are often occupied by other species of termites and ants. The galleries are distinguished by smooth, shiny soil-colored floors and by small pieces of stone incorporated into the 'ceilings.' Indi- vidual deposits of fecal material used in construction are visible on the mound surface.
Procornitermes aragjoi (Fig. 4 k,l): These medium-sized, rounded mounds are often characterized by a thin layer of loose soil covering the outer shell. These mounds are quite brittle and homogenous and have galleries with a mottled lining of black soil and colored parti- cles, probably of fecal origin. They rarely extend below ground. Armitermes euamignathus (Fig. 5 m,n): This species builds very characteristic slightly domed mounds. The walls are very hard but the mound itself is only loosely held to the substratum with a cavity frequently occurring between it and the soil. The internal structure consists of large irregular chambers connected by very small galler- ies. During the alate flight season mounds of this species are charac- terized by earthen turrets several centimeters high built on the outer surface and serving as 'launching platforms' for alates. Cortaritermes silvestri (Fig. 5 o,p): This species builds soft, low rounded mounds with large irregular galleries. The mounds are fre- quently built around grass tussocks and extend several centimeters underground as in Velocitermes.
Orthognathotermes gibberorum (Fig. 5 q,r): The low mounds built by this species are covered with loose soil and bound together by living grass stems. The galleries are regular and homogenous throughout. The mound frequently extends several centimeters underground but can be separated easily from surrounding soil when pried up.
B. Mound hardness and nest material
The 'hardness' of a mound was measured using a soil penetrome- ter which measures the force necessary to push a metal cone into the soil. The resistance to penetration is obtained by dividing the load of penetration (force applied) by the area at the base of the cone, which was 637.939mm3. The resistance to penetration was taken as a measure of hardness of the mound surface. A termite mound is not a solid structure but consists of a complex system of galleries and chambers. The outer wall is often thick enough for penetration of the whole cone. However, at times, the



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19821 Negrer & Redford - Termite Species 93 Figure 4.
Mounds of the termite species studied: external view and Iongitud inai section: g and h. Veloriiermes patiripitis; i and j, Grigioiermes nieIoems; k and I. Prot'orniiermes uruujoi,
cone pushed into a gallery and a low reading was obtained. In o rder to obtain a representative figure for the whole mound ten meas.. ure- ments were taken, each from different positions, e.g. base, m i d dle, top.
The hardness of any mound varies considerably throughout- the
year with the amount of rainfall. To reduce these variations a H the



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94 Psyche [vol. 89
Figure 5. Mounds of the termites species studied; external view and longitudinal section: m and n, Armiierms euamignathus: o and p, CorfariiemexsUvestri; q and r, Orthogna~hoiermes gibbe-rorum.
measurements were made in one month (April) at the end of the rainy season. Some variation in hardness occurs from day-to-day and so on any one day of recording, one mound from each of the eight species was examined. Ten mounds from each species were examined and ten measurements were made from each mound. Care was taken to select approximately the same size of mound for the ten mounds of any one species.
The mean values for the hardness of termite mounds in each species are shown in Table 5. As the range is large (l5.24-O.11 Newtons/mm3) the data were transformed (6) and the differences



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19821 Negret & Redford - Termite Species 95 Table 5.
"Hardness" of outer mound and materials used in mound construction (In column 1, any two means not followed by the same letter are significantly different at p = 0.05. In columns 3 through 6, ++ = usually used; + = occasionally used).
Resistance to
Penetration (Newtons mm')
Nest Construction Material
-
Termite Soil at Regurgitated Fecal
Species Mound Base Soil Soil Material saliva Velocitermes
paucipi1i.s
Nasuritertnes
SP.
Corraritermes
siI\~esrri
Procornitermes
araujoi
Or~hognathotermes
gibberorum *
mermes
dims
Grigiotermes
meioecus
A rn~ilermes
euamignathus
Cornitermes
cumulans
*Determined for only 4 mounds so no statistics performed. between these means tested for significance using Hartley's multiple range test. The ranking obtained from this analysis is shown in Table 5 with the mean values of the raw data. Velociterrnes, Nasuti- termes, Cortaritermes and Procornitermes had the softest nests while Corniterrnes had the hardest nest, 140 times harder than the softest, Velociterrnes.
The composition of material used to build mounds was deter- mined by direct observation of workers. Observations were made on at least ten mounds per species, at different times of the day and year. The results are presented in Table 5. Four types of material



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were observed to have been used by termite workers in nest c o n s rl
tion: soil, regurgitated soil, fecal material and saliva. In some c a s ( such as Procornitermes nests, a11 four were used. Soil and / - r I gurgitated soil were always the most common forms of bui X d i material.
C. Distribution and Abundance of Nests
Information on the distribution and abundance of t e r r n mounds in each vegetation type was collected from a v a r i c y
sources and the results are presented in Table 6. Different S a m p 1i1 methods can produce different results, depending on the s v -ti distribution of the termite mounds, the size of area sampled an d tl
number of areas sampled. It is often difficult to interpret f i g u r e s ( termitaria densities because investigators do not report wheth - r : termitaria examined contained the mound-building species. T h u
the specific methods used to obtain each of the densities reporc c d Table 6 are detailed below.
Mefhod a: (Coles 1980); method b (Domingos 1980); me XIC c (Coles de Negret et al. in prep.).
Blocks of 50 X 50 meters were selected randomly in each o f tl
four vegetation types studied in the Distrito Federal. As some 0 S tl termite species in the present study were occasionally fou n 4 I
mounds built by other species, in these methodologies, all t h e e P geal mounds in the area were completely excavated. The abund n( of each species was thus expressed in numbers of nests per hec zar In order to exclude sites with only foraging termites, a "nest 9v w; defined as a structure in which termite nymphs and larvae -el present.
M~thod d: (Redford in prep.).
Twelve separate transects, each of I00 by 20 meters were ma DT- k e out in the campo limp0 vegetaton of Emas National Park, G %a!
All the mounds built by Corniterrnes ~~umulans in each transect - e r counted. The figure in Table 6 is the mean calculated from t e s
twelve transects (standard deviation = 16. I ). Mefhod P: (Brand20 in prep.).
Two blocks, 100 by I00 meters were marked out in separate a r e a of campo sujo and two others, of the same size, in areas of cerr- a d vegetation in the Distrit Federal. All the Syntermes dirus mo- n d present in each area w t! re counted. As this species frequently cz- a n structs small soil domes, apparently for storing food, nests - e r



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19821 Negret & Redford - Termite Species 9 7 Table 6.
Distribution and densities of termite nests/mounds per hectare in four- vegetation types (Letters correspond to different sampling methods-see text for details).
Campo Campo Cerrado
Species
Limpo SUJO Sensu Strict0 CerradZo
Nasufiferi?ie.s
sp.
again defined as structures in which termite nymphs and larvae w e r e present.
Method$ (Curado et al. in prep.).
All the mounds built by Armitermes euamignathus and Ve/ocz-- tertnespaucipilis in an area of campo sujo (100 by 100 meters) in t h e Distrito Federal were sampled and counted. Method g: (internal report, University of Brasilia). Mounds of Velocitermespaucipili.~ present in a transect 230 by 1 0 meters extending from campo limp0 to campo sujo in the Distrit o Federal were counted.




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[Vol. 89
Feeding habits were deduced from field observations, examina- tion of worker mandibles and gut contents, information in the liter- ature and in some cases, from laboratory food preference experiments. Results are summarized in Table 7. Details of foraging behavior, methods of investigation and food sources are given below. Grigiotertnes tnetoecus
Field observations and examinations of worker mandibles and gut contents indicate that this species is entirely geophagous. lt excavates subterranean galleries in the soil surrounding its mound and is also frequently found in old, disused termite workings, pre- sumably rich in organic material.
Armitermes eumnignathus
In the cerrado and cerrad50 vegetations foraging workers can be found under the bark of living trees and sound, dead trees- How- ever, this species also occurs with equal frequency in campo limpo where few or no woody shrubs exist. Field observations on the foraging behavior of I00 colonies of this species show that in the absence of woody vegetation they can exploit the root systems of grasses (Domingos 1980). Laboratory food preference experiments carried out by the same author on five colonies of A. euamignathus indicates that when presented with a range of food sources, all colonies selected wood in preference to bark, litter and grass roots. Further field observations confirmed that this species selects dead, sound wood in preference to live and to dead, decomposed wood. The workers forage diurnally and reach the food source via subter- ranean galleries. On average, mounds are 0.4 and 0.3 meters from their food sources in cerradao and cerradzo respectively and 1.2 and 1.0 meters in campo sujo and campo limpo, respectively (Domingos op. cit.).
Cornitermes cumulans
Field observations on foraging parties indicate that workers of this species feed on living and dead grasses and herbs, which they reach through subterranean tunnels, occasionally foraging under a fine layer of soil-sheeting. Small pieces of grass are cut from stand- ing grass tussocks and carried to the mound. Feeding in situ has been observed occasionally. Preliminary food preference experi-



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19821 Negret & Redford - Termiie Species 99 Table 7.
Modal feeding habits (++ = commonly consumed: + = occasion all^^ consumed).
SPECIES FOOD SOURCE
ments carried out on laboratory colonies showed that workers col- lect dead grass in greater amounts than live. When presented with only dead roots or dead grass blades, they fed more on the latter. Cot-larilermes sih1est ri
Field observations made in the Distrito Federal and information presented in Mathews (1977) indicate that this species feeds in grass tussocks among the roots and stems. It is not, clear, however, whether it feeds on the organic residues in the soil or on the grass roots themselves.
Nasutilern~es sp.
These termites have not been observed foraging in the open and rarely construct runways over the ground as do many other species in this genus. It is probable that they excavate underground tunnels to their food source, the exact nature of which is not known. Recent



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experiments on laboratory colonies have shown that this species can feed on a range of plant material including sound wood and both living and dead grass.
Prowrniiert~ies arauioi
Field observations have been made on above-ground foraging parties in the open and under soil sheeting. Workers cut and collect grass litter, generally at night, but occasionally on dull, humid days. S-\wiermes dirus
This species forages above ground in the open, at night, and crepuscularly. Workers and soldiers leave the tunnels from small exit holes which are plugged with several millimeters of soil during inactive periods. These foraging holes may be on the mound or at distances of up to 20 meters from it. The above-ground foraging parties consist of major workers and soldiers. At the end of a partic- ular trail the workers spread out over several centimeters and start cutting grass. Some climb up stands of vegetation and cut long pieces of grass which drop to the ground. Other workers cut these into smaller pieces and carry them to the nest. Consumption in siiu has not been observed.
Ve10ciierme.s paucipilis
These termites feed on grass and surface litter which they collect at night in the open. The workers form trails to the food source where they spread out to cover a large area, cut small pieces of grass and leaves, and return with them to the nest. The workers are flanked at regular intervals by soldiers oriented with their raised heads pointing outwards.
0rihognaihoiernie.s gibberorurn
Examination of worker mandibles and gut contents together with information from Mathews (1977) suggests that this species feeds on organic residues in the soil. Observations of foraging behavior have not been made.
Food sources were divided into four categories: humus, sound wood, decomposing wood, and grass and herbaceous litter. The few termites eating sound wood and the many eating grass and herba- ceous litter probably reflect the fact that most of the vegetation types included in this study were open with few trees. Examination of the termite fiduna within the gallery forests would reveal many



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Negret & Redford - Termite Species
more wood-eating species. The predominance of grass-eating ter-
mites is understandable because of the large biomass and rapid turnover of their food source.
Of the 54 species of termites in the cerrado vegetation of the Distrito Federal (excluding gallery forests) only nine mound- building species were examined in this study. Many of the other species do not build mounds and are found instead living within mounds built by one of these nine species. It is probable that many of these non-mound-building species will be found to be geophagous or humivorousl feeding in or near the mounds they inhabit. The cerado vegetation of the Distrito Federal? Brazil has a diverse termite fauna with at least 54 species present (excluding those found in gallery forest vegetation) (Coles 1980). Estimates of the termite density in savanna areas in other continents are much lower with only 19 species in the Sahel, Senegal- 19 in northern Guinea? Nige- ria- 23 in southern Guinea? Nigeria and 36 in savannas of the Ivory Coast (Wood and Sands 1978).
A survey by Coles (1980) indicated that most cerrado species were present in all the physionomic vegetation types; however, in terms of abundance, certain species were more common in one particular type of vegetation. This is clearly illustrated by the data in Table 6. Nests of Nasutitermes sp.? Velocitermes paucipilis, Cortaritermes silvestri, Syntermes dirus and Cornitermes cumulans were all more abundant in the open vegetation types (campo limpo and campo SUJO). Grigiotermes metoecus and A rmitermes euamignathus were equally common in all types while Procornitermes araujoi was more common in woodland areas. Orthognathotermes gibberorurn had an irregular distribution being less common in the cerrado sensu srrictu of the Distrito Federal but more common in the campo limpo of Emas Park. These preferences for particular vegetation types can- to some extent? be related to the feeding habits of each species (Table 7); however- abundance of a species is also influenced by other species present. In some areas conditions were particularly favorable for one species? an example of which was found in Emas National Park where populations of Cornitermes ~wmulans were exception- ally high? with other species much less common. The variation in abundance of a species in different regions can be



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102 Ps-y che [Vol. 89
accompanied by variations in mound form and size. Howse ( 1979) gives several different examples of termite species which build very different mounds in different regions. Macrotermes subh~~~a/inus in western Uganda builds mounds with very thick walls and no open- ings but on the Serengeti Plains, where the soil is volcanic ash, the mounds are low with many pit-like openings. In the semi-arid regions of eastern Africa they are different again, being steeple- shaped and constructed around a central chimney. Even though regional differences can exist, the characteristics of mounds investi- gated in this study showed a remarkable consistency throughout the cerrado region reinforcing observations by Emerson (1938). In constructing a mound, galleries are excavated within the soil by the termites and particles are often transported from considera- ble depth and incorporated in the epigeal portion of the mound. This not only increases aeration of the soil but can also alter its chemical composition (Lee and Wood 197 1). Soil used in building is reinforced with excreta and in some instances wood and other plant material.
Studies on the chemical composition of termite mounds in the cerrado have recently been started in Brasilia. Preliminary results indicate that both Velocitermes and Armitermes mounds have much higher concentrations of calcium, phosphorus, potassium and alu- minum than the soil surrounding the mound (Curado et al. in prep,). However, an analysis of Table 5 shows that the materials used in mound building are not directly related to the hardness of the outer layer of the mound. Such factors as the way in which the material is deposited by the workers at the actual site of construc- tion as well as the size and arrangement of galleries and the thick- ness of walls also contribute to the overall hardness of the mound. The mounds are constructed entirely by the worker caste. This caste takes little active role in the defense of the mound, a role performed by the soldier caste. The proportion of these two castes varies with the species and is apparently finely regulated by phero- mones produced by the queen and the soldiers (Luscher 1961). Haverty (19771, in a comprehensive work, summarized the data available on the relative proportion of workers and soldiers in 1 I2 species of termites. Unfortunately, many of these data, gathered by different investigators, are not strictly comparable because of differ- ences in sampling techniques and types of groups sampled. The



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19821 Negrei & Redford - Termiie Species 103 homogeneity in methodology used in calculating worker-soldier ratios in this study allows for precise comparison between species within the limits of accuracy of this method. The worker-soldier ratios were found to vary greatly between nests in some species (i.e., Procorniiert17e.s) and remain quite ionst ant in others (i.e., V~locii~rt17es). The behavior of nasute soldiers, which respond to a break in the nest by rapidly recruiting to the break, can greatly alter the worker- soldier ratio calculated. As an example of this, on one occasion the number of soldiers counted from a piece of Nu.wiiiert~7e.s mound, which had been excised from the surrounding mound but left in place for 30 seconds, was almost half again the number of soldiers counted from a piece taken from the same mound but removed immediately following excision. Although comparison can be made between the nine species of termites it must be noted that these data were taken during one period of the year and present a static picture of the proportions of workers and soldiers in given nests. It seems probable that in the species examined, as in other species (Sands 1965), the worker-soldier ratio varies seasonally and possibly also with the age and size of the nest.
It is evident from the data that some species have proportionally many more soldiers than other species. Even though the proportion of soldiers in a colony varies, in all cases (when there is a soldier caste) the soldier caste is largely responsible for the defense of the colony and has morphological features which allow it to do this. The type of defense used by soldier termites tends to be based on chemicals, mechanical defense or a combination of both. The sol- dier type using a chemical-based defense has vestigial mandibles (Table 2), is lighter than its workers (Table I), and produces poten- tially toxic and repellent secretions which are ejected from the tip of a long tube or nasus at the front of the head (Nutting et al. 1974, Eisner et al. 1976; Howse 1975; Prestwich 1979). Of the termites studied in this work, Velociiert~~es, Nasuiiiertws and Coriari1et*t?7e.s fall into this category. The soldier type using a mechanical-based defense rarely produces defensive secretions and has a large head, and strong, sharp mandibles. Orihognaihoiert?7e.s is the only species within those here studied that has no development of the nasus, relying solely on its mandibles for defense. S.rniermes, Cot~nii~rt?~e.s and Procornitert71e.s all have strong mandibles which can pierce human skin, drawing blood, together with a greatly reduced level of



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chemical defense (see 'nasus length* Table 2 as one indimto r of
extent to which chemicals are used in defense). Armi~erme-s- sta
in an intermediate position between ihe principally chemical nd
principally mandibulate type soldiers, with a long nasus and ma1
bles which can pierce human skin but not draw blood. Grigi- zero is very interesting in that it has no soldiers; the workers h a w ( produce a large drop of liquid on either side of the abdome n w disturbed, which may serve a defensive purpose. Termites are probably the dominant rorm of animal life i - m, areas of central Brazil, bo~h in number of species and biomas ss - T play major roles in herbivory, decomposi~ion, sod formati e n , alteration, and as an important source of food for other a n irn Ants are probably the major predators of termites, but in =en Brazil mammals are common and important predators as w G 11. aspects of termite biology reported in this study are all imp0 - z an defense by termites against mammalian predators. The smai sizs termites, the type of soldier defense and the proportion of sol ier workers are all factors influencing feeding by mammals 0 ce termite mound has been opened. The shape, six and hardn -ss t mound influence the ways in which a mammalian predae a r break into a nest while the distribution and abundance of nes -a= s a measure of the spatial availability of termites as a food s ~ U I Lastly, the feeding habits of termites are important in deter -in when, and if, termites are availabie outside of the mouncX F( preference tests with large and small mammalian predat- rs i observation of wild giant anteaters (Redford in prep.) have s h c that all of these aspects of termite biology interact in deter -in which species of termites are preferred as food and how a- a i l a they actually are to mammalian predators. Helen Cola de Negrel would like to thank the Trustees of
Royal Society Leverhuhe Scholarships and the Science R sea
Council-Shell Research CASE award for financing this re s e a r The data form part of a Ph.D. ~hesis submitted to Southa m p university in 1980 under the supervision of Dr. P, E. Howse - Kent Redford would like to thank the National Gee- r a p Society, the Museum of Comparative Zoology, the Organiza $or American States and Sigma Xl for help in financing this rp -ear



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19821 Negret & Redford - Termite Species 105 Special thanks to the members of the Order of Saint Benedict and the Laboratory of Ecology, University of Brasilia. Both authors thank Barbara L. Thorne, Alan E. Mill, James F. A. Traniello and Bert Holldobler for reading and criticizing the manuscript. ARAUJO, R. L.
1961.
New genus and species of Brazilian termite. Revta. Bras. Biol. 21, 105-1 1 I.
1969.
Notes on Denti.~pi(sotert)ie.s with description of a new species. (lsoptera, Termitinae). Revta. Bras. Biol. 29, 249-254. 1970.
Termites of the Neotropical Region. In: Biology of Termites. Vol. 11. (Ed. by K. Krishna and F. M. Weesner) pp. 527-571, Academic Press, N. Y. 1977.
Catalog0 dos lsoptera do Novo Mundo. Academia Brasileira de Cien- cias. Rio de Janeiro, RJ.
BANDIRA, A. G.
1979.
Ecologia de cupins (lnsecta: lsoptera) da Ama7onia central: efeitos do desmatamento sobre as popuiacoes. Acta amazonica 9,48 1-499. BRAND~O, D. in prep.
Ecologia de duas especies simpatricas de S,~wterme.~ (lsoptera; Nasu- titermitinae) no Distrito Federal do Brasil. COLES, H. R.
1980,
Defensive strategies in the ecology of Neotropical termites. Ph.D. thesis Southampton University. 243 pp.
COLES DE NEGRET, H. R., DOMINGOS, D. J. AND FONTES, E. G. in prep. Spatial distribution of termite mounds in the cerrado vegetation, Dis- trito Federal, Brazil.
CURADO, W., COLES DE NEGRET, H. R., HARIDASAN, M. in prep. Composition of the nest material of two termite species and the soil of their bases.
DOMINGOS, D. J.
1980.
Biologia, densidade e distribui~ao espacial de duas espkcies de Armi- terme.9 (Termitidae) em cinco formaq6es vegetais do cerrado. M.Sc. thesis Universidade de Brasilia. 22 pp.
EISNER, T., KRISTON, 1. AND ANESHANSLEY, D. J. 1976.
Defensive behaviour of a termite Nasutitern~e.~ e.~itio.sus. Behav. Ecol. Sociobiol. 1, 83-1 25.
EITEN, G.
1972.
The cerrado vegetation of Brazil. Bot. Rev. 38, 201-341. EMERSON, A. E.
1938.
Termite nests. A study of the phylogeny of behaviour. Ecol. Mono- graphs. 8, 247-284.
1952.
The Neotropical genera Procorniternies and Cornitert)ie.s (Isoptera, Termitidae). Bull. Am. Mus. Nat. Hist. 99, 429-471,



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Psyche
[Vol. 89
FONTES, L. R.
1979.
Atlaniiiermes novo genero de cupim, corn duas novas especies do Brasil. (Isoptera, Termitidae, Nasutitermitinae) Rev. Bras. Ent. 23, 219-227. HAVERTY, M. I.
1977. The proportion of soldiers in termite colonies: a list and a bibliography. Sociobiology 2, 199-2 16.
HOWSE, P. E.
1975.
Chemical defenses of ants, termites and other insects: some outstanding questions. Proc. IUSSI. (Dijon), 23-29.
1979.
The uniqueness of insect societies: aspects of defense and integration. In: Biology and Systematics of Colonial Organisms (Ed. by G. Larwood and B. R. Rosen), pp. 345-374. Academic Press. New York. LEE, K. E. AND WOOD, T. G.
1971.
Termites and Soils. Academic Press. New York. LUSCHER, M.
1961.
Social control of polymorphism in termites. In: Insect Polymorphism (Ed. by J. S. Kennedy), pp. 57-67. Roy. Entomol. Soc., London. MATHEWS, A. G. A.
1977.
Studies on termites from the Mato Grosso State, Brazil. Academia Bra- sileira de CiEncias, Rio de Janeiro, RJ. 267 pp. NUTTING, W. L., BLUM, M. A. AND FALES, H. M. 1974. Behavior of the North American termite Tenuirosiriierr77e.s' ienuirostris with special reference to the soldier frontal gland secretion, its chemical composition and use in defense. Psyche, 81, 167- 177. PRESTWICH, G. D.
1979. Chemical defense by termite soldiers. J. Chem. Ecol. 5,459-480. SANDS, W. A.
1965. Mound population movements and fluctuations in Triner1liiermes ebenerianus Sjostedt (Isoptera, Termitidae, Nasutermitinae). Insect. SOC. 12,49-58.
WOOD, T. G. AND SANDS, W. A.
1978. The role of termites in ecosystems. In: Production biology of ants and termites (Ed. by M. V. Brian), pp. 245-292. Cambridge University Press.



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