1982] 
Thorne — Termite-Termite Interactions 
147 
Damage to each antennae and leg was scored separately, and a 
pierced or decapitated head was scored as one head injury, even if 
multiple punctures were present. Thus for 10 dead termites, a max- 
imum of 20 antennal, 60 leg, and 10 head injuries were possible. 
That number of cumulative injuries divided by the total number of 
termites examined yielded the mean number of non-abdominal 
injuries per individual. This index gives some indication of the 
intensity of attack. 
The frequency of antennal, leg, and head injuries shows that Ami- 
termes beaumonti heads appear relatively vulnerable (at least when faced 
by Nasutitermes ), and that N. corniger was prone to numerous leg 
injuries. 
DISCUSSION 
Worker termites of some species join in aggressive encounters 
with members of other colonies and are often adept fighters, partic- 
ularly against other workers. Intensity and outcome of agonistic 
encounters is variable depending on the species, colonies, and 
castes involved. Soldiers also participate in termite-termite conflicts. 
This study suggests that mandibulate soldiers are more effective 
one-on-one inter-specific antagonists than are Nasutitermes sol- 
diers, although nasute soldiers are generally present in higher 
numbers per colony and may be more effective in groups. 
Research on termite-termite encounters has not been extensive, 
but is of interest because the recognized defensive caste, the soldiers, 
are not the sole participants, and may not join in such interactions 
at all. After viewing the attack of an introduced Termes worker by 
nymphs and larvae in a Calotermes colony, Grassi and Sandias 
write in their 1896-1897 account (p. 283), . .similar observations 
have been made several times, and show. . .that the soldiers purpose- 
fully reserve themselves for more important foes.” Pickens (1934) 
noted that workers of established Reticulitermes hesperus colonies 
will attack and kill founding pairs and incipient colonies which 
settle nearby. 
Andrews (1911) did an extensive series of intra-specific interac- 
tion experiments with Nasutitermes ripper tii. Nearly all staged 
encounters resulted in immediate conflict involving both soldiers 
and workers, although occasionally two colonies were completely 
docile towards each other. Andrews also came to the conclusion 
