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Psyche 
[March 
Moore (1968) determined that both limonene and a-pinene were 
rather typical components of termitid soldier secretions whereas myr- 
cene was detected only in one species of Amitermes. Vrkoc et al. 
have recently reported the major volatile components in the soldier 
frontal gland secretion of Nasutitermes rippertii to be a- and /3- 
pinene and limonene, with myrcene among six minor constituents. 
Similarly, with N. costcilis they found a- and /?-pinene and limonene 
among six major constituents of the secretion, and myrcene again 
among three minor components. However, although it is evident that 
monoterpene hydrocarbons are rather characteristic defensive products 
of nasute soldiers, these compounds do not appear to have a wide- 
spread distribution in the Insecta. Indeed, with the exception of the 
myrmicine ant Myrmicaria natalensis F. Smith, which produces 
limonene in its poison gland (Griinanger et al., i960), monoterpene 
hydrocarbons have not been identified in any other insect taxa. 
By taking high speed motion pictures of Nasutitermes soldiers 
attacking vestigial- winged Drosophila , Ernst (1959) determined that 
they move rapidly forward and backward (only once?) in delivering 
the jet of frontal gland secretion. He also observed one soldier to 
move its head from side to side during an attack. Our tracings of 
the shot patterns (Fig. 1) show that either or both of these move- 
ments are also used by soldiers of T. tenuirostris to increase the 
effectiveness of their defense. The basic oscillatory behavior probably 
represents the jerking or rocking movements which termites com- 
monly exhibit in mild alarm situations. We have also shown that 
soldiers are capable of firing more than once, if sufficiently alarmed, 
and certainly do not deliver the entire contents of the frontal gland 
in a single discharge as Ernst suggested. 
Many authors have stated that ants are the chief predators of social 
insects, with the termites not the least among their prey (Wilson, 
1971). There can be little doubt that the nasute soldier is a highly 
effective defender of the colony against arthropod predators close to 
the size range of the termites themselves. A large force of nasutes 
would seem to be of critical importance in protecting the workers on 
their food-gathering expeditions, particularly those that forage in the 
open as does T. tenuirostris. However, this common assumption 
apparently rests largely on casual, subjective observations and cir- 
cumstantial evidence of the type presented here. Quantitative data 
required to prove this assumption are not available and would be 
extremely difficult to obtain. 
