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[Vol. 94 
Table 1. Honeydew excretion rates of Aetalion reticulatum when solicited by 
three species of Hymenoptera. 
Soliciting Hymenoptera 
(size, mm) 
N 
Drops per bout 
(mean + SD) 
Length of bout 
(mean + SD, seconds) 
Formicidae 
Z. porrasi 
20 
2.7 + 2.0 
11.3+ 10.0 
(3.5) 
C. abdominalis 
7 
3.4+ 1.0 
10.6 + 4.5 
(6.0) 
Vespidae 
P. fraternus 
22 
8.6 + 6.5 
13.1+8.9 
(12.9) 
honeydew by gleaning foliage near feeding homopterans. Further- 
more, all studies, except for Polistes fuscatus (Barrows 1979), have 
been reported from tropical areas. Distinct ownership behavior has 
been recorded from only a few species. 
Our observations on two homopteran species and their complex 
of hymenopteran attendants, together with those of other workers, 
add several facts regarding the nature of mutualism between these 
two groups. First, the association between Homoptera and their 
hymenopteran attendants is highly stochastic and often involves a 
multispecies complex. Most studies have focussed on a single hyme- 
nopteran species (e.g., Fritz 1982, Messina 1981), but several 
workers (e.g., Addicott 1979, Bradley and Hinks 1968, Bristow 
1984, O’Neill and Robinson 1977) have now investigated commu- 
nity aspects of the relationship. An individual Homoptera may host 
several species of Hymenoptera during its lifetime. For instance, A. 
reticulatum has been observed to be tended by Trigona amalthea 
and T. spinipes along with a variety of ant species in Brazil (Brown 
1976, Castro 1975, Cockerell 1920). Brown (1976) studied hymenop- 
teran attendance of A. reticulatum on the Osa Peninsula, not far 
from our study site, and found a completely different complex of 
attendant species with diel shifts. An attendant hymenopteran spe- 
cies may also associate with more than one species of Homoptera. 
Trigona amalthea is known to tend A. reticulatum and at least two 
species of membracids (Cockerell 1920, Salt 1929, Schuster 1981). 
Our study also reports that P.fraternus readily associates with both 
A. reticulatum and A. ferruginea. Elements of chance due to nest 
distribution and nutritional need of hymenopteran attendants, and 
