82 
Psyche 
[Vol. 94 
Parachartergus fraternus (Gribodo) (Hymenoptera: Vespidae), a 
major diurnal attendant, occurs from Costa Rica to Argentina and 
commonly nests on trees and saplings (Fig. la) near streams or 
swamps (Richards 1978). Six species of formicine and one species of 
myrmicine ants were also recorded among the hymenopteran 
attendants. 
Behavioral observations were made during 15-18 August 1984 for 
approximately 18 hours in daylight, six at dawn or dusk, and three 
at night. Parachartergus fraternus attendants were marked to 
determine if the same individuals returned to the same groups of 
Homoptera. An extended anal tube of aetalionids allowed inspec- 
tion of honeydew delivery to individual attendants. We noted the 
size class of droplets, and recorded the number of droplets per 
feeding bout and length of feeding bout for three major attendants. 
Common attendant Hymenoptera and Homoptera were collected 
for identification, and voucher specimens were deposited at the 
Museum of Comparative Zoology, Harvard University. 
Results 
Two aggregations of A. ferruginea and two of A. reticulatum 
were tended by P. fraternus during daylight hours (Fig. lb, c). Of 14 
homopteran aggregations, 13 were visited by two or more species of 
ants. These ant species included Camponotus abdominalis (F.), 
C. novogranadensis Mayr, C. sexguttatus (F.), C. simillimus 
(F. Sm.), two unidentified Camponotus spp., Zacryptocerus porrasi 
(Wheeler), and a few other unidentified occasional species. One 
male-female pair of A. reticulatum was not tended during our 
observation period. All homopteran aggregations except one were 
feeding on Piper auritum Kunth, a common plant of forest edges 
and disturbed sites in moist regions from Mexico to Columbia 
(Burger 1971). One aggregation of A. reticulatum was found on 
balsa, Ochroma lagopus Swartz var. bicolor (Rowlee) Standi. & 
Steyermark. 
The most explicit forms of ownership behavior {sensu Brown 
1976) were displayed by P. fraternus, which tended throughout the 
daylight hours. During our observation period, the same individual 
wasps returned to the same homopteran aggregations shortly after 
dawn and remained there until dusk except for several short (less 
than 10 minutes each) breaks. The wasps constantly antennated and 
