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Psyche 
[March 
Discussion 
Female parental investment is well developed in the subfamily 
Membracinae (classification of Dietz 1975), particularly the tribes 
Hoplophorionini ( U . crassicornis and P. vittata) and Aconophorini 
( G . compressa). Although the behavior of G. compressa is similar in 
most respects to species in the Hoplophorionini, certain aspects of 
nymphal behavior are similar to E. bactriana in the subfamily 
Smiliinae (tribe: Polyglyptini). 
Placement of eggs by female G. compressa on top of plant tissue 
and held together by an accessory secretion is typical of the 
Aconophorini (Hinton 1977), while in the Hoplophorionini or 
Polyglyptini, eggs are inserted into plant tissue. Although all 
females sit on egg masses, the insertion of eggs into, as opposed to 
on top of, plant tissue may offer more protection from desiccation, 
parasites or egg predators due to less exposed egg surface area. 
Female G. compressa as with some Pentatomids with similar 
ovipositional habits, may not be able to protect peripheral eggs 
from parasites (Eberhard 1975). 
Female G. compressa on egg masses are extremely sensitive to 
disturbances while females of U. crassicornis and P. vittata usually 
do not desert egg masses, even when given more violent treatment. 
Physically displaced females of the latter 2 species can relocate egg 
masses (Wood 1976b, Wood in preparation), but female U. crassi- 
cornis do not recognize individual egg masses (Wood in prepara- 
tion). Whether individual female P. vittata or E. bactriana recognize 
their own egg masses has not been tested. Female G. compressa 
return to egg masses, but this may be an artifact of this species’ 
patchy distribution and low population densities. A dislodged 
female, which flew 10 or so feet, may encounter an egg mass which 
has a high probability of being her own through random flights or 
walking, but whether females recognize their own egg masses must 
wait until choice tests can be made. Activity which results in egg 
mass relocation by female G. compressa is adaptive since females 
appear to be necessary in preventing mold growth, protection from 
egg parasites or predators, and maintaining offspring aggregations. 
Protective or defensive adaptations of female U. crassicornis on 
eggs are cryptic coloration and lack of movement, but also involve 
the shape and hardness of the pronotum (Wood 1975, 1977a). 
Although mature female P. vittata are not physically protected by 
