OFF LINE   Gerace, D., 1997. Parental Investment in the Class Insecta

Insects Behavior Review Articles

www.colostate.edu/Depts/Entomology/courses/en507/papers_1997/gerace.html 


Abstract:

Parental investment theory in insects involves many complex factors.  Factors that limit parental fitness 
dictate parental investment.  Natural selection acts on parental investment to find optimal levels of 
investment and number of offspring.  There are numerous ecological factors that exhibit the evolution of 
parental care.

Paternal care is related to certainty of paternity.  Natural selection acts against paternal care when paternity 
is uncertain. Paternal care should not include nuptial gifts and spermatophores give to females to nourish 
the eggs.  The complexities of paternal care are shown in three species of Belostomatidae (The Giant Water 
Bug).  Maternal care is the most prevalent parental investment.  Females provide nourishment and tissue 
from their bodies to provision the eggs. Guarding of eggs and nymphs from predators is found in many 
different orders.  The Ovoviviparous leaf beetle (Gonioctena sibirica) stays with larvae until the last larval 
instar. Several species show a more advanced behavior of providing food resources as well as a guarding 
behavior.  In the family Membracidae, females use aggressive guarding  as well as an alarm pheromone 
that is emitted from an injured nymph.  This communication from offspring to parent is another type of 
pre-social behavior.  Groups of females from the genus Elasmucha work together to guard the clutches, 
indicating a pre-social behavior.

Biparental care in dung beetles and burying beetles demonstrates that the evolution of parental care in both 
males and females increases their reproductive success.

Social insects by definition demonstrate parental investment; which may including sibling investment due 
to nepotism or indiscriminate altruism.

Keywords: Parental Investment, Paternal Care, Maternal Care, Insects