Polyembryony

Definition

A developmental phenomenon in which a single fertilized egg divides to produce multiple genetically identical embryos. Unlike typical sexual reproduction, offspring are clones of each other but genetically distinct from both parents. In arthropods, polyembryony represents a derived reproductive strategy that dramatically amplifies fecundity from minimal maternal investment.

Etymology

From Greek poly- (many) + embryon (embryo)

Example

The parasitoid wasp Copidosoma floridanum (Encyrtidae) exhibits extreme polyembryony: one egg deposited into a host caterpillar can proliferate into 1,000–2,000 genetically identical larvae that emerge to pupate externally. This allows a single female to maximize offspring production while minimizing host-searching effort.

Related Terms

• Parthenogenesis
• clonal reproduction
• parasitoid biology
• embryonic proliferation
• cleavage polymbryony
• adventitious embryony

Usage Notes

Distinguish from parthenogenesis (development without fertilization) and budding (asexual outgrowth from parental tissue). In insects, polyembryony occurs primarily in Hymenoptera (Encyrtidae, Platygastridae) and Strepsiptera, where it is associated with endoparasitoid lifestyles. The term can also describe plant phenomena (adventitious embryony) and rare mammalian identical twinning, but these are outside core entomological usage. Specialists reserve 'cleavage polyembryony' for the zygotic division mechanism seen in wasps, versus 'adventitious embryony' for somatic embryo formation in plants.