Mussel scale - Fecundity

Mussel scale females give birth to a moderate number of eggs over a period of about 1 month in summer. The fecundity (total egg production) has been estimated in a number of countries, including New Zealand, and for a number of host plants (see Table). Fecundity is also reported to vary between parthenogenetic (all female) and bisexual populations in Europe. Parasitism of adult female mussel scale insects by Aphytis wasps may not totally prevent egg production and a small number of eggs may still be produced.

Country Reproduction Host plant   Fecundity
Canada (1962-65) parthenogenetic apple   average 38-69, range 10-110 eggs per female
Germany (1972) not stated not stated   average 40 eggs per female
New Zealand (1999) parthenogenetic apple   average 34, range 15-85 eggs per female
Tadzhikistan (1971) not stated not stated   range 10-120 eggs per female
U.S.A. (1965) parthenogenetic apple   average 53-55, range 40-74 eggs per female
U.S.A. (1965) not stated fruit trees   40-100 eggs/female
United Kingdom (1984) parthenogenetic fruit trees   up to 80 eggs per female
U.S.S.R. (1959) parthenogenetic rosaceous   average 40-47 eggs per female
  sexual Padus sp.   average 20 eggs per female
  sexual Tilia sp.   average 68 eggs per female