Effect of environment on reproduction in dusky-veined walnut aphids
William H. Olson, Butte County
California Agriculture 29(5):10-11. DOI: 10.3733/ca.v029n05p10.
Abstract Not Available – First paragraph follows:
The dusky-veined walnut aphid, Panaphis juglandis (Goeze), appears in three distinct forms: alate viviparous parthenogenetic females, apterous oviparous females, and alate males. Commonly, only the alate viviparous parthenogenetic female form of this aphid can be found during the spring and summer months. The apterous oviparae and males appear during the fall. This suggests that temperature, day length, or host plant (English walnut) condition influences form.
W. H. Olson is a Farm Advisor in Butte County. Assistance was provided by Dr. William C. Batiste, formerly with the Division of Entomology and California, Berkeley.