Observations on the biology of the potato tuber moth Phthorimaea operculella Zell. (Lepidoptera, Gelechiidae) in Iraq.
Phthorimaea operculella (Zell.) was first reported from Iraq in 1970, where larvae were found mining the leaves of tree tobacco (Nicotiana glauca), and it has since spread to potato fields, infestation varying from 1% in northern to 65% in central Iraq. The biology of the Gelechiid is described from observations on potato in the laboratory in Iraq in 1973-74. The egg, larval and pupal stages and preoviposition period averaged 2.3-7.2, 6.2-29.5, 4.1-12.6 and 1.6-7.9 days, respectively, and the generation times varied from 17.5 days in summer to 57.2 days in winter. Eight generations were completed in the period between 22nd November and 29th July. There was virtually no mortality in the egg or pupal stages, though it reached 12.8-100% among the larvae. Temperatures of 4 and 36 deg C were lethal to all stages.