The application of discriminant analysis to identify Cryptomyzus aphids

作者：Basilova Jekaterina^*

来源：Zemdirbyste-Agriculture, 2010, 97(4): 99-106.

• Cryptomyzus galeopsidis
• Cryptomyzus maudamanti
• aphids
• morphology
• discriminant analysis

Aphids of the species Cryptomyzus galeopsidis (Kaltenbach) and Cryptomyzus maudamanti Guldemond are very similar morphologically, although their summer host specificity is different. The host plants of C. galeopsidis are Ribes rubrum or R. nigrum and Galeopsis sp., while C. maudamanti feeds on R. rubrum and Lamiastrum galeobdolon. Canonical discriminant functions are proposed for identification of these aphid species, especially in the cases when host plants are unknown. Canonical discriminant functions presented in the identification key to European species of the genus Cryptomyzus appeared to be not as effective as they were supposed to be. They allowed correct classification not of 90% of C. galeopsidis individuals with studied life cycle, but of 64.6% instead. Measurements, counts and ratios characterized by weak or very weak correlation (correlation coefficient vertical bar r vertical bar < 0.5) with body length were used for the forward stepwise discriminant analysis. Canonical discriminant functions for both apterous and alate viviparous females of C. galeopsidis and C. maudamanti enabling separation of 90-100% individuals of these species were obtained through the forward stepwise discriminant analysis of selected characters.

• 出版日期2010