Cruciferous Flea Beetles (Phyllotreta spp.; Coleoptera, Chrysomelidae) in Spring Rape Crops in Leningrad Province

• Published in: Entomological review 2021-04, Vol.101 (2), p.174-180
• Main Authors: Shpanev, A. M., Moseyko, A. G.
• Format: Article
• Language: English
• Subjects: Agricultural industry; Agricultural production; Beetles; Biomedical and Life Sciences; Coleoptera; Crops; Developmental stages; Fleas; Genetic variability; Leaves; Life Sciences; Phyllotreta; Seedlings; Zoology
• ISSN: 0013-8738; 1555-6689
• DOI: 10.1134/S0013873821020032

Observations carried out in 2012–2019 showed that cruciferous flea beetles constituted a serious threat to spring oilseed rape crops at early stages of their development in Leningrad Province. Six species of the genus Phyllotreta were found, of which Ph. undulata Kutsch. and Ph. striolata (Illiger) were the most abundant while the remaining species were far less numerous. Considerable morphological variability of Ph. atra (F.) and Ph. vittula (L. Redt.) may lead to misidentifications. The recent record of Ph. erysimi Ws. from Leningrad Province was not confirmed. The harmfulness of cruciferous flea beetles was so considerable that the presence of 1 ind./m 2 at the rape seedling stage reduced the yield by 0.010 to 0.040 dt/ha, or by 0.05 to 0.15%. With the actual pest densities of 12 to 30 ind./m 2 at the seedling stage and with the rate of leaf surface damage not exceeding 25%, the rapeseed yield loss was 0.12 to 1.20 dt/ha (0.6 to 4.5%). Cruciferous flea beetles were the most harmful in hot dry weather during the seedling stage of rape and in sparse crops; in such cases the leaf surface damage exceeded 25% and the yield loss reached 45%. Improved mineral nutrition of plants increased the damage to seedlings by flea beetles, while the sowing time did not affect the damage rate.