Pests
Pieris brassicae L. - Large Cabbage White.
Systematic position.
Class Insecta, order Lepidoptera, superfamily Papilionoidea, family Pieridae, subfamily Pierinae, genus Pieris.Biological group.
Oligophagous pest of vegetable cultures.Morphology and biology.
Fore wings mealy-white with dark pollination at base (wingspan 55-60 mm); females are larger than males. Wings at top with intensive black crescent limb reaching middle of outer margin and with 2 black rounded spots. Males with 2 spots on the lower side of fore wings only. Hind wings with black stroke at anterior margin from above; grayish-yellow from below, with dense black pollination. Average fertility 150 eggs, maximum to 300. Eggs primrose, are laid by batches on the lower side of leaves. Eggs develop 4 to 16 days. Hatched caterpillars ochre; older ones yellowish-green, with yellow lateral strips and light dorsal strip. Young caterpillars aggregate, scraping the lower side of leaves; older caterpillars (3rd instar and older) live individually, gnawing holes in leaves, contaminating the latter with excrement. Older caterpillars gnaw roughly on leaves, leaving thick veins only. Caterpillars develop in 13 to 38 days depending on temperature, reaching 50-60 mm in length in the last 5th instar. Pupae greenish-yellow with black dorsal and lateral dots. The pupa phase lasts 8 to 15 days. Diapausing pupae do not hibernate far from host plant localities on tree trunks and branches, fences etc.Distribution.
Occurs in Western Europe, Northern Africa, Asia Minor, in mountains of Central Asia; introduced in Chile since 1970s, becoming a pest; in the Baltic States, Byelorussia, Ukraine, Moldova, the Caucasus, Transcaucasia, mountain regions of Kazakhstan and Central Asia. In Russia it is distributed in the whole European part (except for extreme southeast and northeast), in Southern Siberia; it is found in the Chita Region, Khabarovsk and Primorskii Territory, and in the south of Sakhalin.Ecology.
Develops in 2 to 5 generations depending on region. Butterflies fly from May until August, in southern regions from the end of March to mid-October. Butterflies need additional feeding on nectar before oviposition. Caterpillars are capable of long distance migrations, searching for food and occupying neighboring sites. After cold and rainy summers the caterpillars of summer generations diapause until spring. Adverse conditions for Cabbage White development are high temperatures (above 26°C) combined with low air humidity (to 60%). Low winter temperatures (-20°C and lower) limit distribution of the pest. Parasites considerably reduce the pest number, including parasites of caterpillars (Apanteles glomeratus and Hyposoter vulgaris) and pupae (Pteromalus puparium).Economic significance.
Caterpillars damage cabbage, white and colored cabbage especially, swede, turnip, radish, horse-radish, garden radish, rape and other crucifers. They occur also on mignonette, nasturtium, capers, onions, and hedge garlic. Control measures include correct crop rotation; removal of plant debris from fields and deep autumn plowing; treatment of plants with biological preparations and insecticides in the period of caterpillars hatching.Reference citations:
D.yakonov A.M., Kozhanchikov I.V. 1949. Lepidoptera. In: Pavlovskii E.N., Shtakelberg A.A., eds. Pest Animals of Middle Asia (handbook). Moscow & Leningrad: AN SSSR. 22-43 p. (In Russian)Daricheva M.V. 1988. Fauna and ecology of Pieridae (Lepidoptera) of Turkmenistan. Izvestiya AN Turk.SSR. Seriya biol. nauk. Ashkhabad: Ylym. N. 2: 61-68. (In Russian)
Dorozhkin N.A., ed. 1975. Plant protection against pests, diseases, and weeds in Byelorussia. Recommendations. Minsk: Urozhai. 223 p. (In Russian)
Korshunov Yu. 1968. Cabbage White in Western Siberia. Kartofel. i ovoshchi, 3: 42. (In Russian)
Korshunov Yu.P. 2002. Rhopalocera of Northern Asia. Moscow: KMK. 424 pp. (In Russian)
L.vovskii A.L. 1999. Pieridae. In: Kuznetsov V.I., ed. Insects and mites-pests of agricultural plants. Lepidoptera. St. Petersburg: Nauka. V. 3(2): 233-242 (In Russian)
Nekrutenko Yu.P. 1974. Pieridae. In: Vasil.ev V.P., ed. Pests of agricultural crops and forest plantations. V.2. Arthropods. Kiev: Urozhai. 411-414 pp. (In Russian)
Provorotova G.M. 1974. Cabbage White in Krasnoyarsk Territory. In: Plant protection against diseases and pests in Eastern Siberia. Irkutsk: Irkutsk SKHI. 58-59 p. (In Russian)