Pests

Athalia rosae L. - Turnip Sawfly

Systematic position.

Class Insecta, order Hymenoptera, suborder Symphyta, family Tenthredinidae, subfamily Tenthredininae, tribe Selandrini, Athalia.

Synonyms.

Athalia colibri Christ., A. salicis Schr., A. spinarum F., A. centifoliae Panz.

Biological group.

Oligophagous pest of cruciferous and umbelliferous cultures.

Morphology and biology.

Body of adult insect is shiny orange, except its head and notal sides. Its length is about 7-8 mm. Wings are yellow at base and blackish at front border and outer half. Pterostigma is black. Scutellum and middle lobes of notum, meso- and metathorax are yellow underneath. There are two black rhomboid spots on upper side of thorax. Abdomen is thick, pointed in female, rounded in male. The head has a black 11-segmented clavate apically antenna. Big, oval, transparent egg is glasslike. Yellow pupa (6-11 mm) is inserted into brown cylindrical cocoon. Dark or green-gray larva (18-25 mm) has black head and 11 pairs of cylindrical legs. Abdominal side is lighter, dorsal side has dark stripes. The body of larva is wrinkled, covered with small warts. The larva winters in the ground in a cocoon (the depth is about 7-15 cm). Pupation takes place in April, lasting 8-15 days. Adult insects of first generation fly in May - beginning of June. Females and males also feed on wild and agricultural plants of the families Brassicaceae (=Cruciferae) and Apiaceae (=Umbelliferae). Then copulation and oviposition take place. Female cuts leaf by ovipositor and lays eggs inside. Oviposition lasts 2-30 days. The sawfly fecundity varies from 200 to 300 eggs. Light swellings are observed in places of oviposition. Embryonal period varies from 5 to 12 days. Female life span is about three weeks. Larvae roughly eat leaves, with only big ribs and petiole remaining. The pest also damages flowers, ovaries, small pods which fall. Larva lives 15-20 days. It has 4-5 molts, 6 instars. Adult larva penetrates into the ground for pupation. Larvae of the second generation damage in July - August.

Distribution.

The insect is spread in Europe; Asia, North America, Africa. Within the territory of the Former USSR, the species occurs widely from the northwestern regions to Vladivostok. High harmful activity appears in steppe and forest-steppe zones of Ukraine and European Russia, in Transcaucasia, Moldova.

Ecology.

In spring pupation takes place in wintering places at daily temperature 16°C. Flying is observed at daily temperature 18-19°C. Most favorable conditions for the insects are the temperatures 23-26°C at the relative humidity 70-80%. During pupation period the ground humidity must be moderate. The pest diapauses in autumn at 18°C and below and light period 14-15 hours and in Summer at the temperature above 27°C and relative humidity below 50%. The species gives 2-4 generations during a year; i.e., 2 generations in northwestern and central regions of Russia, 2-3 in Ukraine, 3 in North Caucasus and Lower Volga Basin Region, 4 generations in Transcaucasia. The most important predators are Perilampus italicus Fabr., P. splendidus Dalm., Meigenia mutabilis Fall., Erromenus fumatus Bris.

Economic significance.

The insect is oligophagous. It damages rape, turnip, mustard, cabbage and other cruciferous cultures. The pest eats leaf mass, buds, flowers, young pods. At low damage the leaves resemble a net; at strong damage the sawfly roughly feeds leaf mass, leaving only big ribs and petioles. These leaves become dry; the plant dies or weakens, not giving yield. The strongest harming activity is marked on turnip. Yield losses vary from 80 to 95%. Larvae of the first generation are especially dangerous. The pest also feeds on wild cruciferous and umbelliferous species, such as Thlaspi arvense L., Raphanus raphanistrum L., Carum carvi L., Conium maculatum L., Anthriscus silvestris Hoffm. Control measures include eradication of weeds, under-winter plowing, destroying plants remains, trapping crops with following chemical treatments, insecticide treatments against larvae.

Reference citations:

Amiridze N. 1972. Preliminary data to turnip sawfly biology (Athalia colibri Christ.) for Georgian conditions. In: Kanchaveli L.A., ed. The proceedings of Georgian Plant Protection Institute, vol. 23. Tbilisi: Georgian NIIZR. 50-52 p. (in Russian).
Amiridze N. 1973. Some experimental data to ecology of turnip sawfly. In: Kanchaveli L.A., ed. The proceedings of Georgian Plant Protection Institute, vol. 24. Tbilisi: Georgian NIIZR. 105-107 p. (in Russian).
Barteneva R.V. 1977. Turnip sawfly control on mustard sawing. Zernovoe khozyaistvo 5: 40-41 (in Russian).
Ermolaev V.N. & Mamykin A.I. 1930. The turnip sawfly and control measures. Krasnoyarsk: Krasnoyarsk plant protection station. 9 p. (in Russian).
Karavyanskii N.S., Mazur O.P. 1975. Pests and diseases of fodder cultures. Moscow: Rossel'khozizdat. p. 208-209 (in Russian).
Kopaneva L.M. 1981. Turnip sawfly. In: Kopaneva L.M., ed. Keys to dangerous insects and mites on technical cultures in the USSR. Leningrad: Kolos. 20 p. (in Russian).
Kosov V.V., Polyakov I.Ya., ed. 1958. Forecasting and calculation of pests and diseases on agricultural cultures. Moscow: Agricultural Department. 533-534 p. (in Russian).
Shchegolev V.N. 1960. Agricultural entomology. Moscow & Leningrad: State agricultural publishing house. P. 265-266 (in Russian).
Tsinovskii Ya.P. 1953. Insects of Latvian SSR. Horntails and sawflies. Riga: AN Latvian SSR. 114-115 p. (in Russian).
Ust'yantsev M. 1926. Turnip sawfly and control treatments. Irkutsk: Irkutsk plant protection station. 12 p. (in Russian).
Vasil.ev V.P., ed. 1973. Pests of agricultural crops and forest plantations. 2. Kiev: Urozhai. 443-444 p. (in Russian).
Volkov S.M., Zimin L.S., Rudenko D.K., Tupenevich S.M. 1955. Atlas of pests and diseases of agricultural cultures in the Non-Black Earth zone of the European part of the USSR. Moscow & Leningrad: Sel'khozgiz. 164 p. (in Russian).

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