Pests

Stephanitis piri Fabricius - Pear Lace Bug.

Systematic position.

Class Insecta, order Hemiptera (Heteroptera), family Tingidae, genus Stephanitis.

Synonym.

Stephanitis oshanini Vas.

Biological group.

Mainly a pest of pear and apple, though it also affects hawthorn, quince, plum, cherry, and apricot to a lesser degree.

Morphology and biology.

Body length reaches 2.8-3.3 mm. Upper side of the body is covered with semi-transparent, reticulate integument. Suctorial mouthparts. 3rd segment of antennae is 3 times as long as 4th one. Pronotum pentagonal; foliaceous enlargements with 4 rows of cells on each lateral side of pronotum; basal edge is elongated, forming appendage, which covers scutellum. Elytra transparent with dark veins. Adults hibernate under bark of tree, in hollows, and under leaves in orchards and forest belts. Adults appear in spring after the first apple and pear leaves appear and fly 2-5 km away from the place of hibernation. Usually their abundance on fruiters is low in the beginning of spring. After additional feeding, females lay eggs inside parenchyma of leaves on underside along the main vein. Egg length is 0.45 mm. Eggs cone-shaped, gray, with darkened apical part. Oviposition continues for 1.5-2 months; fertility is 20-400 eggs. Egg development lasts 24-37 days. After hatching, nymphs concentrate on underside of leaves, up to 30-40 specimens in a group. Body length of 1st instar nymph is 0.6 mm. Their body is light brown in color with fine spines on each side. Nymph develops over 30 days, passing through 5 molts. Adults feed before hibernation. Nymphs perish in wintertime.

Distribution.

Inhabits Europe to latitudes of 52°N, Northern Africa, Asia Minor, Iraq, Turkey, and perhaps Afghanistan. In the former USSR, it is distributed throughout the southern European region, the Caucasus, Kazakhstan, Central Asia, and parts of Western Siberia. The northern border of the pest distribution area in the former USSR passes through Lutsk, Korosten', Chernihiv, Ramon', Saratov, Ural'sk, Orenburg, and Barnaul.

Ecology.

Mesophilous insects. In the southern part of the distribution area, they prefer shadowy and damp places. They are commonly found on Tilia sp., Corylus sp., and Quercus sp. in the forest-steppe region and on Rosaceae species in the southern regions. In mountainous regions, they occur up to 1000 m above sea level. Monovoltine in the forest-steppe region; bi- and trivoltine in Southern Ukraine, Transcaucasia and Central Asia.

Economic significance.

Adults and nymphs are harmful. Leaves become discolored, polluted by frass and exuvia of the pest, and sometimes fall. Fruit buds do not develop if strongly damage. Burning fallen leaves and old bark in gardens and autumn plowing between tree rows are important preventive control measures against the S. pyri. Additional control measures include pesticide treatment in spring after mass appearance of nymph colonies on leaves.

Related references:

Batiashvili, I.D. 1959. Pests of continental and subtropical fruit crops. Tbilisi: Institut sel'skogo khozyaistva. 455 p. (in Russian).
Bei-Bienko, G.Ya., ed. 1964. Keys to the insects of the European part of the USSR. V. 1. Moscow & Leningrad: Nauka. P. 936 (in Russian).
Fol'kina, M.Ya. 1980. Stephanitis pyri F. in Southern Kazakhstan. Zashchita rastenii, 5: 39-40. (in Russian).
Kirichenko, A.N. 1949. Hemiptera (Heteroptera). In: Pavlovskii E.N. & Shtakelberg A.A., eds. Pest Animals of Middle Asia (handbook). Moscow & Leningrad: AN SSSR. P. 220-222 (in Russian).
Kopaneva, L.M., ed. 1984. Keys to harmful and useful insects and mites on fruit and berry plants in the USSR. Leningrad: Kolos. 288 p. (in Russian).
Krasil'nikova, G.A. 1987. Stephanitis pyri F. - the pest of fruit crops. Agriculture of Turkmenistan (Ashkhabad), 6: 34-35. (in Russian).
Kryzhanovskii, O.L. & Danzig, E.M., ed. 1972. Pest insects and mites of agricultural plants, V. 1. Leningrad: Nauka. 323 p. (in Russian).
Saakyan, Z.A. 1974. Biological peculiarities of the Stephanitis pyri F. in NE of Armenia and control measures. PhD Thesis, Erevan. 38 p. (in Russian).
Savkovskii, P.P. 1976. Atlas of the pests of fruit and berry plants. Kiev: Urozhai. 207 p. (in Russian).
Shevchenko, M.I. 1955. Stephanitis pyri var. sareptana Horv. (Hemiptera, Tingitidae) is the pest of arboreous plants. Entomologicheskoe obozrenie 34(1): 93-94. (in Russian).
Vasil'ev, V.P. 1955. Pests of fruit crops. Kiev: AN Ukr.SSR. 265 p. (in Russian).
Vasil'ev, V.P., ed. 1973. Pests of agricultural crops and forest plantations. V. 1. Kiev: Urozhai. 496 p. (in Russian).

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