Pests
Aelia acuminata L. - Bishop's Mitre Shield Bug
Systematic position.
Class Insecta, order Hemiptera, family Pentatomidae, subfamily Pentatominae, genus Aelia.Biological group.
Oligophagous pests of cereals.Morphology and biology.
The fusiform body of imago is gray-yellow, its length varies from 7 to 10 mm. Lateral margins of triangular head and pronotum are not pointed. Scutum is also triangular, covering less than 2/3 of abdomen. Pronotum has transverse emargination and three longitudinal costulae. Two big black points are on the lower side of both the hindfemur and midfemur. Larva and imago are similar but larva is small, wingless. Nymph has rudiments of wings. The oval eggs (length is about 1 mm) are at first light-green, then they get dark. The overwintering takes place at the stage of imago on cereal fields and wild cereal grasses. Part of population overwinters under the falling leaves in forests. Awakening is observed at the middle of April at the temperature 5-10°C. Bugs begin feeding on cereal grasses of the genera Agropyron and Bromus. When the wheat shoots appear, then the bugs migrate on their main host. During migration, the insects can fly far (40-60 km). Pests feed on leaves, causing formation of light spots. Then the leaves become yellow. Injury near the stem base is especially dangerous. In this case, the central leaf fades and the plant becomes weakened. After additional feeding and coupling, the bugs lay eggs (at the middle of May). Embrional development lasts 6-8 days, and larval period 45-60 days. Insect has five larval ages. The first-age larvae do not move on plant; oldest larvae crawl on plants, looking for food. In June, the bugs migrate to spring wheat, but not reaching high quantity there. Imagoes feed on leaves and stems, larvae feed on young grains. Insects pierce the tissues, brining in proteolitic ferments. Food substrate becomes liquid, and bugs suck it. After harvesting, the pests migrate again to wild cereal grasses, feeding there for a long period. At fall of temperature, the insects begin wintering.Distribution.
The Bishop's Mitre Shield Bug is spread in Western, Central and Eastern Europe; Anterior and Middle Asia. Within the territory of the Former Soviet Union, the species occurs widely (except the Far North); in most part of Ukraine, in Transcaucasia, Middle and Lower parts of Volga Basin Region, in West Siberia, South Ural, Central Black Earth zone, Kazakhstan, Moldova, Baltic States, Byelorussia. Its high harmful activity appears in steppe zone.Ecology.
This species is moderately mesophilous, active at the temperature 5-10°C. Insects essentially perish during cold winters with little snow covering. In spring, awakening bugs endure frequent changes of temperatures and abundant precipitations. The most favorable conditions are the temperature 22-25°C and relative humidity 60-80%. At very high temperatures, the insects diapause (in July and August). At the short day (12-17 hours) and at temperature below 20°C, the pests go into hibernation. Species gives 1-2 generations during a year, 3 in Middle Asia. Most important predators are: Microphanurus vassilievi Mayr., M. cultratus Mayr., Cystogaster globosa Fln., Helomyia lateralis Meig., Cylindromyia auriceps Meig., C. intermedia Meig., Rhodogune rotundatum L.Economic significance.
The pest has 85 species of host-plants, mainly perennial cereal grasses. Among cultural plants, the phytophage prefers winter and spring wheat, rye, feeding also on barley and oats. Injury in the young growth phase is most dangerous: the central leaf is damaged; the plant lags in its growth. At the tillering stage, the pest feeds on lateral shoots (not damaging the rudiment of ear). The central leaf becomes yellow and perishes. At the elongation stage of growth, the bug pierces leaf tissues; the leaf also becomes yellow and withers. Then larvae feed on ears, sucking grains. The grain becomes puny, losing their quality. Control measures include eradication of weeds, early harvesting of grain, under-winter plowing, insecticide treatments against both imago and larvae at their high numbers.Reference citations:
Bilewicz T. 1957. Preliminary survey of spatial distribution of populations of Aelia acuminata L. and Aelia rostrata Boh. [Wstepne obserwacje nadilosciowym wystepowaniem i rozmieszczeniem przestrzennym populacji Aelia acuminata L. i Aelia rostrata Boh.]. Ekologia Polska .Seria A, tom 5. Warsawa: Panstwowe wydawnictwo naukowe, . 166 p. (in Polish).Bryantsev B.A. 1966. Agricultural entomology. Leningrad: Kolos. P. 75 (in Russian).
Burov V.N. 1962. Factors determining the abundance dynamics and harmfulness of wheat stink bugs Aelia (Heteroptera, Pentatomidae) in North Kazakhstan regions. Entomologicheskoe obozrenie 41: 262-273 (in Russian).
Burov V.N. & Terekhin E.S. 1960. Wheat stink bugs. In: Polyakov I.Ya., ed. Survey of distribution of main mass pests and diseases on agricultural cultures in 1960, and their forecast for 1961. Moscow: VASKhNIL. P. 115-116 (in Russian).
Gidayatov D. 1960. Bishop's mitre shield bug (Aelia acuminata L.) (Hemiptera-Heteroptera) in Talysh, its biology and ecology. In.: Topchubashov M.A., ed. Proceedings of AN AzerbSSR, N 1. Baku: AN AzerbSSR. P. 119-123 (in Russian).
Gidayatov D. 1966. Zonal distribution of cereal bugs and their number forecasting in Azerbaijan. In: Ul'yanishchev V.I., ed. Proceedings of Session of Transcaucasian Board to coordination research works on plant protection. Baku. P. 254-257 (in Russian).
Grigor'eva T.G. & Terekhin E.S. 1961. On distribution of cereal bugs Aelia (Hemiptera, Pentatomidae) in Trans-Volga region and in North Kazakhstan. Entomologicheskoe obozrenie 40(1): 262-273 (in Russian).
Gurova N. 1966. The Bishop's mitre shield bugs . pests of winter cereals. Zashchita rastenii 7: 14-16 (in Russian).
Migulin A.A. 1983, ed. Agricultural entomology. Moscow: Kolos. P. 77.
Nurmuratov T.N., ed. 1986. Cereal protection from pests, diseases and weeds. Alma-Ata: Kainar: 68-70 (in Russian).
Samedov N.G. 1957. On biological features of cereal bugs in Azerbaijan. In: Kalandadze L. P. and oth., ed. Proceedings of III conference of VEO. Tbilisi: Georgian SKhI. P. 88-90 (in Russian).
Terekhin E.S. 1959. The Bishop's mitre shield bugs. In: Polyakov I. Ya., ed. Survey of distribution of main mass pests and diseases on agricultural cultures in 1958, and their forecast for 1959. Moscow: VASKhNIL. P. 73-75 (in Russian).
Til'menbaev A.T. 1965. Entomophages of cereal bugs (Aelia, Pentatomidae) in virgin soil region of Kazakhstan. In: Dzhiembaev Zh.T., ed. Proceedings of Kazakhstan plant protection institute, N 9. Alma-Ata: KazNIIZR. P. 157-160 (in Russian).
Vasil.ev V.P., ed. 1973. Pests of agricultural crops and forest plantations. 1. Kiev: Urozhai. p.348-350 (in Russian).
Volkov S.M., Zimin L.S., Rudenko D.K.& Tupenevich S.M. 1955. Atlas of pests and diseases on agricultural cultures in the Non-Black Earth zone of the European part of the USSR. Moscow& Leningrad: Sel'khozgiz. 66 p. (in Russian).