Pests

Dociostaurus maroccanus (Thnb.) - Moroccan Locust.

Systematic position.

The class Insecta, order Orthoptera, family Acrididae, subfamily Acridinae, tribe Dociostaurini, genus Dociostaurus, subgenus Dociostaurus.

Synonyms.

Stauronotus maroccanus; S. cruciatus Charp.; S. vastator F.-W.

Biological group.

Polyphagous insect pests.

Morphology and biology.

Body of imago is medium-sized, slender. Body length, 16.5-28.5 mm (male), 20.5-38.0 mm (female). Individuals of solitary phase are finer, than those of gregarious phase. Vertical fossae broad, quadrangular. Elytra well developed, almost transparent, considerably stretching behind apex of hind femur, sometimes with sparse small-sized brownish or grayish spots. Length of elytra 17.5-27.0 mm in males, 23.0-36.0 mm in females. Wings colorless. Hind femora thin, 3.7-4.2 times longer than wide. Length of hind femur 13.2-17.4 mm in males, 15.5-21.6 mm in females. General tone of body coloring grayish-yellowish, with dark spots. Hind femora can have or have no black bands, depending on a phase. Hind tibia usually red, less often yellow, pinkish, or even whitish. Cruciform figure on pronotum yellowish or whitish, with narrow striae not extending behind transversal furrow. Egg pods density is sometimes very high, from several hundreds to several thousands per square meter. Every female puts 2-3, less often 4 egg pods containing 30-36 eggs on the average. Eggs are quite often laid directly in bulbar fowl-grass hassocks. Larvae having 5 instars. Duration of each larval instar is 5-7 days.

Distribution.

The area of the Moroccan Locust is extended from Atlantic islands (Canaries, Madeira) in the west to Southeast Kazakhstan and Afghanistan in the east. In North Africa the species occurs in Morocco, Algeria, Tunis, Libya, and Egypt, and the latitude 28 N is the southern border of its distribution. The Locust lives in Portugal, Spain, France, and Italy, and in countries of the Balkan peninsula. The species is found in countries of the Middle East and Minor Asia and in Afghanistan. The Locust occurs in the European part of CIS countries, i.e., in the southwest of Ukraine, in Moldova, Crimea, Northern Caucasus, and Transcaucasia, with the latitude 46 N in the Caucasus and the latitude 49 N in the Carpathian region being the northern border of its distribution. In the Asian part this species is found in countries of Central Asia and in the south of Kazakhstan, where there is an extreme north-eastern point of its area (60 km E of Almaty).

Ecology.

The Moroccan Locust characterizes by restriction on definite types of localities in the whole area, namely, submontane semideserts with mosaic ephemeroid green. The altitude of such localities is approximately between 500 and 1000 m a.s.l., sometimes lowering to 100 m or mounting up to 2200 m. One more characteristic feature of the species ecology is confinement of reproduction places to virgin, not ploughed lands. Therefore ploughing up is pernicious for the species. During mass outbreaks larvae almost completely destroy scanty vegetation in places of hatching, starting to move downwards from dry foothills to fruitful plains and damaging sowings on their route. The increase of number of D. maroccanus usually occurs, when temperature exceeds average of many-years values, and precipitations settles out less norm(standard). Thus critical value have the precipitations which are falling out in the spring (since March till May): their optimum quantity are approximately 100 mms. If precipitations in this season(term) settles out a little bit less, and, specially, if such arid spring there are at least 2 years the contract, there is a rise(ascent) of number marokkskoi of a grasshopper. Otrozhdenie descends early, amicable and usually finishes in one statsii for 5-6 days. Since the second age, kuligi of larvas start formation migrations. Density of larvas low vozrastov in driving kuligakh reaches several thousand, and high - several hundreds copies per square meter. Maiden imago occur(come up) at the end of April, in bulk okrylenie descends in the beginning of May. In some days puberal osobi start connubium, and soon after that - to otkladke yaits. In 10-15 days after okryleniya and then during one month osobi stadnoi of a phase the migrations by the shoals can commit. Density imago in the landed shoal from 50 up to 300 copies / m2. The flight is committed at the altitude from 20 up to 100 m, with speed of 8-10 m\s. The maximum range of overflies makes 250 kms, but she is customary much below - on the average 50-75 kms for all season(term) imaginal.noi of life. In the beginning of June, when the green in localities of a grasshopper largely burns out, the withering away starts.

Economic significance.

Marokkskaya a grasshopper - polyphage which is capable to damage practically any cultures, from grain and fabaceous up to vegetables, bakhchevykh and even lesoposadok coniferous. The larvas and adult in batches hardly harm to wheat, barley, corn, rzhi, ovsu, panicum and other graminoids(grasses), peas, string bean, lentil, alfalfa, clover and other fabaceous, sugar-beet, cotton plant, potato, tobacco, sunflower, tong forge, bakhchevym to cultures, cabbage, carrots, onion, salad and other vegetable cultures, different medicinal plants, sowings of fodder grasss, vineyards, and within a mass breeding - pratums, pastures many fruit cultures (rozotsvetnym, walnut, shelkovitse, fig, olive and other), and also different wood and decorative drevesno-kustarnikovym to rocks and polezashchitnym to plantations(stands). For plants it is customary ob.edayut or damage pages, and for graminoids(grasses) also podgryzayut ears and vyedayut unripe grains; For a grapes and fruit arbors ob.edayut also a cortex. In terrain of an european part former USSR last flashes of this kind(view) took place in 1923 in Crimea and in 1929-31 gg. On Northern Caucasus. In eastern part of a geographic range marokkskaya the grasshopper still saves the high potential of injuriousness and in batches gives mass flashes. In Uzbekistan and in the south of Kazakhstans marokkskaya the grasshopper regularly invades(populates) some hundreds thousand hectares, and per separate years - more than 1 million hectares.

Related References:

Bei-Bienko, G.Ya. 1932. A manual of locust survey. Leningrad: Upravlenie Sluzhby ucheta Gos. OBV Narkozema SSSR, 159 pp.
Bei-Bienko, G.Ya. & Mishchenko, L.L. 1951. Locusts of the fauna of the USSR and adjacent countries. Opredeliteli po faune SSSR, N38, parts I & II. Moscow & Leningrad: AN SSSR, 668 pp.
Lachininskii, A.V., Sergeev, M.G., Chil.debaev, M.K. et al. 2002. Locusts of Kazakhstan, Central Asia and adjacent territories. Larami: Association for Applied Akridology International / University of Wyoming, 387 pp.
Sergeev, M.G. 1986. Regularities in distribution of orthopterous insects of Northern Asia. Novosibirsk: Nauka, 238 pp.
Uvarov, B.P. 1977.Grasshopers and Locusts. A Handbook of General Acridology. Vol. II. London: COPR.

© Grichanov I.Ya.