New and little-known lepidopteran (Lepidoptera) phytophages on the poplars (Populus spp.) in Bulgaria

Investigations were carried out during the period 1997-1999 on lepidopteran entomofauna deleterious to poplars (Populus spp.) in Bulgaria. The phytophages were collected in larval and pupal stage and were reared under laboratory con-ditions to the adult stage. In two regions of Bulgaria, Sofia and Montana, 18 new and little-known phytophages in seven families were established on the trees in Populus genus: Limenitis populi (L.) (Nymphalidae); Anacampsis populefia (Cl.), Gelechia turpella (Den. & Schiff.) (Gelechiidae); Synanthedon melliniformis (Lasp.) (Sesiidae); Euproctis similis (Fuessl.) (Lymantriidae); Drymonia velitaris (Hufn.), Notodonta tritophus (Den. & Schiff.) (Notodontidae); Amphipyra pyramidea (L.), Catocala nupta (L.), Cosmia trapezina (L.), Enargia paleacea (Esp.), Eupsilia transversa (Hufn.), Ipomorpha subtusa (Den. & Schiff.), Parastichtis ypsilon (Den. & Schiff.), Scoliopteryx libatrix (L.) (Noctuidae); Gastropacha quercifolia (L.), Phyllodesma tremulifolia (Hb.) and Poecilocampa populi (L.) (Lasiocampidae). G. turpella and S. melliniformis are new records for Bulgaria and D. velitaris was found for the first time in Northern Bulgaria. Thirteen species (L. populi, E. similis, D. velltaris, N. tritophus, A. pyramidea, C. nupta, C. trapezina, E. transversa, I. subtusa, P. ypsilon, G. quercifolia, P. tremulifolia and P. populi) were established for the first time in Bulgaria to have a trophic relationship with poplars. G. turpella and L subtusa were occurred in the highest population densities – up to 1.6 larvae/m and up to 1.1 larvae/m respectively. The remaining species occurred in low population densities in the studied habitats and were not considered to be pests on the poplars.     

New Ichneumonidae (Hymenoptera) parasitoids of forest insect pests in Bulgaria

During the period 1989–1998 investigations were carried out on the parasitoids of some forest insect pests in Bulgaria. Twenty-one ichneumonid species are reported for the first time in Bulgaria as parasitoids of different coleopteran, lepidopteran, and hymenopteran hosts. From these, 6 parasitoids are new records for the parasitoid complexes of the hosts:Exochus decoratus Holmgr. onEudemis profundana (Den. & Schiff.) andGelechia turpella (Den. & Schiff.);Lissonota culiciformis Grav.—onParanthrene tabaniformis (Rott.);Lissonota unicincta Holmgr.—onG. turpella; Xorides gracilicornis (Grav.)—onXylotrechus sp.; andEriborus terebrator Aubert—onClostera anastomosis (L.). Most parasitoids developed as primary parasitoids in the hosts.Itoplectis alternans (Grav.) is a primary parasitoid ofNycteola asiatica (Krul.) and a hyperparasitoid ofE. terebrator: Acropimpla pictipes (Grav.) is secondary parasitoid onAnacampsis populella (Cl.). With the exception of two species ofOlesicampes genus, which destroyed over 50% ofStauronematus compressicornis (F.) andPristophora conjugata (Dahlm.) larvae, andE. terebrator which killed 15.4% ofC. anastomosis population, the rest of the parasitoids occurred in low densities, and did not play an important role in reducing the number of their hosts.     

New parasitoids of Paraphytomyza populi (Kltb.) (Diptera, Agromyzidae) in Bulgaria

The parasitoid complex of Paraphytomyza populi (Kltb.) (Diptera: Agromyzidae) was studied in Sofia, Bulgaria in 1997. Poplar leaves with P. populi larvae and pupae were collected from poplar stump shoots and examined in a laboratory. As a result, eleven parasitoid species were established: Chorebus albipes (Haliday) (Hymenoptera, Braconidae), Pediobius metallicus (Nees), Danuviella subplana Erdos, Chrysocharis nephereus (Walker), Chrysocharis pubicornis (Zetterstedt), Diglyphus crassinervis Erdos, Diglyphus isaea (Walker), Diglyphus albiscapus Erdos, Cirrospilus diallus Walker, Cirrospilus pictus (Nees) (Hymenoptera, Eulophidae) and Elasmus sp. (Hymenoptera, Elasmidae). Six species (D. crassinervis, D. isaea, D. albiscapus, C. diallus, C. pictus and Elasmus sp.) have been recorded as new parasitoids of P. populi. The genus Danuviella was found for the first time in Bulgaria. Five species (C. albipes, P. metallicus, D. subplana, D. crassinervis and D. albiscapus) are new records for the fauna of the country. The total mortality of P. populi caused by parasitoids was 19.1% and 49.0% for the overwintering and the summer generations, respectively. P. metallicus was the most important in reducing the pest number.     

New parasitoids of Paraphytomyza populi (Kltb.) (Diptera, Agromyzidae) in Bulgaria

The parasitoid complex of Paraphytomyza populi (Kltb.) (Diptera: Agromyzidae) was studied in Sofia, Bulgaria in 1997. Poplar leaves with P. populi larvae and pupae were collected from poplar stump shoots and examined in a laboratory. As a result, eleven parasitoid species were established: Chorebus albipes (Haliday) (Hymenoptera, Braconidae), Pediobius metallicus (Nees), Danuviella subplana Erdos, Chrysocharis nephereus (Walker), Chrysocharis pubicornis (Zetterstedt), Diglyphus crassinervis Erdos, Diglyphus isaea (Walker), Diglyphus albiscapus Erdos, Cirrospilus diallus Walker, Cirrospilus pictus (Nees) (Hymenoptera, Eulophidae) and Elasmus sp. (Hymenoptera, Elasmidae). Six species (D. crassinervis, D. isaea, D. albiscapus, C. diallus, C. pictus and Elasmus sp.) have been recorded as new parasitoids of P. populi. The genus Danuviella was found for the first time in Bulgaria. Five species (C. albipes, P. metallicus, D. subplana, D. crassinervis and D. albiscapus) are new records for the fauna of the country. The total mortality of P. populi caused by parasitoids was 19.1% and 49.0% for the overwintering and the summer generations, respectively. P. metallicus was the most important in reducing the pest number.     

Studies on the egg parasitism inThaumetopoea pityocampa over a period of four years (1991–1994) at marikostino/bulgaria

In Bulgaria near Marikostino, in a forest ofPinus nigra Arn. 239 egg batches were sampled over four generations ofThaumetopoea pityocampa (Den. & Schiff.) (Lep., Thaumetopoeidae) in various seasons. Directly after collection the batches were singled in test tubes, closed with cotton stoppers and stored under laboratory conditions at 20–22°C. Oviposition always started from the base towards the tip of the needles. The emergence of egg parasitoids was observed daily, and the parasitoids were counted and identified. The eggs from which parasitoids emerged were marked for further studies. After removing the adults and opening the eggs, the impact of the species of parasitoids was evaluated by identifying the meconia and other rests (left overs). Ooencyrtus pityocampae (Mercet) was the most abundant egg parasitoid, followed byAnastatus bifasciatus (Fonsc.). Only few individuals ofBaryscapus servadeii (Dom.) were collected. The hyperparasitoidBaryscapus servadeii (Dom.) were collected. The hyperparasitoidBaryscapus transversalis Graham, was found at low densities. Only a few eggs were parasitised byTrichogramma embryophagum Htg. Total mortality of the host eggs varied from 34.7 to 79.7% depending on the period of parasitism and on the numbers of sterile eggs. The impact of the parasitoids was calculated to be 9.3–38.9%, depending on the period when parasitism had taken place. The mean number of eggs per batch varied from 203 to 253. The rate of parasitism was reduced by early sampling of the egg batches. In some cases, a very high percentage (up to 29.2%) of undeveloped eggs was found. In all samples a small percentage of empty eggs was always observed.

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Untersuchungen zum Eiparasitismus von Thaumetopoea pityocampa bei Marikostino/Bulgarien w?hrend einer Vierjahresperiode (1991–1994)

Zusammenfassung  In Bulgarien, in der N?he von Marikostino, wurden 239 Eigelege des PinienprozessionsspinnersThaumetopoea pityocampa (Den.& Schiff.) (Lep., Thaumetopoeidae) in einemPinus nigra Forst über 4 Generationen zu verschiedenen Jahreszeiten gesammelt. Die Gelge wurden sogleich einzeln in Reagensgl?ser gegeben, die mit Wattestopfen verschlossen wurden, und unter Laborbedingungen bei 20–22°C aufbewahrt. Die Eiablage fand stets von der Nadelbasis zur Spitze hin statt. Der Schlupf der Parasitoiden wurde t?glich registriert. Nach Entfernen der Gelegeschuppen wurde jedes Ei markiert, aus dem ein Parasitoid schlüpfte. Alle adulten Parasitoide wurden sogleich nach dem Schlupf entfernt und zur Determination vorbereitet. Nach Ende der Schlupfperiode (mindestens 1 Jahr nach dem Raupenschlupf) wurden alle Eier ge?ffnet. Der Einflu? der cinzelnen Parasitoiden-Arten auf die Eimortalit?t wurde anhand der Mekonien und Rückst?nde in den Eiern bewertet. Ooencyrtus pityocampae (Mercet) war in den Eiern die h?ufigste Art, gefolgt vonAnastatus bifasciatus (Fonsc.) VonBaryscapus servadeii (Dom.) wurden nur wenige Individuen gefunden. Auch der Hyperparasitoid,Baryscapus transversalis Graham, war nur in geringer Populationsdichte vertreten. Nur wenige Eier waren vonTrichogramma embryophagum Htg. parasitiert. Die Gesamtmortatit?t der Wirtstiere variierte von 34,7% bis 79,7%; sie war abh?ngig von der Parasitierungsperiode und der Menge an sterilen Eiern. Der Einflu? der Eiparasitoide betrug 32,7–38,9%, wenn sie die gesamte Embryonalentwicklung des Wirtes zur Parasitierung nutzen konnten. Die mittlere Anzahl der Eier pro Gelege variierte in den Sammelproben von 203 bis 253. Die Parasitierungsrate war nach frühem Einsammeln der Gelege (nach Oviposition des Wirtes) stark reduziert. In einigen F?llen war ein sehr hoher Prozensatz (bis zu 29,2%) an nicht entwickelten Eiern zu finden. In allen Eigelegen waren einige Eier vorhanden, die total leer waren.

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The research conducted was supported by the Government of Lower Saxony, Hannover, Germany.     

Phytophthora root and crown rot of raspberry in Bulgaria

Root and crown rot of raspberry (Rubus idaeus L.) was observed in a plantation at the experimental station of small fruits in Kostinbrod, Bulgaria. Isolates ofPhytophthora spp. were obtained from diseased plants. Colony morphology, growth rates, features of asexual and sexual structures were studied and as a result twoPhytophthora species were identified:Phytophthora citricola Saw. andPhytophora citrophthora (R.E. Sm. & E.H. Sm.) Leonian. Their pathogenicity was confirmed in artificial inoculation experiments. The isozyme (-esterase) patterns ofP. citrophthora andP. citricola isolates from raspberry and from the collection of the CBS, Baarn the Netherlands were compared, using micro-gel electrophoresis. Both species are reported for the first time as pathogens of raspberry in Bulgaria. This is only the second report in phytopathological literature ofP. citrophthora on raspberry, the first being from Chile [Latorre and Munoz, 1993].     

Effects of alternative winter cover cropping systems on weed suppression in organically grown tomato (<Emphasis Type="Italic">Solanum lycopersicum</Emphasis>)

Weed control is a major concern for organic farmers around the world and non-chemical weed control methods are now the subject of many investigations. Field studies were conducted in tomato (Solanum lycopersicum L.) from 2004 to 2006 at the Black Sea Agricultural Research Institute experiment field to determine the weed suppressive effects of winter cover crops. Treatments consisted of ryegrass (Lolium multiflorum L.), oat (Avena sativa L.), rye (Secale cereale L.), wheat (Triticum aestivum L.), gelemen clover (Trifolium meneghinianum Clem.), Egyptian clover (Trifolium alexandrinum L.), common vetch (Vicia sativa L.), hairy vetch (Vicia villosa Roth.) and a control with no cover crop. Treatments were arranged in a randomized complete block design with four replications. To determine the weed suppressive effects of the cover crops, weed density and total weed dry biomass were assessed at 14, 28, and 56 days after termination (DAT) of the cover crops from all plots using a 50 × 50 cm quadrat placed randomly in each plot. After cover crop kill and incorporation into soil, tomato seedlings variety ‘H2274’ were transplanted. Broadleaved weed species were the most prominent species in both years. Total weed biomass measured just prior to cover crop incorporation into the soil was significantly lower in S. cereale plots than in the others. The number of weed species was lowest at 14 DAT and later increased at 28 and 56 DAT, and subsequently remained constant during harvest. This research indicates that cover crops such as L. multiflorum, S. cereale, V. sativa and V. villosa could be used in integrated weed management programs to manage some weeds in the early growth stages of organic tomato.     

Powdery mildew (Oidium sp.) on tomatoes in Bulgaria

In 1989, powdery mildew (Oidium sp.) was found on tomatoes (Lycopersicon esculen-tum L. Mill.) under glass in Bulgaria. Microscopic examinations indicated that the mildew was typical ofOidium sp. Forty species, forms, breeding lines and cultivars of tomato were evaluated for their susceptibility to powdery mildew. Seven of them were immune to the disease.     

Absence of 3-(2,4-dichlorophenoxy)propionic acid in plants treated with 2,4-dichlorophenoxyacetic acid‡

Experiments were conducted to establish if the formation of 2.4-dichlorophenol (DCP) from 2.4-dichlorophenoxyacetic acid (2,4-D) in plants proceeds via 3-(2,4-dichtorophenoxy) propionic acid (2,4-DP) as an intermediate. Soybean (Glycine max (L.) Merr.), kidney bean (Phaseolus vtitgaris L.), pea (Pisum. sativum L.), smooth bromegrass (Bromus inermis Leyss.), wild oat (Avena fatua L.), yellow foxtail (Setaria glauca(L.) Beauv.), barley (Hordeum vulgare L.), timothy (Phleum pratense L.). and orchardgrass (Dactylis glomerata L.) were treated with equal weights of 2,4-D and 2,4-DP. After 3 days, all plants contained DCP; however, amounts were larger in plants treated with 2.4-DP than in those treated with 2,4-D. The 2.4-DP was absorbed from the leaf surface more efficiently than 2,4-D. No evidence was found for formation of 2,4-DP from 2,4-D in any of the plant species studied. L'absence de l'acide3-(2,4 dichlorophénoxy) propionique dans les plantes traitées avec I'acide 2,4-dichlorophénoxyacétique Des experiences ont été effectuées pour rechercher si la formation de 2,4-dichlorophénoI (DCP) dans les plantes, à partir de l'acide 2.4-dichlorophénoxy acétique (2,4-D) se produit par l'intermêdiaire de l'acide 3-(2,4-dichlorophenoxy) propionique. Le soja (Glycine max(L.) Merr.). le haricot (Phaseolus vuigaris L.), Ic pois (Pisum sativum L.), le brome (Bromus inermis Leyss.), la folle avoine (Avena fatua L.), la sétaire (Setaria glauca(L.) Beauv.). I'orge (Hordeum vulgare L.), la fléole (Phleum pratense L.) et le dactyle (Dactylis ghmerata L.) ont été traités par des poids égaux de 2.4-D et de 2,4-DP. Trois jours aprés, les plantes contenaient du DCP; toutefois, les quantités trouviés furent plus importantes dans les plantes traitées avec le 2,4-DP que dans celles traitées avec le 2,4-D. Le 2,4-DP a été absorbéà partir de la surface foliaire plus efficacement que le 2,4-D. La formation du 2,4-DP à partir du 2,4-D n'a pu être prouvée dans aucune des plantes étudiécs. Die Abwesenheit von 3-(2,4′Dichlorphenaxy)-propionsäure irt mil 2,4-Dichlorphenoxytesäure behandelten Pflanzen Es wurden Versuche durchgeführt um herauszufinden. ob die Bildung von 2,4-Dichlorphenol (DCP) aus 2.4-Dichlor-phenoxyessigsäure (2,4-D) in Pflanzen über 3-(2,4-Dichlor-phenoxy)-propionsaure (2,4-DP) als Zwischcnprodukt ver-läufl. Sojabohnen (Glycine max(L.) Merr.), Gartenbohnen (Phaseolus vutgaris L.), Erbsen (Pisum sativum L.), Wehrlose Trcspe (Bromus inermis Leyss.), Flughafer (Avena fama L.), Gelbe Borsienhirse (Setaria glauca(L.) Beauv.), Gerste (Hordetim vidgarc L.), Wiesenlieschgras (Phleum pratense L.) und Knaulgras (Dactylis ghmerata L.) wurden mit gleichen Mengen an 2,4-D und 2,4-DP behandelt. Nach drei Tagen enthielten alle PHanzen DCP; aber die Menge an DCP war in den mit 2,4-DP behandelten Pflanzen grosser als in den mit 2,4-D behandelten. 2,4-DP wurde von der Blatt-oberflache besser absorbiert als 2.4-D. In keiner der untersuchten Pflanzenarten konnte ein Hinweis für die Bildung von 2,4-DP aus 2,4-D gefunden werden.     

Studies on the parasitoids of Gelechia senticetella (Stgr.) (Lepidoptera: Gelechiidae) in Bulgaria

The parasitoids of Gelechia senticetella (Stgr.) (Lepid.: Gelechiidae), a pest of Juniperus excelsa M.B., were studied in the Tissata reserve in Bulgaria. They were reared in laboratory conditions from pest larvae and pupae collected in 1991, 1992 and 2000. As a result of this study, 16 species of parasitoids of G. senticetella were recorded: Habrobracon stabilis Wesm., Hormius moniliatus (Nees), Phanerotoma tritoma Marsh. (Hym.: Braconidae), Diadegma consumptor (Grav.), Liotryphon cydiae (Perk.), Scambus pomorum (Ratz.), Scambus foliae (Cush.), Pimpla turionellae (L.), Eudelus simillimus (Tasch.), Mesochorus sp. (Hym.: Ichneumonidae), Sympiesis acalle Walk., Aprostocetus sp. (Hym.: Eulophidae), Eupelmus urozonus Dalm. (Hym.: Eupelmidae), Copidosoma thompsoni Merc. (Hym.: Encyrtidae), Calliprymna bisetosa Grah., and Mesopolobus sp. (Hym.: Pteromalidae). H. stabilis and P. tritoma were discovered as new species for the fauna of Bulgaria. Three species (E. simillimus, Mesochorus sp. and Aprostocetus sp.) are hyperparasitoids, and the remaining species are primary parasitoids. Most of the parasitoid species attack the larvae of G. senticetella and kill the hosts before pupation. In the studied parasitoid complex, D. consumptor and H. moniliatus were the dominant species. In 1991, the level of total parasitism of the host in the Tissata reserve was 24.3%, in 1992 – 57.9% and in 2000 – 12.7%. D. consumptor was the most important parasitoid destroying 26.6% of the pest larvae in 1992.     

Fenitrothion plus (1R)-phenothrin,and pirimiphos-methyl plus carbaryl,as grain protectant combinations for wheat

Duplicate field trials were carried out on bulk wheat in commercial silos in Queensland and New South Wales. Laboratory bioassays on samples of treated grain at intervals over 9 months, using malathion-resistant strains of insects, established that treatments were generally effective. Fenitrothion (12 mg kg^?1)+ (1R)-phenothrin (2 mg kg^?1) was more effective than pirimiphos-methyl (6 mg kg^?1) + carbaryl (10 mg kg^?1) against Sitophilus oryzae (L.) and Ephestia cautella (Walker); the order of effectiveness was reversed for S. granarius (L.). Against Rhyzopertha dominica (F.), Tribolium castaneum (Herbst), T. confusum Jackquelin du Val and Oryzaephilus surinamensis (L.), both treatments effectively prevented the production of progeny. The order of persistence was pirimiphos-methyl> (1R)-phenothrin>carbaryl or fenitrothion. During processing from wheat to white bread, residues were reduced by 98% for carbaryl, >44% for (1R)-phenothrin, 98% for fenitrothion and 85% for pirimiphosmethyl.     

Parasitoids of Saperda populnea (L.) (Coleoptera: Cerambycidae) on aspen ( Populus tremula L.) in Bulgaria

The parasitoids of Saperda populnea (L.) (Col.: Cerambycidae) were studied in Bulgaria during the period 1997–2001. Galls with pest larvae were collected from young aspen trees at eight locations (Sofia, Kokaliane, Plana, Churek, Gorni Lom, Gintzi, Dolno Kamartzi and Klisura) and examined under laboratory conditions. Four species were reared from 1118 galls containing overwintering pest larvae: Iphiaulax impostor (Scop.) (Hym.: Braconidae), Dolichomitus populneus (Ratz.), Schreineria populnea (Gir.) (Hym.: Ichneumonidae) and Billaea irrorata (Meig.) (Dipt.: Tachinidae). All of the parasitoids were solitary. Schreineria populnea was found as a new parasitoid of the host in Bulgaria. B. irrorata emerged mainly from late-stage S. populnea larvae; the remaining species from both early- and mid-stage larvae. In the parasitoid complex of S. populnea, the most numerous were B. irrorata (59.8%) and D. populneus (29.4%). The percentage of host larval parasitism varied from 2.4 to 33.3, with an average of 9.7%. B. irrorata was the most important in reducing the pest number. The average mortality of S. populnea caused by the tachinid was 5.8%, and the highest mortality observed in individual study was 20.2%.     

Control of morningglory species using Fusarium solani and its extracts

Abstract

Natural products of an isolate of Fusarium solani App. & Wr. NRRL 18883 grown on rice medium were discovered to be phytotoxic to morningglory. This isolate was evaluated for biocontrol potential on morningglory species including ivyleaf [Ipomoea hederacea (L.) Jacq.], multicoloured (I. tricolor Cav.), paimleaf (I. wrightii Gray), pitted (I. lacunosa L.), purple moonflower (I. turbinata Lag.), red (I. coccinea L.), sharppod (I. cordatotriloba Dennstedt), smallflower (Jacquemontia tamnifolia (L.) Griseb], and tall [I. purpurea (L.) Roth] morningglory. When sprayed at a concentration of 10 g fungus‐infested rice per 50 ml of water, this isolate caused phytotoxic damage including necrosis, chlorosis, growth inhibition, and mortality. Deleterious effects were recorded in all species, ranging from necrotic spots to death, depending on the species. Mortality ranged from 0% at 3 weeks for purple moonflower to 89% for smallflower morningglory. Soil‐drench application (10–20 ml fungal material per 150 g soil) caused wilting and death. Root lengths of 7‐ and 10‐day‐old plants were reduced between 19 and 89% by soil‐drench application and 17–84% by spray application. Whole plant length reduction of 7‐ and 10‐day‐old plants ranged from 0 to 96%, and 39 to 96% for soil‐drench and spray applications, respectively. Testing of F. solani on weed and crop species showed that most broadleaved species were sensitive but monocotyledons were immune. Tests of the phytotoxic extract for known phytotoxins such as common trichothecene (deoxynivalenol) and non‐trichothecene compounds (fusaric acid, moniliformin, fumonisins) were negative. This is the first report of the use of F. solani against morningglory.     

Cono- and seminiphagous insects of firAbies alba Mill. in the Babia Góra National Park and its surroundings in southern Poland

During 1991–1993 6300 specimens of cono-and seminiphagous insects and 10 specimens of parasitoid were obtained from 450 cones of firAbies alba Mill. This material originated from the Babia Góra National Park and its surroundings. The index of cone infestation by these insects is given for fir localities situated at different heights above the sea level. The seed losses caused by insects were estimated on the basis of analysis of 34,704 of fir seeds.Aus 450 Tannenzapfen (Abies alba Mill.), gesammelt 1991 und 1993 im Babia-Góra-National-Park und in der Forstverwaltung Sucha, Süd-Polen, wurden 6300 Individuen schädlicher Insekten gewonnen.Es handelte sich um die Seminiphagen:Resseliella piceae Seitn. (Dipt., Cecidomyiidae) — 3461 Ex.,Megastigmus suspectus Borr. (Hym., Torymidaea) — 2698 Ex. sowie um die Konophagen:Earomyia impossible Morge (Dipt., Lonchaeidae) — 129 Ex.,Dioryctria abietella (Den. et Schiff.) (Lep., Phycitidae) — 11 Ex. undBarbara herrichiana Obr. (Lep., Tortricidae) — 1 Ex. Aus den Raupen vonD. abietella wurdenLissonota nigricoxis Hab. (Hym., Ichneumonidae) — 10 Ex. gezogen. Als Indikator der Besiedlung von Zapfen erreichteM. suspectus (13,33 in 1993) den höchsten Wert. Die Analyse von 34.704 Samen nach der Schnittmethode ergab, daß die Schäden in den Samen (65%) hauptsächlich vonR. piceae verusacht wurden.     

Tachinidae parasitoids of<Emphasis Type="Italic">Traumatocampa ispartaensis</Emphasis> from Turkey

Tachinid parasitoids ofTraumatocampa ispartaensis Doğanlar & Avcı (Lepidoptera, Thaumetopoeidae), which was found to be a new species, were collected from the cedar forests around Isparta-Kapıdağ. The species found wereBlondelia nigripes (Fall.),Compsilura concinnata (Meig.),Pales processioneae (Ratz.),Phryxe caudata (Rond.),Exorista segregata (Rond.) andCarcelia iliaca (Ratz.). Within the six species of Tachinidae,B. nigripes was the most common one, parasitizing up to 4.6% ofT. ispartaensis pupae. http://www.phytoparasitica.org     

Effect ofMelia azedarach fruit extract on juvenile hormone titer and protein content in the hemolymph of two species of noctuid lepidopteran larvae [insecta: Lepidoptera: Noctuidae]

The effect of an enriched methanolic extract ofMelia azedarach L. (Meliaceae) fruits on the size of the corpora allata (CA), the juvenile hormone (JH) titer and the protein content in the hemolymph of two lepidopteran pests in Egypt,Spodoptera littoralis (Boisd.) andAgrotis ipsilon (Hufn.), was studied. Different concentrations of the extract were incorporated into an artificial diet on which the larvae were allowed to feed. InS. littoralis, a significant reduction in the CA volume of larvae treated at the 1000 ppm extract levelvs that of control larvae was observed. In A.ipsilon, a reduction was found in the right CA gland only. Larvae of both species that had fed on a diet withMelia extract had a higher mean JH-II titer in the hemolymph than did control larvae. In both species, the content of hemolymph protein was decreased significantly after feeding for 6 days on a diet treated with concentrations above 50 ppm extract, followed by 6 days on a normal diet. The results show that aM. azedarach fruit extract has an effect on the neuroendocrine control in the insects. The effect on the hemolymph protein levels is discussed in connection with changes in the morphology/physiology of the gut.     

Modelling the effects of Elymus repens (L.) Gould competition on yield of cereals, peas and oilseed rape

Effects of Elymus repens (L.) Gould competition on yield of winter rye (Secale cereale L.), winter wheat (Triticum aestivum L.), spring barley (Hordeum vulgare L.), peas (Pisum sativum L.), and spring oilseed rape (Brassica napus L.) were studied in field trials conducted on the same location through 3 years. The competitiveness of the five crops against E. repens could be ranked as follows, with the most competitive crop mentioned first: rye wheat, barley rape, peas. Yield losses ranged from 8% in rye to around 35% in peas and rape at a density level of 100 primary shoots m^?2 in spring. The different prevailing climatic conditions in the growing seasons had no effect on the yield-density relationships in rye, peas, and barley, whereas significant interactions were found in wheat and rape. The cumulative emergence patternsof primary shoots were described in the spring-sown crops, and models were derived to simulate the sensitivity of competition parameters to the actual time of shoot recording. The importance of choosing the right time for shoot emergence counts in relation to threshold recommendations and other aspects is discussed. Modélisation de l'effet de la concurrence de Elymus repens (L.) Gould sur les rendements de céréales, de pois et de colza Nous avons étudié au champ les effets de la concurrence de Elymus repens (L.) Gould sur le rendement du seigle d'hiver (Secale cereale L.), du blé d'hiver (Triticum aestivum L.), de l'orge de printemps (Hordeum vulgare L.), du pois (Pisum sativum L.) et du colza de printemps (Brassica napus L.). Les essais ont été conduits durant trois ans sur le même site. L'aptitude à la concurrence des cinq cultures à l'égard de E. repens peut être classée ainsi, en ordre décroissant: seigle blé et orge colza et pois. Les pertes de rendement allaient de 8% chez le seigle à environ 35% chez le pois et le colza, à un densité de pousses primaires 100 m^?2, mesurée au printemps. Les différentes conditions météorologiques ayant régné lors des périodes de croissance n'ont eu aucun effet sur les relations densité-rendement chez le seigle, le pois et l'orge, alors que des interactions significatives ont été observées chez le blé et le colza. Le patron cumulatif de l'émergence des pousses primaires a été décrit pour les cultures de printemps, et des mode les en ont été déduits pour simuler la sensibilité des paramètres de concurrence à la date à laquelle les levées sont enregistrées. L'importance est discutée du choix d'une date correcte pour les comptages de levées dans l'optique de recommandations de seuils de densité. Modellierung der Wirkung der Konkurrenz von Elymus repens (L.) Gould auf den Ertrag von Getreide, Erbse und Raps Die Wirkung der Konkurrenz der Gemeinen Quecke (Elymus repens) auf Winterroggen (Secale cereale L.), Winterweizen (Triticum aestivum L.) Sommergerste (Hordeum vulgare L.), Saat-Erbse (Pisum sativum L.) und Sommerraps (Brassica napus L.) wurde in Feldversuchen über drei Vegetationsperioden am selben Ort untersucht. Für die Konkurrenzkraft der fünf Kulturen gegenüber der Quecke ergab sich folgende Reihenfolge: Roggen Weizen, Gerste Raps, Erbse. Die Ertragsverluste lagen bei einer Dichte von 100 Queckenhalmen m² im Frühjahr zwischen 8 % beim Roggen und rund 35 % bei Erbse und Raps. Die verschiedenen Witterungsbedingungen in den Versuchsjahren blieben ohne Einfluß auf die Ertrags-Dichte-Beziehungen bei Roggen, Erbse und Gerste, während bei Weizen und Raps eine signifikante Beeinflussung gefunden wurde. Das Austriebsverhalten der Queckentriebe wurde in den Sommerkulturen festgehalten, und es wurden Modelle entwickelt, um die Empfindlichkeit der Konkurrenzparameter in Abhängigkeit vom Zeitpunkt der Zählung der Triebe zu simulieren. Die Bedeutung der Wahl des richtigen Zeitpunkts für die Erfassung des Austriebs der Quecke hinsichtlich der Empfehlung von Schwellenwerten und anderen Aspekten wird diskutiert.     

Hymenopterous parasitoids of the cherry bark tortrix, Enarmonia formosana (Scopoli) in central-east Europe (Hymenoptera, Ichneumonoidea; Lepidoptera, Tortricidae)

Strategies targeting the biological control of the cherry bark tortrix (=CBT), Enarmonia formosana (Scopoli) in North America have also included the search for potentially useful native hymenopterous parasitoids of the pest in Europe. The search for such agents undertaken in the central-east Europe (Czech Republic, Slovak Republic, Hungary) resulted in determination of several ichneumonid species (Campoplex cf. dubitator Horst., Liotryphon sp., Lissonotus sp., Pimpla spuria (Grav.), Pimpla turionellae (L.), and some others, and a braconid (Apanteles britannicus Wilk.) in 2001–2002.     

Selective regulation of germination and growth of annual weeds by crop residues

Residues from mature, harvested crops of sorghum (Sorghum bicolor Moench.), sunflower (Helianthus annuus L.), oilseed rape (Brassica napus L.), wheat (Triticum aestivum L.) and field pea (Pisum sativum L.), exhibited selective effects on weed germination and growth under field conditions. Weed species in the study included Avena fatua L., Avena sterilis ssp. ludoviciana (Durieu) Nyman, Echinochloa crus-galli (L.) Beauv., Phalaris aquatica L., Phalaris paradoxa L., Lolium perenne L., Vulpia myuros (L.) Gmel., Hibiscus trionum L., Polygonum aviculare L., Bilderdykia convolvulus (L.) Dumort. and Lamium amplexicaule L. All crop residues tested, and in particular wheat and pea residues, promoted the germination and growth of A. fatua and A sterilis ssp. ludoviciana. Other grass weeds, however, were inhibited by the presence of crop residue, the extent of inhibition being dependent on residue type. Germination response of dicotyledonous weed species was also a function of residue type, H. trionum numbers were significantly higher in plots where oilseed rape, sorghum or sunflower residue had been incorporated, while L. amplexicaule was inhibited by these residue types and stimulated by pea and wheat residues.     

Population growth potential of Epilachna vigintioctopunctata (F.) (Coleoptera: Coccinellidae) on some solanaceous medicinal plants

The spotted ladybird beetle, Epilachna vigintioctopunctata (F.) (Coleoptera: Coccinellidae), is an important pest of solanaceous medicinal plants in India. In this study, we investigated population growth potential of E. vigintioctopunctata in the laboratory at 28 ± 1°C with 80% ± 5% RH and 14:10 L:D photoperiod on seven solanaceous medicinal plants, viz. Solanum nigrum (L.), Datura metel (L.), Datura alba (L.), Solanum surattense Burm. (F.), Withania somnifera (L.) Dunal (wild) and cultivars of W. somnifera, viz. “JA 20” and “JA 134”. The lowest rate of population growth occurred on D. metel, where immature development time, immature survival and pre oviposition period were highest, and fecundity was lowest (183.96 eggs per female). The highest growth rate occurred on S. surrattense and fecundity was also highest (637.08). The lowest net reproductive rate (Ro) (56.60) and the intrinsic rate of population increase (r_m) (0.07) were obtained on D. metel and were highest on S. surattense (305.90 and 0.14 respectively). The mean generation time (T) was shortest on S. surattense (40.95 days). Using these measures, it is recognized that E. vigintioctopunctata performance was best on S. surattense and worst on D. metel. The findings of this study will contribute to the development of effective integrated pest management strategies for E. vigintioctopunctata on cultivated W. somnifera.