The relation between soil water tension and growth rate of larvae of Tipula oleracea and T. paludosa (Diptera) in turf

Growth rates were determined at pF values ranging from less than to 4.2, with the turf being kept as near as possible in the natural state (i.e. with living grass etc.). Growth rates of first, third and fourth instar larvae were found and were usually highest at pF 0.8 and nearly zero at pF 4.2. Growth rates (fourth instars) or log growth rates (first and third instars) varied in inverse proportion to pF between values of pF 0.8 and 4.2. There was generally no difference between growth rates of larvae at pFs 0.8 and .Water gain and loss over the general cuticular surface was measured in T. paludosa third instar larvae kept in sucrose solutions with osmotic pressures equivalent to certain pF values. Rate of weight change per unit surface area varied with the external osmotic pressure, being positive below 6 Atmospheres (equivalent to pF 3.77) and negative above. Larvae growing in turf of pF above 3.77 therefore have to obtain water from the food for the whole of the water component of their net weight increase and also balance water loss through the cuticle.

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Zusammenfassung Die Wachstumsraten wurden bei Feuchtigkeitswerten zwischen pF<1,0 und 4,2 bestimmt, wobei die Rasenstücke in einem möglichst naturnahen Zustand, d.h. mit lebendem Gras usw. gehalten wurden. Die Wachstumsraten des 1., 3. und 4.Larvenstadiums wurden festgestellt und waren gewöhnlich bei pF 0,8 am höchsten und bei pF 4,2 nahe Null. Die Zuwachsraten (der 4.Larvenstadien) oder die Logarithmen der Zuwachsraten (der 1. und 3.Stadien) variierten im umgekehrten Verhältnis zu den pF-Werten von 0,8 bis 4,2. Es bestanden im allgemeinen keine Unterschiede in den Wachstumsgeschwindigkeiten bei pF-Werten zwischen 0,8 und 1,0.Bei Larven des 3.Stadiums von T. paludosa, die in Rohrzucker-Lösungen mit äquivalentem osmotischen Druck bestimmter pF-Werte gehalten wurden, wurde Wasseraufnahme und-abgabe durch die allgemeine kutikulare Oberfläche gemessen. Die Geschwindigkeit der Gewichtsveränderung pro Flächeneinheit änderte sich mit dem osmotischen Außendruck und war bei Drucken unter 6 atü (pF 3,77) positiv und darüber negativ. Larven, die sich in Rasen mit pF über 3,77 entwickeln, müssen deshalb nicht nur den gesamten Wasseranteil ihres Nettogewichts-Zuwachses, sondern auch zum Ausgleich von Wasserverlusten durch die Kutikula Wasser aus der Nahrung erhalten.

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Biological control of Tipula paludosa (Diptera: Nematocera) using entomopathogenic nematodes (Steinernema spp.) and Bacillus thuringiensis subsp. israelensis

Tipula paludosa (Diptera: Nematocera) is the major insect pest in grassland in Northwest Europe and has been accidentally introduced to North America. Oviposition occurs during late August and first instars hatch from September until mid-October. Laboratory and field trials were conducted to assess the control potential of entomopathogenic nematodes (EPN) (Steinernema carpocapsae and S. feltiae) and Bacillus thuringiensis subsp. israelensis (Bti) against T. paludosa and to investigate whether synergistic effects can be exploited by simultaneous application of nematodes and Bti. Results indicate that the early instars of the insect are most susceptible to nematodes and Bti. In the field the neonates prevail when temperatures tend to drop below 10 °C. S. carpocapsae, reaching >80% control, is more effective against young stages of T. paludosa than S. feltiae (<50%), but the potential of S. carpocapsae might be limited by temperatures below 12 °C. Mortality of T. paludosa caused by Bti was not affected by temperature even at 4 °C but the lethal time increased with decreasing temperatures. Synergistic effects of Bti and EPN against T. paludosa were observed in 3 out of 10 combinations in laboratory assays but not in a field trial. The potential of S. carpocapsae was demonstrated in field trials against early instars in October reaching an efficacy of >80% with 0.5 million nematodes m⁻² at soil temperatures ranging between 3 and 18 °C. Results with Bti were strongly influenced by the larval stage and concentration. Against early instars in autumn between 74 and 83% control was achieved with 13 kg ha⁻¹ Bti of 5,700 International Toxic Units (ITUs) and 20 kg ha⁻¹ of 3,000 ITUs. Applications in spring against third and fourth instars achieved between 0 and 32% reduction. The results indicate that application of Bti and nematodes will only be successful and economically feasible during the early instars and that the success of S. carpocapsae is dependent on temperatures >12 °C. Synergistic effects between S. carpocapsae and Bti require more detailed investigations in the field to determine maximal effect.     

Biology of Tipula oleracea L.: Growth of the larva

The growth of larvae, isolated and in groups, in the laboratory at constant temperature is described. The length of the larval stage varies widely even under uniform conditions. The relationship between larval weight and time is exponential in the first three instars, linear in the fourth. The paper is intended as an introduction to further publications on the causes of variation in growth.

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Zusammenfassung Die Larvalentwicklung von T. oleracea kann unter konstanten Bedingungen bei 21° C 4–5 Wochen, aber auch 16–17 Wochen dauern (— die durchschnittliche Dauer für 887 Larven, die in 37 Gruppen gezüchtet wurden, betrug 8,8 Wochen —). Der Gipfel der Entwicklungszeitkurve liegt innerhalb des ersten Abschnittes der Kurve, indem sich 90% der Larven zwischen dem 30. und dem 80. Tag verpuppen.Die ersten drei Larvalstadien werden in 3–6 Wochen durchlaufen; selten in längerer Zeit. Die großen Unterschiede in der Dauer der Larvalentwicklung entstehen daher vor allem im 4. Stadium. Larven in Gruppen entwickeln sich schneller als isolierte Larven.Männliche Larven verpuppen sich ungefähr eine Woche vor den weiblichen Larven. Das Zahlenverhältnis zwischen männlichen und weiblichen Larven beträgt 1. Beide Geschlechter ergeben für die Dauer der Larvalentwicklung die gleiche schiefe Häufigkeitsverteilung.Das Gewicht vergrößert sich in den ersten drei Larvalstadien jeweils während der ersten zwei Drittel potentiell. Im Durchschnitt verdoppeln die Larven während der Gesamtdauer der ersten drei Larvenstadien ihr Gewicht alle 3–4 Tage. Während des ersten Abschnittes des letzten Stadiums vergrößert sich jedoch das Gewicht um den festen Betrag vom 15 mg pro Tag. Es erreicht seinen Höhepunkt und nimmt dann schnell ab, wenn sich in der letzten Woche der Darm entleert und die Puppe sich bildet. Das Gewicht der Puppe beträgt etwa die Hälfte des Höchstgewichtes der Larve.Einige Larven erreichen ihr Höchstgewicht, verlieren aber erst nach 4 Wochen an Gewicht und verpuppen sich dann. Diese Ausnahmefälle sind der Hauptgrund für die oben erwähnte Schiefe der Häufigkeitsverteilung.

     

The gene transformer-2 of Sciara (Diptera, Nematocera) and its effect on Drosophila sexual development

Background  

The gene transformer-2, which is involved in sex determination, has been studied in Drosophila, Musca, Ceratitis, Anastrepha and Lucilia. All these members of Diptera belong to the suborder Brachycera. In this work, it is reported the isolation and characterisation of genes transformer-2 of the dipterans Sciara ocellaris and Bradysia coprophila (formerly Sciara coprophila), which belong to the much less extensively analysed Sciaridae Family of the Suborder Nematocera, which is paraphyletic with respect to Suborder Brachycera.     

橘小实蝇与番石榴实蝇卵及蛹的种间竞争

【背景】实蝇的竞争可能发生在生活史的各个阶段,但未见卵和蛹的种间竞争的相关报道。【方法】将橘小实蝇与番石榴实蝇的卵及蛹按照相应的比例或龄期分别进行混合培养,分析2种实蝇的卵或蛹混合后的发育历期和存活率是否受到彼此影响。【结果】橘小实蝇与番石榴实蝇的卵同龄等量混合,对彼此卵的历期和孵化率无影响。当橘小实蝇和番石榴实蝇的蛹为新鲜蛹时,分别与比它们蛹龄大1 d的对方蛹混合,蛹的羽化率分别为(87.67±3.61)%和(84.33±2.56)%,显著小于对照,说明在此混合蛹处理中,后化蛹者的发育可能受到先化蛹者的抑制。【结论与意义】总体上,在卵和蛹期,橘小实蝇与番石榴实蝇未产生竞争作用;但不排除蛹期竞争的可能性,这种竞争可能存在于特定的蛹期。     

Mycobiota associated with larval mines of Thrypticus truncatus and T. sagittatus (Diptera, Dolichopodidae) on waterhyacinth, Eichhornia crassipes, in Argentina

Thrypticus truncatus is a candidate agent for biocontrol of waterhyacinth; the larvae of this diptera mine in the petioles and feed on the phloem in the vascular bundles. The mycobiota associated with T. truncatus and T. sagittatus mines was investigated during two surveys undertaken in the spring and autumn in the Delta of the Paraná River, Argentina. Isolations were made from the mines and larval feeding points, as well as from the larvae, following dissection of the petioles, and plated onto agar. Young and upper parts of the petioles without Thrypticus mines were used as controls. Twenty eight fungal species were isolated from the mines. Pestalotiopsis guepinii, Mucor attenuatus, Phoma tropica, Achlya americana, Fusarium avenaceum, Cladosporium cladosporioides, Clonostachys rosea, Epicoccum purpurascens, Plectosporium tabacinum, Alternaria alternata, and Acremonium sp. were the most common fungi associated with mines and feeding points. Cladosporium cladosporioides, Cytospora sp., Mucor attenuatus, and Phoma tropica were associated with the larval body. The list of fungi in mines was compared with bibliographic information to determine if the species are known pathogens on waterhyacinth or other plant species. This is the first study on mycobiota associated with T. truncatus and T. sagittatus mines in waterhyacinth petioles in Argentina.     

Origin and development of the tergotrochanteral muscle in Chironomus (Diptera: Nematocera)

The origin and the development of the tubular tergo-trochanteral muscle (TTD) was studied by light and electron microscopy in Chironomus (Diptera: Nematocera). Unlike the flight muscles, the TTD was found to develop from myoblasts located around a larval axon, without contribution from a larval muscle. The myoblasts fuse together to form myotubes. Innervation of the TTD arises from the larval axon. The myotubes send out sarcoplasmic extensions towards the axon branches issued from the larval axon. The first differentiated synapses are described. The TTD begins to grow later than the flight muscles. The implications of this developmental lag are discussed.     

Origin and development of the dorso-ventral flight muscles in Chironomus (Diptera; Nematocera)

The origin and development of the dorso-ventral flight muscles (DVM) was studied by light and electron microscopy in Chironomus (Diptera; Nematocera). Chironomus was chosen because unlike Drosophila, its flight muscles develop during the last larval instar, before the lytic process of metamorphosis. Ten fibrillar DVM were shown to develop from a larval muscle associated with myoblasts. This muscle is connected to the imaginal leg discso that its cavity communicates with the adepithelial cells present in the disc; but no migration of myoblasts seems to take place from the imaginal leg disc towards the larval muscle or vice versa. At the beginning of the last larval instar, the myoblasts were always present together with the nerves in the larval muscle. In addition, large larval muscle cells incorporated to the imaginal discs were observed to border on the area occupied by adepithelial cells, and are probably involved in the formation of 4 other fibrillar DVM with adepithelial cells. Three factors seem to determine the number of DVM fibres: the initial number of larval fibres in the Anlage, the fusions of myoblasts with these larval fibres and the number of motor axons in the Anlage. The extrapolation of these observations to Drosophila, a higher dipteran, is discussed.     

On biology of limoniid flies of the genus Teucholabis Osten-Sacken (Diptera, Limoniidae) with a description of immature stages of Teucholabis esakii (Alexander) and T. yezoensis Alexander

The larvae and pupae of two xylobiont species of limoniid flies, Teucholabis esakii (Al.) and T. yezoensis Al., are described for the first time. The larvae live under bark among bast fibers of Maackia amurensis and Phellodendron amurense, rarely under bark of various species of oak, aspen, birch, and maple. A key to larvae and pupae of the two species is provided. Original Russian Text ? M.G. Krivosheina, 2009, published in Entomologicheskoe Obozrenie, 2009, Vol. 88, No. 1, pp. 185–193.     

Feeding ecology of the freshwater detritivore Ptychoptera paludosa (Diptera, Nematocera)

1. We examined selected aspects of the nutritional ecology of larval Ptychoptera paludosa and their role in nutrient cycling in the Breitenbach, a first-order stream in Hesse, Germany.
2. Food preference experiments demonstrated significant preference for sediments with a high organic matter content and live bacteria.
3. pH was circumneutral in all sections of the gut.
4. Enzymatic activity (β-glucosidase and amino-peptidase) in different parts of the gut was measured using 4-methylumbelliferyl-β- D -glucopyranoside (MUF-Glc) and leucine-4-methylcoumarinyl-7-amide (Leu-MCA). β-glucosidase activity was highest in the hindgut.
5. The mean larval gut passage time was between 7 and 8 h.
6. The egestion rate of last instar larvae was about 0.35 mg dry weight (DW) faeces per larva h^–1 and about 1.25 mg ash-free dry weight (AFDW) faeces per mg larval AFDW day^–1.
7. Larval faeces contained at least 4–18 times more organic matter than the average in the sediments in which they were feeding, that is, larvae fed selectively, extracting organic matter from sediments.
8. P. paludosa larvae are important in the dynamics of detritus in slow-flowing reaches of the Breitenbach. They gather organic material from the sediment to a depth of 3 cm, and release it as faeces onto the sediment surface. A total of 770 g DW faeces m^–2 yr^–1, comprising about 16% organic matter, was produced by the Ptychoptera population.     

The Simuliidae (Diptera, Nematocera) of Tunisia. II. Keys for the identification of species actually collected

The authors give keys for the knowledge of species of Simuliidae (larval, pupal and adult stages). The collected samples represented 44 localities situated on the main tunisian hydrographic networks.     

Redescription of the neotropical Psychodidae (Diptera,Nematocera) described by Rapp and Curran

Five neotropical Psychodidae collected by Curran and described cursorily by Rapp, are redescribed and figured from the type material. Their affinities are discussed. One of Curran's species is placed in synonymy.     

Contribution to the knowledge of female west palaearctic Glyptotendipes Kieff. (Diptera, Nematocera, Chironomidae)

The characters of the genitalia of the females of Glyptotendipes glaucus (Meigen, 1818), Glyptotendipes pallens (Meigen, 1804), Glyptotendipes paripes (Edwards, 1929), Glyptotendipes gripekoveni (Kieffer, 1913), Glyptotendipes aequalis (Kieffer, 1922), Glyptotendipes barbipes (Staeger, 1839) and Glyptotendipes salinus Michailova, 1987 are described. A key for the identification of these species is given.The taxonomic status of Glyptotendipes aequalis is discussed.     

青花菜谷胱甘肽-S-转移酶基因克隆及其表达分析

为探讨青花菜在模拟酸雨胁迫下谷胱甘肽-S-转移酶的表达变化,克隆了青花菜谷胱甘肽-S-转移酶基因(glutathione-S-transferase,GST)的cDNA序列全长,并进行了生物信息学和表达分析。结果表明:青花菜GST基因cDNA全长为915bp,开放阅读框为642bp,编码213个氨基酸,推测分子式为C1091H1719N289O306S5,分子量为23 940.7,没有跨膜螺旋区域和信号肽。系统进化树分析表明,该青花菜基因GST与芥菜的GST聚类关系最近。实时荧光定量PCR结果显示,在模拟酸雨胁迫下,GST基因的表达量在胁迫初期显著增大,随时间延长开始下降,表明其参与了青花菜抗酸雨的应答反应。     

Redescription of the neotropical Psychodidae (Diptera,Nematocera) described by Knab,Dyar and Coquillet

The remarkable neotropical Psychodidae described by Knab, Dyar and Coquillet, hitherto unrecognisable, are re-defined and figured from the type material. Lectotypes are selected, and affinities discussed.     

The effect of soil flooding on the survival and development of the eggs of Tipula oleracea L. and T.paludosa Meigen (Diptera: Tipulidae)

A comparison is made of the survival and development of eggs of Tipula oleracea and T.paludosa, at certain temperatures, under water only or under water standing over soil. The significance the activity of the soil microflora and mechanical disturbance of the water is discussed.     

Influence of the introduced parasitoid Torymus sinensis (Hymenoptera: Torymidae) on T. koreanus and T. beneficus as indigenous parasitoids of the chestnut gall wasp Dryocosmuskuriphilus (Hymenoptera: Cynipidae) on chestnut trees in Nagano Prefecture, Japan

We describe here the parasitoid wasps Torymus sinensis Kamijo and T. beneficus Yasumatsu & Kamijo (early-spring and late-spring strains), which are introduced and indigenous natural enemies of the chestnut gall wasp Dryocosmus kuriphilus Yasumatsu, an invasive chestnut pest in Japan. We recently discovered specimens of T. koreanus Kamijo, endemic in Korea, among Torymus parasitoids collected from D. kuriphilus galls in a Japanese chestnut orchard. In this study we compare the composition of Torymus parasitoids emerging from D. kuriphilus galls before and after the release of T. sinensis. Before the release of T. sinensis, early-spring and late-spring strains of T. beneficus predominated (58.3 and 20.8% of specimens collected). However, a few years after the release, both T. beneficus strains had been almost completely displaced by T. sinensis. In contrast to the rapid decrease in T. beneficus, T. koreanus did not decrease drastically before and even after the release of T. sinensis (approximately 10–20% of specimens collected). These results suggest that not a few T. koreanus were present in the Japanese chestnut orchard investigated at least several years after the release of T. sinensis, although both the T. beneficus strains were rapidly displaced by T. sinensis during this period.     

Revision of the fossil cylindrotomidae (Diptera,Nematocera) from florissant and White River,USA

Fossil species of the genusCyttaromyia Scudder (Diphtera, Cylindrotomidae) described by Scudder in 1877 and 1894 from the Eocene of White River Basin and the Lower Oligocène of Florissant, Colorado, are revised.Cyttaromyia fenestrata Scudder from White River andCyttaromyia princetoniana Scudder are redescribed; the remaining species: C.cancellata Scudder, C.clathrata Scudder and C.oligocena Scudder are regarded as junior synonyms of C.princetoniana.