Side effects of fungicides on the abundance and the species diversity of the natural populations of <Emphasis Type="Italic">Drosophila</Emphasis> and their hymenopterous parasitoids in orchards

Within entomophagous insects, hymenopterous parasitoids are important regulators of natural populations of insects including pests. Pesticide treatments are largely used in orchards for economic reasons. These treatments allow for greater productivity, but they may also impact upon non-target insect populations. Drosophila and their hymenopterous parasitoids are abundant in orchards and are not direct targets of pesticide treatments. In this work, natural populations of Drosophila and their parasitoids were monitored from June to November, and their abundance was reported from two types of orchards. One type was under conventional pesticide treatments, mostly fungicides (“Treated plot”), and the other was under low-input treatments (“Low-input plot”). Five Drosophila species and five parasitoid species were present in both types of orchards. A time effect on abundance was found with two peaks of abundance, one in August and the other in autumn (October), corresponding to a fluctuation of numbers depending on the availability of resources. When comparing insect abundance between the two types of plots, the abundance in the Treated plot was found to be lower than or equal to that in the Low-input plot. Furthermore, a significant decrease in the abundance of two scarce parasitoid species (Leptopilina heterotoma and Asobara tabida) that could lead to their disappearance was also observed. The results are discussed in the context of the diverse lethal and sub-lethal effects of pesticides on the development and reproduction of natural populations of insects and their importance as natural enemies.     

Distribution and migration of insects and mites in flat storage containing wheat

Studies were conducted in a flat storeroom in central Greece, filled with approx. 90 tons of wheat, in order to evaluate insect and mite species abundance, and changes in population density and distribution among sampling units and locations. The surface of the grain bulk was divided into two sampling zones: the central and the peripheral (edge). At 10-day intervals, five wheat samples were taken from the central zone and eight from the peripheral zone, with a non-partitioned grain trier (1.6-m length, 250-g capacity). Fifteen insect species and 12 mite taxa were found during the sampling period, (June 1999–Feb. 2000). The most abundant insect species wereSitophilus oryzae (L.),Cryptolestes ferrugineux (Stephens),Tribolium castaneum (Herbst) andLatheticus oryzae Waterhouse; the most abundant mite species wereAcarus siro L.,Lepidoglyphus destructor (Shrank), and the predatorsBlattisocius tarsalis (Berlese) andB. keegani Fox. Grain temperature decreased during the storage period, more slowly in the central than peripheral zone; grain moisture content increased. The highest population densities for both insects and mites were recorded during September and October. The most numerous species of insects and mites showed an aggregated spatial pattern, as indicated by Iwao’s Patchiness Regression.     

Genome-based PCR Primers for Specific and Sensitive Detection and Quantification of Xylella fastidiosa

Xylella fastidiosa is an important pathogen of many commercial crops. Detection of X. fastidiosa is difficult due to low concentrations of the bacteria in insects and asymptomatic plant tissue, and non-uniform distribution in infected plants. A dual purpose conventional PCR and quantitative PCR (TaqMan™) system was developed for the generic detection of X. fastidiosa strains. Primers HL5 and HL6, designed to amplify a unique region common to the sequenced genomes of four Xylella strains, amplified a 221 bp fragment from strains associated with Pierce’s disease of grapes, almond leaf scorch, and oleander leaf scorch disease and from DNA from an Xf strain associated with citrus variegated chlorosis. Standard curves were obtained using concentrations of Xylella ranging from 5 to 10⁵ cells per reaction in water and grape extracts and 10–10⁵ cells in insect DNA. Regression curves were similar, with correlation coefficients of r ² > 0.97. In quantitative PCR, C_t values ranged between 20 and 36 cycles for 5–10⁵ bacterial cells per reaction. No amplicons were obtained with several non-Xf bacterial strains tested including related plant pathogenic, grape endophytic bacteria and endosymbiotic bacteria isolated from glassy-winged sharpshooters. The method was evaluated for clinical diagnosis of Xf in grapes, almonds and insect vectors. The procedure described is reliable for detection of the pathogen with a high degree of sensitivity and specificity.     

Composition,abundance and phytoplasma infection in the hawthorn psyllid fauna of northwestern Italy

Hawthorn (Crataegus monogyna) is one of the natural hosts of Cacopsylla melanoneura, the acknowledged vector of ‘Candidatus Phytoplasma mali’, the causal agent of Apple Proliferation disease, a serious and growing problem for apple production in Europe, particularly in northern Italy. Wild plants could be important sources of both insects and phytoplasmas, but their role in the epidemiology of phytoplasma diseases and their insect vectors has never been thoroughly examined. Cacopsylla melanoneura’s primary host is hawthorn, a plant closely related to apple which often grows wild near orchards. Other psyllid species feed on hawthorn, but no data are available on their possible role as phytoplasma vectors. We investigated the hawthorn’s psyllid fauna in northwestern Italy using yellow sticky traps, beat trays, and molecular analyses from 2003–2005, to study the relationship between hawthorn, the phytoplasma and the insect vector. Population dynamics were monitored, and insects and hawthorn samples were analysed by polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and DNA sequencing for the presence of phytoplasmas. Cacopsylla melanoneura was the dominant psyllid species, followed by C. peregrina, C. affinis and C. crataegi. PCR and RFLP analyses revealed the presence of different fruit tree phytoplasmas in hawthorn plants, and in all four psyllid species.     

The dynamics of introduction of alien scale insects (Hemiptera: Coccoidea) into Croatia

In recent years, several species of alien scale insects have arrived and spread rapidly through European and Mediterranean countries. One hundred and twenty‐nine species of alien scale insects have so far been recorded in Europe. This paper presents a list of alien scale insect species for Croatia, comprising 56 species from 8 different families. Four of them are new records for Croatia: Aonidiella taxus Leonardi, 1906, Ichnaspis longirostris (Signoret, 1882), Phoenicococcus marlatii (Cockerell, 1899) and Spilococcus mammillariae (Bouche, 1844). The majority of species recorded belong to the following families: Diaspididae (28 species), Coccidae (12 species), Pseudococcidae (10 species), Eriococcidae (two species). The scale insect families Dactylopidae, Margarodidae, Ortheziidae and Pheniococcidae comprised only one recorded alien species each. During the time frame covered in the review (from the beginning of the 20th century until 2015), the majority of alien scale insect species (23) were registered in the period from 2000 to 2015. Data on the origin of introduced alien scale insects shows that the majority of the species originate from Asia (22 species), followed by North America (6 species), Africa, Australia and Central America (5 species each) and South America (4 species), with 9 species being of unknown origin.     

Primary studies on the parasitoid fauna of Coccoidea in cultivated and non-cultivated areas in the east Mediterranean region of Turkey

The parasitoid fauna of Coccoidea in cultivated and noncultivated areas was studied in the east Mediterranean region of Turkey in 1994–1997. In total, 25 parasitoid species belonging to Aphelinidae, Encyrtidae, and Eulophidae (Hymenoptera) were reared from 21 different scale hosts. On crop plants, mainly citrus and peach, 13 parasitoids from eleven Coccoidea hosts were determined while 14 parasitoid species were obtained from twelve scale insects on non-cultivated plants. Seven parasitoid species are new records for the Turkish insect fauna. Only one of them was found on citrus, while the other six species were sampled in non-cultivated areas. The most common parasitoids encountered wereAphytis melinus DeBach,Encarsia berlesei (Howard) (Aphelinidae),comperiella bifasciata Howard (Encyrtidae), andMetaphycus flavus (Howard) (Eulophidae) in cultivated areas andCoccophagus lycimnia (Walker) (Aphelinidae) in non-cultivated areas. All other parasitoids species were obtained only from a few scale insects hosts.

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Erste Untersuchungen zur Parasitoiden-Fauna der Coccoidea in landwirtschaftlich genutzten und nicht genutzten Gebieten der ?stlichen Mittelmeer-Region der Türkei

Zusammenfassung  In der vorliegenden Arbeit wurde die Parasitoiden-Fauna der Coccoidea in landwirtschaftlich genutzten und nicht genutzten Gebieten der ?stlichen Mittelmeer-Region der Türkei in der Zeit von 1994–1997 untersucht. Insgesamt konnten 25 Parasitoiden-Arten aus den Familien Aphelinidae, Encyrtidae und Eulophidae (Hymenoptera) aus 21 verschiedenen Schildlaus-Wirten gezogen werden. Von den Kulturpflanzen, vor allem von Zitrus und Pfirsich, wurden 13 Parasitoide aus 11 Coccoidea-Wirten gewonnen, w?hrend 14 Parasitoiden-Arten aus 12 Schildlaus-Wirten von den Wildpflanzen stammten. Bei sieben Parasitoiden-Arten handelt es sich um Neubeschreibungen der türkischen Insektenfauna. Nur eine von diesen wurde auf Zitrus beobachtet, w?hrend die anderen sechs Arten aus nicht bewirtschafteten Gebieten stammten. Die gel?ufigsten der ermittelten Parasitoiden-Arten warenAphytis melinus DeBach,Encarsia berlesei (Howard) (Aphelinidae),Comperiella bifasciata Howard (Encyrtidae) sowieMetaphycus flavus (Howard) (Eulophidae) auf den bewirtschafteten undCoccophagus lycimnia (Walker) (Aphelinidae) auf den nicht bewirtschafteten Fl?chen. Alle anderen Parasitoiden-Arten wurden auf nur wenigen Schildlaus-Wirten beobachtet.

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The paper was gratefully dedicated to Prof. Dr. Niyazi Lodos.     

Scale insect species (Hemiptera: Coccoidea) in Syria

Scale insects in Syria were surveyed between 2009 and 2015. This study showed that Diaspididae and Coccidae were the most common families, comprising 5 and 8 species, respectively. The remaining families found comprised 1 species each. New records of Coccoidea fauna from Syria were Parlatoria blanchardi, Phoenicococcus marlatti, Coccus hesperidum, Coccus pseudomagnoliarum and Chionaspis etrusca.     

雷州半岛空中昆虫群落结构特征

为明确东亚迁飞场重要通道—雷州半岛空中昆虫的群落结构特征,于2022年在雷州半岛设立探照灯对夜间昆虫进行诱集及种群动态监测,并采用Margalef丰富度指数、Shannon-Wiener多样性指数和Pielou均匀度指数分析物种多样性。结果表明,诱集昆虫隶属于12目61科126属146种,其中鳞翅目、鞘翅目和半翅目昆虫是诱集量和物种丰富度最多的3大类群,分别占所有诱集昆虫总数的72.37%、11.18%和6.58%。诱集昆虫不仅包括草地贪夜蛾Spodoptera frugiperda、劳氏黏虫Leucania loreyi和斜纹夜蛾S. litura等多种重要的迁飞性害虫,还包括中华草蛉Chrysoperla nipponensis、黄蜻Pantala flavescens和异色瓢虫Harmonia axyridis等迁飞性天敌昆虫。空中昆虫的诱集高峰期主要在6—9月。诱集昆虫的Margalef丰富度指数平均数为6.60,Shannon-Wiener多样性指数平均数为2.68。表明雷州半岛空中昆虫群落物种丰富度和多样性均较高,并证实许多重大农业害虫在迁飞过程中途经雷州半岛。     

Auswirkungeh einer frosfspannerbek?mpfung auf die bodenfauna eines elchertwaldes

Studies were made in 1998 and 1999 In an oak forest (“Meuenburger Holz”) in Northern Germany for the purpose of testing the effect of some insecticides on the soil fauna. The preparations “Fastac” (active agent:a-Cypermeth-rin) and “Foray 48 B” (active agent:Bacillus thuringiensis var.kurstaki) were used for the control of winter moths (Operopbthera brumata). The insects and spiders were caught using the following methods: soil samples, pitfalls and net sweeps. There were differences In the spectrum of species and In the density of individuals between the three experimental areas, but these did not depend on effects of the used insecticides.      

Auswirkungeh einer frosfspannerbek?mpfung auf die bodenfauna eines elchertwaldes

Studies were made in 1998 and 1999 In an oak forest (“Meuenburger Holz”) in Northern Germany for the purpose of testing the effect of some insecticides on the soil fauna. The preparations “Fastac” (active agent:a-Cypermeth-rin) and “Foray 48 B” (active agent:Bacillus thuringiensis var.kurstaki) were used for the control of winter moths (Operopbthera brumata). The insects and spiders were caught using the following methods: soil samples, pitfalls and net sweeps. There were differences In the spectrum of species and In the density of individuals between the three experimental areas, but these did not depend on effects of the used insecticides.     

The activity of some compounds extracts byAllium on stored-product insectsOryzaephilus surinamensis (L.),Sitophilus oryzae (L.) andTribolium castaneum (Herbst)

The bioactive metabolites of someAllium plants, all exhibiting interesting pharmacological activities, were tested for their attractive/repellent activity against saw-toothed grain beetle,Oryzaephilus surinamensis (L.), rice weevil,Sitophilus oryzae (L.), and rust-red flour beetle,Tribolium castaneum (Herbst), insects infesting the stored-products. The data obtained showed significant repellent effect of the thiosulfinates againstS. oryzae. Part 6 in the series “Chemistry of the genus Allium”.     

Reduced consumption of pea protein-treated flour disks by stored-product insects

Consumption of pea (Pisum sativum L.) protein-treated wheat flour by the red flour beetleTribolium castaneum (Herbst.), the rice weevilSitophilus oryzae (L.) and the lesser grain borerRhyzopertha dominica (F.), was significantly reduced compared with wheat flour alone. Consumption was affected when the insects were exposed for 3 days to flour disks containing protein-rich fraction of the ‘Bonneville’ pea variety. Antifeedants present in the pea protein fraction are apparently responsible for the reduced feeding response in these species. http://www.phytoparasitica.org posting May 6, 2004.     

Lethal doses of ozone for control of all stages of internal and external feeders in stored products

BACKGROUND: Gaseous ozone (O₃) has potential for control of insects in stored grain. Previous studies have focused on freely exposed insects. Immatures of internal pests (e.g. Sitophilus spp. and most stages of Rhyzopertha dominica F.) are protected within kernels and probably require higher doses and/or longer treatment times for full control. A laboratory study determined the doses of ozone necessary for full control of freely exposed and internal stages of eleven stored‐product pest species. Test insects were three species of Sitophilus, R. dominica, Tribolium confusum Jacquelin du Val, T. castaneum Herbst, Plodia interpunctella Hübner, Sitotroga cerealella Olivier, Oryzaephilus surinamensis L., Ephestia kuehniella Zeller and Stegobium paniceum L. Insects were exposed to continuous flows of ozone in doses of 10–135 ppm and exposure times of 5–8 days. Dose‐mortality bioassays were conducted on three species of Sitophilus and P. interpunctella. RESULTS: Freely exposed stages (with a few exceptions) were controlled with 35 ppm of ozone for 6 days. Full mortality of internal stages within kernels required exposure to 135 ppm for 8 days. CONCLUSION: This study confirms that higher doses and/or longer treatment times are necessary for control of internal stages of stored‐product pests. Copyright © 2012 Society of Chemical Industry     

The use of dyes to mark populations of beneficial insects in the field

Dyes and dusts have been used to mark insects internally and externally for decades, the majority of examples coming from laboratory-reared pest species used in mark-release-recapture studies. Using dyes or dusts to mark populations of pests and beneficial insects simultaneously in the field has received less attention. We evaluated a water-soluble fluorescent dye and a resin-based fluorescent pigment sprayed on crops to mark beneficial and pest insects, and monitored the dispersal of marked insects. Our results show that resin-based dyes provide an effective mark on several species of insects among several orders. The resin-based dye is also relatively inexpensive, non-toxic, UV-stable and water resistant, unlike a water-soluble dye. Using the resin-based dye in a broccoli production system, we were able to monitor simultaneously the movement of field populations of the parasitoids, Diadegma semiclausum (Hellén) (Hymenoptera: Ichneumonidae), and Apanteles ippeus (Nixon) (Hymenoptera: Braconidae) and the adult stage of the host, diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). Resin-based dye applied on a crop is an effective way to mark and monitor the dispersal of populations of beneficial and pest insects in relation to agricultural practices, integrated pest management and conservation biological control.     

昆虫基因组组装大小偏差的原因解析

为明确昆虫基因组组装大小产生偏差的原因,利用流式细胞术估测来自6目10科的21种常见农业昆虫的基因组大小,同时从动物基因组大小数据库收集和整理1 345个经流式细胞术估测的昆虫基因组大小信息,并从NCBI、GigaDB、DDBJ、i5k workspace@NAL、InsectBase和VectorBase等14个物种遗传信息数据网站获取536种昆虫的基因组组装信息进行比较分析。结果表明,收集的昆虫中有202种同时具有流式细胞术估测的基因组大小和基因组组装大小的信息,以更接近真实值的流式细胞术估测基因组大小为参照,比较发现其中42种昆虫的基因组组装大小偏大,98种昆虫的基因组组装大小偏小,而62种昆虫的基因组组装大小和经流式细胞术估测大小相似。基因组组装大小比经流式细胞术估测大小更大的物种,通过Wilcoxon秩和检验发现显著具有更多的重复序列,但与GC含量、contig N50及基因组测序和组装策略并无显著相关性。综合分析认为,在大多数情况下昆虫基因组组装大小更小,表明组装并不完整,但在重复序列占比较高的情况下,昆虫基因组的组装出现了冗余,导致组装大小更大。     

Further studies on the role of monoterpenes in pine host selection and oviposition ofThaumetopoea pityocampa

In a young mixed pine plantation (Pinus nigra andP. pinea) in central Italy, the influence of the pine needle monoterpenes (R)-(+)-limonene, (S)-(−)-limonene and (1S)-(−)-β-pinene on the oviposition activity of the pine processionary moth,Thaumetopoea pityocampa (Denis et Schiffermüller), was assessed. Two application methods were compared: spraying the trees with the substances emulsified with water, and setting up polyethylene dispensers from which the monoterpenes evaporated. During the moth’s flight period weekly treatments (at 500 mg of monoterpene /l water) were carried out and the evaporation from the polyethylene dispensers (each with 5 g of a single monoterpene) was checked on each occasion by weighing the dispensers. The GLM analysis did not uncover any difference between the methods of application or between the pine species.T. pityocampa laid a significantly (P=0.01) lower number of egg masses on the trees treated with (1S)-(−)-β-pinene than on those treated with the other substances and on the control trees. A ∼45% reduction in egg mass number was obtained on the pines treated with (1S)-(−)-β-pinene, independent of the level of infestation, method of application or pine species. (R)-(+)-limonene and (S)-(−)-limonene were not effective. http://www.phytoparasitica.org posting July 29, 2008.     

‘<Emphasis Type="Italic">Candidatus</Emphasis> Phlomobacter fragariae’ and the proteobacterium associated with the low sugar content syndrome of sugar beet are related to bacteria of the arsenophonus clade detected in hemipteran insects

The phylogeny of ‘Candidatus Phlomobacter fragariae’(Ca. P. fragariae), the agent of the strawberry marginal chlorosis (SMC), and the proteobacterium associated with the low sugar content syndrome of sugar beet (SBRp) is not well understood. The spoT-spoU-recG genetic locus initially characterised by genome walking from a ‘Ca. P. fragariae’ partial spoT sequence was used to determine relatedness of ‘Ca. P. fragariae’ and SBRp with bacteria detected in hemipteran insects. Both plant pathogenic bacteria belong to the same phylogenetic group as bacteria of the arsenophonus clade detected in hemipteran insects. The SBRp is closely related to arsenophonus-like proteobacteria from cixiids and more distantly related to psyllid and delphacid secondary endosymbionts, whereas the relatives of ‘Ca. P. fragariae’ remain to be discovered. No genetic variability was found among isolates of ‘Ca. P. fragariae’ or SBRp. Implications for explaining the emergence of both ‘Ca. P. fragariae’ and SBRp as epidemic plant pathogens are discussed.     

布氏白僵菌的研究与应用

对７０年代以来布氏白僵菌的生物学、致病性、生理生化特性等基因研究以及该菌的规模征税和田间防治应用地综述。目前已发现该菌能寄生７个目的７０种昆虫,特别对鞘翅目害虫具有独特寄生效果,已在林区、农田、草地、果园中用于防治各种金龟子和天牛。在法国、瑞士等地,用布氏白僵菌连续多年防治林区的西方五月鳃金龟,取得了令人瞩目的防治效果和生态效果,日本用该菌防治杉树天牛、我国用该菌防治农田及苗圃蛴螬都取得明显成效。     

Parasitoids Associated with <Emphasis Type="Italic">Mussidia</Emphasis> spp. (Lepidoptera: Pyralidae) in Kenya

The pyralid Mussidia nigrivenella, a pest of cotton, maize and Phaseolus bean in West Africa, has never been reported as a crop pest in East and Southern Africa, although reportedly it exists in the wild. It is hypothesized that the difference in pest status of M. nigrivenella between western and eastern Africa was either due to differences in natural enemy compositions or that there exist several populations and/or species of Mussidia, which vary in their host plant range. Thus, a catalogue of parasitoids of Mussidia spp. was established through surveys in mid-altitude and coastal Kenya, between 2006 and 2007. Mussidia spp. eggs, larvae and pupae were collected from fruits of plants known to host Mussidia spp. and were examined for parasitoid-related mortality. The trichogrammatid Trichogrammatoidea sp. nr. lutea was obtained from eggs of Mussidia fiorii. A braconid egg-larval parasitoid, Phanerotoma sp., was reared from the larvae of unknown species of Mussidia (which we are referring to as Mussidia “madagascariensis”, Mussidia “quanzensis”) and M. fiorii, while the bethylid Goniozus sp. and the braconid Apanteles sp. were obtained from Mussidia nr. nigrivenella. Moreover, the ichneumonid larval parasitoid Syzeuctus sp. was obtained from M. fiorii, while the tachinid Leskia sp. was obtained from Mussidia “madagascariensis”. Overall, mortality caused by parasitoids was negligible; hence they were not considered key mortality factors in the population dynamics of the Mussidia spp. in Kenya.     

Spongy tissue development in Alphonso mango: association with <Emphasis Type="Italic">Staphylococcus xylosus</Emphasis>

A Gram-positive and catalase positive Staphylococcus strain was found to be associated with spongy tissue defect of Alphonso mango. The organism was identified to species level by physiological, morphological and biochemical characterization and fatty acid profile. The strain was identified as Staphylococcus xylosus (IMTECH, India, Accession No. MTCC 7441). The optimal growth of the organism was observed in the pH range of 5.0–9.0 and temperature range of 10–45°C. It was mannitol and arabinose-positive and able to produce acid from various sugars. The organism was able to grow in a medium containing 2–10% NaCl. It was further identified to species level by genomic sequencing of 1,387 base pairs of DNA (Gene Bank accession No. EU019195). Based on nucleotide homology and phylogenetic analysis, the microbe was found to be S. xylosus. The survey of Alphonso mango trees with a known history of producing spongy fruits showed that some of the twigs, leaves and flowers were coated with a honeydew-like sticky substance and mango hopper insects were observed over the inflorescence. The source of contamination of spongy fruits by S. xylosus was in the sticky mass. Gram staining, the catalase test and morphological features of the culture isolated from the sticky mass exhibited characteristics identical to the Staphylococcus strain isolated from the spongy pulp. Pathogenicity tests on different varieties of mangoes, apples and guavas indicated that the disease was experimentally transmitted from infected to healthy fruits. This observation suggested that this organism develops spongy symptoms in the fruits post-harvest and lacks specificity. In inoculated fruits, catalase and peroxidase enzymes were expressed as in naturally infected fruits. This report shows that the infection by S. xylosus could be a major initiating factor for spongy tissue development in Alphonso mangoes.