Infestation of Phalaenopsis aphrodite Rchb.f. (Asparagales: Orchidaceae) flower buds by Japanagromyza tokunagai (Sasakawa) (Diptera: Agromyzidae) in a greenhouse on Shikoku Island,Japan

To protect endangered and commercially important orchid species, it is important to monitor and accurately identify orchid pests. Japanagromyza tokunagai (Sasakawa) larvae are known to infest the flower buds, stems, and ovaries of various Japanese orchid species. Given that J. tokunagai can infest diverse orchid hosts, J. tokunagai has the potential to be an economically important orchid pest in greenhouses. However, damage by J. tokunagai has previously only been reported in outdoor habitats. Here we revealed that the dipteran larvae infesting the flower buds of Phalaenopsis aphrodite Rchb.f. (Orchidaceae) cultivated in a greenhouse are J. tokunagai based on DNA barcoding, using COI sequences. Infested flower buds remained closed and eventually dropped to the ground, making the P. aphrodite plants commercially worthless. Phalaenopsis aphrodite is one of the most economically important ornamental orchids. Therefore, J. tokunagai is a potential threat to orchid production and we recommend taking precautions to prevent its spread.     

Effects of Melia azedarach, (Meliaceae) fruit extracts on the leafminer Liriomyza huidobrensis, (Diptera, Agromyzidae): Assessment in laboratory and field experiments

Control of the widely distributed pest Liriomyza huidobrensis, is complicated due to the protected habit of the leafmining larvae, and their resistance to insecticides. The effects of Melia azedarach, (Meliaceae) fruit extracts against adults and larvae of L. huidobrensis, were investigated. In the laboratory, leaves of Cucurbita, sp. infested with first and third instar larvae were treated with different extract solutions. Larval and pupal survival, as well as wing‐spread of adults, were ssessed. Female adult behaviour towards the extract was also analysed in terms of number of feeding punctures and number of offspring left on treated/untreated leaves. In the field, an infested Vicia faba, crop was sprayed four times at weekly intervals with plant extract, water, and a blank solution. The number of adult leafminers and parasitoids emerging from sampled leaves from each treatment were compared. The laboratory tests showed translaminar action of the extracts, which negatively affected leafminer pupal survival, while body size was not affected. The extracts also deterred feeding by adult females and may also have caused reduction in oviposition rates. All solutions and concentrations tested had similar effects. In the field, extract effects were consistent with those from laboratory trials, number of pupae and pupal survival being lower on treated plants. Percentage parasitism was not affected by plant extract treatment, suggesting a selective activity.     

Kairomone attractant for the leafmining fly, Liriomyza bryoniae (Diptera, Agromyzidae)

A field test carried out in an industrial greenhouse in Lithuania revealed the attractiveness of synthetic methyl salicylate (MeSa) towards an economically important leafmining tomato pest, Liriomyza bryoniae (Kaltenbach) (Diptera, Agromyzidae). The behavioural reaction of the flies depended very much on the simultaneous presence of both olfactory and visual stimuli. The attractiveness depended on the colour of a sticky trap: MeSa attracted significantly more flies (ca. 2.2 times) when placed in yellow traps than in aluminium foil colour ones, when catches in such traps were compared to a corresponding control. L. bryoniae is the first species within the Agromyzidae family attracted by MeSa. The attractant was attributed to kairomones, as the compound is known as a plant-produced volatile. MeSa can be an effective extra-tool for increasing the attractiveness of traps. It should be evaluated in future whether such trap/bait combination is effective for the mass trapping of L. bryoniae leafminers in greenhouses (closed area).     

Plant-feeding dipterans (Diptera,Chloropidae, Agromyzidae) from Wrangel Island (the Chukchi Sea)

Flies of the family Chloropidae were found in the arctic tundra for the first time. Oscinella frit L. was collected in several areas of the mountainous part of Wrangel Island, occurring mainly in the ground layer. Among three species of Agromyzidae, Napomyza mimula Spencer was the most numerous; it was found both in the mountains and on the coastal plain. Two other species, Phytomyza cineracea Hendel and Chromatomyia sp., were rare. The only biotope where all the four species were collected simultaneously was a zoogenic forb-grass meadow patch which developed around the arctic fox burrow.     

福建省双翅目潜蝇科昆虫的初步研究

作于1997－2000年对福建省主要蔬菜和花卉作物上潜蝇科昆虫进行了调查,经研究发现福建省现知潜蝇各类计有12属20种;其中,南美斑潜蝇Liriomyza huidobensis(Blanchard）和蒿萼潜蝇Calycomyza artemisiae(Kalt.）为福建省新记录种。本详细报道福建省潜蝇科昆虫的各类、分布和寄主,并就某些潜蝇害虫在省内的发生危害情况作一简要分析。     

中国萼潜蝇属研究(双翅目: 潜蝇科)

对中国萼潜蝇属Calycomyza Hendel进行了系统研究。该属在我国现知5种,其中包括一新种,中华萼潜蝇C. chinensis sp. Nov.,及一中国新记录种,一枝黄花萼潜蝇C. Solidaginis(Kaltenbach)。除新种描述并附特征图外, 还提供中国已知种类分种检索表。     

Polyandry and Reproduction in the Serpentine Leaf Miner Liriomyza trifolii (Diptera: Agromyzidae)

We investigated the hypotheses that Liriomyza trifolii is a polyandrous species and that multiple mating is required to maximize female fecundity. In addition, the hypothesis that male copulating frequency reduces female fecundity was examined. Using sterile and fertile males, we found that L. trifolii females mate more than once during their life span, and that multiple mating is required to maximize female fecundity. A similar amount of sperm was transferred during five successive male copulations with an equal insemination probability. However, the probability of reproduction failure was strongly correlated with the male copulating sequence. Moreover, the failure rate of sperm transfer was found to be 6.8%. In light of these results, possible selection pressures driving for polyandry in L. trifolii are discussed.     

中国萝潜蝇属分类研究 (双翅目: 潜蝇科)

研究了中国萝潜蝇属Napomyza Westwood,确认该属在我国现知下列6种：环萝潜蝇Napomyza annulipes (Meigen),角萝潜蝇N.hirticornis(Hendel),菊茎萝潜蝇N.lateralis (Fallen),拟土萝潜蝇N.paratripolii sp. Nov.,毛萝潜蝇N. plumea Spencer和西藏萝潜蝇N. xizangensis sp. Nov.。除描述二新种并附特征图外, 还提供中国已知种类的鉴别特征和分种检索表。     

Infestation of roe deer by Cephenemyia stimulator (Clark) (Diptera, Oestridae) in Trent province

Cephenemya stimulator (Clark) (Diptera Oestridae) is first recorded in Italy parasiting roe deer (Capreolus capreolus). Diagnosis was made by examination of II-III instar larvae (fig. 1-2) from roe deers killed in Trient province. In these last years in the Trentin region, there was an increasing of roe deers number (actually about 20.000); at the same time growed roe deers infestation by C. stimulator (Tab. 1). Females of C. stimulator probably attack young roe-deers lying down on field-pastures near forest (fig. 3). From examination of killed roe-deers (Tab. 2) there is evidence of debilitation status of infested specimens. Location and dislocations of parasitising larvae in the head cavity was that shown in fig. 4 and 5.     

Infestation of the orchid Cephalanthera spp. by Parallelomma vittatum (Meigen, 1826) (Diptera: Scathophagidae) in Japan

It is important to understand the interactions between orchids and their herbivores, especially considering the rarity of most orchids and the potential negative effects of pests on orchid reproduction. Here, we report the infestation of leaves of Cephalanthera spp. orchids by Parallelomma vittatum (Scathophagidae) in Japan. The present study represents the first report of P. vittatum on orchid hosts in Asia.     

Development and stability of insecticide resistance in the leafminer Liriomyza trifolii (Diptera: Agromyzidae) to cyromazine, abamectin, and spinosad

Three populations of the leafminer, Liriomyza trifolii (Burgess), were collected from commercial ornamental production greenhouses in the United States and tested for susceptibility to three commercial insecticides. A leaf dip bioassay of leaves containing young (1-2-d-old) larvae was used. Based on larval mortality and compared with a susceptible laboratory reference colony, the three strains varied in spectrum and level of resistance to the insecticides. CA-1, collected from Gerbera daisy, was moderately resistant to cyromazine (18.1-fold) and abamectin (22.0-fold), but highly resistant to spinosad (> 188-fold). CA-2, collected from chrysanthemums, was not resistant to abamectin, had a low level of resistance to cyromazine (8.2-fold), but was extremely resistant to spinosad (1,192-fold). GA-1, collected from chrysanthemums, had very low levels of resistance to cyromazine (5.4-fold) and spinosad (1.9-fold) but was moderately resistant to abamectin (30.6-fold). When reared in the absence of insecticide selection pressure, all three strains reverted to approximately the level of the reference strain. The CA-1 strain reverted in nine generations to cyromazine; however, the lowest levels of abamectin and spinosad resistance reverted to was 3.1-fold at F8 and 3.2 at the F10, respectively. The CA-2 strain reverted in five generations to both cyromazine and spinosad. GA-1 reverted in five generations to abamectin. Based on the results, resistance to these three insecticides was unstable. Additionally, there was no cross-resistance among these three insecticides.     

Infestation of cassava genotypes by Neosilba perezi (Romero & Ruppell) (Diptera: Lonchaeidae)

The objectives of this work were to assess the infestation of ten genotypes of cassava by the shoot fly Neosilba perezi (Romero & Ruppell) and to investigate effects of plant age, temperature or precipitation on cassava plants infestation by the shoot fly. Thirty-two individuals of each cassava genotype were planted and analyzed every two weeks in order to calculate the percentage of plants infested by shoot fly larvae at each sampling event and per genotype. Infestation by the fly was different across the genotypes. Genotype IAC Caapora 105-66 and genotype IAC Cascuda were resistant to shoot fly infestation, whereas the genotype IAC 15 was the most susceptible to this insect. Plant age may have an influence on infestation by shoot flies. Advanced plant age apparently favors lower or even inexistent infestation rates. However, infestation rate does not seem to be affected by temperature or precipitation.     

Analysis of acoustic stimulus to Liriomyza trifolii (Diptera: Agromyzidae) through Electroantennogram (EAG) technique

The study utilized the Electroantennogram (EAG) technique as biological acoustic stimulus to Liriomyza trifolii (Diptera: Agromyzidae). Pure tone sounds and courtship songs were tested in the excised head of test specimens. Significant EAG stimuli were detected when released at 20 Hz pure tone sound together with the courtship song having long pulse train patterns of Cryptonevra inquilina and Lipara japonica (Chloropidae). For their biological effectiveness, movement behaviors were analyzed with stimulus taken from EAG recordings. No attraction effect was observed even with and without acoustic stimulus. However, movement activities were transformed by information entropy and observed to be clearly different when selected acoustic stimuli were broadcast. The combination of response to EAG and behavioral observation would be useful to determine effective movement modification through acoustic stimulus in insect pests that are necessary toward the development of an acoustic pest management tool in agriculture.     

Host-associated allozyme variation in tree cambium miners,Phytobia spp. (Diptera: Agromyzidae)

The larvae of the agromyzid flies that belong to the genus Phytobia Lioy feed by mining in the differentiating xylem just below the cambium of growing forest trees. The genus, which is apparently one of the most primitive groups in the Agromyzidae, comprises over 50 currently recognized species. Most of the species are mono- or oligophagous, and the host plants belong to numerous genera in about 60 families. Thus, Phytobia is an attractive candidate for studies on the evolution of insect-plant relationships. In spite of this, the taxonomy of Phytobia is currently poorly understood, mainly because the morphological differences between species are small. We used allozyme electrophoresis to investigate whether molecular markers could be used to separate and identify species in Phytobia, and to study the patterns of host use in the group. For this, we collected Phytobia larvae from eight host tree species occurring in southern Finland. An analysis of 10 variable allozyme loci showed that there are probably five species of Phytobia that feed on the hosts included in our study: one occurs on birches (Betula pubescens Ehrh. and B. pendula Roth) and alders (Alnus incana (L.) Moench and A. glutinosa (L.) Gaertn.), one on rowan (Sorbus aucuparia L.), and three species with overlapping feeding ranges on aspen (Populus tremula L.) and two willow species (Salix phylicifolia L. and S. caprea L.). Because birches and alders belong to the plant family Betulaceae, rowan to Rosaceae, and aspen and willows to Salicaceae, the host associations of the individual fly species can be explained by the taxonomic affinities of the hosts. However, our results also show that on a larger scale the evolution of host-plant associations in Phytobia cannot be explained by strict parallel cladogenesis (cospeciation) between the flies and their hosts.     

Molecular evidence of cryptic species within the Liriomyza huidobrensis (Diptera: Agromyzidae)

Phylogenetic relationships among populations of the polyphagous pea leafminer, Liriomyza huidobrensis (Blanchard), were investigated using DNA sequence data. Maximum parsimony analysis of 941 bp of mitochondrial cytochrome oxidase I and II genes showed that L. huidobrensis contains two well-defined monophyletic groups, one composed of specimens from California and Hawaii and one composed of specimens from South and Central America together with populations that have been recently introduced into other parts of the world. The differentiation between the two clades within L. huidobrensis is equivalent to that seen between other agromyzid species, suggesting that L. huidobrensis as currently defined contains two cryptic species. This finding is consistent with field observations of differences in pest status and insecticide resistance between L. huidobrensis populations. Until additional studies are complete, no changes in L. huidobrensis taxonomy are proposed. However, researchers and quarantine officials may wish to consider the findings of the current study in designing research, pest management, and quarantine programs for L. huidobrensis.     

Oviposition and mining by Phytobia betulae (Diptera: Agromyzidae) in genotypes of European white birch (Betula pendula)

Abstract 1 The colonization success of herbivorous insects depends partly on the ability of females to choose suitable host plants. Phytobia betulae Kangas (Diptera: Agromyzidae), a miner of differentiating xylem, infests birch (Betula pendula Roth and Betula pubescens Ehrh.) trees. 2 In a field experiment we measured successful ovipositions in the long shoots of eight 5‐year‐old‐birch genotypes. Later in the growing season, in the same experiment, we counted the number of larvae from the same birch genotypes (different replicates). 3 We attempted to determine where Phytobia females lay their eggs in the birch canopy, what kind of shoots Phytobia utilize, whether birch genotypes differ in their susceptibility to Phytobia, and which tree characteristics correlate with successful utilization of birch for oviposition and larval development. 4 The ovipositions were concentrated in fast growing shoots and only 5% of the available shoots were utilized. Usually a shoot contained only one oviposition (80% of the cases). However, oviposition pattern resulted in significant aggregations (two to four ovipositions per shoot): 11% of shoots selected for oviposition contained more than one Phytobia and 22% of larvae shared their shoot with at least one other larva. Although birch shoots were much more abundant than Phytobia, there may be intraspecific competition for host resources among Phytobia. 5 Birch genotypes differed in the number of ovipositions but not in the number of larvae, although in general the number of larvae was correlated positively with the number of ovipositions. There were more ovipositions in the faster growing genotypes.     

Imbibition of Swietenia macrophylla (Meliaceae) seeds: the role of stomata

BACKGROUND AND AIMS: The occurrence of stomata in seed coats is uncommon and there is limited information about their function(s). The aim of this study was to verify the distribution of stomata in seed coats of Swietenia macrophylla and to relate it to the imbibition process and aspects of the structure of the outer integument layers. METHODS: For the structural and ultrastructural studies, the seeds were processed using the usual techniques and studied under light and scanning electron microscopes. Histochemical tests were employed to identify the cell wall composition in the different seed coat portions. To assess the role of the stomata in the imbibition, non-impervious seeds were compared with partially impervious ones, in which only the embryo, median or hilar regions were left free. Further, the apoplastic pathway marker was employed to confirm the role of the stomata as sites of water passage during imbibition. KEY RESULTS: A positive relationship was observed between seed coat thickness and stomata density. The stomata were devoid of movement, with a large pore. They occurred in large numbers in the embryo region and extended with lower frequency towards the wing. Imbibition rates were related to stomata density, suggesting that the stomata act as preferential sites for water entry in the S. macrophylla seeds. CONCLUSIONS: At maturity, the stomata in the seed coat play a significant role in seed imbibition. The data may also infer that these permanently opened stomata have an important role in gas exchange during seed development, aiding embryo respiration.     

福建省发现加藤斑潜蝇（双翅目：潜蝇科Diptera：Agromyzidae）

1995年在调查潜叶蝇种类时，在菊花上发现加藤斑潜蝇，属中国大陆首次报道，本文对其形态特征进行描述。