Biological invasion of the lime leafminer Phyllonorycter issikii Kumata (Lepidoptera,Gracillariidae) in Europe

This review covers the history of invasion of the lime leafminer in Europe and the European part of Russia; it observes forage plants, leafminer entomophaga, and features of its development cycle. Biocenotic mechanisms and ecological consequences of invasion are analyzed.     

The parasitoid complex (Hymenoptera, Eulophidae) of the leafminer Phyllonorycter issikii (Kumata) (Lepidoptera, Gracillariidae) from the Middle Volga Basin

In the Middle Volga Basin, Phyllonorycter issikii, an invasive species new to Europe, is attacked by many native parasitoids of the family Eulophidae (the percentages of infestation are given in parentheses): Sympiesis gordius (42), Minotetrastichus frontalis (20), Chrysocharis laomedon (11), Pnigalio soemius (10), S. sericeicornis (8), Apanteles sp. (4), Hissopus geniculatus (4), Entedon sp. (0.4), Aprostocetus sp., Cirrospilus lyncus, C. diallus, C. viticola, and Pteromalidae (0.2). Six species of parasitoids: Aprostocetus sp., C. lyncus (Walker 1838), C. diallus (Walker 1838), C. viticola (Rondani 1877), H. geniculatus (Hartig 1838), and Apanteles sp. (Braconidae), are recorded for the first time. The number of ectoparasitoids is 5.5 times that of endoparasitoids. The second generation of Ph. issikii is reduced by 22% due to parasitoids, and its propagation rate also decreases. However, the climate warming may level the pressure of parasitoids and promote development of the third generation in Ph. issikii.     

Citrus leafminer (Lepidoptera: Gracillariidae) density: effect on yield of 'Tahiti' lime

The relationship between damage by citrus leafminer, Phyllocnistis citrella Stainton, and 'Tahiti' lime yield were investigated in a 15-yr-old and a 5-yr-old lime orchard. Citrus leafminer population densities were controlled by insecticide applications of abamectin plus FC 435 oil, abamectin plus FC435 oil plus imidacloprid, and methomyl. The control was not treated. To ensure adequate citrus leafminer densities, adult citrus leafminer were periodically released in the experimental plots during fall and winter. For the 15-yr-old trees, the least amount of leaf area damage occurred in the abamectin plus FC 435 oil plus imidacloprid (1.9%) and the abamectin plus FC435 oil (2.3%) treatments compared with the control treatment (10-21%). In the 5-yr-old orchard, the least amount of leaf area damaged occurred in the abamectin plus FC 435 oil plus imidacloprid (0.4%) and the imidacloprid (0.1%) treatments compared with the control (20.85%). The percentage of leaf area damaged was linearly correlated with the average number of mines per leaf, average mine days, and cumulative mine days in both orchards. In both orchards, the percentage of leaf area damaged and cumulative mine days was linearly correlated with the number of fruit per tree and total fruit weight per tree. Calculating the economic injury levels indicated that 16-23% and 18-85% of leaf area damaged caused significant yield reductions in 15-yr-old and 5-yr-old trees, respectively.     

The lime leafminer Phyllonorycter issikii in Western Siberia: Some ecological characteristics of the population of the recent invader

The detection of the lime leafminer Phyllonorycter issikii in Novosibirsk in 2008–2009 is reported. Mines of this pest have been found on the small-leaved lime Tilia cordata and the Siberian lime T. sibirica, but not on the Amur lime T. amurensis (common host plant of moth). Leaves of T. cordata carried 2–3 times more mines than T. sibirica. On both host plants, the parasitism of mature larvae and pupae did not exceed 7%. Lack of control by local parasitoids can give the pest an opportunity to increase population density and spread further in Western Siberia.     

Distribution of the lime leafminer <Emphasis Type="Italic">Phyllonorycter issikii</Emphasis> (Lepidoptera,Gracillariidae) in natural stands

The spatial distribution of the lime leafminer Phyllonorycter issikii was studied in natural stands. The number of mines increased with shading of host-plant leaves. The maximum density of the miner was found in closed lime and spruce forests. The number of mines increased vertically from the tree top to its butt and horizontally, from the apex of branches to their base.     

Parasitoids as a mortality factor for the lime leafminer (<Emphasis Type=Italic>Phyllonorycter issikii</Emphasis>, Lepidoptera,Gracillariidae)

The species structure and dynamics of the parasitoid complex of the lime leafminer Phyllonorycter issikii Kumata (Lepidoptera, Gracillariidae) were studied in three test plots in Izhevsk (Udmurtia) during 2001–2005. The leafminer mortality rate associated with activity of this complex was assessed.     

Sex pheromone of the spotted tentiform leafminer moth Phyllonorycter blancardella (Fabr.) (Lep., Gracillariidae)

Dodecyl acetate (12:OAc) ( E )-10-dodecenyl acetate ( E 10-12:OAc) and ( E )-10-dodecenol ( E 10-12:OH) in the ratio 8 : 80 : 12 were collected by solid phase micro-extraction of the volatiles emitted by virgin signalling females of the spotted tentiform leafminer moth, Phyllonorycter blancardella . The same compounds in the ratio 8 : 79 : 13 were extracted from the sex pheromone glands of virgin signalling females of the same species. The chemical structures of the compounds were identified by gas chromatography and mass spectrometry. Trapping results obtained from field tests using synthetic components of the sex pheromone demonstrated that only one component, E 10–12:OAc, was essential for the attraction of conspecific males and should be considered as a sex pheromone.     

Parasitoids (Hymenoptera) of the Lime Leafminer Phyllonorycter issikii (Lepidoptera,Gracillariidae) in Different Cities of the Russian Federation and Their Role in the Mortality of the Invasive Pest

Entomological Review - The assemblage of hymenopteran parasitoids associated with the invasive lime leafminer Phyllonorycter issikii (Lepidoptera: Gracillariidae), which develops on the lime Tilia...     

Phyllonorycter medicaginella (Lepidoptera, Gracillariidae) and its parasitoids (Hymenoptera, Eulophidae) in the Middle Volga River basin

Fifteen species of parasitoids, Chrysocharis idyia (Walker, 1983), Ch. laricinellae (Ratzeburg, 1848), Ch. submutica Graham, 1963, Ch. viridis (Nees, 1834), Hemiptarsenus ornatus (Nees, 1834), Neochrysocharis formosa (Westwood, 1833), Pediobius cassidae Erd?s, 1958, P. metallicus (Nees, 1834), Pnigalio nemati (Westwood, 1838), P. mediterraneus Ferriére & Delucchi, 1957, P. pectinicornis (Linnaeus, 1758), P. soemius (Walker, 1839), Rhicnopelte crassicornis (Nees, 1834), Sympiesis gordius (Walker, 1839), and Hyssopus sp. n., were reared from Phyllonorycter medicaginella on Melilotius offlcinalis for the first time. Hyssopus simbirskiensis sp. n. reared from Ph. medicaginella is described. Eight ectoparasitoid species (Hyssopus ornatus, H. simbirskiensis sp. n., Rh. crassicornis, P. mediterraneus, P. nemati, P. pectinicornis, P. soemius, and S. gordius) attack all the larval instars of Ph. medicaginella. Seven endoparasitoids (P. cassidae, P. metallicus, Ch. idyia, Ch. laricinellae, Ch. submutica, Ch. viridis, and N. formosa) attack only the 4-5th-instar larvae.     

A novel pheromone dispenser for mating disruption of the leafminer Phyllocnistis citrella (Lepidoptera: Gracillariidae)

The sex pheromone of the leafminer Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) was deployed in a Florida citrus (Citrus spp.) grove by using a novel deployment device (IFM-413) containing SPLAT, a flowable formulation of an emulsified wax compound designed to provide slow release of semiochemicals. The device consisted of two disks connected by string. Each disk was loaded with 1 g of SPLAT containing either 0.15% (Z,Z,E)-7,11,13-hexadecatrienal (triene) or 2% (Z,Z)-7,11-hexadecadienal (diene). The devices were deployed using a two-dimensional multivariate design to determine the optimal rate of pheromone per unit area and degree of aggregation of the deployment devices (number of trees treated per unit area). The IFM-413 device proved effective at becoming securely entangled in tree branches. Furthermore, the devices effectively delivered pheromone-loaded SPLAT that resulted in disruption of trap catch of male P. citrella. Response surfaces showed a quadratic response of trap catch disruption to both total amount of pheromone per unit area and the degree of aggregation of the deployed devices (number of treated trees per unit area). The response surfaces for 0.15% triene or 2.0% diene were similar. The diene produced an effect similar to that of the triene at approximately 13 times the rate of the triene. The greatest disruption of trap catch occurred when the number of treated trees per unit area was greatest (no aggregation of deployment devices). Manufacturing, packaging, and mechanical deployment of the devices remain to be investigated.     

Pheromone Release Behaviour in Females of Phyllonorycter junoniella (Z.) (Lepidoptera, Gracillariidae) Under Constant and Cycling Temperatures

The calling activity of virgin Phyllonorycter junoniella (Z.) females under a cycling thermal regime differed from that under constant temperature in the following ways: the percentage of females calling at the morning activity peak was increased; the morning period of calling activity was prolonged; the total period of calling activity of an individual female was increased; an extra peak of activity occurred at the end of the photophase, and females changed the calling pattern during the active period. We assume that the occurrence of two calling peaks and the extension of the calling period might be adaptive for a Ph. junoniella species with a sex ratio strongly shifted towards females (8:1 females:males), as it could lead to an increased proportion of females mated.     

Ecological consequences of invasion of <Emphasis Type="Italic">Phyllonorycter issikii</Emphasis> (Lepidoptera,Gracillariidae) in lime forests in Udmurtia

The influence of the lime miner, Phyllonorycter issikii, on the productivity and reproductive parameters of the small-leaved lime Tilia cordata was studied. An increasing infestation of the host plant had a significant negative effect on the linear growth of the shoots and the radial increment of the trunk, the formation of annual rings, the number of inflorescences, and sugar content in the nectar. The latter factor may create a direct threat to the efficiency of local beekeeping. It is recommended that the lime miner be included into the list of domestic quarantine objects of the Russian Federation, and that the population state of this pest be monitored.     

Towards the identification and synthesis of the sex pheromone of the citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae)

The objective of this work was to characterize the sexual behavior of the citrus leafminer, Phyllocnistis citrella Stainton, as the foundation for the isolation, identification, and synthesis of the complete sex pheromone of this species. Mating occurred in a time window of 2h, starting 1h before the onset of photophase. The large majority of tested insects mated in the first two days after emergence, with no significant difference between mating at day 1 and day 2. A stereotypical courtship and copulation behavior were described for this species. When mating was successful, the copulation was recorded in average for 49.6 min. In Y-olfactometer tests conducted at the time of mating activity, males were strongly attracted to caged virgin females as well as to extracts from putative pheromone glands.     

Weak parasitoid-mediated apparent competition between two Phyllonorycter (Lepidoptera: Gracillariidae) leaf miner species on a deciduous oak Quercus dentata

Parasitoid assemblages and the rates of parasitism on tissue-feeding larvae of two Phyllonorycter leaf miner species, P. persimilis and P. leucocorona , were studied from the autumn generation in 2002 to the summer generation in 2005 to understand whether parasitoids mediate interactions between the two leaf miner species. Fourteen species of parasitoids emerged from P. persimilis and 11 emerged from P. leucocorona . The parasitism rate was high: 24.1–92.6% in P. persimilis and 58.9–81.7% in P. leucocorona . Thus, parasitism was a major mortality factor in the present Phyllonorycter species. The parasitoid composition was distinctly different between the two host species, although most parasitoids were able to parasitize both leaf miner species. The analysis based on the quantitative parasitoid overlap revealed that the present parasitoids could mediate interactions between the present leaf miner species, but their effects would be weak. This is attributable to parasitoid's preferential uses of either of the leaf miners as a host.     

Mortality factors affecting the leaf-mining stages of Phyllonorycter (Lepidoptera: Gracillariidae) on oak and birch 1. Analysis of the mortality factors

Mortality of life stages of Phyllonoycter species in mined leaves of oak and birch was investigated in a Cheshire locality during 1974. Phyllonotycter species are mostly bivoltine, but P. cavella is univoltine. Parasitism and host-feeding (predation) by Hymenoptera caused most mortality. Parasitism was heaviest in the first generations, with ectoparasitism predominating, although endoparasitism caused inore mortality in the second generations. The incidence of host-feeding increased to leaf-fall when more mines contained host-fed remains than either parasites or healthy Phyllonoycter . Host-feeding occurred particularly in the first three (sap-feeding) larval instars; ectoparasitism affected mainly the two subsequent (tissue-feeding) larval stages and pupae; and endoparasitism occurred in all stages although affected hosts are killed only from the fourth larval instar onwards. Highest mortality was suffered by tissue feeders in the first generation but by sap feeders in the second. Total mortality was greatest in second generation mines and, in a given generation, survival curves for Phyllonotycter were similar on both tree species. The observed density of second generation mines relative to first in the sample was higher than predicted from first generation mortality levels, and this is discussed.     

Mortality factors affecting the leaf-mining stages of Phyllonorycter (Lepidoptera: Gracillariidae) on oak and birch 2. Biology of the parasite species

Parasitic Hpenoptera attacking Phyllonorycter species mining leaves of oak and birch were studied at a Cheshire locality during 1974. The host developmental stages killed, and attacked, by each parasite species are analysed. Smaller species and males tend to kill earlier Phyllonorycter instars than do larger species and females, and certain of the endoparasites as well as the ectoparasites must discriminate between small hosts which receive haploid eggs and large hosts which receive diploid eggs. Host-feeding is very widely practised, and facultative hyperparasitism is engaged in by all except the braconids and a few specialized chalcids. The biology of a parasite species generally allows its allocation to one of three groups according to the size of host larva that it attacks, whether it is endoparasitic or ectoparasitic, whether or not the host continues to develop after parasitization, the extent of its hyperparasitic behaviour, its reproductive capacity, and the width of its host range. Different strategies, together with different specific host and habitat preferences, provide the basis for parasite complexes of high species diversity.     

Changes in the Structure of the Parasitoid Complex (Hymenoptera,Eulophidae, Braconidae) in an Outbreak Focus of the Aspen Leafminer (Phyllonorycter apparella,Lepidoptera, Gracillariidae)

Entomological Review - The assemblage of hymenopteran parasitoids associated with the aspen leafminer Phyllonorycter apparella (Lepidoptera, Gracillariidae), developing on the aspen Populus tremula...     

小叶黑面神与小叶头细蛾互惠共生系统的种群调控机制(英文)

【目的】探索小叶黑面神Breynia vitis-idaea对小叶头细蛾Epicephala vitisidaea种群数量的调控机制。【方法】跟踪记录小叶黑面神物候及头细蛾的生物学。解剖在小叶黑面神上访花头细蛾的外生殖器,鉴定头细蛾种类。对不同时期小叶黑面神有梗和无梗的果实进行解剖,统计果实内幼虫数量、果实表面孔的数量以及果实表面产卵疤数量,计算头细蛾幼虫存活率。统计不同时期小叶黑面神有梗和无梗的果实的比例。【结果】在福建厦门小叶黑面神每年有5个花果期,相应地,为小叶黑面神传粉的头细蛾每年有5个生活世代。通过解剖,该种头细蛾被鉴定为小叶头细蛾。一头小叶头细蛾幼虫需要消耗2~4粒种子才能发育成熟。小叶黑面神有两种不同形态的果实:有梗和无梗。头细蛾幼虫在无梗果实内的存活率明显高于有梗果实,并且晚秋时期头细蛾幼虫的存活率要高于夏季。小叶黑面神无梗果实的比例在晚秋(82.04%)要高于夏季(31.53%)。【结论】本研究揭示了维持互利共生体系稳定的机制。小叶黑面神能够通过果实基部果梗的有无来调节小叶头细蛾幼虫的存活率。小叶黑面神通过季节性的调节有梗果实的比率,既有效避免了夏季种子被过度消耗的风险,又提高了头细蛾在冬季的存活率。小叶黑面神这种自身调控机制对维持小叶黑面神与小叶头细蛾互惠共生系统的稳定性起到了至关重要的作用。     

The effects of host plant phenology on the demography and population dynamics of the leaf-mining moth, Cameraria hamadryadella (Lepidoptera: Gracillariidae)

Abstract.

• 1 We examined the effects of variation in the timing of spring leaf production and autumn leaf fall on the survival, mortality and abundance of Cameraria hamadryadella on Quercus alba and Q.macrocarpa.
• 2 We monitored and manipulated the timing of foliation on field and potted Q.alba trees and observed the abundance of C.hamadryadella on those trees. We also monitored and manipulated the timing of leaf fall on Q.alba and Q.macrocarpa trees in the field and observed its effects on survival, mortality and abundance of C.hamadryadella.
• 3 Variation in the timing of spring leaf production has no effect on C. hamudryadella abundance. However, a warm winter and spring in 1991 led to accelerated development and the imposition of a facultative third generation in one out of ten years of observation.
• 4 In 1989, leaves fell relatively early and leaf fall in the autumn accounted for more than 50% of the mortality of C.hamudryadella. in 1990 and 1991 leaves fell relatively late and leaf fall induced mortality was substantially reduced and overwinter survival was markedly increased.
• 5 The abundance of C.hamadryadella remained constant in the spring and summer of 1990 following the previous autumn's relatively early leaf fall, but increased by 10-fold in the spring of 1991 following the relatively late leaf fall of autumn 1990. The abundance of C.hamadryadella also increased 4-fold between the summer of 1991 and the spring of 1992 after another autumn of relatively late leaf fall. We attribute these increases in abundance in part to reduced mortality because of later leaf fall.
• 6 Variation in the timing of autumn leaf fall may be responsible for initiating outbreaks of C.hamadryadella.