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Gall Midge (gall + midge)
Kinds of Gall Midge Selected AbstractsFemale reproductive biology of Platygaster diplosisae (Hymenoptera: Platygastridae) and Aprostocetus procerae (Hymenoptera: Eulophidae), two parasitoids associated with the African Rice Gall Midge, Orseolia oryzivora (Diptera: Cecidomyiidae)ENTOMOLOGICAL SCIENCE, Issue 2 2008Souleymane NACRO Abstract We investigated the female reproductive system of Platygaster diplosisae (Hymenoptera: Platygastridae) and Aprostocetus procerae (= Tetrastichus pachydiplosisae) (Hymenoptera: Eulophidae), two parasitoids associated with the African rice gall midge, Orseolia oryzivora (Diptera: Cecidomyiidae). Both optical and electron microscopy were used. The female reproductive system of P. diplosisae includes two large ovaries of the meristic polytrophic-type, each composed of several tens of ovarioles. The system includes also a venomous gland that extends to a common oviduct. This gland had a filiform secretory portion, in which the epithelium was thin and surrounded a common evacuation canal. The secretory cells secrete into a large reservoir. Parasitism due to P. diplosisae is gregarious. The female reproductive system of A. procerae includes two ovaries of the meristic polytrophic-type, and each ovary has a few ovarioles. Each ovariole includes one or two oocytes, which can be seen in the vitellarium. Two accessory glands, which extend to the oviduct, are also visible. The secretory epithelium of the accessory gland is made up of a dense network of secretory cells surrounded by muscle fibers. Females of A. procerae pierce the tissues of the gall and probably deposit one egg on or close to the pupa of the midge. Aprostocetus procerae is a solitary parasitoid of the midge. The two parasitoids exploit the same host at different developmental stages. These findings improve our knowledge of the reproductive biology of these two parasitoids associated with the African rice gall midge, an important pest in Africa. [source] Non-random distribution among a guild of parasitoids: implications for community structure and host survivalECOLOGICAL ENTOMOLOGY, Issue 6 2006ANTHONY M. ROSSI Abstract 1.,Immature stages of the gall midge, Asphondylia borrichiae, are attacked by four species of parasitoids, which vary in size and relative abundance within patches of the gall midge's primary host plant, sea oxeye daisy (Borrichia frutescens). 2.,In the current study, a bagging experiment found that the smallest wasp, Galeopsomyia haemon, was most abundant in galls exposed to natural enemies early in the experiment, when gall diameter is smallest, while the wasp with the longest ovipositor, Torymus umbilicatus, dominated the parasitoid community in galls that were not exposed until the 5th and 6th weeks when gall diameter is maximal. 3.,Moreover, the mean number of parasitoids captured using large artificial galls were 70% and 150% higher compared with medium and small galls respectively, while stem height of artificial galls significantly affected parasitoid distribution. Galls that were level with the top of the sea oxeye canopy captured 60% more parasitoids compared with those below the canopy and 50% more than galls higher than the plant canopy. 4.,These non-random patterns were driven primarily by the differential distribution of the largest parasitoid, T. umbilicatus, which was found significantly more often than expected on large galls and the smallest parasitoid of the guild, G. haemon, which tended to be more common on stems level with the top of the plant canopy. 5.,Large Asphondylia galls, especially those located near the top of the Borrichia canopy, were more likely to be discovered by searching parasitoids. Results using artificial galls were consistent with rates of parasitism of Asphondylia galls in native patches of sea oxeye daisy. Gall diameter was 19% greater and the rate of parasitism was reduced by almost 50% on short stems; as a result, gall abundance was 24% higher on short stems compared with ones located near the top of the plant canopy. 6.,These results suggest that parasitoid community composition within galls is regulated by both interspecific differences in ovipositor length and preferences for specific gall size and/or stem length classes. [source] Gall size determines the structure of the Rabdophaga strobiloides host,parasitoid communityECOLOGICAL ENTOMOLOGY, Issue 5 2003Brian H. Van Hezewijk Abstract., 1.,The relationship between gall size and mortality of the willow pinecone gall midge Rabdophaga strobiloides (Diptera: Cecidomyiidae) was examined by determining the fate of all galls in a 30-ha area in central Alberta, Canada over 4 years. It was found that gall size has a large effect on the type and intensity of mortality experienced by the gall midge, and consequently this factor has the potential to influence the dynamics of the host,parasitoid interaction through the creation of phenotypic refuges. 2.,Total midge mortality ranged from 51% to 78% over the course of the study and was dominated by parasitism by Torymus cecidomyiae (Hymenoptera: Torymidae) and Gastrancistrus sp. (Hymenoptera: Pteromalidae) as well as predation by birds. Gall size had a strong, non-linear effect on the attack rates of each of these natural enemies. 3.,Birds attacked the smallest size classes. Torymus cecidomyiae preferentially attacked medium diameter galls and thus avoided predation by birds in smaller galls. Gastrancistrus sp. preferentially attacked the largest galls and consequently suffered lower rates of predation by both T. cecidomyiae and birds. 4.,This study emphasises the importance of understanding the interactions among mortality factors in order to describe adequately the susceptibility of R. strobiloides to parasitism and predation, and ultimately its population dynamics. [source] Inheritance of resistance against biotype 2 of the Asian rice gall midge, Orseolia oryzaeENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2000J. Pani Abstract The inheritance of resistance in the rice cultivars Phalguna, ARC5984, ARC 5158, Veluthacheera, and T1477 to the Asian rice gall midge biotype 2 was studied under both natural and artificial infestation conditions against the susceptible cultivars Jaya and IR20. A single recessive gene in Veluthacheera and two recessive complementary genes in T1477 control resistance. Phalguna and ARC5984 possess a single dominant gene while ARC5158 has a single dominant and a single recessive gene for resistance. Allelism studies showed that genes for resistance in Veluthacheera and T1477 are allelic but non-allelic to the resistance genes in Phalguna and ARC5984, which are allelic to each other. Genes for resistance in ARC5158 are allelic to resistance genes of the other four donors. There was no cytoplasmic inhibition of resistance by the susceptible parents. [source] Female reproductive biology of Platygaster diplosisae (Hymenoptera: Platygastridae) and Aprostocetus procerae (Hymenoptera: Eulophidae), two parasitoids associated with the African Rice Gall Midge, Orseolia oryzivora (Diptera: Cecidomyiidae)ENTOMOLOGICAL SCIENCE, Issue 2 2008Souleymane NACRO Abstract We investigated the female reproductive system of Platygaster diplosisae (Hymenoptera: Platygastridae) and Aprostocetus procerae (= Tetrastichus pachydiplosisae) (Hymenoptera: Eulophidae), two parasitoids associated with the African rice gall midge, Orseolia oryzivora (Diptera: Cecidomyiidae). Both optical and electron microscopy were used. The female reproductive system of P. diplosisae includes two large ovaries of the meristic polytrophic-type, each composed of several tens of ovarioles. The system includes also a venomous gland that extends to a common oviduct. This gland had a filiform secretory portion, in which the epithelium was thin and surrounded a common evacuation canal. The secretory cells secrete into a large reservoir. Parasitism due to P. diplosisae is gregarious. The female reproductive system of A. procerae includes two ovaries of the meristic polytrophic-type, and each ovary has a few ovarioles. Each ovariole includes one or two oocytes, which can be seen in the vitellarium. Two accessory glands, which extend to the oviduct, are also visible. The secretory epithelium of the accessory gland is made up of a dense network of secretory cells surrounded by muscle fibers. Females of A. procerae pierce the tissues of the gall and probably deposit one egg on or close to the pupa of the midge. Aprostocetus procerae is a solitary parasitoid of the midge. The two parasitoids exploit the same host at different developmental stages. These findings improve our knowledge of the reproductive biology of these two parasitoids associated with the African rice gall midge, an important pest in Africa. [source] Sex ratio bias in the F1 adult progeny of African rice gall midge, Orseolia oryzivora H. and G. (Dipt., Cecidomyiidae)JOURNAL OF APPLIED ENTOMOLOGY, Issue 6-7 2006A. A. Omoloye Abstract:, Against the background of conflicting reports of variable sex ratio distribution in different populations of the African rice gall midge (AfRGM), Orseolia oryzivora Harris and Gagne, the number and sex ratios of F1 adult progeny produced per female from wild and screen house populations were investigated in the screen house at 27 ± 3°C, 60,70% relative humidity and 12 : 12 h (light : dark) photoperiod. Results indicated the occurrence of a single sex-biased ratio in all the F1 adult progeny produced per female of this pest. Regardless of the source, whether from wild or screen house population, each mated female AfRGM produced a full complement of either sex only but never both. The difference between the number of eggs laid and F1 adult progeny that emerged per female from wild and screen house populations was not significant (P > 0.05), indicating consistency in the occurrence of this phenomenon among AfRGM populations. The reason for this could not be ascertained in this study but AfRGM eggs must be fertilized for development and eclosion to occur. No F2 adults emerged when a cohort of emergents from the same female were allowed to re-infest susceptible seedlings, indicating absence of parthenogenesis. [source] Tritrophic interactions and trade-offs in herbivore fecundity on hybridising host plantsECOLOGICAL ENTOMOLOGY, Issue 3 2004Maria V. Cattell Abstract., 1. Interspecific plant hybridisation can have important evolutionary consequences for hybridising plants and for the organisms that they interact with on multiple trophic levels. In this study the effects of plant hybridisation on the abundance of herbivores and on the levels of herbivore parasitism were investigated. 2. Borrichia frutescens, B. arborescens, and their hybrid (B. × cubana) were censused for Asphondylia borrichiae galls and Pissonotus quadripustulatus plant hoppers in the Florida Keys. Levels of egg parasitism were determined by dissecting parental and hybrid stems and galls for herbivore and parasite eggs and larvae. Stem toughness and gall size are plant-mediated modes of protection from parasitism and these were also measured. For gall midges, fly size was measured as an estimate of fecundity. 3. Field censuses indicated that herbivore abundances varied on hybrid hosts relative to parent plant species and that the different herbivore species exhibited different patterns of abundance. Asphondylia borrichiae gall numbers followed the additive pattern of abundance while P. quadripustulatus numbers most closely resembled the dominance pattern. 4. Parasitism of P. quadripustulatus eggs was high on B. frutescens and the hybrids, and low on B. arborescens, which also had significantly tougher stems. Asphondylia borrichiae suffered the highest levels of parasitism on B. frutescens, the host plant which produced the smallest galls. On B. arborescens, which produced the largest galls, levels of A. borrichiae parasitism were lowest. Both parasitism and gall size were intermediate on the hybrid plants. Galls on B. arborescens and hybrid plants produced significantly smaller flies then those from B. frutescens suggesting that, when selecting hosts from among parent species and hybrids, gall flies may face a trade-off between escape from natural enemies and maximising fecundity. [source] Plants, gall midges, and fungi: a three-component systemENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2008Odette Rohfritsch Abstract Larvae of gall midges (Diptera: Cecidomyiidae) induce the activation of plant cells, partial cell lysis, and differentiation of nutritive tissue. Specialized nutritive tissue is essential for larval development and plays a key role in gall organization. Midges of the tribes Lasiopterini and Asphondyliini, however, do not induce nutritive tissues as part of the formation of their galls. Instead, these ,ambrosia galls' contain fungal mycelia that line the interior surface of the chambers. The fungi not only provide Lasiopterini with nutrition, they also penetrate the stems, induce the lysis of the middle lamella of host cells, and open a channel to the vascular bundles. Larvae of Lasioptera arundinis (Schiner) (Lasiopterini) follow the fungus and feed on its mycelium along with adjoining stem cells of Phragmites australis (Cav.) Trin. (Poaceae). Eggs together with fungal conidia are deposited by the imago on the host. Asphondyliini use a needle-like ovipositor to introduce fungal conidia and eggs into the organs they attack. Larvae of Schizomyia galiorum Kieffer (Asphondyliini) are unable to initiate the gall or to develop in the flowers of Galium mollugo L. (Rubiaceae) without their fungal associate. In this article, I provide an overview of oviposition behaviour in the Asphondyliini, as well as descriptions of the ovipositor and the female post-abdominal segments. Gall formation by Lasiopterini and Asphondyliini and the role of associated fungi are discussed, as is the role of the fungus as an inquiline or an organizer of gall tissues and a nutritive device. [source] | ||||||||||