Preference and performance of western flower thrips

Differences in performance on, and preference for, different plant parts were studied on cucumber plants. On these plants thrips are often most abundant on the youngest plant parts. This suggests that the youngest leaves are most suitable for western flower thrips. We assessed if differences in suitability of leaves of different age could explain the distribution of thrips on cucumber plants. Evidence was obtained for a correlation between preference and performance on cucumber leaves of different age. Differences in performance on, and preference for, different host plant species were studied with selected isofemale lines. Thrips from these isofemale lines showed differences in performance on different host plant species. It was assessed whether these differences in performance were correlated with differences in preference. No clear evidence was obtained for correlations between preference and performance on different host plant specie

The phase-space distribution of infalling dark matter subhalos

We use high-resolution numerical simulations to study the physical properties of subhalos when they merge into their host halos. An improved algorithm is used to identify the subhalos. We then examine their spatial and velocity distributions in spherical and triaxial halo models. We find that the accretion of satellites preferentially occurs along the major axis and perpendicular to the spin axis of the host halo. Furthermore, the massive subhalos show a stronger preference to be accreted along the major axis of the host halo than the low-mass ones. Approximate fitting formulae are provided for the physical properties of subhalos. Combined with analytical and semi-analytic techniques, these empirical formulae provide a useful basis for studying the subsequent evolution of subhalos and satellite galaxies in their hosts. Future studies should however account for satellites that may not be undergoing the first infall in their evolution.Comment: revised version in press in MN with added material and references, 21 pages and 25 figure

Kesesuaian Dan Preferensi Liriomyza Huidobrensis (Blanchard) (Diptera: Agromyzidae) Pada Berbagai Tumbuhan Inang

Host suitability and the preference of Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) on different host plants. Potato leafminer, Liriomyza huidobrensis has become a major pest on highland vegetables since its invasion in Indonesia in 1994. The objectives of this research was to elucidate the level of suitability and the preference of L. huidobrensis on different host plant species. Research was conducted in Insect Ecology Laboratory, Department of Plant Pests and Diseases, Faculty of Agriculture-IPB. The result of laboratory experiments indicated that host plants showing the highest level of suitability (based on the intrinsic rate of increase, r) were potato (Solanum tuberosum), chinese cabbage (Brassica chinensis var. parachinensis), kacang endul (P. vulgaris), and snap bean (P. vulgaris). Low host suitability were found on cucumber (Cucumis sativus), tomato ( S. lycopersicum), wild radish (Nasturtium indicum) and a non-crop vegetation, galinggang (Galinsoga parviflora). There was consistency between suitability and host preference. The first four host plants mentioned above were preferred for feeding and laying eggs

Interspecific interactions between a new invasive Tephritid fruit fly, Bactrocera dorsalis, and other resident species in an insular context

The impact of biological invasions of insects considered as pests have important negative impacts on the economy and the environment, particularly in insular ecosystems. Since the detection of one of the most harmful pest of fruit and vegetable crops, Bactrocera dorsalis, in April 2017, La R´eunion counts nowadays nine pests species of Tephritid fruit flies of economic importance. A biological control agent, the braconid wasp, Fopius arisanus, was initially introduced in La Reunion in 2003 to control another fruit fly of the same genus: the peach fruit fly, Bactrocera zonata. Bactrocera dorsalis, in its native area is the main host of this braconid wasp and will probably be able to parasitize it in La R´eunion. To understand the invasion process of B. dorsalis and the impact of this new introduced fruit fly on the community structure of the resident Tephritid species, and the parasitoid, F. arisanus, it is necessary to study the competition interactions. We first assessed the interspecific competition between Bactrocera dorsalis and four other fruit flies, Bactrocera zonata, C. capitata, C. quilicii and Ceratitis catoirii. Three of those fruit flies are successive invaders in La Reunion and one endemic species. We focused our study on the interference competition among pairs of adults, measuring the ability of a female to remove another one from a fruit for the laying behavior in controlled environments.The parasitoid preference for both sympatry species of genius Bactrocera were observed. On one hand, we observed the preference for eggs only and on the other hand, the preference for one particular species according to the host fruit in choice experiments

A Split-Stem Lesion on Young Hybrid \u3ci\u3ePopulus\u3c/i\u3e Trees Caused by the Tarnished Plant Bug, \u3ci\u3eLygus Lineolaris\u3c/i\u3e (Hemiptera: [Heteroptera]: Miridae)

The tarnished plant bug, known principally as an agricultural pest, injures young hybrid Populus by feeding on the stems and meristems. Tarnished plant bug eggs, fungi associated with some lesions, and simple mechanical stimuli alone from feeding appeared not to cause lesion formation. Of 20 Populus hybrids tested in a clonal trial, four appeared to be consistently susceptible to lesion injury, with Populus nigra var. betulifolia x trichocarpa the most susceptible. Several clones showed high resistance in the trial but a few were susceptible in other plantings and in host preference tests when caged with tarnished plant bugs. Lesions diminished tenfold on Populus where horseweed, the insect\u27s principal wild host, grew along with susceptible poplars. The tarnished plant bug can be suppressed by ultra-low volume pesticides and cultural manipulation of understory vegetation

The chemosensory basis for behavioral divergence involved in sympatric host shifts II: olfactory receptor neuron sensitivity and temporal firing pattern to individual key host volatiles

The Rhagoletis species complex has been a key player in the sympatric speciation debate for much of the last 50years. Studies indicate that differences in olfactory preference for host fruit volatiles could be important in reproductively isolating flies infesting each type of fruit via premating barriers to gene flow. Single sensillum electrophysiology was used to compare the response characteristics of olfactory receptor neurons from apple, hawthorn, and flowering dogwood-origin populations of R. pomonella, as well as from the blueberry maggot, R. mendax (an outgroup). Eleven volatiles were selected as stimuli from behavioral/electroantennographic studies of the three R. pomonella host populations. Previously, we reported that differences in preference for host fruit volatile blends are not a function of alterations in the general class of receptor neurons tuned to key host volatiles. In the present study, population comparisons involving dose-response trials with the key volatiles revealed significant variability in olfactory receptor neuron sensitivity and temporal firing pattern both within and among Rhagoletis populations. It is concluded that such variability in peripheral sensitivity and temporal firing pattern could influence host preference and contribute to host fidelity and sympatric host shifts in the Rhagoletis comple

Absence of Behavioral Induction in Oviposition Preference of \u3ci\u3ePapilio Glaucus\u3c/i\u3e (Lepidoptera: Papilionidae)

This study addressed the possible behaviora induction effects of previous exposure to several specific host plants on subsequent host preference hierarchy and specificity (i.e .. how far down the ranking order a female will go) the most polyphagous swallowtail butterfly in the world, Papilio glaucus (Papilionidae). Multi-choice preference bioassays using individual females in revolving arenas were used to assess one of the potentially most significant non-genetic sources of variation: learned (or induced) oviposition preferences. Results of the 4-choice studies using tulip tree (Liriodendron tulipifera; Magnoliaceae), black cherry (Prunus serotina; Rosaceae), quaking aspen (Populus tremuloides; Salicaceae), and hoptree (Ptelea trifoliata; Rutaceae), fail to show any significant oviposition preference induction with two-day prior exposure to any of the host species tested. It appears that the eastern tiger swallowtail butterfly, while polyphagous as a species (feeding on more than 9 families of plants), and variable in its population responses to oviposition favorites, has what may be considered a genetic hard-wiring at an individual level, with no evidence that preferences change with recent oviposition experience. Older females were not and did not become more random in their choices, and in fact increased in their specificity for tulip tree leaves

Preference and performance of Phyllocnistis citrella Stainton (Lepidoptera:Gracillariidae) on three citrus hosts: Laboratory and field assessment

The relationship between preference and performance is crucial to the ecology and evolution of plant-insect interactions. Oviposition preference and offspring performance were evaluated for a citrus pest, the leafminer Phyllocnistis citrella (Lepidoptera: Gracillariidae), on three of its host plants: lemon (Citrus limon L. Burm.), orange (Citrus sinensis L. Osbeck), and grapefruit (Citrus paradisi Macfadyen) in Tucumán province (northwest Argentina). Choice and no-choice tests were performed in open and enclosed environments, and performance parameters (development time, survival, pupal size, and sex ratio) were estimated from laboratory rearing and 3-yr field sampling data. Parasitism rates were studied in laboratory choice test and field assessments. Preference trends were inconsistent, with lemon receiving more eggs in some tests, whereas no preference was observed in others. Patterns of host use in the field did not show significant differences among species. Leafminer performance, including parasitism and predation rates, was generally homogeneous among host plants. From these results, lemon, orange, and grapefruit seem to represent intrinsically similar resources for P. citrella populations in northwest Argentina, a trend that was accompanied by a lack of consistent oviposition preferences in foraging females. Ecological conditions might be more important than physiological adaptation in shaping a probably labile host ranking in this pest species.La relación entre preferencia y rendimiento es crucial para la ecología y evolución de las interacciones insecto-planta. Se evaluó la preferencia de puesta y el rendimiento de la descendencia para una plaga de cítricos, el minador de la hoja Phyllocnistis citrella (Lepidoptera: Gracillariidae), sobre tres de sus plantas hospederas: limonero (Citrus limon [Linn.] Burm.), naranjo (Citrus sinensis [Linn.] Osbeck) y pomelo (Citrus paradisi Macfadyen) en la provincia de Tucumán (Noroeste de Argentina). Se realizaron pruebas con y sin elección en ambientes abiertos y cerrados, y se estimaron parámetros de rendimiento (tiempo de desarrollo, supervivencia, tamaño pupal y proporción de sexos) a partir de individuos criados en laboratorio y datos de tres años de muestreos de campo. Las tasas de parasitismo se estudiaron en pruebas de laboratorio con elección y evaluaciones en campo. Las tendencias de preferencia fueron inconsistentes, con limonero recibiendo más huevos en algunas pruebas, mientras que no se observó preferencia en otras. Los patrones de uso de hospedero en campo no mostraron diferencias significativas entre especies. El rendimiento del minador, incluyendo las tasas de parasitismo y depredación, fue generalmente homogéneo entre plantas hospederas. Con estos resultados, las plantas de limonero, naranjo y pomelo representarían intrínsecamente recursos similares para las poblaciones del minador de los cítricos en el NO de Argentina, tendencia que fue acompañada por la ausencia de preferencias consistentes en la puesta de huevos por parte de las hembras. Las condiciones ecológicas podrían ser más importantes que la adaptación fisiológica al moldear un rango de hospederos probablemente voluble en esta especie plaga.Fil: Goane, Lucía. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Valladares, Graciela Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Willink, Eduardo. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentin