Population variability of three Delia species (Diptera: Anthomyiidae) from the same agricultural habitat in Québec, Canada

2017 ◽  
Vol 150 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Robert J. Lamb ◽  
Guy Boivin

AbstractLong-term trap catches of seedcorn maggot, Delia platura (Meigen), onion maggot, Delia antiqua (Meigen), and cabbage maggot, Delia radicum (Linnaeus) (Diptera: Anthomyiidae), were used to test the hypothesis that related species have more similar population variability than unrelated ones. Annual abundance was estimated from trap catches for 32 years (two species) or 17 years (one species). Population variability was quantified as PV, a proportion between 0 and 1. The three Delia Robineau-Desvoidy species had PV values of 0.51–0.55 that did not differ significantly. These PV values were found to differ significantly from two unrelated species studied over the same time period in the same habitat, which had PV values of 0.39 and 0.67. The hypothesis that related species have more similar population variabilities than unrelated species in the same habitat was supported. These data strengthen the view that PV is a species-specific trait reflecting the adaptation of life histories to their habitat, with related species showing more similar adaptations than unrelated species. The polyphagous and saprophagous seedcorn maggot had PV similar to the two oligophagous herbivores, casting doubt on the hypothesis that more generalist feeders have less variable populations than more specialised feeders.

2004 ◽  
Vol 136 (3) ◽  
pp. 427-442 ◽  
Author(s):  
Peggy L. Dixon ◽  
Juanita R. Coady ◽  
David J. Larson ◽  
Dean Spaner

AbstractThe cabbage maggot, Delia radicum (L.), is a serious pest of cruciferous crops in temperate regions of North America and Europe. The effects of undersowing rutabaga, Brassica napus L. subsp. rapifera Metzg. (Brassicaceae), with white clover, Trifolium repens L. (Leguminosae), on second-generation cabbage maggot and its natural enemies were studied in Newfoundland in 1997 and 1998. In 1997, totals of 1311 and 724 eggs were recovered from bare and undersown plots, respectively. More eggs were present in bare plots than undersown plots on various specific dates. In 1997, rutabagas from bare plots weighed more than those from undersown plots, although damage ratings were similar, suggesting that competition, not cabbage maggot feeding, caused the yield differences. In 1998, there were few cabbage maggots present and little damage or yield reduction in either treatment. Similar numbers of cabbage maggot pupae were extracted and reared from each treatment in each year. In 1997, of the pupae reared from undersown plots, 48% produced cabbage maggot flies, 14% produced parasitic Hymenoptera, and 8% produced Aleochara bilineata Gyllenhal (Coleoptera: Staphylinidae); 19% of the pupae from bare plots produced cabbage maggot flies, 8% produced parasitic Hymenoptera, and 36% produced A. bilineata. More A. bilineata were captured in pitfall traps in bare plots than in undersown plots. The effect of clover on carabid beetles was species specific. There were more Bembidion lampros (Herbst) and Amara bifrons (Gyllenhal) in bare plots in 1997, and more Pterostichus melanarius (Illiger) in undersown plots in both years. Despite consistently lower egg numbers in undersown plots than in bare plots, the numbers of pupae in the two treatments were similar at the end of the season. We speculate that this may be due to differential, density-dependent mortality of immature stages of cabbage maggot caused by predators and parasitoids.


1979 ◽  
Vol 57 (5) ◽  
pp. 979-982 ◽  
Author(s):  
Emmanuel C. Igbokwe

Species-specific patterns of larval protein electrophoregrams obtained among three species of Aedes mosquitoes were analyzed numerically. A behavioral profile was derived and illustrated for the larval protein complex of each species. Patterns of interspecific divergence in molecular behavior not detectable otherwise from the electrophoregrams were evident in the behavioral profiles of the proteins. The degree of electrophoretic correspondence obtained from the number of shared fractions among the species differs from that derived from the collective behavior of proteins. The numerical and graphic approach to the interpretation of protein electrophoregrams offers another parameter for gauging molecular divergence among related species of insects.


Parasitology ◽  
1959 ◽  
Vol 49 (3-4) ◽  
pp. 374-386 ◽  
Author(s):  
R. J. Thomas

1. The life history of N. battus is described, and a comparative description of the life history of N. filicollis is given.2. The life histories of these two species are compared with those of N. spathiger and N. helvetianus, two closely related species, and are shown to follow the same basic pattern, with minor variations in timing which appear to be specific in nature, and not related to differences in culture methods or host species.3. The pathogenesis of Nematodirus species is discussed and related to the migration of larvae into the intestinal mucosa during development.


2019 ◽  
Author(s):  
Andrea Acurio ◽  
Flor T. Rhebergen ◽  
Sarah Paulus ◽  
Virginie Courtier-Orgogozo ◽  
Michael Lang

AbstractBackgroundMale genitals have repeatedly evolved left-right asymmetries, and the causes of such evolution remain unclear. TheDrosophila nannopteragroup contains four species, among which three exhibit left-right asymmetries of distinct genital organs. In the most studied species,Drosophila pachea, males display asymmetric genital lobes and they mate right-sided on top of the female. Copulation position of the other species is unknown.ResultsTo assess whether the evolution of genital asymmetry could be linked to the evolution of one-sided mating, we examined phallus morphology and copulation position inD. pacheaand closely related species. The phallus was found to be symmetric in all investigated species exceptD. pachea, which display an asymmetric phallus with a right-sided gonopore, andD. acanthoptera, which harbor an asymmetrically bent phallus. In all examined species, males were found to position themselves symmetrically on top of the female, except inD. pacheaandD. nannoptera, where males mated right-sided, in distinctive, species-specific positions. In addition, the copulation duration was found to be increased innannopteragroup species compared to closely related outgroup species.ConclusionOur study shows that gains, and possibly losses, of asymmetry in genital morphology and mating position have evolved repeatedly in thenannopteragroup. Current data does not allow us to conclude whether genital asymmetry has evolved in response to changes in mating position, or vice versa.


Author(s):  
Gary C. Longo ◽  
John Harms ◽  
John R. Hyde ◽  
Matthew T. Craig ◽  
Ana Ramón-Laca ◽  
...  

AbstractThe vermilion rockfish complex, which consists of the cryptic sister species vermilion and sunset rockfish, is one of the most valuable recreational fisheries on the U.S. West Coast. These species are currently managed as a single complex, and because of uncertainty surrounding the relative contribution of each species within existing data sources, the stock status of each species is not fully known. A reliable and cost-effective method is needed to disentangle these species that will allow for the development of abundance indices, life history profiles, and catch histories that may potentially support species-specific stock assessments. Using restriction-site associated DNA sequence (RADseq) markers we generated 10,003 polymorphic loci to characterize the vermilion rockfish complex. PCA and Bayesian clustering approaches based on these loci clearly distinguished between sunset and vermilion rockfishes and identified hybrid individuals. These loci included 203 highly differentiated (FST ≥ 0.99) single nucleotide polymorphisms, which we consider candidates in the planned development of a diagnostic assay capable of distinguishing between these cryptic species. In addition to clearly delineating to species, subsets of the interspecific markers allowed for insight into intraspecific differentiation in both species. Population genetic analyses for sunset rockfish identified two weakly divergent genetic groups with similar levels of genetic diversity. Vermilion rockfish, however, were characterized by three distinct genetic groups with much stronger signals of differentiation and significantly different genetic diversities. Collectively, these data will contribute to well-informed, species-specific management strategies to protect this valuable species complex.


2015 ◽  
Vol 370 (1662) ◽  
pp. 20140019 ◽  
Author(s):  
T. M. Brooks ◽  
A. Cuttelod ◽  
D. P. Faith ◽  
J. Garcia-Moreno ◽  
P. Langhammer ◽  
...  

‘Key biodiversity areas' are defined as sites contributing significantly to the global persistence of biodiversity. The identification of these sites builds from existing approaches based on measures of species and ecosystem diversity and process. Here, we therefore build from the work of Sgró et al. (2011 Evol. Appl. 4 , 326–337. ( doi:10.1111/j.1752-4571.2010.00157.x )) to extend a framework for how components of genetic diversity might be considered in the identification of key biodiversity areas. We make three recommendations to inform the ongoing process of consolidating a key biodiversity areas standard: (i) thresholds for the threatened species criterion currently consider a site's share of a threatened species' population; expand these to include the proportion of the species' genetic diversity unique to a site; (ii) expand criterion for ‘threatened species' to consider ‘threatened taxa’ and (iii) expand the centre of endemism criterion to identify as key biodiversity areas those sites holding a threshold proportion of the compositional or phylogenetic diversity of species (within a taxonomic group) whose restricted ranges collectively define a centre of endemism. We also recommend consideration of occurrence of EDGE species (i.e. threatened phylogenetic diversity) in key biodiversity areas to prioritize species-specific conservation actions among sites.


2020 ◽  
Vol 77 (2) ◽  
pp. 295-313 ◽  
Author(s):  
Joseph Munyandorero

The recruitment compensation metrics, the stock–recruit steepness (h) and compensation ratio (κ), are difficult to estimate, yet they are integral components of contemporary fishery models. To aid in the estimation of κ and h, a hybrid method to construct their prior distributions for a species is developed. The method is hybrid because it integrates (i) a meta-analysis of the relationship between maximum rates of recruit production (α) and asymptotic lengths obtained across fish species of different life histories and (ii) species-specific unfished spawning biomass per recruit (Φ0). This method is applied to five finfish species found off the East Coast of the United States. Uncertainty is introduced by sampling growth parameters, α, and natural mortality and — through Monte Carlo simulations — propagated into Φ0, κ, and h for the Beverton–Holt and Ricker stock–recruit relationships. Descriptive statistics and parameters from probability density functions of the simulated distributions of κ and h are generated. The method developed requires fewer inputs than the reproductive ecology method while likewise allowing the development of species-specific statistics for κ and h. These statistics, rather than their counterparts generated from classical meta-analyses, are better suited for use in fishery models.


1996 ◽  
Vol 21 (1) ◽  
pp. 413-413 ◽  
Author(s):  
Richard Meadow ◽  
John D. Vandenberg ◽  
Anthony M. Shelton ◽  
D. Wesley Watson

Abstract Adult CM were exposed to dry conidia of isolates of Beauvaria bassiana (Bb), Metarhizium anisopilae (Ma) or Paeciomyces fumosoroseus (Pf). Two B. bassiana isolates were from Cornell University (P89, L90) isolated from Musca domestica (Diptera: Muscidae), one was from Mycoteh Corp., Butte, MT (Myc 726) originally isolated from southern corn rootworm, Diabrotica undecimpuntata (Coleoptera: Chrysomelidae), re-isolated from a grasshopper, Melanoplus sp. (Orthoptera:Acrididae), and then re-isolated from silverleaf whitefly, Bemesia argentiflora (Homoptera: Aleyrodidae). The other isolates were from the USDA-ARS Collection of Entomophagous Fungal Cultures. One B. bassiana isolate, 4012, was isolated from Delia radicum (Diptera: Anthomyiidae). The P. fumosoroseus isolates were number 1626 from M. autumnalis (Diptera: Muscidae), 1644, 1645, 1867 and 1868 from M. domestica, 1646 from Calliphora spp. (Diptera: Calliphoridae), and 887 from unidentified Diptera. The M. anisopilae isolates were 2521 from Deois spp. (Homoptera: Cercopidae), 3540 from Gelleria mellonella (Lepidoptera: Pyralidae) and 4862 and 4865 from soil. Flies from rearings at the New York State Agricultural Experiment Station, Geneva, NY, were exposed to the fungi by placing 5 flies in a centrifuge tube containing conidia scraped directly from culture plates. The flies were then released into small screened plastic cages, which were placed in chambers with constant temperature of 21° C and L:D 15: 9. There were 3 replicates. Mortality was assessed after 48, 120 and 160h. Dead flies were placed in petri dishes with moistened filter paper to assess infection.


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