714 research outputs found
Pupal and Adult Parameters as Potential Indicators of Cottonwood Leaf Beetle (Coleoptera: Chrysomelidae) Fecundity and Longevity
Cottonwood leaf beetle, Chrysomela scripta, pupae from a laboratory colony were weighed and monitored through adult emergence, oviposition, and mortality to determine if correlations existed between various pupal or adult parameters and fecundity or longevity. Forty-three female cottonwood leaf beetles were monitored. Pupal weight was not a good indicator of fecundity, total oviposition events, number of eggs/beetle/day, or adult longevity. In addition, adult weight showed very low correlation with fecundity, adult longevity, total oviposition events, or number of eggs/beetle/day. However, adult weight was a marginal indicator of the number of eggs/beetle/day, and correlated well with adult body length. Adult longevity could be used to predict fecundity
Carrion Beetles (Coleoptera: Silphidae) of Northeastern Iowa: A Comparison of Baits for Sampling
Carrion beetles (Coleoptera: Silphidae) were inventoried over a 8-week period from June into August of 1996 at 10 sites in 4 counties of extreme northeastern Iowa. Carrion preference and relative abundance of carrion beetles were studied by use of non-lethal pitfall traps constructed from large plastic plant pots and baited with aged fish, beef liver, chicken, or piglets. A total of 3,183 carrion beetles were collected, representing 11 different species. The most commonly encountered species of carrion beetles in northeastern Iowa included Necrophila americana (71.5%) and Oiceoptoma novaboracense (18.5%). When comparing baits, chicken and fish attracted the greatest number of carrion beetle species, individual beetles, and the most diverse assemblage of beetles as compared to beef liver and piglets. No American Burying Beetles (Nicrophorus americanus), a federally-listed endangered species last documented in Northeastern Iowa in 1921, were found. We propose aged chicken as the most useful bait for future surveys of carrion beetles
Pupal and Adult Parameters as Potential Indicators of Cottonwood Leaf Beetle (Coleoptera: Chrysomelidae) Fecundity and Longevity
Cottonwood leaf beetle, Chrysomela scripta, pupae from a laboratory colony were weighed and monitored through adult emergence, oviposition, and mortality to determine if correlations existed between various pupal or adult parameters and fecundity or longevity. Forty-three female cottonwood leaf beetles were monitored. Pupal weight was not a good indicator of fecundity, total oviposition events, number of eggs/beetle/day, or adult longevity. In addition, adult weight showed very low correlation with fecundity, adult longevity, total oviposition events, or number of eggs/beetle/day. However, adult weight was a marginal indicator of the number of eggs/beetle/day, and correlated well with adult body length. Adult longevity could be used to predict fecundity
Effects of Clone, Silvicultural, and Miticide Treatments on Cottonwood Leafcurl Mite (Acari: Eriophyidae) Damage in Plantation Populus
Aculops lobuliferus (Keifer) is a little known pest of plantation Populus spp., which is capable of causing substantial damage. This is the first documented occurrence of A. lobuliferus in South Carolina. Previous anecdotal data indicated clonal variation in Populus susceptibility to A. lobuliferus damage. A damage rating scale was created to monitor mite damage in 2000-2001 in a short-rotation woody crop plantation; damage descriptions and seasonal phenology also were recorded. Foliar damage and terminal mortality were monitored on two Populus deltoides Bartr. clones, ST66 and S7C15, receiving one of three silvicultural treatments (irrigated, fertilized or both) or no treatment (control). In 2001, early season foliar damage ratings were significantly higher on clone S7C15; however, damage on clone ST66 was greater after miticide treatments later in the year. Terminal mortality did not differ between clones. Silvicultural treatments significantly affected foliar damage levels in both clones. Application of a commercially available miticide significantly reduced A. lobuliferus damage levels. This study demonstrates that A. lobuliferus damage levels can be influenced by Populus clone and silvicultural treatment. Foliar and terminal damage levels observed in this study indicate the potential for substantial economic impact of A. lobuliferus on plantation Populus. Although an effective control method may be to select and plant resistant Populus clones, chemical control remains a viable option
Bark Beetle (Coleoptera: Curculionidae: Scolytinae) Community Structure in Northeastern and Central Minnesota
Large-scale surveys of forest insects provide two distinct benefits: the detection of invasive and exotic species that cause millions of dollars of damage annually to forest and ornamental industries, and the addition of a wealth of species distribution and diversity information to the scientific community. We intensively surveyed the Northeast and East-central regions of Minnesota from 2006-2008 for invasive/exotic and native Scolytinae using Lindgren funnel traps baited with one of four lures (a/β-pinene, ultra-high-release ethanol [EtOH], EtOH+a-pinene, and Ips 3-part). We captured 16,841 scolytines (representing 25 genera) of which over 40% were Ips pini (Say) and Ips grandicollis (Eichhoff). We found two exotic Scolytinae, Scolytus multistriatus (Marsham) and Scolytus schevyrewi Semenov, both of which had previously been recorded in Minnesota. Two native species, Conophthorus coniperda (Schwarz) and Crypturgus pusillus (Gyllenhal), were reported for the first time in Minnesota. Non-metric multi- dimensional scaling and analysis of similarities indicate that lure types capture different Scolytinae communities, while year, weather pattern and region factors were not significant. We also report the seasonal phenology of the seven most abundantly captured species; Dendroctonus valens LeConte, Hylastes porculus Erichson, Hylurgops rugipennis pinifex (Fitch),I. grandicollis, I. pini, Orthotomicus caelatus (Eichhoff) and Pityophthorus spp. Eichhoff
Mitochondrial genotype influences the response to cold stress in the European green crab Carcinus maenas
Author Posting. © Company of Biologists, 2019. This article is posted here by permission of Company of Biologists for personal use, not for redistribution. The definitive version was published in Journal of Experimental Biology 222(17), (2019):jeb.20352, doi: 10.1242/jeb.203521.Hybrid zones provide natural experiments in recombination within and between genomes that may have strong effects on organismal fitness. On the East Coast of North America, two distinct lineages of the European green crab (Carcinus maenas) have been introduced in the last two centuries. These two lineages with putatively different adaptive properties have hybridized along the coast of the eastern Gulf of Maine, producing new nuclear and mitochondrial combinations that show clinal variation correlated with water temperature. To test the hypothesis that mitochondrial or nuclear genes have effects on thermal tolerance, we first measured the response to cold stress in crabs collected throughout the hybrid zone, then sequenced the mitochondrial CO1 gene and two nuclear single nucleotide polymorphisms (SNPs) representative of nuclear genetic lineage. Mitochondrial haplotype had a strong association with the ability of crabs to right themselves at 4.5°C that was sex specific: haplotypes originally from northern Europe gave male crabs an advantage while there was no haplotype effect on righting in female crabs. By contrast, the two nuclear SNPs that were significant outliers in a comparison between northern and southern C. maenas populations had no effect on righting response at low temperature. These results add C. maenas to the shortlist of ectotherms in which mitochondrial variation has been shown to affect thermal tolerance, and suggest that natural selection is shaping the structure of the hybrid zone across the Gulf of Maine. Our limited genomic sampling does not eliminate the strong possibility that mito-nuclear co-adaptation may play a role in the differences in thermal phenotypes documented here. Linkage between mitochondrial genotype and thermal tolerance suggests a role for local adaptation in promoting the spread of invasive populations of C. maenas around the world.We would like to thank T. Suskiewicz and L. Johnson for help collecting crabs from Halifax, NS, and Robin Seeley for collections from the Isle of Shoals. We thank Timothy Fuller for designing and testing the SMC primers. We thank Mark Murray for facilitating a productive stay on Kent Island, and Nick Keeney for assistance with animal care at the Schiller Coastal Studies Center. This is publication no. 5 from the Bowdoin Marine Laboratory.2020-07-0
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Forest production responses to irrigation and fertilization are not explained by shifts in allocation.
Production increases in intensively managed forests have been obtained by improving resource availability through water and nutrient amendments. Increased stem production has been attributed to shifts in growth from roots to shoot, and such shifts would have important implications for below ground carbon sequestration. We examined above and below ground growth and biomass accumulation and distribution in two eastern cottonwood clones and American sycamore receiving irrigation(I), fertilization(F), orirrigation+fertilization(IF) and compared with non-treated controls(C). Above ground growth and biomass accumulation responded positively to both I and F in all genotypes. After three growing seasons, the largest trees were sycamore receiving the IF treatment, with a total mean annual biomass production of 9.4 Mg ha -1 yr -1. Total cottonwood mean annual biomass production in both clones was >5.0 Mg ha -1 yr -1 in the IF treatment. Above ground biomass production was 6.3 and >3.1 Mg ha -1 yr -1 for sycamore and cottonwoods, respectively. Total root mass fraction was lower in high resource treatments and declined as stands aged. To compare allocation in trees of equal size, we used allometric relationships between above and below ground tissue. Allometric relationships between woody perennial tissues rarely differed among treatments. Improved resource availability caused large increases in growth and consequently accelerated development, but it had little effect on below ground allocation that was not explained by development. Reports of shifting below ground allocation due to soil resource availability must account for developmental effects if they are to accurately evaluate direct impacts of soil resources
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Ice damage in loblolly pine: Understanding the factors that influence susceptibility.
Abstract: Winter ice storms frequently occur in the southeastern United States and can severely damage softwood plantations. In January 2004, a severe storm deposited approximately 2 cm of ice on an intensively managed 4-year-old loblolly pine (Pinus taeda L.) plantation in South Carolina. Existing irrigation and fertilization treatments presented an opportunity to examine the effects of resource amendments on initial ice damage and subsequent recovery. Fertilized treatments showed more individual stem breakage, whereas non fertilized treatments showed more stem bending; however, the proportion of undamaged trees did not differ between treatments. Irrigation did not influence the type of damage. Trees that experienced breakage during the storm were taller with larger diameter and taper and leaf, branch, and crown biomass compared with unbroken trees. One growing season after ice damage, relative height increases were significantly greater for trees experiencing stem breakage compared with unbroken trees; however, relative diameter increases were significantly lower for these trees. Relative diameter increases for broken trees were smaller for fertilized treatments compared with nonfertilized treatments. A reduction in wood strength was ruled out as the cause of greater breakage in fertilized trees; rather, fertilized trees had reached an intermediate diameter range known to be susceptible to breakage under ice loading
Irrigation and Fertilization Effects on Nantucket Pine Tip Moth (Lepidoptera: Tortricidae) Damage Levels and Pupal Weight in an Intensively-Managed Pine Plantation2
The widespread application of intensive forest management practices throughout the southeastern U.S. has increased loblolly pine, Pinus taeda L., yields and shortened conventional rotation lengths. Fluctuations in Nantucket pine tip moth, Rhyacionia frustrana (Comstock), population density and subsequent damage levels have been linked to variations in management intensity. We examined the effects of two practices, irrigation and fertilization, on R. frustrana damage levels and pupal weights in an intensively-managed P. taeda plantation in South Carolina. Trees received intensive weed control and one of the following treatments; irrigation only. fertilization only, irrigation + fertilization, or control. Mean whole-tree tip moth damage levels ranged from <1 to 48% during this study. Damage levels differed significantly among treatments in two tip moth generations in 2001, but not 2000. Pupal weight was significantly heavier in fertilization compared to the irrigation treatment in 2000, but no significant differences were observed in 2001. Tree diameter. height. and aboveground volume were significantly greater in the irrigation + fertilization than in the irrigation treatment after two growing seasons. Our data suggest that intensive management practices that include irrigation and fertilization do not consistently increase R. frustrana damage levels and pupal weights as is commonly believed. However, tip moth suppression efforts in areas adjacent to our study may have partially reduced the potential impacts of R. frustrana on this experiment
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