Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Insects”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34Linked to original sources
USGS2020

Molecular sequencing and morphological identification reveal similar patterns in native bee communities across public and private grasslands of eastern North Dakota

Bees play a key role in the functioning of human-modified and natural ecosystems by pollinating agricultural crops and wild plant communities. Global pollinator conservation efforts need large-scale and long-term monitoring to detect changes in species’ demographic patterns and shifts in bee community structure. The objective of this project was to test a molecular sequencing pipeline that would utilize a commonly used locus, produce accurate and precise identifications consistent with morphological identifications, and generate data that are both qualitative and quantitative. We applied this amplicon sequencing pipeline to native bee communities sampled across Conservation Reserve Program (CRP) lands and native grasslands in eastern North Dakota. We found the 28S LSU locus to be more capable of discriminating between species than the 18S SSU rRNA locus, and in some cases even resolved instances of cryptic species or morphologically ambiguous species complexes. Overall, we found the amplicon sequencing method to be a qualitatively accurate representation of the sampled bee community richness and species identity, especially when a well-curated database of known 28S LSU sequences is available. Both morphological identification and molecular sequencing revealed similar patterns in native bee community structure across CRP lands and native prairie. Additionally, a genetic algorithm approach to compute taxon-specific correction factors using a small subset of the most concordant samples demonstrated that a high level of quantitative accuracy could be possible if the specimens are fresh and processed soon after collection. Here we provide a first step to a molecular pipeline for identifying insect pollinator communities. This tool should prove useful for future national monitoring efforts as use of molecular tools becomes more affordable and as numbers of 28S LSU sequences for pollinator species increase in publicly-available databases.

North Dakota↗
USGS2020

Short-term impact of sediment addition on plants and invertebrates in a southern California salt marsh

The implementation and monitoring of management strategies is integral to protect coastal marshes from increased inundation and submergence under sea-level rise. Sediment addition is one such strategy in which sediment is added to marshes to raise relative elevations, decrease tidal inundation, and enhance ecosystem processes. This study looked at the plant and invertebrate community responses over 12 months following a sediment addition project on a salt marsh located in an urbanized estuary in southern California, USA. This salt marsh is experiencing local subsidence, is sediment-limited from landscape modifications, has resident protected species, and is at-risk of submergence from sea-level rise. Abiotic measurements, invertebrate cores, and plant parameters were analyzed before and after sediment application in a before-after-control-impact (BACI) design. Immediately following the sediment application, plant cover and invertebrate abundance decreased significantly, with smothering of existing vegetation communities without regrowth, presumably creating resulting harsh abiotic conditions. At six months after the sediment application treatment, Salicornia bigelovii minimally colonized the sediment application area, and Spartina foliosa spread vegetatively from the edges of the marsh; however, at 12 months following sediment application overall plant recovery was still minimal. Community composition of infaunal invertebrates shifted from a dominance of marsh-associated groups like oligochaetes and polychaetes to more terrestrial and more mobile dispersers like insect larvae. In contrast to other studies, such as those with high organic deposition, that showed vegetation and invertebrate community recovery within one year of sediment application, our results indicated a much slower recovery following a sediment addition of 32 cm which resulted in a supratidal elevation with an average of 1.62 m (NAVD88) at our sampling locations. Our results indicate that the site did not recover after one year and that recovery may take longer which illustrates the importance of long-term monitoring to fully understand restoration trajectories and inform adaptive management. Testing and monitoring sea-level rise adaptation strategies like sediment addition for salt marshes is important to prevent the loss of important coastal ecosystems.

California↗
USGS2024

Allochthonous marsh subsidies enhances food web productivity in an estuary and its surrounding ecosystem mosaic

Terrestrial organic matter is believed to play an important role in promoting resilient estuarine food webs, but the inherent interconnectivity of estuarine systems often obscures the origins and importance of these terrestrial inputs. To determine the relative contributions of terrestrial (allochthonous) and aquatic (autochthonous) organic matter to the estuarine food web, we analyzed carbon, nitrogen, and sulfur stable isotopes from multiple trophic levels, environmental strata, and habitats throughout the estuarine habitat mosaic. We used a Bayesian stable isotope mixing model (SIMM) to parse out relationships among primary producers, invertebrates, and a pelagic and demersal fish species (juvenile Chinook salmon and sculpin, respectively). The study was carried out in the Nisqually River Delta (NRD), Washington, USA, a recently-restored, macrotidal estuary with a diverse habitat mosaic. Plant groupings of macroalgae, eelgrass, and tidal marsh plants served as the primary base components of the NRD food web. About 90% of demersal sculpin diets were comprised of benthic and pelagic crustaceans that were fed by autochthonous organic matter contributions from aquatic vegetation. Juvenile salmon, on the other hand, derived their energy from a mix of terrestrial, pelagic, and benthic prey, including insects, dipterans, and crustaceans. Consequently, allochthonous terrestrial contributions of organic matter were much greater for salmon, ranging between 26 and 43%. These findings demonstrate how connectivity among estuarine habitat types and environmental strata facilitates organic matter subsidies. This suggests that management actions that improve or restore lateral habitat connectivity as well as terrestrial-aquatic linkages may enhance allochthonous subsidies, promoting increased prey resources and ecosystem benefits in estuaries.

Washington↗
USGS2025

Neonicotinoid exposure causes behavioral impairment and delayed mortality of the federally threatened American burying beetle, Nicrophorus americanus

Among the most immediate drivers of American burying beetle ( Nicrophorus americanus Olivier) declines, nontarget toxicity to pesticides is poorly understood. Acute, episodic exposure to neonicotinoid insecticides at environmentally relevant concentrations is linked to negative impacts on beneficial terrestrial insect taxa. Beyond mortality, behavioral indicators of toxicity are often better suited to assess sublethal effects of residual concentrations in the environment. First, Nicrophorus spp. congeners were used to generate and identify a low-dose exposure rate (lethal dose 10%; LD10) from an acute, 24-hour exposure and the concentration-series was confirmed by LC–MS/MS. Next, we evaluated the effects of single and repeated low-dose (LD10 = 58.9 ng/beetle) imidacloprid exposure on N . americanus behavior (10 minutes post-dose) and mortality (10 days post-dose). Behavior parameters were analyzed using EthoVision-XT. Control N . americanus were significantly less mobile, demonstrating death-feigning, an anti-predator behavior. Single LD10 dosed N . americanus were hyperactive, traveling over 4 times farther (total distance; p = 0.03) and faster (mean velocity; p = 0.02) than controls. Single and repeated LD10 dosed N . americanus extended their wings without taking flight and flipped on their backs. All control N . americanus survived 10 days post-dose; single LD10 and repeated LD10 exhibited 30% and 50% mortality, respectively. A single LD10 exposure event was sufficient to significantly elicit greater movement and high predation risk behaviors, whereas repeated LD10 exposure did not worsen behavioral impairment but increased mortality over time. Collectively, generalized linear mixed effects models indicated that distance traveled, velocity, and extended wings were significant predictors of mortality. Recently reclassified, the federally threatened N . americanus may be at greater risk to insecticide exposure than previously thought and vulnerable to episodic, low-dose neonicotinoid exposure.

Nebraska, Oklahoma↗
USGS1996

Late quaternary environments, Denali National Park and Preserve, Alaska

Late Quaternary pollen, plant macrofossils, and insect fossils were studied from sites along three rivers in the foothills north of the Alaska Range in Denali National Park and Preserve. The aim was to carry out a reconnaissance of late Quaternary organic sediments in the region, emphasizing the mid-Wisconsin, or Boutellier interstadial interval. Samples of probable early-to mid-Boutellier age (ca. 60 000 to 40 000 B.P.) from Unit 2 at the Toklat High Bluffs site indicate open boreal woodland with dense alder shrub vegetation. Organic Unit 1 at the Foraker River Slump site indicates open taiga with shrubs of probable Boutellier age. Fossil evidence from the youngest horizon in this unit indicates graminoid tundra environments, marking the transition from interstadial to late Wisconsin glacial environments. Early Holocene samples from the Foraker exposures suggest birch shrub tundra; coniferous forest apparently became established only after 6500 B.P. Local variations in forest composition at the Foraker and Sushana sites were probably the result of disturbances, such as fire.

Alaska↗
USGS1996

Behavioral studies of contaminant effects on aquatic invertebrates: A review of Russian investigations

Studies by Russian scientists have documented significant alterations and impairment of critical behavioral functions in aquatic organisms following exposure to environmental contaminants. Behavioral responses disrupted by sublethal exposure to toxicants are intimately involved in habitat selection, foraging, competition, predator-prey relationships, and reproduction, and are essential to survival. Behavioral responses of benthic invertebrates have received considerable study in Russia. A range of invertebrate taxa have been studied, including leeches, insects, molluscs, plankton, and crustaceans. In addition, aquatic invertebrates exhibit a large number of behavioral responses which are sensitive to contaminant exposure and are easily quantified. Standardized behavioral methodologies for measuring contaminant effects are being developed.

Book chapter↗
USGS1981

Use of captive starlings to determine effects of pollutants on passerine reproduction

Three reproductive trials were conducted to develop techniques for propagation of captive starlings (Stumus vulgaris) which could determine the effects of environmental contaminants on passerine reproduction. Trials were conducted during the spring of 1979 in five adjacent 2.4 by 3 by 12-m outdoor wire pens containing four or ten pairs of starlings, a similar number of nest boxes, perches, water, commercial turkey starter, and alfalfa hay as nesting material. Nestling diets consisted of combinations of Nebraska Brand bird of prey diet, live or frozen mealworms (Tenebrio molitor) and crickets (Acheta domestica), or live earthworms (Pheretima sp.). Starlings reproduced successfully when the number of breeding pairs per pen was reduced from ten to four. The average clutch sizes for each pen (4.3 to 4.9) were similar to those reported for wild starlings. Hatching (60 to 90.4 percent) and fledging (0 to 100 percent) success varied among pens. The fledging success was greatest in the pens which received the most diverse nestling diets: Nebraska Brand diet plus frozen or live mealworms and crickets. Whether the insects were presented alive or frozen appeared to have little effect on the reproductive success. The starlings did not consume or carry earthworms to their young. The body weights of 20-day-old nestlings raised in captivity (X=73.9 g) were similar to those of starlings in the wild. The use of single pairs per pen may eliminate problems in presentation of nestling diets due to asynchrony in breeding between pairs and excessive interactions among individuals, which may interfere with parental care. The starling appears to be an excellent model for examining the effects of environmental contaminants on the reproduction of songbirds in captivity.

Book chapter↗
USGS2011

Tamarisk biocontrol using tamarisk beetles: Potential consequences for riparian birds in the southwestern United States

The tamarisk beetle ( Diorhabda spp.), a non-native biocontrol agent, has been introduced to eradicate tamarisk ( Tamarix spp.), a genus of non-native tree that has become a dominant component of riparian woodlands in the southwestern United States. Tamarisk beetles have the potential to spread widely and defoliate large expanses of tamarisk habitat, but the effects of such a widespread loss of riparian vegetation on birds remains unknown. We reviewed literature on the effects of other defoliating insects on birds to investigate the potential for tamarisk beetles to affect birds positively or negatively by changing food abundance and vegetation structure. We then combined data on the temporal patterns of tamarisk defoliation by beetles with nest productivity of a well-studied riparian obligate, the Southwestern Willow Flycatcher ( Empidonax traillii extimus ), to simulate the potential demographic consequences of beetle defoliation on breeding riparian birds in both the short and long term. Our results highlight that the effects of tamarisk biocontrol on birds will likely vary by species and population, depending upon its sensitivity to seasonal defoliation by beetles and net loss of riparian habitat due to tamarisk mortality. Species with restricted distributions that include areas dominated by tamarisk may be negatively affected both in the short and long term. The rate of regeneration and/or restoration of native cottonwoods ( Populus spp.) and willows ( Salix spp.) relative to the rate of tamarisk loss will be critical in determining the long-term effect of this large-scale ecological experiment.

Arizona, Colorado, New Mexico, Utah↗
USGS2012

Spatial analysis of Northern Goshawk territories in the Black Hills, South Dakota

The Northern Goshawk ( Accipiter gentilis ) is the largest of the three North American species of Accipiter and is more closely associated with older forests than are the other species. Its reliance on older forests has resulted in concerns about its status, extensive research into its habitat relationships, and litigation. Our objective was to model the spatial patterns of goshawk territories in the Black Hills, South Dakota, to make inferences about the underlying processes. We used a modification of Ripley's K function that accounts for inhomogeneous intensity to determine whether territoriality or habitat determined the spacing of goshawks in the Black Hills, finding that habitat conditions rather than territoriality were the determining factor. A spatial model incorporating basal area of trees in a stand of forest, canopy cover, age of trees >23 cm in diameter, number of trees per hectare, and geographic coordinates provided good fit to the spatial patterns of territories. There was no indication of repulsion at close distances that would imply spacing was determined by territoriality. These findings contrast with those for the Kaibab Plateau, Arizona, where territoriality is an important limiting factor. Forest stands where the goshawk nested historically are now younger and have trees of smaller diameter, probably having been modified by logging, fire, and insects. These results have important implications for the goshawk's ecology in the Black Hills with respect to mortality, competition, forest fragmentation, and nest-territory protection.

South Dakota↗
USGS1993

How well can fishes prey on zebra mussels in eastern North America?

Literature on mollusk-eating fishes was reviewed to determine the potential for different species of fish to control zebra mussels in eastern North America. At least six species are potential predators of zebra mussels because they possess (1) both upper and lower pharyngeal teeth or (2) lower pharyngeal teeth and chewing pads located on the dorsal roof for crushing mollusk shells. Freshwater drum ( Aplodinotus grunniens ) and two centrarchids, redear sunfish ( Lepomis microlophus ) and pumpkinseed ( L. gibbosus ), possess both upper and lower pharyngeal teeth and are likely to consume more zebra mussels than fishes with only lower pharyngeal teeth. Only two catostomid species, copper and river redhorses ( Moxostoma hubbsi and M. carinatum ), have chewing pads that enable them to crush mollusks. The exotic omnivorous common carp ( Cyprinus carpio ), possessing lower teeth and a chewing pad, may prey on zebra mussels when aquatic insect larvae, its preferred food, become rare. Managing populations of drum, sunfishes and redhorses to reduce exploitation of large individuals and improve their habitats are suggested as means to intensify biological control of zebra mussels in eastern North America. Other Eurasian molluscivores, the roach ( Rutilus rutilus ) and the black carp ( Mylopharyngodon piceus ) should not be introduced into North America because research has shown repeatedly that an introduced biological controller usually does not forage for unwanted pests or reside only in preferred habitats of pests. Drum, sunfishes and redhorses should be preferred over these exotics as biological controllers of zebra mussels in North America because these native fishes will likely occupy newly established habitats of zebra mussels.

Fisheries↗
USGS1961

Food of the American smelt in Saginaw Bay, Lake Huron

In order to determine possible sources of vitamin A for quail, 37 species of insects and other invertebrates were analyzed for vitamin A and for carotene, and 26 species of seeds and fruits were assayed for carotene. The invertebrates showed no trace of vitamin A; but 8 herbivorous invertebrates and the praying mantis contained carotene. Most of the plants contained carotene--some of them a lot (dotted smartweed, some legumes, sumac, roses, bittersweet, etc.). The amount of carotene varied among plants of the same species and even among fruits on the same plant.

Transactions of the American Fisheries Society↗
USGS1963

Food of the bloater, Coregonus hoyi, in Lake Michigan

Stomachs were examined from 1,469 Lake Michigan bloaters, Coregonus [Leucichthys] hoyi, greater than 7 inches long which contained identifiable food. An additional 461 ciscoes less than 7 inches long were incorporated into the study; these latter fish were not positively identified, but most of them undoubtedly were bloaters. The specimens were caught in bottom nets except for 49, all less than 6 inches long, taken in midwater trawls. Lake Michigan bloaters under 7 inches long depend heavily on zooplankton. Those larger than 7 inches feed predominantly on Pontoporeia affinis and Mysis relicta, although fish of the 7.0- to 7.9-inch size range commonly eat zooplankton, expecially in shallower water. Generally, Mysis becomes more important, and Pontoporeia less so, as the depth increases and as the season progresses from spring to fall. Incidence of Pontoporeia increases and that of Mysis declines as the fish size increases. Other food items, in decreasing order of importance, are fingernail clams, midges (all stages of development), fish eggs, ostracods, and miscellaneous adult and immature insects other than midges.

Transactions of the American Fisheries Society↗
USGS1996

Feeding response by northern squawfish to a hatchery release of juvenile salmonids in the Clearwater River, Idaho

We collected gut contents from northern squawfish Ptychocheilus oregonensis captured in the Clearwater River, Idaho, 0–6 km from its confluence with the Snake River, following the release of 1.1 million yearling chinook salmon Oncorhynchus tshawytscha from the Dworshak National Fish Hatchery. Before the hatchery release, northern squawfish gut contents (by weight) in the study area were 38% crayfish Pacifastacus spp., 26% insects, 19% nonsalmonid fish, and 16% wheat kernels Triticum spp. Juvenile salmonids constituted 54% of gut contents about 24 h after the hatchery release, 78% after 5 d, and 86% after 7 d. The mean number of salmonids per gut (1.2) after release was higher than typically seen in guts from northern squawfish collected in mid-reservoir areas away from hydroelectric dams on the Snake and Columbia rivers. Length-frequency distributions of juvenile salmonids eaten and those captured in a scoop trap 4 km upstream of the study area indicated that northern squawfish were selectively feeding on the smaller individuals. We attribute the high rates of predation in the study area to the artificially high density of juvenile salmonids resulting from the hatchery release and to the physical characteristics of the study area in which the river changed from free flowing to impounded. Our results suggest that northern squawfish can quickly exploit hatchery releases of juvenile salmonids away from release sites in the Columbia River basin.

Idaho↗
USGS1997

Food resource partitioning by nine sympatric darter species

We compared the diets among members of the diverse darter community of French Creek, Pennsylvania, in relation to seasonal prey availability, feeding ontogeny, and sex. Prey taxa and size attributes were characterized for nine syntopic darter species; taxon, size, and availability of macroinvertebrate prey were also analyzed from Surber samples. In general, darters fed opportunistically on immature insects; few taxa were consumed in greater proportions than they were found in the environment. Some variation in diet composition was expressed, however, among different life stages and species. Juvenile darters consumed smaller prey and more chironomids than did adults. Etheostoma blennioides and E. zonale consumed the fewest taxa (2–3), whereas E. maculatum , E. variatum , and Percina evides had the most diverse diets (7–10 taxa). Etheostoma maculatum , E. flabellare , E. variatum , and P. evides consumed larger prey (1–13 mm in standard length), whereas E. blennioides , E. caeruleum , E. camurum , E. tippecanoe , and E. zonale rarely consumed prey longer than 6 mm. Percina evides fed on larger prey, fewer chironomids, and more fish eggs than Etheostoma species. Females consumed more prey than males and overlapped less in diet composition with males during the spawning season than afterwards. Fish diets did not seem related to habitat use. Greater trophic partitioning was observed in April, when prey resources were scarce, than in July, when prey were abundant. Darter species fed opportunistically when prey were dense, whereas they partitioned food resources mainly through the prey size dimension when prey were less abundant. The divergence of darter diets during a period of low food availability may be attributed to interspecific competition. Alternatively, the greater abundance of large prey in April may have facilitated better prey size selectivity, resulting in less overlap among darter species.

Pennsylvania↗
USGS2003

Effects of pulsed, high-velocity water flow on larval robust redhorse and V-lip redhorse

The pulsed, high-velocity water flow characteristic of water-flow patterns downstream from hydropower-generating dams has been implicated in the declining abundance of both aquatic insects and fishes in dam-regulated rivers. This study examined the effects of 0, 4, and 12 h per day of pulsed, high-velocity water flow on the egg mortality, hatch length, final length, and survival of larval robust redhorse Moxostoma robustum , a presumedly extinct species that was rediscovered in the 1990s, and V-lip redhorse M. collapsum (previously synonomized with the silver redhorse M. anisurum ) over a 3–5 week period in three separate experiments. Twelve 38.0-L aquaria (four per treatment) were modified to simulate pulsed, high-velocity water flow (>35 cm/s) and stable, low-velocity water flow (<10 cm/s). Temperature, dissolved oxygen, zooplankton density, and water quality variables were kept the same across treatments. Fertilized eggs were placed in gravel nests in each aquarium. Hatch success was estimated visually at greater than 90%, and the mean larval length at 24 h posthatch was similar in each experiment. After emergence from the gravel nest, larvae exposed to 4 and 12 h of pulsed, high-velocity water flow grew significantly more slowly and had lower survival than those in the 0-h treatment. These results demonstrate that the altered water-flow patterns that typically occur when water is released during hydropower generation can have negative effects on the growth and survival of larval catostomid suckers.

Transactions of the American Fisheries Society↗
USGS2011

Bridging the energy gap: Anadromous blueback herring feeding in the Hudson and Mohawk rivers, New York

Adult blueback herring Alosa aestivalis (N = 116) were collected during the 1999, 2000, and 2002-2004 spawning runs from sites on the Hudson and Mohawk rivers, and gut contents were analyzed. Thirty-four fish (33% of those examined) were found to contain food material. Food items were present in 41% of Mohawk River samples and 11% of Hudson River samples; all Hudson River fish containing food were captured in small tributaries above the head of tide. Hudson River fish predominantly consumed zooplankton, while Mohawk River fish consumed benthic aquatic insects in large quantities, including Baetidae, Ephemeridae, and Chironomidae. Using stable isotope analysis and a mixing model, we found that fish collected later in the season had significantly decreased marine-derived C. Condition indices of later-season fish were equal to or greater than those of fish collected earlier in the season. Blueback herring in this system may face increased energy requirements as they migrate farther upstream during spawning runs, and feeding may provide energy subsidies needed to maintain fitness over their expanded migratory range. ?? Copyright by the American Fisheries Society 2007.

Transactions of the American Fisheries Society↗
USGS2008

Morphology and histology of the alimentary canal of Lygus hesperus (Heteroptera: Cimicomoropha: Miridae)

Microdissection and transverse semithin sections were used to perform a light microscopy survey of the gross morphology and cellular anatomy of the alimentary canal, respectively, of Lygus hesperus Knight, a key pest of cotton (Gossypium hirsutum L.), alfalfa (Medicago sativa L.), and other crops. The gross morphology of the alimentary canal showed a relatively unadorned tube compared with other hemipterans, with variably shaped compartments and one small diverticulum. However, the epithelial cell anatomy of the gut was relatively complex, with the midgut having the most diverse structure and cell types. The midgut was typical of the "Lygus-type gut" seen in the older literature, i.e., it consisted of three major regions, the first (descending), second (ascending), and third (descending) ventriculi, with different variants of three major epithelial cell types in each region. Our light microscopy (LM) study suggests that the three cell types are nondifferentiated regenerative cells (which sparsely occurred throughout the midgut but were abundant in the anterior region of the first ventriculus), endocrine cells, and columnar cells. Although the Lygus gut cells strongly resemble those cell types seen in other insects, their identification should be confirmed via transmission electron microscopy to be considered definitive. These cell types differed in the size and opacity of vesicles, geometry of cell surface in the gut lumen, and size, shape, and concentration of brush-border microvilli and location within the gut. Comparison of gut structure in L. hesperus with that of other hemipterans, especially in relation to hemipteran phylogeny and feeding strategies, is discussed.

Annals of the Entomological Society of America↗
USGS2017

Control of invasive weeds with prescribed burning

Prescribed burning has primarily been used as a tool for the control of invasive late-season annual broadleaf and grass species, particularly yellow starthistle, medusahead, barb goatgrass, and several bromes. However, timely burning of a few invasive biennial broadleaves (e.g., sweetclover and garlic mustard), perennial grasses (e.g., bluegrasses and smooth brome), and woody species (e.g., brooms and Chinese tallow tree) also has been successful. In many cases, the effectiveness of prescribed burning can be enhanced when incorporated into an integrated vegetation management program. Although there are some excellent examples of successful use of prescribed burning for the control of invasive species, a limited number of species have been evaluated. In addition, few studies have measured the impact of prescribed burning on the long-term changes in plant communities, impacts to endangered plant species, effects on wildlife and insect populations, and alterations in soil biology, including nutrition, mycorrhizae, and hydrology. In this review, we evaluate the current state of knowledge on prescribed burning as a tool for invasive weed management.

Weed Technology↗