Simulium Jenningsi Research Articles

Recurring Late December Outbreaks of Adult Simulium jenningsi Group Black Flies (Diptera: Simuliidae) in Seminary, Mississippi, USA

Abstract Black flies (Diptera: Simuliidae) are reemerging as biting and nuisance pests in many southern states, presumably from improving water quality in creeks and rivers. Since 2009, entomologists at Mississippi State University and the Mississippi Department of Health have conducted surveys to ascertain what black fly species are present in the state as well as their geographic distribution and seasonality. These surveys revealed what appears to be a recurring, significant emergence of black flies every year around 25 December at one site in southern Mississippi. In this study, adult black flies were collected from 1 January 2018 to 31 December 2021 by hand netting in the exact same way each time at Okatoma Creek, Seminary, MS. Forty-eight collecting trips to the site over the 4-yr period yielded a total of 176 black flies, all morphologically identified as Simulium jenningsi Group Malloch. Molecular identification was successfully performed on 17 specimens collected during the December outbreaks. Of the 17 specimens analyzed, 10 and 7 specimens grouped with 100% bootstrap confidence inside clades comprising S. jenningsi or S. podostemi, respectively.

Environmental and Spatial Predictors of the Distribution Patterns of the Host-Seeking Black Fly, Simulium jenningsi (Diptera: Simuliidae).

Black flies are nuisance pests as adults, yet they are best managed in the larval stage in flowing waters. As a result, more effort is put into understanding the distribution of the immature life stages than the blood-seeking females that form nuisance. The seemingly localized nature of Simulium jenningsi Malloch (Diptera: Simuliidae) pest problems in western Maryland offered a study system to investigate the spatial and environmental correlates to their severity. Collections of adult black flies were taken at 260 sites within a 2,000 km2 region centered on Washington County, Maryland, during June, July, and August of 2 yr. Average S. jenningsi counts were greater in the June of both years compared to July and August. Although S. jenningsi was found at the majority of sampling sites, higher fly counts were significantly clustered in the southern portion of the county where the majority of resident complaints originated. A generalized linear mixed-model (GLMM) approach was used to determine the correlates to S. jenningsi abundance. The highest performing model showed a negative relationship of S. jenningsi counts with the amount of surrounding impervious surface, distance to the riffles along the confluence of the Shenandoah and Potomac Rivers, distance to the closest body of flowing water, and light intensity, as well as a positive relationship with elevation and air temperature. The results suggest S. jenningsi females are not readily found in urban environments in this study region, and the most relevant monitoring locations for S. jenningsi may be outside of human population centers.

Perceptions and Responses of Residents to the Nuisance Black Fly Simulium jenningsi (Diptera: Simuliidae) in the Mid-Atlantic United States.

Current management practices of nuisance black flies are conducted on an area-wide level and rely on the support of the public to implement programs. In Maryland, a vocal group of residents campaigned their representatives to begin a management program for the black fly Simulium jenningsi Malloch. To determine how residents in Maryland and its surrounding states perceived the severity of black fly nuisance, we deployed surveys online and in-person on the ways their outdoor activities were impacted and the preventive methods used to mitigate nuisance. Online respondents, those with children, and those who had lived in the region for a shorter amount of time were more likely to report black flies as 'extremely annoying'. Quality-of-life concerns stemming from black fly swarms were primarily related to avoiding outdoor exercise and recreation. The majority of respondents used at least one method of personal protection against black fly annoyance, but satisfaction with any method was low. Methods used by respondents included the removal of standing water and rotting vegetation from their properties, indicating a lack of knowledge about black fly breeding habitats. The results contextualized the needs of residents in future management and topics for outreach efforts to address misconceptions about black fly biology. This study offers an example of the application of social science methodology in understanding the needs of stakeholders in area-wide pest management.

Pollution Tolerance Values for Predicting the Spread of Black Flies (Diptera: Simuliidae) in New Jersey, with Implications for Control

ABSTRACTBlack flies are a perennial pest problem in New Jersey, and paramount among them are the S. jenningsi group species. Pollution tolerance values are reported for the 39 species of black flies known in New Jersey. Morphologically similar species were identified chromosomally to ensure accurate identification. Species of the same genus varied markedly in tolerance values, questioning the accuracy of generic-level tolerance values for the Simuliidae. An index for predicting the colonization and spread in New Jersey of the Simulium jenningsi group, which includes the major pest species of black flies in the eastern United States, is proposed, with implications for control programs worldwide.

Molecular systematics of the Simulium jenningsi species group (Diptera: Simuliidae), with three new fast-evolving nuclear genes for phylogenetic inference

A molecular phylogeny was inferred for the 22 nominal species of black flies in the Simulium jenningsi species group, which includes major pests of humans and livestock in North America. Females are structurally monomorphic, presenting a problem for identification of the pests. For each species, we sequenced approximately two kilobases from the mitochondrial genome (ND2, Cox I, proximal one-half of Cox II) and about six kilobases from the nuclear genome (ca. 2 kilobases each from 3 rapidly evolving nuclear genes: big zinc finger [BZF], “5-intron gene” [5intG], and elongation complex protein 1 [ECP1]) and analyzed them phylogenetically using maximum likelihood and Bayesian methods. The three nuclear loci have not previously been used in phylogenetic studies. The mitochondrial region recovered 6 group members as monophyletic. BZF, 5intG, and ECP1 sequences each permitted identification of 13 species and recovered the S. fibrinflatum and S. taxodium subgroups. Simulium aranti Stone and Snoddy and S. luggeri Nicholson and Mickel were consistently recovered at the base of the group. Simulium ozarkense Moulton and Adler, S. dixiense Stone and Snoddy, S. krebsorum Moulton and Adler, and S. haysi Stone and Snoddy branched off before two well-supported sister groups of the remaining species. This remainder consisted of species occupying slow, sandy lowland streams—S. definitum Moulton and Adler, S. jonesi Stone and Snoddy, and the S. taxodium subgroup (S. taxodium Snoddy and Beshear, S. chlorum Moulton and Adler, S. confusum Moulton and Adler, and S. lakei Snoddy)—as sister to two clades of species inhabiting swift, rocky upland streams—the S. fibrinflatum subgroup (S. fibrinflatum Twinn, S. notiale Stone and Snoddy, and S. snowi Stone and Snoddy) and a clade comprised of S. anchistinum Moulton and Adler, S. jenningsi Malloch, and S. nyssa Stone and Snoddy, plus species having cocoons without anterolateral apertures (S. infenestrum Moulton and Adler, S. podostemi Snoddy, S. penobscotense Snoddy and Bauer, and S. remissum Moulton and Adler). Simulium snowi Stone and Snoddy is here considered a synonym of S. notiale Stone and Snoddy. Trees inferred from BZF and 5intG were largely concordant with those from ECP1, but slightly less resolved. Combining mitochondrial and nuclear data sets did not greatly improve the performance of the ECP1 data set alone. We, therefore, propose ECP1 as the gold standard for identification of members of the S. jenningsi group. Maximum likelihood analysis of combined sequences from all three nuclear genes, with three morphological constraints imposed, yielded a tree proposed as the best hypothesis of relationships among group members, based on all available data.

Effects ofBacillus thuringiensis israelensison Black Flies and Nontarget Macroinvertebrates and Fish in a Large River

Abstract Six field experiments tested the effects of the microbial pesticide Bacillus thuringiensis israelensis (Bti) on pestiferous black flies (primarily the Simulium jenningsi group) as well as nontarget macroinvertebrates and fish in the Susquehanna River, Pennsylvania. The response of black fly drift after the Bti application was similar across all experiments. Black fly drift increased significantly within 0.5 h after application, peaked 2-3 h after application, and then remained high for several hours. Significant changes in drift were observed after Bti application for 31 of the 50 nontarget macroinvertebrate taxa examined, but none of these taxa exhibited an increase in drift density similar in magnitude and timing to that of black flies. Furthermore, none of the 31 taxa exhibited the same drift changes in all experiments, as was observed for black flies; most of the taxa exhibited a drift density change during only one posttreatment sample period within a single experiment. Most nontarget macroi...

New Species of Black Fly in the Simulium jenningsi Group (Diptera: Simuliidae) from the Southeastern United States

The larva, pupa, adults, and polytene chromosomes of a new species of black fly (Diptera: Simuliidae) in the Simulium jenningsi group are described and illustrated, and the taxonomy and ecology of the group are discussed. Simulium krebsorum Moulton & Adler, new species, occurs in small, swamp streams of the Sandhills and Upper Coastal Plain of South Carolina and Upper Coastal Plain of North Carolina. The pupa and male of this species are readily distinguished from those of all other North American species. The polytene chromosomes are a minimum of 11 fixed inversions from the Simulium jenningsi standard.

Life Cycle of Simulium jenningsi (Diptera: Simuliidae) in Southern West Virginia

The life cycle of Simulium jenningsi Malloch was compared at two study sites representing the largest and smallest streams (New River and Indian Creek, respectively) where this species is known to breed in southern West Virginia. Larvae first appeared in March, and the first generation emerged in April, followed by two to four more generations by September. A few larvae and adults persisted in autumn, then the population overwintered in the egg stage. There were considerable differences in life cycle at the two study sites. In the New River, emergence of the first generation was 2-3 wk earlier, there were five generations rather than three, and the last larvae of the season persisted 1 mo later as compared with Indian Creek. Warmer temperature and higher quality food in the New River are probable explanations for differences in life cycle. Effective pest management of this species will require larviciding at frequent intervals (1-2 wk) from April through September in many streams over a broad geographic area because of the species' nonsynchronous life cycle, occurrence in different size streams, and strong dispersal ability.

A TRAP/SAMPLING UNIT FOR EAR-FEEDING BLACK FLIES

AbstractThe construction of a simulated-ear-insect-trap (SEIT) for ear-feeding black flies is described. The SEIT, which consists of a styrofoam container with dry ice and a mock sticky ear mounted on a tripod, was developed to capture Simulium jenningsi Malloch and S. vittatum Zett., both widespread pests of livestock. SEIT units set on horse farms within 5 km north of the Potomac River in south-central Maryland, USA (n = 36 samples of 30 min each), consistently captured S. jenningsi and S. vittatum ( and 7.1 per sample, respectively), whereas units set simultaneously on farms > 5 km north of the river (n = 99 samples of 30 min each) captured progressively fewer individuals of both species.

Flight Patterns of Simulium Jenningsi (Diptera: Simuliidae) in Central Pennsylvania, Usa1

Flight data gathered from suction trap (1982) and airplane (1981 and 1982) collections are presented for Simulium jenningsi , one of Pennsylvania's most noxious pests. In central Pennsylvania, the seasonal flight peak occurred in mid-July; the hourly flight peak came between 1800 and 1900 h. The number of females captured was highly correlated with maximum daily temperature. Virtually all females ( n = 374) were inseminated, but fewer than 1% carried mature eggs. A 99.2% reduction in trap catches occurred between 2.1 and 7.6 m, and only 4 females were collected in 100 airplane flights. These data indicate that most flights of S. jenningsi occur within the boundary layer.

The cytotaxonomy of three species in the jenningsi-group of the subgenus Simulium (Diptera: Simuliidae) in New York State

The chromosomal constitutions of three species in the jenningsi-group in the Adirondacks and the Finger Lakes Region in New York State are detailed. No sibling species were found in Simulium jenningsi, S. fibrinflatum, or S. luggeri in these areas. The species were found to differ by 6 fixed inversions and by 19 floating inversions. 4 of which are related to sex determination in S. jenningsi. The major chromosomal differences between the venustutm-group and the jenningsi-group are detailed. The ancestral condition for each arm was determined using ex-group and L′ analyses. A phylogenetic sequence for these three species from the ancestral condition is proposed.

Observations on the Limnological Factors Associated with Three Species of the Simulium jenningsi Group (Diptera:Simuliidae) in New York State

A survey of three species of Simulium (S. jenningsi, S. luggeri and S. fibrinflatum) was conducted from April to October, 1978, in the Adirondacks and Finger Lakes region of New York State. These species were distributed within the study area as follows: S. fibrinflatum, Adirondacks; S. luggeri, Finger Lakes region: and S. jenningsi, both areas. All three were found from June through September. Of the 21 limnological parameters studied, the most important in separating the species were pH and ionic concentration of the water. Simulium fibrinflatum occurred in mildly acidic to neutral, dilute streams whereas S. luggeri occurred in basic, rich streams. Simulium jenningsi was found in both types of streams.

Seasonal fluctuations of macroinvertebrate drift in a South Carolina Piedmont stream

The seasonal fluctuations of larval macroinvertebrate drift, exuvial drift and larval benthic density were quantitatively examined over a 1-year period in a fourth order, spring-fed stream in the Piedmont area of South Carolina. The drift was dominated by the mayfly Baetis spp. and by two species of blackfly (Prosimulium mixtum and Simulium jenningsi). Peak drift densities were noted during early spring and especially late summer. Strong correlations were noted between larval drift densities and exuvial drift, indicating a relationship between drift and seasonal growth and emergence patterns. Seasonal trends in drift and benthic densities, though less strongly correlated, were also generally similar.

Biochemical Genetic Variation in the Family Simuliidae: Electrophoretic Identification of the Human Biter in the Isomorphic Simulium jenningsi Group

This paper describes inter- and intraspecific protein variation in the 3 closely related species of the Simulium jenningsi black fly group, S. jenningsi Malloch, S. nyssa Stone and Snoddy, and S . n. sp. P. Snoddy and Bauer. Variation is described at single loci coding for the enzymes, phosphoglucomutase, phosphoglucoisomerase, malate dehydrogenase, and lactate dehydrogenase. Data are analyzed to assign genetic relationships among the 3 species and to suggest their status as sibling species. The application of electrophoretic methodology has revealed S . n. sp. P. to be the principle biter of humans of this group during the early autumn in north-central Maine.

Observations on Black Flies in Two Maryland Counties1

In recent years residents of the Maryland suburbs of Washington, D. C., have been bothered by small lion-biting flies that swarm around the head and enter the eyes, ears, nose, and mouth. It was known that some of the flies causing annoyance were black flies Surveys were conducted during 1956 and 1957 to identify annoying flies and to learn as much as possible about their ecology and distribution within Prince Georges and Montgomery Counties. In 1956, 215 observations were made on habits of adults of various species at 43 stations; 92 collections were made at 21 stations; H3 observations were negative. Simulium jenningsi Malloch adults were collected at 18 stations and were present at one or more stations during each 10-day period from .May to November. There were 186 different observations on larvae at 40 stations during 1956 with collections made at 36 stations; 42 observations were negative. S. jenningsi larvae were collected at only five stations, four of which were located in the Potomac River. Additional observations in 1957 provided further evidence that S. jenningsi was the predominant species. Adults were common throughout the metropolitan areas of the two counties, but larvae were found almost exclusively in the Potomac River where they were associated with water willow, Dianthera Americana L. It appears that there are two principal generations which usually emerge early in May and early in June. Ten different species of black flies were collected during the surveys: Prosimulium hirtipes (Fries), P. magnum and Shannon, Cnephia mulata (Malloch), Simulium fibrinflatum Twinn, S. venustum Say, S. parnassum Malloch, S. vittatum Zetterstedt, S. decorum Walker, S. jenningsi , and S. tuberosum (Lundstroem). Adult Chloropidae and Drosophilidae were collected occasionally. Adult females of Simulium decorum, S. venusturn, and S. parnassum were recorded as biting Ulan during this survey. Various formulations of BHC, DDT, and malathion were used in fog machines, and formulations of BHC and DDT were used in mist blowers for control of adults. Unsatisfactory results were obtained in that relief from fly annoyance lasted for only a few hours probably because relatively small areas (500 acres) were treated.