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The widespread nominal black fly Simulium(Simulium) rufibasisBrunetti was reexamined morphologically, chromosomally, and molecularly to determine the status of populations in Japan and Korea with respect to S. rufibasisfrom the type locality in India and to all other known species in the S.(S.) tuberosumspecies-group. Morphological comparisons established that the species previously known as S. rufibasisin Japan and Korea is distinct from all other species. Consequently, it was described and illustrated as a new species, Simulium(S.) yamatoense. Simulium yokotenseShiraki, formerly a synonym of S. rufibasis, was morphologically reevaluated and considered a species unplaced to species-group in the subgenus Simulium. Chromosomal analyses of S. yamatoensesp. nov. demonstrated that it is unique among all cytologically known species of the S. tuberosumgroup and is the sister species of the Taiwanese species tentatively known as S. (S.) arisanumShiraki. Populations of S. yamatoensesp. nov. included two cytoforms, based on the sex chromosomes. Cytoform A, including topotypical representatives, was found in Kyushu, Japan, whereas cytoform B was found in Korea and Honshu, Japan. Molecular analysis based on the COI mitochondrial gene generally corroborated morphological and chromosomal data that S. yamatoensesp. nov. is a distinct species and, like the chromosomal data, indicate that it is most closely related to S. arisanum, with interspecific genetic distance of 2.92–4.63%.

Hovering hawkmoths expend significant energy while feeding, which should select for greater feeding efficiency. Although increased feeding efficiency has been implicitly assumed, it has never been assessed. We hypothesized that hawkmoths have proboscises specialized for gathering nectar passively. Using contact angle and capillary pressure to evaluate capillary action of the proboscis, we conducted a comparative analysis of wetting and absorption properties for 13 species of hawkmoths. We showed that all 13 species have a hydrophilic proboscis. In contradistinction, the proboscises of all other tested lepidopteran species have a wetting dichotomy with only the distal ∼10% hydrophilic. Longer proboscises are more wettable, suggesting that species of hawkmoths with long proboscises are more efficient at acquiring nectar by the proboscis surface than are species with shorter proboscises. All hawkmoth species also show strong capillary pressure, which, together with the feeding behaviors we observed, ensures that nectar will be delivered to the food canal efficiently. The patterns we found suggest that different subfamilies of hawkmoths use different feeding strategies. Our comparative approach reveals that hawkmoths are unique among Lepidoptera and highlights the importance of considering the physical characteristics of the proboscis to understand the evolution and diversification of hawkmoths.

Accurate species identifications are the essential first step in understanding the medical, economic, and ecological importance of black flies. The utility of DNA barcoding based on cytochrome c oxidase subunit 1 (COI) sequences was evaluated for identifying six common species of Palearctic black flies in the subgenus Wilhelmia, including several that are virulent pests. Chromosomally identified larvae from Turkey and Germany and COI sequences in GenBank were analyzed. Intraspecific genetic divergence was 0.7–3.5% (mean 1.6%), whereas interspecific genetic divergence was 2.7–16.9%. On the basis of COI barcodes, the six nominal species of Simulium(Wilhelmia) were clustered in three distinct clades with high levels of genetic divergence, using maximum likelihood and Bayesian analyses. All specimens of Simulium equinum(L.), Simulium pseudequinumSéguy, and Simulium paraequinumPuri were correctly identified. However, >75% of identifications were ambiguous for Simulium lineatum(Meigen) and Simulium turgaicumRubtsov (Meigen) because of overlapping intra- and interspecific divergence of the two species and Simulium balcanicum(Enderlein), all three of which are chromosomally similar and nearly isomorphic. Phylogenetic evaluation showed that S. balcanicum, S. equinum, S. pseudequinum, and S. paraequinumwere monophyletic, with high bootstrap and posterior probability values, but it also showed that S. lineatumand S. turgaicumwere paraphyletic, each clustering in two distinct groups, suggesting the presence of cryptic taxa. Although DNA barcoding provided a partial means of identification and indications of additional biodiversity, other molecular markers are needed to clarify the limits of all pest species of the subgenus Wilhelmia.

The ability of Lepidoptera, or butterflies and moths, to drink liquids from rotting fruit and wet soil, as well as nectar from floral tubes, raises the question of whether the conventional view of the proboscis as a drinking straw can account for the withdrawal of fluids from porous substrates or of films and droplets from floral tubes. We discovered that the proboscis promotes capillary pull of liquids from diverse sources owing to a hierarchical pore structure spanning nano- and microscales. X-ray phase-contrast imaging reveals that Plateau instability causes liquid bridges to form in the food canal, which are transported to the gut by the muscular sucking pump in the head. The dual functionality of the proboscis represents a key innovation for exploiting a vast range of nutritional sources. We suggest that future studies of the adaptive radiation of the Lepidoptera take into account the role played by the structural organization of the proboscis. A transformative two-step model of capillary intake and suctioning can be applied not only to butterflies and moths but also potentially to vast numbers of other insects such as bees and flies.

AbstractSimulium(Simulium) acrotrichumRubtsov, a black fly from Central Asia, provides a platform for examining the evolutionary relationships of selected species groups in the subgenus SimuliumLatreille. The female, male, pupa, and larva of S. acrotrichumare properly associated and morphologically redescribed and illustrated. The banding sequence of the larval polytene chromosomes is compared with that of the Simuliumsubgeneric standard, from which it differs by nearly 30 fixed rearrangements. Structural and chromosomal features indicate that S. acrotrichumis the sister species of S. flavidumRubtsov. Simulium acrotrichumcan be placed confidently in a group consisting of the S. malyscheviDorogostaisky, Rubtsov, and Vlasenko and S. reptans(L.) groups, which are part of a larger clade that also includes the S. jenningsiMalloch group. This more inclusive clade is defined chromosomally by a minimum of four fixed inversions, compared with the standard map for the subgenus Simulium. All four inversions are uniquely derived relative to the two selected outgroups, Simulium(Psilozia) vittatumZetterstedt and Simulium(Boophthora) erythrocephalum(De Geer). The independent monophyly of the S. malyscheviand S. reptansgroups, however, cannot be tested without study of additional group members. The problems illustrated by the taxonomic identity and phylogenetic placement of S. acrotrichumargue for an integrated approach to simuliid systematics, drawing from the character stores of morphology, cytology, and molecular biology.

Trichospores of Harpella melusinaein larval black flies from four streams in northwestern South Carolina were measured. The longest fresh trichospore was 242 μm, 38% longer than the reported maximum length of trichospores for this species. After staining with lactophenol cotton blue, trichospore length was significantly reduced by up to 24.4% in fresh larvae and up to 4.9% in fixed larvae. Mean trichospore length differed significantly between seasons and between sampling sites but did not differ significantly between middle and final instars. Trichospore length correlated significantly with host size. We suggest that taxonomic descriptions of trichomycetes should include measurements of fresh, fixed and stained trichospores.

A total of 2063 mid- to late-instar larval black flies were collected from 64 stream sites in South Carolina and screened for the presence of the trichomycete fungus Harpella melusinae. Sixteen of 18 host species were colonized by H. melusinaeon at least one occasion. Prevalence of H. melusinaein larvae of Simulium tuberosumcytospecies “A” was highest in acidic streams with low conductivity, whereas H. melusinaecolonized larvae of Simulium verecundummost frequently in slower-moving streams. Ecological conditions, therefore, can serve as predictors of the prevalence of H. melusinae. Prevalence in host larvae was significantly lower in the Piedmont ecoregion than in the Mountain ecoregion. Prevalence did not differ in the host species S. verecundumacross ecoregions, suggesting that different prevalences among host species might indicate some host preference. The prevalence of H. melusinaediffered significantly between two univoltine host species (Simulium venustumand Prosimulium magnum) at the same site but not between two multivoltine host species (S. tuberosumcytospecies “FG” and S. tuberosumcytospecies “CDE”), suggesting that host life history could be important in determining fungal prevalence.

The midgut-inhabiting fungi (Harpellaceae) Harpella melusinaeand Stachylina pediferwere induced to form zygospores, using an application of a pH 10 potassium hydroxide solution with culture media. The previously unknown zygospores of S. pediferare borne perpendicular to the zygosporophore, as in Harpella melusinae. The zygospores of the hindgut-inhabiting species Smittium coloradense, borne obliquely to the zygosporophore (in vivo), are described for the first time.

Abstract:The boreal biome is rich in running waters suitable for the development of black flies. Here we review the ecological roles of black flies and the options available for their management. Large numbers of these insects play quantitatively important roles in a number of processes, not only in the running-water habitats of the larvae but also in the terrestrial environments of the adults. Black flies suck blood from mammals, including humans, and from birds, with negative effects including occasional death of animals. Black flies also transmit parasites, including filarial worms and haemosporidians. In the last two decades, programs to control black flies by treating the larvae, using Bacillus thuringiensisvar. israelensis, have been developed, with predominantly positive results but with limited understanding of the indirect impacts to the aquatic and terrestrial ecosystems. On a more positive side, adult black flies are food for a variety of predators and may favour pollination, as well as helping in nature conservation by deterring people from visiting wilderness areas. Black fly larvae feed on suspended particles, linking this energy source to invertebrate and vertebrate predators (e.g.,salmonids). Because larval densities often are high, considerable amounts of sedimenting faecal pellets increase the local retention of organic material, and this provides nutrition for invertebrates and micro-organisms, and potentially fertilizes river margins. Larvae also produce silk, the role of which in the ecosystem is poorly known but potentially important.

Trichomycete fungi are common endobionts of aquatic insect larvae, but little is known of their ecology. In this study, the seasonality of trichomycete colonization of larval black flies (Diptera: Simuliidae) was investigated in three streams in northwestern South Carolina. At least eight species of trichomycetes were found in two species of black flies, and 93.8% of 1819 larval black flies examined contained trichomycetes. Significant differences were found in the seasonal prevalence of Harpella melusinae, Simuliomyces microsporus, and Paramoebidiumspp. at one of three sites. At this site, the lowest mean prevalence for H. melusinaeoccurred in winter (67%) versus the other seasons (96–100%), whereas mean prevalence was lowest in summer for Simuliomyces microsporus(1%) versus the other seasons (2–21%) and lowest in summer for P. spp. (9%) versus the other seasons (45–67%). Significant differences in levels of colonization among seasons were not detected. Conjugations of H. melusinae(representing early stages of sexual reproduction) occurred most frequently in the spring and winter (up to 14% of larvae). Sexual reproduction (represented by zygospores) of Legeriomycetaceae occurred most frequently in the spring and fall (up to 17% of larvae).

AbstractSmittium megazygosporum, previously known only from southern France, was collected in South Carolina, USA, indicating a Holarctic distribution. An axenic culture was obtained from a black fly (Diptera, Simuliidae) that was probably a spurious host. The holdfast, with a refractive secreted-material base, is described for the first time, and verticillate branching in vegetative growth is confirmed. Zygospores, the largest known for the genus, were found in chironomids co-occurring with the black fly host. Trichospore sizes varied significantly depending on the host and medium in which they grew. This host-related size variation could have consequences for species diagnoses of Smittiumthat often are based on trichospore size.

A new species of microsporidium, Caudospora palustris(Microsporidia: Caudosporidae), is described from 3 species of black flies (Cnephia ornithophiliaand diploid and triploid cytospecies of Stegopterna mutata), bringing to 7 the total species of caudosporids recorded from North America. This new species of caudosporid is recorded from swamp streams of the Coastal Plain from New Jersey to Georgia, with single records from the New Jersey mountains and the Upper Peninsula of Michigan. Densities of patently infected larvae (up to 10,600/m2) and spore production (nearly 8×1011/m2) are the greatest recorded for any microsporidium of black flies. The ultrastructure of this new species is presented, along with the first molecular characterization for a microsporidium of black flies. The phylogenetic position of black fly microsporidia within the phylum Microsporidia is presented; however, the analysis does not support the inclusion of C. palustrisin any clade. Key features of all North American caudosporids are provided, and possible evolutionary trajectories are proposed based on optimization of caudosporid species on the phylogeny of their 22 known host species, including 16 that represent new host species records.

AbstractA 5-year study of the black flies of east-central Saskatchewan revealed 21 species, including Simulium incognitumsp.nov. Chromosomal and ecological evidence for reproductive isolation is presented for this new species, formerly known as S. venustumSay CC4, and S. venustumSay CC. All 21 species in the study are associated with productive streams and rivers. As many as nine of these species might comprise the pest assemblage harassing livestock. The major pest, S. luggeriNicholson and Mickel, is cytologically distinct from populations in the eastern United States on the basis of a two-step, Y-linked inversion in the IIS chromosomal arm. Simulium luggeriis the only livestock pest that breeds almost solely in large streams and rivers. The other eight probable pests breed entirely or partly in streams less than 10 m wide, often below beaver dams, suggesting that management efforts should specifically target these sites.

AbstractResults are presented for a 4-year (1986–1989) cytological survey of the Simulium venustum/verecundumcomplex on the Avalon Peninsula, Newfoundland, Canada. Based on 4578 larval identifications from 72 sites, six species in the S. venustum/verecundumcomplex were found: S. truncatumLundström (= S. venustumEFG/C), S. venustumCC2, S. venustumCC3, S. venustumAC(gB), S. verecundumStone and Jamnback (= S. verecundumAA), and S. rostratumLundström (= S. verecundumACD). The possibility that S. venustumA/C and S. venustumSay (= S. venustumCC) exist on the Avalon Peninsula in low numbers cannot be excluded, although this is doubtful. Discoveries of EFG/C and CC2 reciprocal sex exceptions support the hypothesis that exceptional individuals are the product of crossover. Cytological results confirm the supposition that S. truncatum, S. venustumCC2, S. venustumCC3, S. venustumAC(gB), S. verecundumAA, and S. rostratumare all distinct species. Results are interpreted within the broader geographic context of the S. venustum/verecundumcomplex. Three new cytotypes are recognized: one, from Quebec, we place under AC(gB); the other two, from the eastern United States, fall under CC2.

Larval (5th-final instar) drift patterns of five species of black flies (Prosimulium mixtum, Stegopterna mutata, Simulium tuberosum FG, S. vittatum IIIL-1, and S. vittatum IS-7) were analyzed. The diel drift patterns were not species-specific, but consistently exhibited a marked increase after sunset, preceded by a period of minimal drift. The drift minimum generally occurred during or shortly after the period of maximum water temperature. Larvae showed significantly more nocturnal than diurnal drift. Pupal drift was attributed to accidental detachment from the substrate. Adult drift was over 90% diurnal and usually composed primarily of teneral individuals. Upstream larval movements of the S. vittatum and S. tuberosum complexes were each less than 6.5% of the total upstream and downstream larval movements. The proportion of parasitized larvae of the S. vittatum and S. tuberosum complexes was generally higher in the benthos than in the drift.

Abstract: This study examines species-specific distributions of preimaginal black flies (Diptera: Simuliidae) over two large spatial scales (within and across ecoregions) and two seasons (spring and summer). The study area in the western two-thirds of South Carolina, United States, was divided into three ecoregions (Mountains, Piedmont, Sandhills). The mean correct classification of species distributions among stream sites was 81.3%. Predictability of species distributions varied with spatial scale, location, and time. Species occurrence was not independent of ecoregion; distributions of 12 of the 13 species examined at this scale were predictable on the basis of changes in water column (temperature, percentage dissolved oxygen) and channel characters (velocity, streambed-particle size). However, with the exception of the Mountains during the summer, predicting species distributions within ecoregions was far less successful than predicting distributions across these regions; predictability was particularly poor in the Sandhills. Seasonal effects on predictability were most pronounced in the Mountains. As stream sites became more homogeneous, predictive capability declined. Species-level identifications, aided by cytogenetic techniques, were of paramount importance in recognizing the association between species distributions and stream conditions, emphasizing that considerable ecological information is lost when species are not considered. This study emphasizes the critical role of taxonomic resolution, linked with spatial and temporal scale of observation, in elucidating patterns of species assemblages. It also demonstrates that predictability of species distributions at a fixed scale can vary with geographic location and time.

The efficiency of gastric lavage for the removal of stomach contents of two species of fish was tested at The Pennsylvania State University in 1981. This technique was effective for 98% of the brook trout (Salvelinus fontinalis) examined, and 100% for slimy sculpins (Cottns cognatus). No mortality occurred in either species during the 3-week post-lavage period

AbstractThree new nearctic species of Simuliidae near Simulium vernumMacquart are described and illustrated: Simulium craigin.sp., S. caledonensen.sp., and S. decolletumn.sp. Descriptions of larval polytene chromosomes are included. Notes on biology and distribution are given for each species and larval comparisons are made with three European siblings in the S. vernumcomplex.

The pattern of assemblages for species of black flies (Diptera:Simuliidae) among 18 small (mean width <3.25 m) streams in Yellowstone National Park, Wyoming, was analyzed using Monte Carlo simulations. Of specific interest was the amount of species co-occurrence among physically similar streams located in a small geographic area. Results indicate that black fly assemblages among similar streams were largely unpredictable in terms of species co-occurrence. There were no significant correlations between Jaccard's coefficient of similarity and distance between pairs of stream sites, indicating that faunal similarity among sites was not a function of the distance between them. Results are consistent with non-equilibrium community-structure theory. We also suggest that success at predicting black fly species assemblages in other studies is the result of correctly identifying different species pools associated with different stream types.

We studied the courtship and copulation ofFlorinda coccinea (Hentz) and described 18 behavioral acts for this species.F. coccinea exhibits many behaviors typical of the Linyphiidae such as web reduction, abdominal vibration, palpal jabbing, stridulation, pseudocopulation, and prolonged copulation. The numbers of palpal insertions during pseudocopulation and copulation are positively correlated to the durations of these phases. Pseudocopulation requires over three times more time on average than copulation, although females copulate longer than is required for fertilization. We found no correlation between the durations of pseudocopulation or copulation and fitness characters, and we hypothesize that lengthy pseudocopulation and copulation may function as a form of internal courtship.

Three species of crane flies-Dactylolabis montana, Limonia simulans,and Antocha saxicola-gather near streams to mate and oviposit. All species are polygamous and sex ratios at these sites are male-biased. After a short mating bout, males guard females by standing over them during oviposition. Sperm competition appears to be intense and to follow last-male advantage, based on the packing of sperm within the two elongate spermathecae. Males of A. saxicolasuccessfully defend against rivals over 85% of the time. In contrast, defending males of D. montanaand L. simulanslose the female over 65% of the time during interactions with rivals. Despite the high frequency of loss, defending males gain additional oviposition time by engaging rivals in combat while the female continues to oviposit. Thus, a guarding male does not have to retain the female for guarding to be adaptive. Legs and claws of all species are sexually dimorphic and play an important role in guarding and defending.

The proboscis of butterflies and moths consists of two C-shaped fibres, the galeae, which are united after the insect emerges from the pupa. We observed that proboscis self-assembly is facilitated by discharge of saliva. In contrast with vertebrate saliva, butterfly saliva is not slimy and is an almost inviscid, water-like fluid. Butterfly saliva, therefore, cannot offer any viscoelastic adhesiveness. We hypothesized that capillary forces are responsible for helping butterflies and moths pull and hold their galeae together while uniting them mechanically. Theoretical analysis supported by X-ray micro-computed tomography on columnar liquid bridges suggests that both concave and convex liquid bridges are able to pull the galeae together. Theoretical and experimental analyses of capillary forces acting on natural and artificial proboscises show that these forces are sufficiently high to hold the galeae together.

We access the molecular diversity of the black fly Simulium nobile De Mejiere, using the universal cytochrome c oxidase subunit I (COI) barcoding gene, across its distributional range in Southeast Asia. Our phylogenetic analyses recovered three well-supported mitochondrial lineages of S. nobile, suggesting the presence of cryptic species. Lineage A is composed of a population from Sabah, East Malaysia (Borneo); lineage B represents the type population from Java, Indonesia; and lineage C includes populations from the mainland of Southeast Asia (Peninsular Malaysia and Thailand). The genetic variation of lineage C on the mainland is greater than that of lineages A and B on the islands of Borneo and Java. Our study highlights the value of a molecular approach in assessing species status of simuliids in geographically distinct regions.

Most adult Lepidoptera depend on a proboscis for fluid uptake. Although the proboscis has been regarded as a sealed tube with fluid uptake restricted to the distal end, recent evidence indicates that it is permeable along its entire length in at least some species. We, therefore, tested the effectiveness of the seal during feeding in four species of butterflies. Feeding rates in monarchs (Danaus plexippus L.), painted ladies (Vanessa cardui L.), and tiger swallowtails (Papilio glaucus L.) did not differ significantly when the proboscises were straightened and fully, versus partially, submersed in 1 or 15% sucrose solutions. To explore these results, we tested fluid uptake along the nearly transparent proboscises of buckeye butterflies (Junonia coenia Hübner) by applying colored droplets of water to the legular seam between the paired galeae. Colored fluid appeared in the food canal of straightened and naturally flexed proboscises within 10 s, regardless of whether the chemosensilla were stimulated with sugar. Statistically significant entry of fluid, however, occurred ≈30 s after droplets were applied and only if the proboscis was naturally flexed and stimulated with sucrose. The results suggest that fluid uptake along the length of the proboscis is influenced by changes in legular spacing when the butterfly naturally bends the proboscis and on activation of the cibarial pump when chemosensilla are stimulated with sugar.

Mouthparts of fluid-feeding insects have unique material properties with no human-engineered analogue: the feeding devices acquire sticky and viscous liquids while remaining clean. We discovered that the external surface of the butterfly proboscis has a sharp boundary separating a hydrophilic drinking region and a hydrophobic non-drinking region. The structural arrangement of the proboscis provides the basis for the wetting dichotomy. Theoretical and experimental analyses show that fluid uptake is associated with enlargement of hydrophilic cuticular structures, the legulae, which link the two halves of the proboscis together. We also show that an elliptical proboscis produces a higher external meniscus than does a cylindrical proboscis of the same circumference. Fluid uptake is additionally facilitated in sap-feeding butterflies that have a proboscis with enlarged chemosensory structures forming a brush near the tip. This structural modification of the proboscis enables sap feeders to exploit films of liquid more efficiently. Structural changes along the proboscis, including increased legular width and presence of a brush-like tip, occur in a wide range of species, suggesting that a wetting dichotomy is widespread in the Lepidoptera.

Symbioses are major drivers in ecology and evolution. Although nearly omnipresent in flowing waters, they remain poorly studied in these systems. To examine fundamental aspects of the ecology of symbioses in flowing-water systems, we use larval black flies as hosts and various fungi, nematodes, and protists as symbiotes, focusing on aspects of distribution, diversity, and scale. Most symbiotes of larval black flies are considered parasitic, although the dynamic nature of the relationship is becoming apparent for some systems in which it shifts along a continuum involving commensalism, mutualism, and parasitism. Perspective also is moving from a pairwise view of symbiotic associations to a multispecies network of interactions. Distributions of symbiotes are related to scale-dependent processes that influence the hosts and the stream habitats of the hosts; thus, characteristics of streams, as well as hosts, can be useful in predicting spatial patterns of symbiotes. As the taxonomy of symbiotes improves, so too does the understanding of ecological relationships of symbiosis, such as host specificity and patterns of diversity along spatial and temporal scales.

The black soldier fly, Hermetia illucens L., was reared on a grain-based diet at 27, 30, and 36°C. Survival of 4- to 6-d-old larvae to adults averaged 74–97% at 27 and 30°C but was only 0.1% at 36°C. Flies required a mean of ≈4 d (11%) longer to complete larval and pupal development at 27°C than at 30°C. At 27 and 30°C, females weighed an average of 17–19% more than males but required an average of 0.6–0.8 d (3.0–4.3%) longer to complete larval development. At both temperatures, adult females lived an average of ≈3.5 d less than adult males. The duration of larval development was a significant predictor of adult longevity. Temperature differences of even 3°C produce significant fitness tradeoffs for males and females, influencing life history attributes and having practical applications for forensic entomology.

This study, the last in a series, examines empirical relationships between the community structure of larval black flies from Newfoundland's Avalon Peninsula (Canada) and stream conditions. The primary emphasis is on spring and summer Simulium species. Principal component and correlation analyses were used to assess correlative relationships between species distribution and stream site variables. Fifty-five stream sites were sampled between May and August of 1987, 1988, and 1989. The spatial distribution of species examined was nonrandom and correlated with stream size (Simulium caledonense Adler & Currie, S. craigi Adler & Currie, S. tuberosum Lundström cytospecies AB, Prosimulium mixtum Syme & Davies) and proximity to lake outlets (S. tuberosum Lundström cytospecies FGH, S. vittatum complex Zetterstedt, S. decorum Walker). S. craigi, S. tuberosum AB, S. tuberosum FGH, and S. aureum Fries cytospecies C are reported from Newfoundland for the first time. Because this is the first cytotaxonomic investigation of the S. tuberosum complex from Newfoundland, notes on the cytology of the two sibling species are presented.

Decomposition and insect colonization of rat, Rattus rattus L., carrion on land and in water were compared during summer and winter in a plowed field in northwestern South Carolina. During winter, carcasses on land reached the dried-remains stage of decomposition, whereas carcasses in water reached the early-floating stage. During summer, carcasses in both habitats entered the final-remains stage of decomposition in 1–2 wk. Fewer than 30 species of carrion insects were recorded from the carcasses over the duration of the study, probably reflecting the small size of the carcasses and the depauperate fauna of the habitat. Three species of blow flies—Cynomyopsis cadaverina (Robineau-Desvoidy), Calliphora vicina Robineau-Desvoidy, and Lucilia illustris (Meigen) — colonized carrion on land during winter, but no insects colonized carrion in water during winter. Two species of blow flies, Cochliomyia macellaria (F.) and Phaenicia sericata (Meigen), and 1 species of flesh fly, Sarcophaga bullata Parker, colonized the carrion on land and in water during summer; the blow fly, Phonnia reglna (Meigen), colonized only the carrion on land. This study demonstrated seasonal variation in decomposition and colonization patterns of carrion in contrasting habitats, with important implications for forensic entomology.

Behaviors associated with intraspecific encounters in Heliothis zea (Boddie) larvae are described, and paired contests in laboratory arenas are used to determine the effects of sex, instar, and molting on cannibalism. The frequency of eight behavioral responses (freezing, flicking, striking, recoiling, wriggling, moving away, rolling, and no response) differed significantly among intermolting larvae of the five instars. Among all instars, the most frequent (>35%) response to contact was a recoil. When contacted by their opponents, later instars struck more often than did earlier instars, whereas first and second instars moved away or ceased movement more often than did later instars. Molting larvae struck at their opponents significantly less often than did intermolting larvae, and generally displayed less maneuverability. Sex of the larvae had no significant effect on cannibalism. Among intermolting larvae, later instars were highly successful against earlier instars; no larva cannibalized a later instar. The greatest amount of time (up to 96 h between fifth instars) was required for a larva to cannibalize another of the same instar. Molting larvae were especially vulnerable to cannibalism, particularly when paired with an intermolting larva of a later instar. In extended contests, intermolting larvae occasionally cannibalized molting larvae of later instars. The results of this study suggest that cannibalism in H. zea can be predicted on the basis of instar and molting status.

The courtship and mating behavior of Eucelatoria bryani (Sabrosky), a larval parasitoid of Heliothis spp. and a potentially significant biological control agent, was examined. This laboratory study is the first quantitative study of courtship and mating behavior in the Tachinidae. A stereotypical sequence of behaviors was evident, although the number of behavioral repetitions was variable. Courtship began when a male flew and grasped a walking or flying female from behind. The remainder of courtship following this pair flight occurred on the substrate. The male courted while standing on the female dorsum and copulated with his body positioned behind that of the female. The most conspicuous part of courtship was the male waving his forelegs. Females rejected some copulatory attempts by bucking, although in all cases where a male grasped and held a female, copulation eventually occurred. Mating success depended on the ability of the male to grasp and hold the female.

Flight patterns of the Simulium vittatum complex (IIIL-1 and IS-7 sibling species) over a central Pennsylvania stream were studied with the aid of an adhesive trap (1.2 by 2.1 m), a Malaise trap, and naturally occurring spider webs. The combined use of the adhesive trap and Malaise trap provided the greatest capture efficiency. Females showed predominant (78.2%) upstream flight. One quarter of the females captured by the adhesive trap were within 7.5 cm above the water. Males were concentrated near the water and near the top of the adhesive trap. Spider webs captured more females near the surface of the water but more males higher above the water. Female S. vittatum (IIIL-1 sibling) had a 41.2% probability of escape from spider webs once captured, whereas males of this species had only a 19.4% escape probability.

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.

Of the known species of Neohaematopinus s. lat. (sensu Ferris 1951), the 3 genera Johnsonpthirus, Linognathoides and Neohaematopinus s. str. are recognized and redefined on the basis of nymphs and adults. Johnsonpthirus is a senior synonym of Alenapthirus. The adults and 3 nymphal instars of J. spinosissimus are redescribed and illustrated, and the lectotype of J. heliosciuri is designated. The inclusive species for each genus are listed with host and distribution

Feeding behavior of the corn earworm, Heliothis zea (Boddie). was studied by administering known quantities of sugar solutions (0. 6.25, 12.5, 25, and 50%) to restrained, unmated moths. Feeding rates decreased over time, within a feeding bout (for concentrations ≤12.5%) and from day to day. The rate of volume intake reached a maximum at 12.5%. although the rate of sucrose intake peaked at 50%. The kind of sugar (sucrose. fructose, or glucose) did not significantly affect feeding rate. At concentrations of 12.5 to 50%. Moths ingested more solution on the first day after emergence than on subsequent days; distilled water was taken only in minute quantities on the first day. A curvilinear relationship existed between sucrose intake and both fecundity and longevity. Sugar type did not significantly affect fecundity or longevity.

A behavioral time budget was constructed for larvae of Heliothis zea (Boddie) held at 26 ± 1°C from egg hatch through the final feeding bout of the ultimate instar. Within the confines of 31-ml cups with artificial diet, larvae spent the majority of time resting (41.5%), followed by molting (23.4%), feeding (23.3%), pivoting (i.e., grooming, depositing silk, sampling the environment, and miscellaneous activities; 11.4%), and moving (0.4%). Time allocated to each behavior varied within an instar, with larvae resting less and feeding more as they approached the molting period. The duration of molting increased with instar, reaching a maximum of ca. 17 h for the molt from penultimate to ultimate instar. There were no statistically significant differences in larval behavior between sexes. The complete time budget provides a baseline for assaying behavioral changes caused by environmental factors.

The words black fly might conjure up images of blood-sucking demons that “stick to their prey like bulldogs” and render their hapless victim “a frightful spectacle … bloody, and covered with punctures”—a view certainly shared by explorers who pioneered the North Country (Cabot in Agassiz 1850). The ability to evoke these images has been honed over evolutionary time by natural selection, producing some of life's most proficient phlebotomists and vectors of disease. The need for blood as a source of nutriment for the eggs has inflicted enormous economic losses on many facets of human activity, from forestry and agriculture to tourism and entertainment. Transmission of diseases, such as human onchocerciasis (or river blindness), mansonellosis, avian leucocytozoonosis, bovine onchocerciasis, and probably several arboviruses, continues to cause great human anguish and economic damage (Crosskey 1990).

Two species of black flies in the Prosimulium mixtum (IIIL-1) group are named and described. Prosimulium arvum sp. nov., previously known chromosomally as P. approximatum, is morphologically similar to P. fuscum and P. mysticum. P. transbrachium sp. nov. is most closely related to P. mixtum. The larva and its associated salivary gland chromosome preparation were designated as the type for each species in order to minimize ambiguity in future taxonomic work. The taxonomic problems of sibling species in Simuliidae are discussed and a procedure for standardizing the designation of type material is suggested.

Diurnal and nocturnal feeding patterns of Heliothis zea (Boddie) on pigeonpea nectar were studied in South Carolina. Feeding rhythms of males and females over time were statistically similar; feeding was most intense before and during sunset. Feeding on pigeonpea nectar was correlated positively with sugar concentration, nectar volume, total sugar, and ambient temperature, and inversely with relative humidity and percentage of flowers without reward. Nearly 17% of sugar feeding in pigeonpeas was on sap flows from buds damaged by larval feeding. Foraging patterns are considered adaptive in relation to reward, time available for mating, and breadth of diet.