Browsing by Author "Kosztarab, Michael"

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    The armored scale insects of Venezuela (Homoptera: Coccoidea: Diaspididae)
    D'Ascoli, Alfredo (Virginia Tech, 1971-04-05)
    Scale insects are among the most serious plant pests throughout the world. The Diaspididae is the largest scale insect family and probably the most important economically. No comprehensive taxonomic study dealing with the scale insects of Venezuela has been conducted in the past. Forty-nine species are described and illustrated in this study, of which 2 are new species. Twenty-seven additional species are recorded from Venezuela for the first time. Keys are provided for determination of the 49 species. The material studied was borrowed from several institutions. Mounting techniques are given. The description of each species is based on females, since males and nymphs were available only in a few species. While this is essentially a taxonomic and faunistic study, the hosts on which the scale insects were found are listed. It is hoped that this study would be used as basis for future research in Venezuela. More collections need to be made throughout the many ecologically different areas of the country; especially from non-cultivated plants. The accumulation of additional distributional and biological records, and will lead to a better understanding of the Venezuelan armored scale insect fauna.
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    A biosystematic revision of the Nearctic species of the mayfly genus Isonychia (Ephemeroptera: oligoneuriidae)
    Kondratieff, B. C. (Virginia Polytechnic Institute and State University, 1982)
    The Nearctic species of the genus Isonychia Eaton are revised. Eighteen species are recognized, of which three are described as new; eleven species names are placed in synonymy. Isonychia campestris McDunough is recognized as a fully valid geographically restricted species. Two subgenera, Isonychia sensu stricto and Prionoides Kondratieff and Voshell are recognized on the basis of adult and nymphal characteristics. Isonychia s.s. includes four species groups: bicolor group with four species, arida group with one species, sicca group containing five species, and diversa group with one species. The subgenus Prionoides includes seven species. A Neotype is designated for l. arida (Say). Previously undescribed characters of the nymphal gills are described and illustrated. The male genitalia and eggs are illustrated for every species. The distribution of each species is mapped. Diagnostic keys to male adults and nymphs are presented. A discussion of the nomenclatural history of the genus and each species is included. Diagnostic characters, rearing and collecting techniques are also discussed. The life histories and life cycles of two populations of Isonychia (Isonychia) bicolor (Walker) and one population of Isonychia (Prionoides) obscura Traver are presented in detail. Many features used in the past as specific criteria, especially in the bicolor and sicca Groups are found to be related to developmental periods of given populations involving geography, elevation, water temperature and stream size. The life cycle of I. bicolor is probably bivoltine at both sites. At the trout stream site there is a large-sized spring emerging generation and a much smaller summer emerging generation with considerable overlap. Isonychia obscura Traver is univoltine with adult emergence in mid-June and with egg diapause during the summer months. Additional life history information is also presented for I. (l.) tusculanensis Berner and I. (P.) serrata Traver. The evolution of the genus Isonychia and the two subgenera l. (Isonychia) and I. (Prionoides) is hypothesized. The North American biogeography of Isonychia may have included an invasion of North America via the "asiamerican" land mass of the Cretaceous. The early Isonychia mayflies may have been adapted to low order cool streams of high elevations. This lineage was probably similar to the subgenus Prionoides. Isonychia s.s. has been successful in colonizing the upper and lower austral zones and appears to be a warm water adapted group.
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    Biosystematics of the family dactylopiidae (Homoptera: Coccinea) with emphasis on the life cycle of dactylopius coccus costa
    Pérez Guerra, Gema (Virginia Tech, 1991-02-00)
    The cochineal insects include nine species assigned to the genus Dactylopius Costa, 1835, the only genus in the family Dactylopiidae. The present research is a comprehensive review of all the species in the family Dactylopiidae, with special emphasis on the life cycle of the type species Dactylopius coccus Costa. The adult females of the nine species have been redescribed and illustrated in detail, with a discussion on their morphological affinities and relationships. Their hosts, natural enemies, distribution, etymology, and role as biological control agents are discussed. For several species many new distribution and host records are given. Also, new types have been designated for some of the species. These included designation of one neotype and three paratypes for Dactylopius coccus Costa, one neotype for D. tomentosus (Lamarck), and designation of eight new topotypes for D. opuntiae (Cockerell). Methods are given on collecting, preservation and slide mounting, also on measurements and on preparation of illustrations. Cuticular ultrastructure is shown in scanning electron micrographs. All developmental stages of the type species D. coccus are described. The life cycles under two temperatures and relative humidities, for both males and females are discussed. Aspects of reproduction in D. coccus, its dispersal methods, factors affecting development, and its economic importance are also included. A separate chapter deals with the host-plants of Dactylopiidae. This includes data on host plant suitability and host plant resistance. Three identification keys are presented: one to the suborders of Homoptera, the other to the superfamilies and families of Coccinea, and another one for the determination of the species of Dactylopius. The phylogenetic relationships of the family Dactylopiidae with respect to all the Coccinea families is discussed. A phylogenetic tree for the Dactylopius species is proposed.
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    A contribution to the knowledge of the odonata
    Carle, Frank Louis (Virginia Tech, 1982-06-16)
    Theories concerning the origin of insect wings and flight are reviewed and a new scenario for their origin proposed. It is suggested that environmental conditions of the small stream were responsible for the evolution of insect flight, and that thermoregulation as well as respiration was important in the preadaptation of wings. The possibility that the five paired convex-concave vein systems each represented a dorsal-ventral blood channel is suggested. Odonate wing vein homology and nomenclatural systems, and phylogeny are reviewed. The process of vein loss is evaluated in the Palaeoptera and a new system of odonate wing vein homologies proposed. The odonate wing mechanism is analyzed and the heretofore overlooked discal nodus characterized. Reevaluation of the comparative morphology of fossil and recent Odonata indicates that Protozygoptera and Protanisoptera represent evolutionary side branches, that the Anisozygoptera is polyphyletic, and that Isophlebiidae and Calopterygoidea are the most generalized Odonata known. Previous scenarios explaining evolution of the unique odonate copulatory process are reviewed. Considering the copulatory behavior of the Calopterygoidea generalized supports evolutionary trends toward male domination and in-flight completion of the process. Assuming direct sperm transfer the original odonate mode requires that originally oviposition be in tandem and that sperm transfer to and from male anterior abdominal sterna be accidental. In contrast, assuming an original indirect transfer of sperm leads to a copulatory sequence similar to that of the Odonata. The proposed scenario differs from others in that extraordinary postures are not envisioned, the process is completed at rest, and the odonate tandem hold is developed prior to copulation. Anisopteran morphology and phylogeny are reviewed and reliable dentification keys developed for North American families and genera, and for 180 anisopteran species collected in Virginia and vicinity. Each species is described and photographed, including seven new species. The biogeography of Virginia Anisoptera is best explained by overlapping biotic regions, the fauna being a mixture of eastern North American, boreal, and tropical elements. New efficient methods for collecting, preserving, and rearing Odonata are described.
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    Contributions to the autecology and ecosystematics of immature ceratopogonidae (Diptera), with emphasis on the tribes heteromyiini and sphaeromiini in the middle atlantic United States
    Knausenberger, Walter Ingolf (Virginia Tech, 1986-12-05)
    Biological and systematic study of the immature stages of the biting midges (Diptera: Ceratopogonidae) has been infrequent, although the family is one of the largest in the order, with over 4,000 species worldwide, and is ubiquitous among aquatic/semiaquatic environments. An ecosystematic analysis is presented here of the Ceratopogonidae in Virginia and contiguous states based mainly on a diversified biological field survey, with particular attention to associating immature stages with adults, and acquisition of ecological data. I emphasized (a) extraction of larvae and pupae; (b) two methods of rearing, developed for this study: individual rearing(IR) with an agar-nematode technique, and collective rearing from the habitat substrate in rearing cartons(RC); and (c) field trapping of adults at the habitats. In Section I, a faunistic assessment - the first of its sort - is provided of the total Virginia-region ceratopogonid fauna, in all developmental stages, with a focus on Culicoides, including a comparative evaluation of the relative abundance of the ceratopogonid genera with respect to methods of collecting and extracting. High taxonomic richness of the ceratopogonid fauna in the Middle Atlantic states is reflected in the 150 described and 42 undescribed (new) species recovered. A detailed geographic checklist for the 222 species of Virginia and the five contiguous states is presented and interpreted. At least 54 Culicoides species are present in the Middle Atlantic u.s. About half of the larval species can be determined in Virginia. With the results of this study, 93% of breeding sites for the genus are known in Virginia, more than for any other state. Section II assembles and synopsizes data on the autecology, life history, habitat, morphology, systematics, as well as geographic and seasonal occurrence of 28 species (3 new) and 10 genera in two related tribes of predaceous biting midges, Heteromyiini and Sphaeromiini (subfamily Ceratopogoninae). Shorelines are the "archetypical arena" in which these larvae thrive, typically above and below the water line. Their habitats and substrates are characterized in detail. The greatest diversity of larvae in these tribes consistently occurs in and along mid-reach streams{Order: 3 to 5). Mechanisms of ecological partitioning by sympatric species, and the differential adaptive significance of larval, pupal and adult morphological characters are evaluated. Taxonomic and ecological diversity in these groups are clearly related.
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    Euonymus scale, Unaspis euonymi (Comstock): host preference, and distribution of native and imported natural enemies in Virginia
    Jefferson, David Kirk (Virginia Tech, 1994-04-05)
    Studies were conducted in 1992 and 1993 to determine which of six Euonymus species and cultivars would sustain the highest populations of Unaspis euonymi (Comstock), as a food source for Chilocorus kuwanae (Silvestri). Analysis of data collected from field-grown plants and container-grown plants indicates that Euonymus japonicus (Thunb.) 'Albo-marginatus' would sustain the highest populations of U. euonymi. In 1992 and 1993, surveys were conducted to determine the presence of existing natural enemies in Virginia as well as to determine the establishment of the imported predator, Chilocarus kuwanae. In 1992, C. kuwanae and parasites from the genera Aspidiatiphagus and Encarsia was found at several locations in Virginia Beach. In 1993, C. kuvanae was recovered in seven of the twelve Virginia counties surveyed. Either Aspidiotiphagus or Encarsia were found in nine of the twelve counties. A single specimen of Cybocephalus sp. was recovered from a sample taken in Fredericksburg.
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    Interactions between the rust fungus Puccinia carduorum Jacky and the musk thistle herbivores Trichosirocalus horridus (Panzer), Rhinocyllus conicus Froelich (Curculionidae: Coleoptera), and Cassida rubiginosa Muller (Coleoptera; Chrysomelidae)
    Abad, Reynaldo Gallego (Virginia Tech, 1990-12-01)
    The compatibility of the rust fungus Puccinia carduorum Jacky with three biological control agents, Trichosirocalus horridus (Panzer), rhinocvllus conicus Froelich, and Cassida rubiginosa Müller and their combined impact on must thistle, Carduus thoermeri Weinmann were studied.
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    The macrobenthos of a new reservoir, Lake Anna, Louisa County, Virginia
    Voshell, J. Reese Jr. (Virginia Polytechnic Institute and State University, 1976)
    The macrobenthos of a new reservoir in central Virginia, Lake Anna, was studied for the first three years after impoundment, 1972-1975. Prior to this, extensive macrobenthic collections had been made in the river destined for impoundment, the North Anna River. The biota of this river had been seriously affected by acid mine drainage for over 100 years. Macrobenthos consists of the organisms living on the bottom or the solid-liquid interface. The occurrence of these organisms is significant, because they are major items in the diet of many fish, and are thus important in the flow of energy through an ecosystem. The basic objectives of this study were to determine the changes in macrobenthic community structure brought about by impoundment, and then to observe the successional changes which occurred in the following years. This information was then compared to a hypothetical model predicting the productivity of new reservoirs. It was discovered that traditional grab sampling was not reliable in new reservoirs because of the abundant submerged terrestrial vegetation. An original sampling method was developed which involved the use of SCUBA to place and retrieve artificial substrate samplers. This SCUBA method was compared to grab sampling, and found to more reliably estimate macrobenthic community structure. Following impoundment, there was an immediate change in macrobenthic community structure. Colonization of the new reservoir occurred very quickly, especially during the first summer period. The acid mine drainage did not affect the distribution of macrobenthos in the new reservoir, probably because of dilution. Identification of over 525,000 organisms revealed that they could be classified into three groups: first colonizers, omnipresent species, and second colonizers. A review of the food habits of these organisms indicated that there were four trophic functional groups: micropredators, macropredators, collector-microgatherers, and collector-microfilterers. The first colonizers consisted of three species, one of which was completely dominant in each of the first three functional groups the first year. The second colonizers consisted of many additional species, several of which shared dominance in each of the same three functional groups the second and third years. The omnipresent group consisted of midge larvae which were dominant in the fourth functional group, collector-microfilterers, in all three years. This information, in conjunction with analysis of the horizontal, vertical, and temporal distribution, indicated that the development of macrobenthic community structure in Lake Anna followed the general trends expected in ecological succession. These trends are increased number of species, increased equitability of species composition, and better organization of distribution. A comparison of the development of macrobenthos in new reservoirs with a model of expected productivity indicated that the abundance of macrobenthos. may also exhibit the same trends as productivity. These trends are an initial increase in productivity for several years, followed by a sharp decline for several years, to be finally followed by a small increase and stabilization. This sequence of events probably requires at least 15 years for macrobenthos.
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    A morphological and systematic study of the first and second instars of the Kermesidae in the Nearctic region (Homoptera: Coccoidea)
    Baer, Ronald G. (Virginia Tech, 1978-08-01)
    The Cocco idea or scale insects are among the most important pests of sylvicultural, ornamental, agricultural and greenhouse plantings throughout the world. There are 21 families comprising 6,000 species. Direct injury occurs from the withdrawal of sap while feeding and from the production of galls. Some scale insects are host specific while others are polyphagous. They feed on many different parts of plants including the roots, trunk, stems, leaves, buds and fruit.
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    Morphology and taxonomy of the first instars of the genus Cerococcus Comstock (Homoptera:Coccoidea:Cerococcidae)
    Hamon, Avas B. (Virginia Tech, 1976-09-15)
    The taxonomy of species in the genus Cerococcus has been unstable and adequate keys and descriptions have not been available for identification. This detailed study of the first instars is one step in the revision of the genus and reevaluation of the taxa which have been referred to the genus. The first instars of 31 species of Cerococcus are included in this study. Each species studied is fully described, including measurements of morphological characters, and illustrated. Cerococcus first instars were found to have well developed legs; well developed mouthparts with a 3-segmented labium; 6-segmented antennae; 2 pairs of spiracles with associated quinquelocular pores; acornshaped spiracular setae or regular setae-shaped spiracular setae; well developed anal lobes which are armed with spines on the inner margin and terminated by long apical setae; large conspicuous dorsal B-shaped pores in longitudinal rows; dorsal trapezoid-shaped anal plate; and 6 setae on the anal ring. The classification of Cerococcus first instars generally agreed with the classification of the adult females, and keys are provided for separation of the first instars studied. Species of the genus Cerococcus were found to be morphologically distinct from the species in the genera Asterococcus and Solenophora. It appears that the genus Cerococcus is only distantly related to the genera in the families Asterolecaniidae, Eriococcidae, and Lecanodiaspidiae.
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    Revision of the tribe Serrolecaniini Shinji (Pseudococcidae) with discussion on other "legless" mealybugs
    Hendricks, Harlan Judson (Virginia Tech, 1993-12-05)
    Of the estimated 1100 species of mealybugs, approximately 6% are described as possessing degenerative legs and antennae in the adult female developmental stage or having lost these structures altogether. Fifteen genera composing 63 species are often separated into their own taxonomic group based on these vestigial features (e.g., Sphaerococcinae), and are collectively known as the "legless" mealybugs. A comparative morphological analysis of adult females was undertaken to clarify the taxonomic placement of these species and to determine their relationships. Methods were included on collecting, preserving, slide-mounting, and measuring specimens, and on preparing illustrations. Keys to genera and species of "legless" mealybugs were developed. Reduction or loss of legs and antennae apparently occurred convergently in response to similar environmental conditions and was not found supportive of homogeneity in the "legless" group as a whole. However, the genera Chaetococcus Maskell, Idiococcus Takahashi & Kanda, Kermicus Newstead, Serrolecanium Shinji, Tangicoccus Kozar & Walter, and a newly established genus share many characteristics and were treated as the tribe Serrolecaniini Shinji. The adult females of 13 species contained in these genera were redescribed, with illustrations produced for 12. A phylogenetic analysis of the tribe showed that converse to simplification in appendages, adaptations in other features (e.g., latero-projecting lobes and a caudally-directed vulva) probably developed to increase reproductive success and survivorship. The genera Acinococcus Williams, Antonina Signoret, Antoninoides Ferris, Cypericoccus Williams, Nesticoccus Tang, Paludicoccus Ferris, Parapaludicoccus Mamet, Peridiococcus Williams, Pseudantonina Green, and Sphaerococcus Maskell are not closely related to one another or to members of the tribe Serrolecaniini based on adult female morphology. These 10 genera and their type species were redescribed, and illustrations produced for all but Nesticoccus sinensis Tang. Comments or redescriptions are provided for the 21 additional species that comprise these genera; however, the taxonomic placement of 18 additional species erroneously assigned to Pseudantonina and Sphaerococcus is uncertain. Lectotypes were designated for Antonina crawi Cockerell, A. graminis Parrott, A. phragmitis Marchal, A. purpurea Signoret, A. waterstoni Newstead, Jdiococcus bambusae Takahashi & Kanda, Pseudantonina bambusae Green, Pseudolecanium disticlium Kuwana, and Sphaerococcus ethelae Fuller. A replacement name was proposed for the junior homonym Antoninella Sulc. The species names Antonina anceps Green, Antonina maritima Green, and Jdiococcus maanshanensis Tang & Wu are considered junior synonyms. Two species of Serrolecanium were described, and a new genus was established for the placement of Serrolecanium jiuhuaensis Wu and Serrolecanium sasae (Siraiwa). Six new name combinations are also made.
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    Spiders of alfalfa with notes on the biology of Tetragnatha laboriosa Hentz
    Howell, James O. (Virginia Tech, 1969-04-05)
    Several areas of the bionomics of spiders of alfalfa in Virginia were given preliminary investigation. The species complex of the spider fauna was determined and the seasonal occurrence of the four major species were plotted. The D-Vac sampler and the sweep net were the major sampling methods utilized. Fourteen families consisting of 75 genera and 112 identifiable species were found. Tetragnatha laboriosa Hentz, Pachygnatha tristriata Koch, Misumenops asperatus (Hentz) and Oxyopes salticus Hentz were the most common species found.
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    Studies on the morphology and systematics of scale insects. No. 12
    Bullington, Stephen W.; Kosztarab, Michael; Baer, Ronald G. (Virginia Agricultural Experiment Station, 1985)
    The family Kermesidae in North America is revised for the first time, based on slide-mounted, newly-molted young adult females. Fifteen species are redescribed, four are synonymized, and four are described as new. A literature review is given for these and 14 other species for which slide-mounted specimens were not available. Two new genera, Allokermes and Nanokermes, are proposed and described, and with the genera Kermes and 01/iffiella a re placed in the family Kermesidae. The third instar of one species in each genus is described and illustrated. Keys are given to the genera, based on both third instar females and newly-molted adult females, and to the species in each genus. Known host plants and geographical distribution records are listed for each species. The brood chamber of Allokermes rattani Ehrhorn is described and illustrated, and the mechanism for the escape of the first instars from the brood chamber is illustrated. Using Hennig's (1965) method, the phylogenetic inter-relationships among the genera are determined.
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    Studies on the morphology and systematics of scale insects. No. 13, An annotated list of generic names of the scale insects (Homoptera : Coccoidea), third supplement
    Kosztarab, Michael; Ben-Dov, Yair; Kosztarab, Matilda P. (Virginia Agricultural Experiment Station, 1986)
    When Morrison and Morrison (1966) published "An annotated list of generic names of scale insects (Homoptera: Coccoidea)" they introduced a valuable reference book which proved useful to workers in systematics of the group. Subsequent issues of the first (Russell, 1970) and second (Kosztarab and Russell, 1974) supplements are obvious indications of the need among coccidologists for a continuation in publishing such compilations. This third supplement lists 106 names. These were described between December 31, 1972, the cutoff date of the second supplement, and December 31, 1985, with one exception, Oregmopyga.
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    Studies on the morphology and systematics of scale insects. No. 14, A selected bibliography of the Coccoidea (Homoptera), third supplement (1970-1985)
    Kosztarab, Michael; Kosztarab, Matilda P. (Virginia Agricultural Experiment Station, 1988)
    The Third Supplement to "A Selected Bibliography of the Coccoidea" cites the important literature on the classification of coccoids that appeared between January 1, 1970, the cutoff date of the Second Supplement (United States Department of Agriculture Miscellaneous Publication 1281, 1974), and December 31, 1985. In addition, it includes numerous earlier articles that were omitted from the previous bibliographies but that are now available and appear to be relevant. Letters following dates are a continuation from earlier bibliographies where they are needed to insure the continuity of the citation system and the sequence of publication. Where the date of publication differs from that on the title page of the volume containing the article, the latter date is shown in parenthesis before the volume number of the serial. This Supplement contains about 2400 entries and more than 850 author cross-references to assist users in finding articles by other than the first author. The general format and scope of this supplement, with few exceptions, is similar to the earlier bibliographies as outlined in the introduction of the original bibliography (United States Department of Agriculture Miscellaneous Publication 734, 1957)...
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    Studies on the morphology and systematics of scale insects. No. 15
    Liu, Tong-Xian; Kosztarab, Michael; Rhoades, Mary; Bullington, Stephen W.; Jiang, Guang-Zao (Virginia Agricultural Experiment Station, 1989-06)
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    Studies on the morphology and systematics of scale insects. No. 16, Biosystematics of the family Dactylopiidae (Homoptera Coccinea) with emphasis on the life cycle of Dactylopius coccus Costa
    Perez Guerra, Gema; Kosztarab, Michael (Virginia Agricultural Experiment Station, 1992-03)
    The cochineal insects include nine species assigned to the genus Dactylopius, the only genus in the family Dactylopiidae. This is a review of all the species in the family Dactylopiidae, with special emphasis on the life cycle of the type species Dactylopius coccus Costa. The adult females of the nine species have been redescribed and illustrated, with a discussion on their morphological affinities and relationships. Their hosts, natural enemies, distribution, etymology, and role as biological control agents are discussed. For several species many new distribution and host records are given. Also, new types have been designated for the following species: one neotype and three paratypes for Dactylopius coccus Costa; one neotype for D. tomentosus (Lamarck); and designation of eight new topotypes for D. opuntiae (Cockerell). Methods are given on collecting, preservation, slide mounting, measuring, and preparing illustrations. Cuticular ultrastructure is shown in scanning electron micrographs. All developmental stages of the type species, D. coccus, are described. The life cycles under two temperatures and two relative humidities, for both males and females, are discussed. Aspects of reproduction in D. coccus, its dispersal methods, factors affecting development, and its economic importance are also included. A separate chapter deals with the host-plants of Dactylopiidae. This chapter includes data on host plant suitability and host plant resistance. Three identification keys are presented: one to the suborders of Homoptera, the other to the superfamilies and families of Coccinea, and another one for the determination of the species of Dactylopius. The phylogenetic relationships of the family Dactylopiidae with respect to all the Coccinea families are discussed, and a phylogenetic tree for the Dactylopius species is proposed.
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    The Virginia Tech Entomologist
    (Virginia Tech. Department of Entomology, 2009)
    This book, published in 2009, commemorated the 50 year anniversary of the Department of Entomology.