George Ball, longtime Professor of Entomology at the University of Alberta, has retired. This does not mean that his contributions to entomology will cease; in fact, this academic earthquake will surely unleash a new tidal wave of excellent systematic work about ground-beetles. Nevertheless, many of George's friends, colleagues, and former students gathered in Edmonton on 6 November 1992 to participate in an entomological symposium entitled “Ball's Circle: a merry go 'round of systematics” to mark this occasion and to celebrate George's outstanding record of achievement as an entomologist and university teacher. We begin the proceedings with some rather personal reflections about George.

A phylogenetic hypothesis of relationships among the species of the broad-nosed weevil genus Panscopus Schönherr indicates sister-taxon relationships between pairs of species, and pairs of ancestral lineages, which today exhibit disjunctions between their geographical distributions. The range disjunctions in these sister lineages appear to correlate with known geological or palaeoecological events. These correlates suggest dates of later Eocene to Miocene for some branching points in the phylogeny. These observations are consistent with the hypothesis that one or more ancestral form(s) of Panscopus were extant by the Eocene or earlier, and that most of the cladogenesis in the history of this genus occurred likely in middle to late Tertiary times. These hypotheses, in turn, suggest that adelognathan weevils must be a much older group than the oldest known representative fossils would suggest (Eocene), and that they likely arose during the Mesozoic.

The issue of biodiversity is examined from the viewpoint of human values and three questions are posed: What kinds of human values affect biological diversity? Why do humans think about the loss and conservation of biological diversity? Does it really matter? The conclusion is that human values are contributing to the loss of biological diversity and could lead to massive extinctions in the future just as major natural events did in the past. However, as it did in the past, evolution will continue, so will speciation, and so will biological diversity.

The structure of the parameres (lateral lobes) of aleocharine aedeagi was examined in detail, with special attention to the basal lineages. Paramere structure was compared in the context of a hypothesis of phylogeny of the basal lineages of the Aleocharinae and the Tachyporine Group of subfamilies. The ancestor of all contemporary aleocharines had parameres with the following characteristics: dorsobasal and ventrobasal lobes of more similar size than in extant higher aleocharines; dorsobasal lobe (condylite) continuous with distal lobe (not articulated); a striated velum (velar sac), extended from near the base of the dorsobasal lobe to near the apex of the distal lobe and derived from the dorsal surface of the distal lobe; distal arm entire, without articulations or independently movable parts; and four apical setae on the distal lobe, probably with the most apical and basal ones directed mediad and the two medial ones directed more-or-less laterad. In addition, each paramere was articulated with a separate condyle of the median lobe of the aedeagus near the middle of the condylite of the paramere, and the apices of the dorsobasal lobes of the two parameres articulated with each other substantially distal to the articulation with the median lobe of the aedeagus. The most parsimonious resolution of paramere evolution suggests that aleocharine parameres were derived from structures similar to those found in Trichophyinae, Phloeocharinae, and Olisthaerinae and that they are not de novo structures. Hypotheses about homologous regions between aleocharine parameres and those of these latter three groups are suggested.

Adults and larvae of Eustilicus relictus sp.nov. are described from the Edwards Plateau of Texas. The species is brachypterous and lives in deep leaf litter. Morphological characters of both stages indicate that E. relictus belongs in its own group and has a near-basal phylogenetic position in the genus. I infer that the group to which E. relictus belongs was in the United States before formation of the dry belt which currently separates mesic areas of the United States and Mexico. All other species of Eustilicus in the United States belong to younger groups that spread north from Mexico much later.

Larvae of the Australian fossorial carabid Carenum anthracinum Macleay are described from reared material and compared with the reared larva of C. elegans Macleay and eight different unassociated larval types belonging to the complex. These larvae exhibit an extraordinary range of character states indicating clearly that their placement in the tribe Scaritini cannot be retained. An examination of adult characters and, in particular, the fore tibial dentition confirms that Carenum and allied genera form a separate tribe, the Carenini, which appears to be a sister group of the remaining Scaritini (including Clivinina).

Based on external and internal structural features of larvae and adults, the phylogeny of Trictenotomidae, Salpingidae, Pythidae, Boridae, Tydessa Peacock (included previously in Pilipalpinae), Pilipalpinae, Pyrochroinae, and Pedilinae is reconstructed as: (Trictenotomidae + Salpingidae + Pythidae) + (Boridae + {Tydessa + [Pilipalpinae + (Pyrochroinae + Pedilinae)]}). The genus Tydessa is placed in its own monobasic subfamily, Tydessinae. Both Tydessinae and Pilipalpinae are included in Pyrochroidae, along with Pyrochroinae, Pedilinae, and possibly Cononotus and Agnathus. A historical account of the classification of Pilipalpinae is presented, along with a revised subfamilial classification of Pyrochroidae and Pythidae.

Eversible sacs (= "scent organs" or "eversible tubes" or "eversible glands" of previous authors) are present in the abdomens of females of species of Stenoxenus Coquillett, Paryphoconus Enderlein, Clastrieromyia Spinelli and Grogan, Bezzia Kieffer, Phaenobezzia Haeselbarth, Amerohelea Grogan and Wirth, Pachyhelea Wirth, and Palpomyia Meigen. In Bezzia varicolor (Coquillett) they are attached by muscles to dorsal internal tergal apodemes. When retracted, the sacs lie along the length of the apodemes. Suggested functions of the eversible sacs have ranged from roles in mating, mimicry of adult mayfly cerci to enhance predation, to glandular. However, histological examination showed no evidence of glandular tissue associated with the sacs, so a glandular function is discounted. We suggest other possible functions.

A brief biography of a little-known Hanoverian entomologist, Johann Dietrich Herschel (1755–1827), is given. The more important events of his life, his entomological interests, and his relationships to other entomologists are covered. Included is a table of the species of beetles known to have been described from his collection by several entomologists of the late-18th and early-19th centuries.

A group of subarboreal tropical beetles, the Xystosomi of subtribe Xystosomina new subtribe, is revised and reclassified based on a reevaluation of structural characters. Xystosomi are found in tropical Australia (Queensland) and tropical/subtropical America (Guerrero, México, to Aguas Blancas, Argentina). The largest concentration of species occurs near the equator in the Amazon Basin, but a significant radiation of flightless forms was recently discovered in the northern Andes of Colombia, Ecuador, and Venezuela. Xystosomina also includes the Mioptachyi, which at present is composed of the genera Mioptachys and Inpa.Seventy-six species of Neotropical and Australian Xystosomi are described or re-described, illustrated, or keyed. This assemblage includes 12 classic species, 24 species described in the last 3 decades, and 40 new species, a 6-fold increase since the time of Henry Walter Bates, the last 19th-century entomologist to study this remarkable lineage of carabid beetles. The Xystosomi are now arrayed in five genera: Philipis gen.nov. (type: Tachys trunci Darlington, Australia), Geballusa gen.nov. (type: Xystosomus microtretus Erwin, Costa Rica), Gouleta gen.nov. (type: Bembidion cayennense Dejean, Brazil), Batesiana gen.nov. (type: Xystosomus gruti Bates, Brazil), and Xystosomus Schaum (type: Xystosomus inflatus Schaum, Brazil).The following specific taxa are described as new (type-locality in parentheses): Geballusa rex (Brazil: 06°02′N 050°17′W), oligotreta (Panamá: 08°40′N 079°56′W), nannotreta (Brazil: 02°54′S 059°57′W), Gouleta gentryi (Perú: 12°50′S 069°20′W), Batesiana para (Brazil: 01°22′S 048°20′W), angustia (Perú: 05°08′S 074°45′W), samiria (Perú: 05°08′S 074°45′W), esheje (Perú: 05°08′S 074°45′W), crassa (Perú: 03°15′S 072°55′W), notesheje (Perú: 03°15′S 072°55′W), manusculptilis (Perú: 12°07′S 070°58′W), parapara (Brazil: 02°28′S 046°26′W), am (Perú: 05°08′S 074°45′W), indetecticostis (Ecuador: 00°57′S 077°48′W), nox (Ecuador: 00°57′S 077°48′W), parkeri (Perú: 03°15′S 072°55′W), hamatilis (Ecuador: 01°02′S 077°40′W), notparkeri (Colombia: 00°08′N 075°51′W), pfunorum (Perú: 03°15′S 072°55′W), quadrata (Perú: 03°15′S 072°55′W), protosculptilis (Perú: 12°50′S 069°20′W), misahualli (Ecuador: 01°02′S 077°40′W), depressisculptilis (Ecuador: 01°02′S 077°40′W), irisculptilis (Ecuador: 00°24′S 076°37′W), foveosculptilis (Brazil: 02°28′S 046°26′W), punctisculptilis (Perú: 03°15′S 072°55′W), eugeneae (Perú: 11°56′47″S 071°17′00″W), anchicaya (Colombia: 03°43′N 076°57′W), jefe (Panamá: 09°12′N 079°21′W), exigupunctata (Perú: 05°08′S 074°45′W), rosebudae (Ecuador: 00°57′S 077°48′W), equanegrei (Ecuador: 00°57′S 077°48′W), henryi (Ecuador: 00°28′S 077°53′W), baeza (Ecuador: 00°57′S 077°48′W), huacamayas (Ecuador: 00°28′S 077°53′W), dannyi (Ecuador: 00°57′S 077°48′W), alticola (Colombia: 04°21′S 074°22′W), jacupiranga (Brazil: 24°42′S 048°00′W), chiriboga (Ecuador: 00°15′S 078°44′W), wygo (Colombia: 04°53′N 074°31′W).The following names are resurrected from synonymy for good species: hilaris Bates and belti Bates. Several name combinations were changed as a result of the generic reorganization: Philipis trunci (Darlington), Geballusa microtreta (Erwin), G. polytreta (Erwin), Gouleta notiophiloides (Erwin), G. spangleri (Erwin), G. cayennense (Dejean), Batesiana bisulcifrons (Erwin), B. negrei (Erwin), B. hilaris (Bates), B. belti (Bates), B. ampliata (Bates), B. strigosa (Bates), B. gruti (Bates), B. nigripalpis (Erwin), B. villiersi (Perrault), B. apicisulcata (Erwin), B. iris (Erwin), B. sculpticollis (Bates), B. sulcicostis (Bates), B. anterocostis (Erwin), B. ovatula (Bates), B. grossipunctata (Erwin), B. batesi (Erwin), B. seriata (Erwin), B. sublaevis (Bates), B. aetholia (Erwin), B. parainsularis (Erwin), NEW COMBINATIONS.Results of the Xystosomi character analysis provided impetus for a reanalysis of the classification of the major lineages of the more inclusive group, Bembidiini, to discover where the Xystosomi might belong and, in turn, if our understanding of the Bembidiini itself needed adjustment. These results are implied in Part I, but presented in detail in a separate paper, Part II. Phylogeny and Zoogeography, along with supplemental taxonomic information.

In Rhysodini the greatly enlarged mentum forms the entering edge as the beetle wedge-pushes its way through wood. The mandibles cannot bite either wood fibers or food items, but function as a cover for the other mouthparts. The palpi are completely retractile. Each maxilla bears two stylets, the galea and lacinia, and the ligula consists of two bilobed structures. These are apparently the sole feeding structures enabling the beetles to prey on the amoeboid stage of slime molds. The large internal cavity of the head is interpreted as a compromise between a greatly reduced head volume, resulting from reduced jaw musculature, and the need to retain the surface of a full-sized head as part of the wedge-pushing apparatus.

Metamasius callizona (Chevrolat), a previously obscure weevil species known from Mexico, Guatemala, and Panama, was discovered in Florida (USA) in 1989. In Mexico and Florida its larvae mine meristemmatic tissue and flower-stalks of epiphytic Tillandsia bromeliads, which they kill. In Florida, populations of Tillandsia utriculata L. are being decimated; the weevils also mine and kill introduced ornamental bromeliads of 12 other genera, including Ananas. Fruits of Ananas comosus (L.) (pineapple) are destroyed. Where they occur in southern Florida, populations of the weevil are now much greater than could be found in Mexico in July 1992. In Florida, M. callizona seems to breed throughout the year. Females deposit eggs singly into slits cut in leaf bases of the host-plants. Fully grown larvae pupate in a fibrous cocoon, and development time from oviposition to adult is approximately 11 weeks in the laboratory. No insect parasitoids of the weevil have been found, but Beauveria bassiana (Balsamo) was found as a pathogen in Mexico.

The various characteristics used to describe Forcipatorina and to fix its limits with Clivinina are analyzed and checked against the different genera concerned. New definitions for the subtribes and a key to the genera included in Forcipatorina are given. It is shown that the genus Stratiotes Putzey s is heterogenous and must be divided into several genera, two of which are described as new: Kultianella and Whiteheadiana.

Species richness and relative abundance of arthropod taxa from an Upper Cretaceous (Campanian: 75 Mya) amber deposit in Alberta are described. About 130 hexapod species have been recognized to date from this deposit, making it the most diverse Cretaceous insect assemblage so far known. Taxa present, in order of abundance, are Hemiptera (66 specimens per kg), Diptera (28), Acari (21), Hymenoptera (13), Aranaea (12), Psocoptera (4), Coleoptera (2), Blattodea (1), Thysanoptera (1), and Trichoptera (0.6). Representatives of Lepidoptera, Collembola, Dermaptera, Mantodea, Phasmatodea, and Ephemeropteraare are also present. In the total of 65 identified families, 15 are extinct. Only one of about 77 genera identified in this deposit is extant. All recognized species are extinct. In comparison, virtually all families reported from Baltic and Dominican Republic ambers are extant, as are the majority of the genera. Morphology and feeding structures are well within the variation seen in modern insects. It is hypothesized that the taxonomic structure of modern insect communities was well established before the end of the Cretaceous and that the structure and interrelationships of insect guilds were also very similar to those of today.

A new species, Platydipteron balli (type locality near San José, Costa Rica), and first male specimens of Platydipteron are described. Based on these specimens, the genus is transferred from the Aenigmatiinae to the Metopininae. Male terminalia of Postoptica platypezoidea are described, and the genus is placed in the subfamily Phorinae.

The spatial and temporal distribution of microsympatric species of marsh-inhabiting Agonum were investigated in central Alberta. Agonum nigriceps LeC., A. ferruginosum Dej., A. thoreyi Dej., and A. lutulentum (LeC.) were the most abundant carabid species in the emergent vegetation of the flooded zone. Agonum nigriceps was segregated from the other species through habitat use, being most abundant in emergent sedge tussocks. Agonum ferruginosum was most abundant in floating cattail mats, whereas A. thoreyi was rather evenly distributed across macrohabitats. Within flooded macrohabitats both A. ferruginosum and A. thoreyi predominantly occupied microsites with emergent substrate or clumps of dead vegetation. In one marsh where A. ferruginosum co-occurred with A. lutulentum, their macrohabitat distributions were mutually exclusive. Reproduction began earlier and teneral adults emerged earlier for both A. nigriceps and A. ferruginosum than for A. thoreyi. Agonum nigriceps, A. ferruginosum, and A. thoreyi were all nocturnal and showed no differences in daily activity pattern. In laboratory experiments, adults of A. nigriceps displayed the highest propensity to climb on narrow vertical structures, a behavior correlated with their main habitat association with structurally simple emergent sedge habitat. Adults of A. nigriceps are cryptically colored to blend into their habitat background.

Tenthredo retura Ross is here placed in synonymy under T. maxima (Norton) as the subspecies T. maxima retura Ross (syn.nov., stat.nov.). The range of T. maxima is associated with montane meadows or semi-open forest habitats in the montane zone of the Rockies, the Cascades, and the Sierra Nevada. Following the analysis of 24 characters from 2405 specimens, we recognized 12 geographically distinct populations, clustered into two subspecies, T. m. maxima and T. m. retura. Originally included in the originalis group of the genus Tenthredo, T. maxima is characterized as a group of its own with no close relatives in North America. We describe the species and its subspecies, give their distribution, discuss their geographical variation, and attempt to reconstruct their zoogeographical history during the Pleistocene.

Nine species of Ceromya Robineau-Desvoidy (Diptera: Tachinidae: Siphonini) are recognized in the Nearctic region, including four new species, and one described species known previously only from the Palearctic region. The species are arranged into three species groups, with each group hypothesized to be monophyletic and each containing extralimital members. The three species groups and nine Nearctic species are as follows: the bicolor-group with C. bicolor (Meigen) (a Holarctic species newly recorded from the Nearctic region); the flaviseta-group with C. Ontario (Curran) and C. palloris (Coquillett); and the americana-group with C. americana (Townsend), C. balli sp.nov. (type-locality Masham Township, Quebec, Canada), C. elyii (Walton), C. flava sp.nov. (type-locality Masham Township, Quebec, Canada), C. oriens sp.nov. (type-locality Masham Township, Quebec, Canada), and C. occidentalis sp.nov. (type-locality Lakelse Lake, British Columbia, Canada). The bicolor-group has an Old World – Nearctic distribution, the flaviseta-group has an European–Nearctic distribution, and the americana-group has a Neotropical–Nearctic distribution. Adults of the nine Nearctic species of Ceromya are keyed and described, known hosts are listed (including corrections to published records), distributions are mapped, and taxonomically useful features are illustrated.

I review reports on the genetic basis for species differences in the Lepidoptera. In the six best-studied species complexes, more than half of all ecological, behavioral, or physiological differences among species are controlled by X-linked genes. Because Lepidoptera have about 30 pairs of chromosomes, this finding clearly indicates strong bias toward X-linkage of genes for species differences. The proportion of X-linked species differences ranges from complete X-linkage in Colias butterflies, to almost none in Yponomeuta moths. Four other complexes all have at least one X-linked gene that is crucial to species differences, including the Choristoneura fumiferana Clemens, Papilio glaucus L., and Papilio machaon L. species groups, and Ostrinia nubilalis Hübner pheromone strains. The mechanisms that account for this phenomenon are open to speculation. Nonetheless, an interesting implication of disproportionate X-linkage is that reproductive isolation may frequently arise by selection on linkage complexes, rather than as a random byproduct of evolution in geographically isolated populations. If confirmed, the bias toward X-linked species differences may also help efforts to find characters that distinguish host races and sibling species, as well as provide an avenue by which genes crucial to speciation can be more easily mapped and characterized at the molecular level.

The naturally occurring weevil (Curculionidae) fauna of Dade and Monroe counties in southern Florida is composed of 100 genera and 222 species. Another 20 species are adventive; their presence is due to the unintentional action of humans. Twenty-eight species occur only on the islands of the Florida Keys, 118 species occur only on mainland south Florida, and 76 species are shared by the mainland and the islands. Greater habitat diversity on the mainland accounts for its higher species diversity. The species distributions and faunal affinities are 60% Nearctic and 40% Neotropical or West Indian. Thirty-five species are known to occur only in southern Florida. This probably reflects poor knowledge of their distribution in the Caribbean rather than southern Florida as an important site for species origin. Most of the weevil species (133; 60%) are habitat specific and few species (22; 10%) are found in three or more habitat types. Wetland-inhabiting species are predominant (76; 34%), followed by hardwood hammock species (47; 21%). Flightlessness in adults is uncommon (35 species; 16%), but more prevalent in the species endemic to southern Florida (12 species; 34%). Extrapolation from data on weevil diversity yields a conservative estimate of over 5000 species of insects in southern Florida.