Francis Howarth - Academia.edu (original) (raw)

Papers by Francis Howarth

EYELESS, PALE, GHOSTLIKE OBLIGATE cave species (troglobites) have long intrigued evolutionary bio... more EYELESS, PALE, GHOSTLIKE OBLIGATE cave species (troglobites) have long intrigued evolutionary biologists and laymen, and many theories on their evolution have been proposed (Barr 1968, Culver 1982, 1986, Howarth 1988a). Howarth (1983a) and Huppop (1986) postulated that some of the physiological adaptations displayed by cave animals (e.g., their low metabolic rate) might be in response to selection to cope with high levels of carbon dioxide theoretically possible in their environment. "Bad-air" caves are common in many karst and volcanic areas of the world (James 1977, Lewis 1981, Renault 1982, Deharveng and Bedos 1986), but until now they have been assumed to be devoid of life. During our continuing survey of the biology of North Queensland caves, we had the opportunity to survey Bayliss Cave (about 200 km southwest of Cairns, 18°I0' S, 144°30' E, 700 m elevation). Bayliss Cave

ONE OF HAWAII'S most intriguing ecosystems is found in lava tubes that have been (and still are b... more ONE OF HAWAII'S most intriguing ecosystems is found in lava tubes that have been (and still are being) formed by volcanism. Within these lava tubes a remarkably adapted fauna has been discovered during the last 20 yr, mainly by F. G. Howarth, F. D. Stone, and collaborators (Howarth 1987). Among the important elements of this fauna are the caveadapted and morphologically highly modified planthoppers of the genus Oliarus in the family Cixiidae. Oliarus polyphemus Fennah from lava tubes on the island of Hawaii

International Journal of Speleology, 1987

The discovery of terrestrial troglobites living in caves on young oceanic islands with closcl epi... more The discovery of terrestrial troglobites living in caves on young oceanic islands with closcl epigean relatives living in nearby surface habitats offers unique opportunities to develop and tclSthypotheses concerning their evolution. Studies comparing the physiological ecology of troglobites with their epigean relatives suggest that troglobites arcl highly specialized to exploit resources within the system of interconnected medium-sized voids (mesocaverns) and only colonize cave passages (macrocaverns) with a stable, water vaporsaturated atmosphercl. Few other animals can live in the mesocaverns. Rather than being relicts isolated in caves by the extinction of their epigean ancestral population, troglobites appear to evolve by a process called adaptive shift from specicls that are frequent accidentals in the mesocaverns.

As the most isolated group of high islands in the world, the Hawaiian archipelago occupies a very... more As the most isolated group of high islands in the world, the Hawaiian archipelago occupies a very special place in insect conservation: first as a cradle of evolution of a remarkable endemic fauna and second as a prime example of the vulnerability of island environments to anthropogenic changes – especially the effects of alien species. Lessons from both these themes are of global relevance, and the recognition that these same phenomena are occurring in continental systems has been important in maturing attitudes to insect conservation. Mirrored in other parts of the Pacific, such as New Zealand (Watts et al. this volume; Howarth and Ramsay 1991), external disturbances have had massive impacts on the Islands’ biota. These losses – together with the prospect of continuing severe losses – have contributed to debates over the rationale justifying alien species introductions, including non-native biological control agents. The impacts of introduced control agents are increasingly recognized as an important issue in insect conservation over the last few decades.

Proceedings of the Hawaiian Entomological Society., Sep 1, 1982

Biting midges of the genus Forcipomyia are some of the most important pollinators of cacao and ot... more Biting midges of the genus Forcipomyia are some of the most important pollinators of cacao and other tropical crop plants. A study of the species known as F. ingrami revealed that it has been misidentified, and that the African species formerly known as ingrami, now psilonota, does not occur in Hawaii. Instead there are at least four other species: palikuensis Hardy, a large, shining blackish species from Hawaii and East Maui; kaneohe n. sp., a small shining species from Oahu; pholeter n. sp., a small pale species living in lava tube caves on Hawaii; and hardyi n. sp., a dull brownish species which is extremely common on all the islands; all probably endemic to the Hawaiian Islands. The immature stages of these midges, which breed in wet, decaying vegetation, leaf axils, and aquatic vegetation, have excellent characters diagnostic for species. Characters are illustrated and discussed showing how these species may be distinguished from their closely related congeners from the Pacific, Asia, and Africa. Forcipomyia clara Chan and LeRoux from Singapore is a junior synonym of F. sauteri Kieffer (N. SYNONYMY). Biting midges were first recorded from the Hawaiian Islands by Grimshaw (1901) as Ceratopogon sp. Perkins (1913:clxxxi) in the introduction to the Fauna Hawaiiensis reported "The smaller chironomids such as Tanytarsus and Ceratopogon are found in the mountain forests and the species may prove to be endemic." Bridwell (1920:284) reported "finding (in a salt marsh at Waikiki) rather numerously a species of Ceratopogon, of which genus there is a different species in the mountains." Of this note, Bryan (1934:405) added: "Related specimens, sent to Johannsen, were referred to the subgenus Prohelea. Perkins (1913, p. clxxxi) stated that more species probably exist in the mountains. At times small clouds of these gnats are to be seen." Macfie (1934a: 134) listed Forcipomyia ingrami Carter from nine collections made by F.X. Williams and O.H. Swezey in Hawaii, and gave the following notes casting some doubt on the correctness of his determination: "The specimens are exceptionally dark in colour, but do not seem to differ from typical examples of F. ingrami in any material respect, except in having the first tarsal segment in the males unusually long, slightly longer than the second segment instead of rather shorter, the tarsal ratio being about 1.1 instead of about 0.8. The genitalia of the males appear to be indistinguishable from those of F ingrami. For this reason and because F. ingrami is known to be somewhat variable, there does not seem to be any sufficient reason for considering these specimens as distinct from that species." Williams (1936a:111) reported Forcipomyia ingrami Carter from various points on Oahu and Hawaii. Again (1936b:325) he mentioned F ingrami as occurring in Hering Valley, Honolulu, on algae-covered wet banks along with

The Hawaiian Islands offer great potential for evolutionary research. The discovery of specialize... more The Hawaiian Islands offer great potential for evolutionary research. The discovery of specialized cavernicoles among the adaptively radiating fauna adds to that potential. About 50 lava tubes and a few other types of caves on 4 islands have been investigated. Tree roots, both living and dead, are the main energy source in the caves. Some organic material percolates into the cave through cracks associated with the roots. Cave slimes and accidentals also supply some nutrients. Lava tubes form almost exclusively in pahoehoe basalt, usually by the crusting over of lava rivers. However, the formation can be quite complex. Young basalt has numerous avenues such as vesicles, fissures, layers, and smaller tubes which allow some intercave and interlava flow dispersal of cavernicoles. In older flows these avenues are plugged by siltation or blocked or cut by erosion.-~-Volcano 1130 m .<100 m + 18. Blair Cave Volcano 910 m 1000 m + Lava Tubes on Hawaii (Hualalai ;.~assif) Jlo. Name of Cave LoC'\lity Elevation Length :Park Zone

Systematic Entomology, Oct 1, 1989

The monophyletic genus Solonaima, endemic to northern Queensland, is reviewed and six new species... more The monophyletic genus Solonaima, endemic to northern Queensland, is reviewed and six new species are described: S.sullivani sp.n., S.pholetor sp.n., S.stonei sp.n., S.halos sp.n., S.irvini sp.n. and S. baylissa sp.n. The previously known epigean species, S.solonaima Kirkaldy and S.pallesens (Distant) are illustrated and redescribed. The six new species represent four separate independent cave invasions and nearly double the number of known cavernicolous cixiids in the world. This is the first report of a closely related group of cave‐dwelling Homoptera showing varying degrees of cave adaptation. One facultative cave species, S.sullivani, shows virtually no modification from surface relatives. Two species, S.pholetor and S.stonei, show some eye, colour, and wing‐reduction, but they are still flighted and are considered facultative cave species. S.halos and S. irvini are nearly blind and have reduced, non‐functional wings and are considered obligate cave species. S. baylissa, the most remarkable obligate cave species, is highly modified: eyeless, nearly wingless and colourless. The evolutionary trends displayed in cave adaptation are illustrated and discussed. These include reduction in body colour, eyes and wings, alteration of head and thorax shape, and possibly simplification of the male genitalia. The geology of the caves is complex and ranges from greater than 5‐million‐year‐old caves in Silurian‐aged metamorphosed limestone to 190,000‐year‐old lava tubes. The facultative species are generally found in the most open caves, the two intermediate obligate species are found in deeper caves, and the most highly modified species is restricted to damp cave passages with high CO2 levels. There is no correlation between the ages of the caves and the degree of cave adaptation.

Annual Review of Entomology, 1983

Page 1. Ann. Rev. Entomol. 1983. 28:365-89 Copyright © 1983 by Annual Reviews Inc. All rights res... more Page 1. Ann. Rev. Entomol. 1983. 28:365-89 Copyright © 1983 by Annual Reviews Inc. All rights reserved ECOLOGY OF CAVE ARTHROPODS Francis G. Howarth Department of Entomology, B. P. Bishop Museum, Honolulu, Hawaii 96819 PERSPECTIVES AND OVERVIEW ...

Proceedings of the Hawaiian Entomological Society, Apr 5, 2019

An annotated list of 393 adventive terrestrial arthropod species plus three new varieties of know... more An annotated list of 393 adventive terrestrial arthropod species plus three new varieties of known established species, which have been recorded in Hawaii since the Fourth Edition of Bishop Museum's Hawaiian Terrestrial Arthropod Checklist (Nishida 2002), is presented. This compilation includes records of over 362 nonnative arthropod species published between the years of 2001 and 2017 as well as over 30 new Hawaii State records that have not been previously recorded. Annotations include date first detected, island distribution, citation, relevant biological notes, and for new state and island records, the collection data. A separate table with about 150 entries lists the synonyms, misidentifications, deletions, and changes of status for species included in the 2002 checklist that were discovered during our research. However, the latter list is not comprehensive as a complete revision of the 2002 checklist was beyond the scope of our project. Also included is a bibliography of the approximately 270 source documents that were consulted. We intend for this publication to be a useful supplement to the 2002 edition of the Hawaiian Terrestrial Arthropod Checklist.

Journal of Cave and Karst Studies, 2002

Australian Journal of Entomology, Feb 1, 1990

This paper is a systematic report and a biological analysis of the Mesoveliidae from Hawaiian cav... more This paper is a systematic report and a biological analysis of the Mesoveliidae from Hawaiian caves. Most important is a new species of Speovelia Esaki, ~. sp. (Hawaii I.), described from material collected on moist walls in lava tubes. This apparently represents the world's first troglobitic heteropteran. Morphologically, all instars show lack of pigmentation, functionless eyes and prolongation of the appendages and head. Biologically, it is restricted to the dark zone of lava tubes. Notes on its biology are given. It also represents the first known endemic species of the family for the Hawaiian Islands. Another species, Mesovelia amoena Uhler, is troglophilic. This is the first record of this immigrant American species in the Hawaiian Islands. The remaining species in Hawaii, the immigrant'M• mulsanti White, has only been found in epigean situations. A key to the species is also presented.

This paper describes the world's second troglobitic heteropteran, Nesidiolestes sp., and presents... more This paper describes the world's second troglobitic heteropteran, Nesidiolestes sp., and presents notes on its biology. The species is restricted to the dark zones of high altitude lava tubes on Hawaii Island. Body pigmentation is lacking and the eyes are strongly reduced. This discovery again demonstrates that adaptive radiation of the epigean fauna into cave situations has occurred in Hawaii. Rather than exhibiting relictual characteristics, the species seems recently derived from a surface-dwelling (epigean) ancestor and most closely resembles the extant M• selium Kirkaldy of the same island. Epigean species of Nesidiolestes Kirkaldy have a predisposition for the cave habitat in that they are cryptic, dark-seeking, apparently nocturnal, slow-moving insects frequenting the mossy undersides of fallen logs and ferns in the rain forest. The existence of M• sp. was actually predicted on the basis of the apparently preadaptive habits mentioned. This brings the number of described troglobitic arthropods in Hawaiian lava tubes to eight species.

Zoological Journal of the Linnean Society, May 1, 2009

Although temperate cave-adapted fauna may evolve as a result of climatic change, tropical cave dw... more Although temperate cave-adapted fauna may evolve as a result of climatic change, tropical cave dwellers probably colonize caves through adaptive shifts to exploit new resources. The founding populations may have traits that make colonization of underground spaces even more likely. To investigate the process of cave adaptation and the number of times that flightlessness has evolved in a group of reportedly flightless Hawaiian cave moths, we tested the flight ability of 54 Schrankia individuals from seven caves on two islands. Several caves on one island were sampled because separate caves could have been colonized by underground connections after flightlessness had already evolved. A phylogeny based on approximately 1500 bp of mtDNA and nDNA showed that Schrankia howarthi sp. nov. invaded caves on two islands, Maui and Hawaii. Cave-adapted adults are not consistently flightless but instead are polymorphic for flight ability. Although the new species appears well suited to underground living, some individuals were found living above ground as well. These individuals, which are capable of flight, suggest that this normally cave-limited species is able to colonize other, geographically separated caves via above-ground dispersal. This is the first example of an apparently cave-adapted species that occurs in caves on two separate Hawaiian islands. A revision of the other Hawaiian Schrankia is presented, revealing that Schrankia simplex, Schrankia oxygramma, Schrankia sarothrura, and Schrankia arrhecta are all junior synonyms of Schrankia altivolans.

Annual Review of Entomology, 1991

Biological control, the use of living organisms to control pest populations, dates from ancient t... more Biological control, the use of living organisms to control pest populations, dates from ancient times (117, 127). However, 100 years have passed since Albert Koebele intentionally introduced the Australian vedalia lady beetle via New Zealand (6, 86) into California orange groves ...

Science, Jan 21, 1972

Cave-adapted arthropods have evolved in lava tubes in Hawaii. This is the first report of caverni... more Cave-adapted arthropods have evolved in lava tubes in Hawaii. This is the first report of cavernicoles from the Hawaiian islands. The specialization of the cavernicolous insects and the recent origin of the lava tubes suggest that subterranean connections between lava tubes regularly occur and provide dispersal routes. The discovery that lava tubes were colonized by representatives of the adaptively radiating native fauna oflers significant potential for evolutionary

Elsevier eBooks, 2009

Publisher Summary This chapter discusses the subterranean biome, highlighting terrestrial systems... more Publisher Summary This chapter discusses the subterranean biome, highlighting terrestrial systems and the insects that are obligately adapted to live permanently in underground voids. The most conspicuous aspect displayed by obligate cave arthropods is the reduction of structures normally considered adaptive. Cave species also often lack a circadian rhythm and have relatively low metabolic and reproductive rates. A few characters are often enhanced, including modified structures such as increased hairiness, enlarged sensory organs, longer appendages, and specialized tarsi. Insects, arachnids, and millipedes are the dominant terrestrial groups living in caves. Beetles (Coleoptera), especially the families Carabidae, Leiodidae, and Staphylinidae, are well represented in the temperate caves. Troglobitic species are also found in the orders Diplura, Thysanura, Blattodea, Dermaptera, Grylloblattodea, Psocoptera, and Lepidoptera. Troglobitic bristletails (Diplura) occur mainly in temperate caves. The fantastic adaptations displayed by obligate cave animals have long intrigued biologists. Their often narrow environmental tolerances, coupled with their island-like habitats, have reinforced the view that these animals are fragile, lead an endangered existence, and are in need of conservation. Ecological studies are needed that improve our understanding of the functioning ecosystem, as well as understanding of natural successional processes. However, experimental ecological studies in caves are problematic because in few other habitats are humans so dramatically intruders as in caves.