Norman J. Fashing

Life-History Patterns of Astigmatid Inhabitants of Water-Filled Treeholes

It has been known for well over 100 years that certain terrestrial plants hold small bodies of water, and that these bodies of water often contain communities of aquatic arthropods (Fish 1983). Varga (1928) coined the term “phytotelmata” (Greek: phyton = plant, telma = pool) to describe such habitats which include the modified leaves of pitcher plants, inflated leaf axils of such plants as bromeliads and palms, water-collecting flowers such as Heliconia, internodal spaces of broken bamboo stems, and the water-collecting depressions on trees (treeholes). In fact, Fish (1983) estimated that habitats suitable for aquatic arthropod development can be found in over 1500 plant species.

Infanticidal Behavior in the Subsocial Beetle Odontotaenius disjunctus (Illiger) (Coleoptera: Passalidae)

Infanticide, the killing of young, reproductively immature individuals of the perpetrator’s same species, has many interesting implications for reproductive fitness. Here we provide the first experimental description of infanticidal behavior in the passalid beetle Odontotaenius disjunctus (Illiger). To test our hypothesis that infanticide is triggered by the takeover of burrows by adults that had yet to reproduce in the mating season, we measured the mortality of larvae when housed with adults that were reproducing or had not yet reproduced. A significantly higher mortality was observed in larvae housed with adults that had not reproduced than when housed with their own parent or with unrelated reproducing adults. Infanticidal behavior of O. disjunctus is thought to result from the reproductive advantage obtained by taking over an existing burrow and thereby securing one with high food resource quality.

Algophagus pennsylvanicus-A new species of Hyadesidae from water-filled treeholes

ABSTRACT A new species of Hyadesidae, Algophagus pennsylvanicus, is established based on specimens collected from water-filled treeholes in Pennsylvania. A key to the species of the subfamily Algophaginae is provided.

Biology of the genus Hericia (Algophagidae: Astigmata), with the description of a new species from the eastern United States

Abstract New observations concerning the biology of the genus Hericia are provided, as well as a discussion of past observations from the literature. A new species, Hericia janehenleyi, is described and illustrated from adults, phoretic deutonymphs and non-phoretic deutonymphs collected from fermenting sap flux on oak trees (Quercus spp.) in eastern Virginia, U.S.A. Deutonymphs are phoretic on the sap flux inhabiting beetle Glischrochilus obtusus (Say) (Coleoptera, Nitidulidae).

The ability of Rhizoglyphus robini Claparède (Astigmata: Acaridae) to subsist solely on a diet of filter paper

Abstract Rhizoglyphus robini Claparede, commonly known as the bulb mite, has been reported to complete its life-cycle utilizing filter paper as a sole dietary source. However, a complete cellulase complex necessary for crystalline cellulose degradation rarely occurs in arthropods. Experiments demonstrate that R. robini probably derives nutrients from the fungal mycelia growing on the filter paper rather than from the filter paper itself.

Mate-guarding in the genus Creutzeria (Astigmata: Histiostomatidae), an aquatic mite genus inhabiting the fluid-filled pitchers of Nepenthes plants (Nepentheaceae)

Abstract A number of genera of Histiostomatidae inhabit phytotelmata, being found fully submerged and filtering organic matter from the fluid. One such phytotelm habitat is the fluid-filled pitchers of species of Nepenthes, a carnivorous plant genus widely distributed in the Old World tropics. As in most histiostomatid species, males of Nepenthes-inhabiting mites seek out tritonymphal females and guard them from other males, a behavior termed “precopulatory mate-guarding”. Upon ecdysis of the tritonymph to adult, mating takes place. Successful mate-guarding prevents other males from gaining access to a virgin female and helps ensure the guarding males paternity of any resultant offspring. While most Nepenthes-inhabiting genera are ambulatory, walking about on decomposing arthropods in the pitchers, species of the genus Creutzeria are natatory and propel themselves through the fluid using legs greatly modified for this purpose. Males of purely ambulatory species typically climb onto the dorsum of a tritonymphal female and firmly clasp her idiosoma with their legs. Some species do not move about on their own accord, but rely on the female to carry them. In others, two pairs of legs are used for clutching the female; the other two pairs are very long, thereby allowing the male to walk about while holding the securely clasped female off the substrate. Swimming is a more laborious task, especially since the male must propel not only himself through the fluid but also the female. The mate-guarding behavior of Creutzeria spp. was studied by direct observation under a stereomicroscope and from videos filmed through a stereomicroscope. In addition, phase contrast and scanning electron microscopy were used to examine the morphological adaptations associated with mateguarding and mating. Legs I of males are greatly modified for clasping a tritonymphal female during mateguarding and legs III and IV for swimming. Legs II are a morphological compromise, being used for swimming as well as for grasping the substrate for resting when legs I are occupied with a female.

Systematics and ecology of Naiadacarus nepenthicola, a new species of acaridae (Acari: Astigmata) inhabiting the pitchers of Nepenthes bicalcarata hook. f. in Brunei Darussalam

Abstract A new species, Naiadacarus nepenthicola, is described from adults and deutonymphs collected in Belait District, Brunei Darussalam, from the fluid-filled pitchers of Nepenthes bicalcarata Hook. f. This constitutes the first record of a member of the family Acaridae inhabiting Nepenthes pitchers. It is quite probable that N. nepenthicola feeds on decomposing leaves that fall into pitchers as well as on decomposing insects trapped by pitchers. Dispersal is accomplished through phoresy on Campanotus schmitzi Staercke, an ant that nests exclusively in the hollow tendrils of N. bicalcarata pitchers.

Carpoglyphus nidicolus - a new species of Carpoglyphidae (Acarina: Astigmata) inhabiting the nests of swallows

Abstract A new species of Carpoglyphidae, Carpoglyphus nidicolous, (Acarina : Astigmata) is established based on specimens collected from the nests of cliff swallows (Petrochelidon pyrrhonota Vieillot) and barn swallows (Hirundo rustica Linnaeus) in Oregon, U.S.A.

Observations on the feeding biology of Algophagus pennsylvanicus (Astigmata: Algophagidae), a mite restricted to water-filled treeholes

ABSTRACT Morphological as well as biological evidence indicates that Algophagus pennsylvanicus, an obligate inhabitant of water-filled treeholes in eastern North America, is a “scraper” (= grazer) and feeds by shearing fungal hyphae from the surface of decomposing leaves. In addition, it is probable that this species filters fine particulate organic matter from the water surface film and is therefore a filtering “collector” as well.

A new Fusohericia (Acari: Astigmata: Algophagidae) from Costa Rica

Abstract A new species, Fusohericia heliconiae, is described and illustrated from adults and phoretic deutonymphs collected from Heliconia imbricata flower bracts at La Selva Biological Station and Reserve, Heredia Province, Costa Rica. Notes on the biology of F. heliconiae are also presented.