Ronald A. Hellenthal

Restoration of an Indiana, USA, stream: bridging the gap between basic and applied lotic ecology

Abstract Stream restoration attempts to reverse the global degradation of rivers and streams, but rigorous evaluations are needed to advance the science. We evaluated a 3rd-order channelized Indiana (USA) stream that was restored in 1997 by constructing two meanders, each ∼400 m long. Pool and riffle sequences were constructed, coarse substrate and wood were added to the channel, banks were stabilized and revegetated, and sedimentation was reduced by creating a sediment retention basin upstream. Habitat, periphyton, macroinvertebrates, and fishes were measured before restoration and for 5 y after restoration in the restored reaches and in an upstream, unrestored reach. Restoration improved habitat conditions (e.g., more pools, fewer fine sediments) in both restored reaches compared to the unrestored reach. Within 1 y after restoration, major trophic groups (i.e., periphyton, macroinvertebrates, and fishes) recovered to or exceeded levels in the degraded, unrestored reach. However, biotic responses varied with time, trophic level, and community parameter measured. Five years after the restoration, habitat quality, algal abundance, and macroinvertebrate density remained higher in the restored reaches, whereas macroinvertebrate diversity and fish abundance in the restored reaches were similar to or below levels in the unrestored, channelized reach. Although biotic recovery was relatively rapid, long-term persistence is uncertain because of continued sedimentation at a watershed scale. In many instances, reach-scale restorations may be ineffective in the face of basin-wide degradation. This study illustrates the importance of conducting long-term assessments of stream restorations, which can improve both knowledge and management of stream ecosystems.

Phylogeny of Geomydoecus and Thomomydoecus pocket gopher lice (phthiraptera, trichodectidae) inferred from cladistic analysis of adult and first instar morphology

The phylogeny for all 122 species and subspecies of chewing lice of the genera Geomydoecus and Thomomydoecus (Phthiraptera: Trichodectidae) hosted by pocket gophers (Rodentia: Geomyidae) is estimated by a cladistic analysis of fifty‐eight morphological characters obtained from adults and first instars. The data set has considerable homoplasy, but still contains phylogenetic information. The phylogeny obtained is moderately resolved and, with some notable exceptions, supports the species complexes proposed by Hellenthal and Price over the the last two decades. The subgenera G. (Thaelerius) and T. (Thomomydoecus) are both shown to be monophyletic, but the monophly of subgenus T. (Jamespattonius) could not be confirmed, perhaps due to the lack of first‐instar data for one of its component species. The nominate subgenus of Geomydoecus may be monophyletic, but our cladogram was insufficiently resolved to corroborate this. Mapping the pocket gopher hosts onto the phylogeny reveals a consistent pattern of louse clades being restricted to particular genera or subgenera of gophers, but the history of the host‐parasite association appears complex and will require considerable effort to resolve.

The role of Chironomidae in energy flow of a lotic ecosystem

Chironomid secondary production was estimated on a species-specific basis for 14 dominant taxa in a third-order woodland stream. Results from this study were used to provide an expalanation for the common observation that benthos secondary production in streams is insufficient to account for levels of fish production,i.e., the ALLEN paradox. Annual chironomid secondary production was 29.7 g dry mass m−2 and accounted for 80% of the total aquatic insect secondary production. A contribution by chironomids this high has not been reported previously from similar streams and indicates that chironomids are an energetically important group available for fish consumption. Most studies examining chironomid secondary production group all taxa at the family level and calculate secondary production for the entire family using the size-frequency method. This approach violates assumptions of the size-frequency method and will result in inaccurate and unpredictable estimates of chironomid secondary production. The species-specific approach to estimate chironomid production used in this study, combined with non-chironomid production, yielded a benthos annual production rate that exceeded consumption necessary to support fish production.

Behavioral Responses of Hydropsyche sparna (Trichoptera: Hydropsychidae) and Related Species to Deposited Bedload Sediment

Abstract Laboratory experiments using small artificial streams were performed on 3rd–5th instars of the net-spinning caddisflies Hydropsyche sparna (Ross), H. betteni Ross, H. morosa (Hagen), and H. slossonae (Banks) to examine behavioral responses after exposure to sand particles ranging from 126 to 2,000 μm in diameter. Sediment loads up to 14.6 kg/m2 were applied. When buried, the insects drifted, died, or remained “buried-alive.” When buried-alive, the larva remained in contact with its retreat and extended head, thorax, and anterior abdomen into the overlying water. Drift predominated when particle diameters were below 1,000 μm. Larger particles induced the buried-alive behavior. Mortality rates varied from 0 to 4.8%. Behavioral response to deposited sediment was similar in 3rd, 4th, and 5th instars. Larvae of H. betteni, H. morosa, and H. slossonae exhibited similar behaviors to H. sparna. The buried-alive behavior may represent an adaptation to frequent exposure to bedload sediment transport. Bedload sediment transport of the duration and magnitude studied is either a lethal or a sublethal disturbance, depending on the sediment particle size.

New synonymies and host records for lice of the genus Menacanthus (Phthiraptera: Menoponidae) from the Passeriformes (Aves)

Twenty new synonymies are proposed and 42 new host associations are given for chewing lice of the genus Menacanthus Neumann, 1912, parasitic on members of the avian order Passeriformes.

Effects of suspended particles on net-tending behaviors for Hydropsyche sparna (Trichoptera : Hydropsychidae) and related species

Abstract Laboratory experiments using small artificial streams were performed on 3rd-5th instars of the net-spinning caddisflies Hydropsyche sparna (Ross), H. betteni Ross, H. morosa (Hagen), and H. slossonae (Banks) to examine the effects of suspended particle transport on their behavior, drift, and mortality. Larvae were exposed to suspended particles 0.4–500 μm in diameter at suspended concentrations between 667 and 6000 mg/liter for 24 h. Water velocity was held constant at 23 cm/s in all experiments to eliminate the confounding effects of flow on net-tending. Drift and mortality rates were also measured but did not occur in the experimental or control populations. Four net-tending behaviors occurred that varied in the degree of filter net modification. One behavior was to clean the net of particles and leave it intact. Three other behaviors, involving modification of the filter net strands, were detachment of one side, cutting a hole in the middle of the filtering surface, and total removal of the net. For particles >64 μm in diameter, the frequency of net modification increased with increased particle size and load. Intraspecific differences in net-tending behaviors occurred in only 1 instance, and there were no interspecific differences. We speculate that H. sparna individuals modify their nets to change the local hydrology and therefore prevent excessive fine particle transport into their retreats. Observed net-tending behaviors might represent adaptations to frequent exposures to suspended sediment transport. Fine suspended particle transport of the duration and magnitude studied represents a sublethal disturbance to hydropsychids.

A Review of Machaerilaemus (Phthiraptera: Amblycera: Menoponidae) from the Passeriformes (Aves), with the Description of Five New Species

Abstract The 25 nominal species of the menoponid genus Machaerilaemus have been studied, with 10 determined to be valid and 13 to be new junior synonyms and two assigned to another genus. Descriptions are given for the previously described species and for five new species: M. cyanocittae (type host Cyanocitta cristata), M. diglossae (type host Diglossa baritula), M. laticapitus (type host Leptasthenura aegithaloides), M. tangarae (type host Tangara larvata) and M. hirsutus (type host “Honeycreeper”). A key is provided for identification of the 15 species now recognized in the genus.

Phthiraptera: Chewing and Sucking Lice

Publisher Summary This chapter describes the phthiraptera, an obligatory and lifelong ectoparasites of birds. They are hemimetabolous and wingless, with dorsoventrally flattened bodies, three pairs of well-developed legs, and a single- or double-segmented tarsus usually with one or two claws, but occasionally with claws absent. Ocelli are absent, eyes are reduced or absent, and antennae are short with 3–5 segments. Body length of adults ranges from 0.3 to 12 mm. Over 5000 louse species are recognized. Lice formerly were classified in two orders, Mallophaga (chewing lice) and Anoplura (sucking lice). However, they now are combined into the order Phthiraptera, with the former Mallophaga comprising three suborders (Amblycera, Ischnocera, and Rhynchophthirina) and the Anoplura, a fourth. Although the suborders show substantial differences, they are believed to form a hemipteroid monophyletic unit whose sister group is the Psocoptera (psocids or booklice). Chewing lice have mandibulate mouthparts and probably evolved on birds. They are thought to have fed initially on skin and feathers, with some groups ultimately expanding their diets to include tissue fluids and blood. Some chewing lice eventually made a transition from birds to mammals and some Ricinidae (Amblycera) have mouthparts adapted to pierce host skin.

A new species of Geomydoecus (Mallophaga: Trichodectidae) from Pappogeomys (Rodentia: Geomyidae) pocket gophers in Jalisco, Mexico

The new species Geomydoecus telli is described and illustrated for material taken from the pocket gopher taxa Pappogeomys gymnurus tellus [type host], P. tylorhinus atratus, and P. t. zodius from J...

A New Genus and New Species of Chewing Louse (Phthiraptera: Menoponidae) from the Lesser Melampitta (Aves: Passeriformes)

Abstract The new genus Oculomenopon is described to include the single new species, O. melampittae, with the type host being the Lesser Melampitta, Melampitta lugubris (Passeriformes: Genera Incertae Sedis), from New Guinea.