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1. Coprophagous hydrophilid beetles (Coleoptera: Hydrophilidae) as carriers of phoretic deutonymphs of Uropoda orbicularis (Acari: Mesostigmata) in Poland

Creator:
Bajerlein, Daria and Przewózny , Marek
Type:
article, model:article, and TEXT
Subject:
Coprophagous beetles, Hydrophilidae, Uropoda orbicularis, Acari, phoresy, and Poland
Language:
English
Description:
During a study 20 hydrophilid beetle species and 2,457 individuals of beetles belonging to 4 genera: Cercyon, Cryptopleurum, Megasternum and Sphaeridium were collected. On the surface of the bodies of 59 beetles (2.40% of the beetles collected) belonging to six species, 174 cases of phoresy [55 deutonymphs of Uropoda orbicularis (Müller, 1776) and 119 pedicels without deutonymphs] were observed. New hydrophilid beetle carriers of phoretic deutonymphs of U. orbicularis are given. Most mites were carried by Sphaeridium species. The population dynamics of both groups of arthropods was also studied. Most cases of phoresy were recorded in May and in the second half of July. However, phoretic deutonymphs were not present on the body surface of hydrophilid beetles throughout the whole period of this study.
Rights:
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2. Descriptions of the egg case and larva of Anacaena and a review of the knowledge and relationships between larvae of Anacaenini (Coleoptera: Hydrophilidae: Hydrophilinae)

Creator:
Archangelsky, Miguel and Fikáček, Martin
Type:
article, model:article, and TEXT
Subject:
Anacaena, Paracymus, Anacaenini, Hydrophilidae, Coleoptera, larva, egg case, Argentina, and Neotropics
Language:
English
Description:
The third instar larva of Anacaena cordobana Knisch, and the egg case of Anacaena lutescens (Stephens) are described and illustrated. The taxonomic status of the immature stages of Anacaenini is clarified by comparing their morphology with that described in the literature. Larval descriptions of Anacaena and Paracymus published by Richmond (1920) are interchanged, as are the identifications of all subsequent authors based on Richmond's work. All Anacaenini genera for which larvae are known are diagnosed. A comparative morphological study of Anacaena larvae shows many similarities between Crenitis and Anacaena larvae, suggesting a close relationship between these two genera.
Rights:
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3. Dung feeding in hydrophilid, geotrupid and scarabaeid beetles: Examples of parallel evolution

Creator:
Holter, Peter
Type:
article, model:article, and TEXT
Subject:
Dung beetles, Hydrophilidae, Geotrupidae, Scarabaeidae, feeding habits, particle feeding, mouthparts, and evolution
Language:
English
Description:
The maximum size of ingested ball-shaped particles was determined in three species of adult dung feeding beetle: Anoplotrupes (Geotrupes) stercorosus and Geotrupes spiniger (Geotrupidae, Geotrupinae) and Sphaeridium lunatum (Hydrophilidae, Sphaeridiinae). Maximum diameters were 40-65 µm, 60-75 µm and 16-19 µm in A. stercorosus, G. spiniger and S. lunatum, respectively, and it was concluded that these beetles feed in the same way as found in previous studies on coprophagous scarabaeids (Scarabaeinae and Aphodiinae). Coarse particles, mainly indigestible plant fragments, are rejected by an unknown filtering mechanism, and only very small particles are actually ingested. The two geotrupids, however, tolerate somewhat larger particles than do scarabaeines of similar size. This may reflect a lower degree of specialisation towards dung feeding in the geotrupids than in the scarabaeines. In several ways, the mouthparts of the coprophagous Scarabaeidae, Geotrupidae and Hydrophilidae show essentially the same morphological modifications that must be adaptations for dung feeding. For the hydrophilid (Sphaeridium), such modifications are described for the first time. They include asymmetric mandibular molars (right convex, left concave), fitting exactly into each other, with highly specialised surfaces that may concentrate the food prior to ingestion by squeezing fluid out of it. Other examples are the conjunctives (scarabaeids and geotrupids) or similar structures (the hydrophilid) and the large, hairy, pad-like distal lobes of the maxillar galeae. Provided that current views on the evolutionary history of these beetles are correct, dung feeding has arisen independently in the Scarabaeidae, Geotrupidae and Hydrophilidae. If so, the feeding on very small particles and the concomitant modifications of mouthparts in these three groups must be results of parallel evolution.
Rights:
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