Lagrioida Fairmaire et Germain 1960

Introduction

Lagrioidinae is a small group of beetles. It contains the single genus Lagrioida and 5 recent species. No fossil records are hitherto known for Lagrioidinae. Members of this group are known from Australia, New Zealand, Chile and Brazil.

The genus Lagrioda has been placed into various groups of tenebrionoid Coleoptera by earlier authors. Abdullah & Abdullah (1968) established a new tribe - Lagrioidini - for this genus and placed it into Eurygeniinae Anthicidae. Later, Abdullah (1974) elevated this tribe to subfamily level within Anthicidae. Nowadays Lagrioida formally remains in Anthicidae, but there is a serious doubt about its phylogenetic relationships (Lawrence, Britton 1991).

Characteristics

Adults

Body 2.50-6.50 mm long, ~2.30-2.75 times longer than wide. Body colouration yellowish or reddish brown to uniformly brown or black. Dorsal surface evenly covered with fine subdecumbent pubescence.

Head not strongly constricted posteriorly to eyes, not forming narrow neck. Eyes entire, strongly prominent. Insertions of antennae concealed dorsally. Frontoclypeal suture absent. Antennae with 11 antennomeres, 3 terminal ones forming indistinct club or all antennomeres filiform. Mandibles short and broad, bidentate at apex.

Pronotum as long to ~1.2 times longer than wide, widest in anterior part. Base distinctly narrower than elytral base. Lateral margins sinuate to slightly rounded. Anterior angles not produced, basal angles broadly rounded. Procoxal cavities narrowly separated, broadly open externally and closed internally.

Elytra ~1.70-2.10 times longer than their maximum combined width. Punctures of disc irregular. Epipleura narrow and incomplete. Elytral apices meets at suture. Mesocoxal cavities narrowly separated, open laterally. Metacoxal cavities narrowly separated, not expanded laterally to meet lateral margin of elytra. Hind wings with apex of radial bar being very thick. Radial cell without base.

Legs inconspicuous, slender. Tibial spurs paired, usually well developed. Tarsal formula 5-5-4. Penultimate tarsomere distinctly and deeply bilobate.

Abdomen with 5 ventrites, the first two of them connate. Ventrites I-VII with functional spiracles in their pleural membrane. Aedeagus of inverted tenebrionoid type, symmetrical and with ventral tegmen. Parameres fused but articulated to phallobase. Ovipositor, with the exception of the baculi, slightly sclerotized.

Preimaginal stages

Larva elongate, parallel-sided, slightly flattened dorso-ventrally. Sclerotization slight with the exception of the urogomphi. Head prognathous with the posterior edge of the head capsule being indistinctly emarginate. Frontoclypeal suture absent. Frontal arms U-shaped, contiguous on bases. Mandibles bidentate, strongly constricted toward apices. Hypopharyngeal sclerome transverse, molar-like.

Prothorax is not longer than combined lenght of meso- and metathorax. Legs inconspicuous, 5-segmented. Pretarsus with a pair of setae.

Abdomen more than two times longer than thorax. Segment IX well developed, excluding appendages shorter than segment VIII. Segment X slightly transverse. Spiracles annular-biforous, on segment VIII nearly of same size as others on abdomen.

Biology and Ecology

All known species of Lagrioida occur in coastal sand dunes. Imagoes are usually collected from green vegetation (Poaceae) or among roots of various grasses and herbs, under fallen trees, or beneath seaweed Mesembryanthemum sp. (Aizoaceae). Adults of Lagrioida nortoni have been reported to feed on grass spikelets (Costa et al. 1995).

Larvae were found by sifting sand collected at the bases of various grasses in the same habitat with imagoes (coastal sand dunes). They possibly feed on detritus, fallen leaves and root debris (Costa et al. 1995).

Relationships of Lagrioidinae to Other Tenebrionoidea

Genus Lagrioda was included in the Lacconotinae of Pythidae (now - Eurypinae of Mycteridae) by Blair (1928) and Blackwelder (1945). Later, Crowson (1955) transferred this group to his Cononotidae, together with Cononotus LeConte and Agnathus Germar.

Abdullah & Abdullah (1968) described a new tribe Lagrioidini of Eurygeniinae Anthicidae, and moved Lagrioida, Agnathus and Cononotus to it. In 1974, Abdullah elevated the  tribe to subfamily level within Anthicidae; on the basis of larval morphology, Agnathus and Cononotus were moved to Pedilidae (now Pedilinae of Pyrochroidae). Costa et al. (1995) presented morphological comparisons of imago and larvae of Lagrioida and some other Anthicidae, but no phylogenetic conclusions were made.

Lagrioida and Lagrioidinae formally remains in Anthicidae, but these are serious doubts about phylogenetic relationship of this group (Lawrence, Britton 1991).

Classification and Species List

Note: all taxa below are listed alphabetically.

• Lagrioida australis Champion, 1895 - Australia
• Lagrioida brouni Pascoe, 1876 - New Zealand
  
• Lagrioida nortoni Costa, Vanin, Ide, 1995 - Brazil
  
• Lagrioida obscurella Fairmaire & Germain, 1860 - Chile
  
• Lagrioida rufula Fairmaire & Germain, 1860 - Chile

Other Names for Lagrioida Fairmaire et Germain 1960

• Lagrioidinae Abdullah et Abdullah 1968

References

Abdullah M., Abdullah A. 1968. The Taxonomic Position of Lagrioida with a Proposed New Tribe of the Eurygeniinae (Col., Anthicidae). - Entomologist’s monthly magazine 104: 73-74.

Abdullah M. 1974. My Concept of the Beetle Family Cononotidae Crowson = Anthicidae (Coleoptera) - a New Interpretation of the Old Observations. - The Coleopterists Bulletin 28, No. 1: 17-25.

Blackwelder R.E. 1945. Checklist of the Coleopterous Insects of Mexico, Central America, the West Indies, and South America. Part 3. - Smithsonian Miscellaneous Collections 185: 343-550.

Blair K.G. 1928. Pars 99. Pythidae, Pyrochroidae: 1-56. In: Junk W., Schenkling S. (eds) Coleopterorum Catalogus. W.Junk, Berlin.

Costa C., Vanin S.A., Ide S. 1995. Larvae of Neotropical Coleoptera XXII. Description of Adults and Immatures of Lagrioida nortoni sp. n., and Bionomics (Coleoptera, Tenebrionoidea, Anthicidae). – Iheringia, Serie Zoologia, Porto Alegre 78: 113-126.

Crowson R.A. 1955. The Natural Classification of the Families of Coleoptera. Nathaniel Lloyd, London: 1-187.

Fairmaire L., Germain P. 1860. Coleoptera Chilensia. Extrait des Annales de la Société Entomologique de France. F.Malteste et Cie, Paris: 1-9.

Lawrence J.F., Britton E.B. 1991. Coleoptera (Beetles): 543-683. In: CSIRO Division of Entomology (ed.) Insects of Australia: a Textbook for Students and Research Workers, Second Edition. Vol. 2. Melbourne University Press, Carlton, Victoria.