FNZ 59 - Erotylinae (Insecta: Coleoptera: Cucujoidea: Erotylidae) - Materials and methods
Skelley, PE; Leschen, RAB 2007. Erotylinae (Insecta: Coleoptera: Cucujoidea: Erotylidae): taxonomy and biogeography. Fauna of New Zealand 59, 59 pages.
(
ISSN 0111-5383 (print),
;
no.
59.
ISBN 978-0-478-09391-9 (print),
).
Published 07 Sep 2007
ZooBank: http://zoobank.org/References/351ADE1F-65D8-44E1-9F57-C94CACEA93DF
Materials and methods
Material examined. Material used in this study (listed in the Appendix) are deposited in the following collections and in the care of the curators listed:
AMSA Australian Museum, Sydney, N.S.W., Australia, D. Britton
ANIC Australian National Insect Collection, CSIRO, Canberra City, A.C.T., Australia, A. Ślipiński
BPBM Bernice P. Bishop Museum, Honolulu, HI, U.S.A., A. Samuelson
CASC California Academy of Sciences, San Francisco, CA, U.S.A., D. Kavanaugh
CUMZ Cambridge University Museum of Zoology, Cambridge, U.K., W. Foster and R. Stebbings
FMNH Field Museum of Natural History, Chicago IL, U.S.A., A. Newton and P. Parrillo
FREY Frey Collection, Natural History Museum, Basel, Switzerlnd, E. Sprecher
HNHM Hungarian Natural History Museum, Budapest, Hungary, O. Mërkl
JNIC John T. Nunn collection, Dunedin, N.Z.
LUNZ Entomology Research Museum, Lincoln University, Canterbury, N.Z., J. Marris
NHML Natural History Museum, London, U.K. (formerly BMNH), M. Barclay
NMNH National Museum of Natural History, Smithsonian Institution, Washington, DC, U.S.A., N. Vandenberg
NZAC New Zealand Arthropod Collection, Auckland, N.Z., R. A. B. Leschen
OXUM Oxford University Museum of Natural History, Entomology, Oxford, U.K. (formerly HCOE), D. Mann
PESC Paul E. Skelley collection, Gainesville, FL, U.S.A.
Type Specimens. The types for many previously described species are located in the Natural History Museum, London, which houses the collections of Pascoe, Sharp, and most of the Broun collection (Horn et al. 1990). Reitter’s collection was split and the type of C. ferrugata Reitter may be in the A. Grouvelle collection, currently housed at the Museum National d’Histoire Naturelle, Paris (Horn et al. 1990), but the specimen could not be located. White’s species was located in Crotch’s Erotylidae Collection at Cambridge University.
Lectotypes were designated where the literature, available specimens, or label data presented an unclear case of which specimen was the “type”. These lectotypes are here designated to fix the identity of the species to a single specimen (ICZN 1999, Art.74.7.3). Where possible, type data for all species are presented to aid future researchers in locating and recognising primary types, or the specimens on which the present concept is based. Details are presented in the text under the species in question. In the type label notation, “/” is used to separate labels.
Specimen preparation. Many specimens required cleaning and remounting. Specimens remounted on card stock were glued with a water-soluble glue. Specimens remounted on points were fixed in place with glues which are soluble in either water or 95% ethanol. Dissected genitalia were placed in a drop of dimethyl hydantoin formaldehyde (DMHF) on a card mount usually separate from the remainder of the body as a means of preparation. The medium DMHF is soluble in water. Supplemental material was completely slide-mounted or kept in glycerin using the methods listed in Leschen (2003). Specimens chosen for genitalic dissection came from across the range of distribution and character variation of all species, and included most of the type specimens. Sexual dimorphism was noted in several species, although it is quite subtle in some. The degree of dimorphic male development varied between species, but not much occurs within species.
Examination of the internal sac. An interesting phenomenon occurred during preparation of many male genitalic dissections. When the aedeagus was removed from the KOH solution used for clearing, or from the DMHF, and placed in a drop of water, the internal sacs inflated. Transferring the genitalia briefly into a KOH solution and back into water frequently aided in this inflation. Apparently, the tissues were intact and, it is suspected, there was some blockage through the medial lobe which created diffusion pressures inflating the internal sac, allowing a detailed examination of its structures. Without this, species recognition would have been nearly impossible. This phenomenon needs to be studied further to determine its potential use in the study of other erotylids.
Images. Scanning electron micrographs were taken of uncoated specimens at low acceleration voltages (1.5–5.0 kv) with a JEOL JSM-5510LV. Thus, we were able to acquire quality images of all type specimens studied and make detailed studies of their external morphology. This aided tremendously in character evaluations.
Morphological terms. Where possible, structural names used here follow the definitions outlined in Leschen (2003), otherwise we follow McHugh et al. (1997) or Boyle (1956). Structures discussed below are labeled in the figures of the ventral body (Fig. 3) and male genitalia (Fig. 24). A list of important features used in the keys and in the cladistic analysis follows (a more complete list of morphological terms is provided by Leschen 2003):
Aedeagus: male intromittent organ of the cucujoid type (Crowson 1955) (Fig. 24) consisting of a tegmen and a median lobe (or penis) with an internal sac (with a flagellum, sclerotised base, and dorsal and ventral lobes), and a median strut. The tegmen is not useful for species identification.
Gula: ventral region of the head (see Fig. 12).
Legs: consisting of the basal coxa (with a small trochantin that is hidden), a short trochanter, elongate femur and tibia, and 5-segmented tarsus; the prolegs (first pair of legs) may be variable in shape between the sexes; the profemur and protibia of males may have tubercles on the inner margin.
Maxilla: appendage located below the mandible consisting of an inner galea and lacinea and outer palp of 3 segments, the terminal palpomere is dilated in Cryptodacne (see Fig. 13).
Mesoventrite: ventral portion of the mesothorax (Fig. 15).
Metaventrite: ventral portion of the metathorax which articulates anteriorly with the mesoventrite and posteriorly with the first ventrite of the abdomen; mesosubcoxal lines (or femoral lines) are present posteriorly to the mesocoxae in most species (see Fig. 17).
Ocular line: distinct lines, carinae or grooves located just dorsal to the eyes on the vertex of the head, which may extend along the lateral edges anteriorly or posteriorly.
Ovipositor: female genitalia involved in egg laying (Fig. 32).
Pronotum: dorsal portion of the prothorax consisting of a disc (entire portion of the pronotum above the carina) with well developed posterior and anterior angles; the lateral margin or lateral carina is smooth, a well developed marginal or basal bead or raised rim may be present. A longitudinal median strip that lacks punctures is diagnostic for some Cryptodacne.
Prosternum: the anterior and mesal walls of the coxal cavity (Fig. 19); the prosternal process is variable at the apex (it may be may be bilobed, weakly convex, or truncate apically).
Punctures: shallow pit-like impressions which extend into the cuticle and are often marked by a seta and/or a pore.
Setae: hair-like extensions of the cuticle which tend to be erect or suberect.
Distributions. Geographic distribution is recorded based on the codes developed by Crosby et al. (1998).
Species recognition. To determine the limits of Cryptodacne species we followed the phylogenetic species definition as outlined by Wheeler & Platnick (2000): “A species is the smallest aggregation of (sexual) populations or (asexual) lineages diagnosable by a unique combination of character states.” External morphological characters were used to identify what we hypothesised were species, but some of these characters were highly variable (e.g., setation, punctation). After dissection of specimens of Cryptodacne, it was clear that there were seven distinct species based on invariant male genitalic characters. For some species, females without associated males or females which lacked adequate label data were impossible to identify with confidence.