Physiomorphus Pic, 1917

Pollock, D. A., Ide, S. & Costa, C., 2000, Review of the Neotropical genus Physiomorphus Pic (Coleoptera: Mycteridae: Lacconotinae), with description of the larvae of three species, Journal of Natural History 34 (12), pp. 2209-2239 : 2211-2214

Genus Physiomorphus Pic

Physiomorphus Pic, 1917a: 16 . Type species Physiomorphus atricolor Pic , by monotypy. See below for discussion on spelling of generic name.

Batobiomorphus Pic, 1920: 16 . Type species Batobiomorphu s laticollis Pic, by monotypy. New synonymy.

Laccoderus Champion, 1916a: 106 . Type species Laccoderus chilensis Champion [5 Batobius humilis Fairmaire and Germain ], by original designation. New synonymy, in part.

Taxonomic notes

Champion himself (1916b) synonymized his genus Laccoderus , thinking that it was congeneric with Batobius Fairmaire and Germain. This conclusion was prompted by comparison of B. humilis Fairmaire and Germain , and Laccoderus chilensis Champion. However , the other two species originally included by Champion (1916a) in Laccoderus are not referable to Batobius . One, L. melanurus Champion , is a Physiomorphus , as detailed below. A new genus will be described (Pollock, in prep.) for placement of Laccoderus scaber Champion , as the name Laccoderus is unavailable for the other two species described by Champion in that genus.

There is some question as to the correct spelling of Physiomorphus . The original orthography is Physiomorphus , although Pic (1917a) compares it to Physcius Champion. Presumably , the generic name Physiomorphus was meant to draw attention to this fact. Therefore, it is unknown why Pic spelled it Physiomorphus and not Physciomorphus . A label written by Pic on the holotype of P. atricolor has` Physiomorphus ng’, indicating that the original spelling was not a lapsus. However, Pic (1917b) spells it Physciomorphus and then Physiomorphus (Pic, 1921) . There have been several other subsequent misspellings of this name (see Spilman, 1954: 90). The original spelling is not emended in the present work.

Biological data

See Appendix 1 for details on rearing and life cycle and Appendix 2 for description of the habitats in which the immature stages of Physiomorphus were collected.

Observations on rearing, biology and life cycle. The data on biology and life cycle were based on observations on material collected alive in the ®eld and kept in the laboratory. All examined Physiomorphus larvae were collected from under loosely attached bark of dead trees.

In the laboratory it was observed that many larvae built a chamber before moulting to the prepupa. These chambers were oval in shape and were of two kinds: (i) composed of small fragments of wood agglutinated forming a cocoon-like structure; or (ii) a cavity made by larva between the layers of the bark of the wood.

The larval gut contents could be observed through the transparent cuticle, and were composed of very tiny pieces of wood that had the same dark, reddish brown colour as the bark under which the larvae were found.

Cannibalism was observed in larvae of P. melanurus and P. subcostulatus . In some containers, two or more larvae were accidentally placed together; the body of one or more larva was found mutilated in one or two regions and just one larva was alive.

Parasitism. Parasitism by a species of the family Encyrtidae ( Hymenoptera, Apocrita, Chalcidoidea ) is recorded here for the ®rst time in the Mycteridae . Noyes (1980) and Noyes and Hayat (1984) listed the host insects and arachnids parasitized by Encyrtidae for the Neotropical and Indo±Paci®c Regions. Few families of Coleoptera , all of them belonging to the suborder Polyphaga , are recorded as hosts of encyrtids: Buprestidae (Buprestoidea) ; Anobiidae (Bostrichoidea) ; Nitidulidae , Silvanidae , Erotylidae , Coccinellidae , Lathridiidae (Cucujoidea) ; Tenebrionidae (Tenebrionoidea) ; Cerambycidae , Chrysomelidae (Chrysomeloidea) ; and Curculionidae ± Scolytinae (Curculionoidea) .

Three mature larvae of P. subcostulatus were parasitized by an unidenti®ed species of Encyrtidae . One larva was found on 28.vii and two others on 29.vii.1993, each of which was inside a chamber. The translucent integument made possible the observation of the pupae with parasitoids inside the larval body (seven to eleven per larva). Also, granular remnants (meconium) were observed at the lateral side, or more commonly, at the posterior end of the parasitoids.

Parasitoid pupae were separated inside the larval host skin by a kind of sheath. This method of pupation occurs in some polyembryonic Encyrtidae and the sheath could be formed by the cast of larval cuticle, or could be a product of the host, formed mainly from phagocytic blood cells surrounding the parasitoid ( Finlayson, 1987; Marchal, 1904; Thorpe, 1936).

The larva found parasitized on 28.vii was kept until the emergence of parasitoids, which occurred on 16.viii. Two male and ®ve female wasps emerged. The emergence of adult parasitoids was not seen, but the Physiomorphus larval skin was found with irregular openings made by the adult encyrtids, probably with the mandibles.

Prepupa. Costa and Vanin (1985) recognized three diOEerent types of prepupa in the Holometabola, one of them being found in Mycteridae . In this family the prepupa was described for Eurypus muelleri Seidlitz by Costa and Vanin (1977) and Stilpnonotus postsignatus (Fairmaire) by Costa and Vanin (1984). It was characterized as an intermediate and morphologically distinct phase between the last larval instar and the pupa, always involving an extra process of moulting and an extra period of nonfeeding quiescence ( Costa and Vanin, 1985: 344; Costa et al., 1988: 274, de®ned).

The prepupa of Physiomorphus (®gures 21±23) constitutes the third contribution to the knowledge of this phase of Mycteridae and, as pointed out by Costa and Vanin (1985), it is very probably an autapomorphic character of the family, which seems to be related to its diversi®ed habitats.

Diagnosis, adult

Adults of Physiomorphus may be separate d from other Neotropical Lacconotinae , by the following combination of characters: eyes large, relatively widely separated, with small ommatidia; antennae short, antennomeres submoniliform to slightly serrated (elongate, ¯abellate in P. mimeticus , new species); pronotal disc without lateral carina, with paired medial depressions; elytra with distinct vestiture, not marmorate.

Description, adult

Body (®gures 27±28) elongate, slightly ovate, subcylindrical to slightly depressed; body TL 3.9±9.4 mm; GEW 1.1±2.7 mm; body with sparse to dense, adpressed to semi-erect vestiture.

Head (®gures 29 ±36). Relatively short, only slightly narrowed behind eyes; frontoclypeal suture indicated by variously impressed arcuate depression; frons slightly depressed between antennal insertions, with two parallel grooves laterally; clypeus with short strip of unsclerotized cuticle; labrum transverse, outer surface truncated to slightly emarginate; antennal insertions slightly concealed by short lateral extension of frons. Antennae (®gures 37, 40, 42, 44, 47, 50, 52) relatively short, antennomeres variously shaped from moniliform to ¯abellate; scape globose to slightly elongate; in most species, antennomeres 2±10 moniliform, distinctly wider than long [slightly serrated in P. atricolor (®gure 40), antennomeres almost as long as wide in P. antennatus (®gure 47), and ¯abellate from antennomere 3 in P. mimeticus (®gure 37)]. Eyes large, subhemispherical; facets very ®ne, with very short, scattered, intrafacetal setae; inner edge slightly emarginate near antennal insertion; eyes moderately separated, inner margins slightly to distinctly ( P. mimeticus ) divergent posteriorly. Mandibles relatively slender, symmetrical; apices sharp, bidentate; terebral teeth present, especially distinct on right mandible; mola relatively large, subquadrate, similar on both mandibles, surface appearing smooth; ventral groove and microtrichia absent; prostheca long, digitiform, extended along inner margin of mandible from mola to near apex, fringed with ®ne microtrichia along occlusal margin. Maxilla with elongate palpi, apical palpomere slightly expanded to distinctly securiform; lacinia and galea both rounded, blunt distally, densely setose apically; mentum very slightly transverse; ligula transverse, expanded laterally and signi®cantly anterad of base of labial palpi; labial palpi short, distal palpomere generally similar in shape to distal maxillary palpomere, slightly less expanded; gula moderate in length, sutures convergent anteriorly, surface slightly convex.

Thorax. Prothorax (®gures 53±60) subquadrate, wider than long (GPW/PL 1.2±1.6); lateral margins of pronotal disc variously arcuate, somewhat angulate in some species, without lateral carina; disc with paired dorsal depressions, separated or joined; posterior pits present, joined by narrow, transverse groove; punctation uniform, simple or umbilicate; prosternal process narrow, knife-like to triangular, extended between but not posterior of coxae; internal portion indistinct; coxal cavities open externally; protrochantin concealed; prosternum distinct anterior of coxae, convex except for near coxal process, sunken slightly; mesosternum triangular, lateral margins straight; mesepisterna narrowly separated, or touching, anteriorly, with elliptical setose excavations anterolaterally; mesocoxal cavities closed partly by mesepimera; trochantins concealed; mesosternal process elongate, slender, in contact with short metasternal process; metasternum distinctly convex, with discrimen in posterior half; elytra elongate (EL/GEW 1.9 ±2.6), slightly ¯attened to moderately convex; epipleura distinct, narrow, attaining apex of elytra or to V3±V5 only; disc with ®ne to coarse, relatively uniform, dense punctation, with vestiture of mostly adpressed setae with few scattered, erect setae; area along suture with lighter coloured setae in some species; apical binding patch present, relatively short, visible or invisible dorsally; legs relatively slender, of equal size and similar shape on each thoracic segment; femora only slightly enlarged medially; tibiae slender, straight; tibial spurs short, inconspicuous, of equal size on each leg; tarsi 5±5± 4 in both sexes, penultimate tarsomere expanded ventrally, forming ¯eshy lobe; tarsal claw with large basal tooth; metendosternite with relatively wide stalk; laminae large, somewhat lobate laterally; insertion points of anterior tendons between lateral arms, relatively close to midline; wings (®gure 67) of normal size in all specimens examined, relatively darkly pigmented; membrane relatively short distal of closed radial cell; four veins reaching wing margin in medial region.

Abdomen. With ®ve ventrites, V1±V3 connate and distinctly longer than V4±V5; males with elevated, setose sex patch medially on V2; aedeagus (®gures 61±62) with tegmen consisting of two distinct parts, subequal in length; apical piece cleft deeply, distinctly emarginate along inner margin; median lobe simple, very wide basally and tapered apically, without discernible endophallic armature; tegmen oriented ventrad of median lobe; ovipositor (®gures 64±65) ¯exible, elongate; coxites three-segmented, sparsely setose, proximal segment longest; distal segment more darkly pigmented than other two; two pairs of elongate baculi present; styli relatively short, spindleshaped (®gure 68); bursa copulatrix relatively small, with accessory chamber; small, possibly glandular structure attached distally to accessory chamber.