Dimorfismo sessuale dei tubuli malpighiani rilevato in Mastigus pilifer Kraatz (Coleoptera Scydmaenidae)

A further peculiarity of this species is described; it deals with the anatomical condition of the Malpighian tubules in the adults, where each tubule includes a basal sack-like sector. Because literature refers similar modifications to the symbiosis with microorganisms, an inspection in this direction has been carried out. Although the above sector is markedly larger in the females, the study of its content didn’t provide any evidence about the presence of symbiotic microorganisms. Paper is dedicated to the memory of the clever entomologist, Prof. Baccio Baccetti. Key words: anatomical diversity, males, females, full-grown larvae. Al di là delle varie peculiarità morfologiche già note in letteratura per i membri del suo genere, Mastigus pilifer Kraatz manifesta una particolare condizione anatomica dei tubuli malpighiani. Infatti, i singoli tubuli presentano negli adulti un diverticolo sacciforme, che è nettamente più grande nelle femmine. In letteratura, simili modificazioni vengono messe in relazione con fenomeni di simbiosi con microrganismi; ma l’esame del contenuto dei diverticoli di Mastigus pilifer non ha fornito alcuna indicazione in tal senso

Studio sulla diversità anatomica della spermateca nei Coleotteri

ANATOMICAL DIVERSITY OF THE SPERMATHECA STUDIED IN COLEOPTERA Out of 144 figured species of Coleoptera, 5 patterns of this organ were detected throughout; they separate from each other by presence/absence of the three fundamental parts: receptacle, duct and gland. The most common pattern (55%) includes every part; whereas the rare pattern of Lacon punctatus includes the gland only. Observed in fresh preparations, spermatheca parts were recognized by following some criteria. (I) Receptacle does usually contain a dense mass of sperm; it was recognised in the parthenogenetic species, Ptinella mekura (Ptiliidae), by examining the amphygonic species of the same family. (II) A study of comparative anatomy allowed to recognized the receptacle of some Scolytidae, Curculionidae and Staphylinidae, where females are used to store sperm also into the adjacent gland. (III) Usually, duct doesn’t contain sperm; sometimes, it contains a low number of the latter if its connection to the receptacle is restricted in any way. (IV) Spermathecal gland, according to Berlese’s definition, is an anatomically separate part and usually includes an efferent duct and a large reservoir or a net of canalicles, both lined by hypertrophic epithelium. (V) Anatomical comparison with species of the same families allowed to recognize the spermathecal gland in two intriguing instances: (a) when gland is engaged to store sperm together with the adjacent receptacle; (b) when it is lone to represent spermatheca. Iconography reports on further details: (Figs. 6-7) receptacle as single part of the spermateca; (Fig. 9) receptacle internal protuberances; (Fig. 11) septate receptacles; (Fig. 14) inflatable receptacles; (Figs. 15-17) receptacles branched or subdivided; (Figs. 18-19) hypertrophic condition of the receptacle epithelium; (Figs. 20-21) extended muscular sheath; (Figs. 22-23) mechanical support for unsclerotized receptacles; (Figs. 24- 27) receptacle shape arrangements to support the compressor muscle; (Figs. 28-29) mechanical receptacle peculiarities; (Fig. 30) duct-lacking spermatheca; (Figs. 31-32) enormously long ducts; (Fig. 34) enlarged duct; (Figs. 35-36) heavy sclerotized duct cuticle; (Figs. 38-39) duct pumping devices even related with inflatable receptacles; (Fig. 41) sclerotized gland reservoir; (Figs. 42-43) gland pumping/valvular device; (Fig. 45) exceedingly large gland; (Fig. 46) gland reservoir overcoming the receptacle volume; (Fig. 47) gland exit at the duct or at genital chamber. Key words: terminology, fundamental patterns, anatomical peculiarities. Si espongono i risultati di uno studio basato sull’esame di preparati a fresco. Le tre parti tipiche della spermateca dei Coleotteri sono state riconosciute tenendo conto di una serie di criteri, in parte predeterminati e in parte emersi nel corso del medesimo studio. In rapporto alla presenza/assenza di “ricettacolo”, “dotto” e “ghiandola spermofila” sono stati individuati 5 modelli di spermateca, dei quali si annota la ricorrenza nelle 144 specie esaminate. Lo studio evidenzia alcune condizioni anatomiche eccezionali, tra cui: (a) una spermateca rappresentata dal solo ricettacolo; (b) una ghiandola spermofila impegnata a conservare una rilevante quantità di sperma; (c) varie forme di dispositivi pompanti del dotto. Parole chiave: terminologia, condizioni fondamentali, particolarità anatomiche

STUDI SULLE LARVE DEI COLEOTTERI DITISCIDI IV. Morfologia dei tre stadi larvali di Copelatus haemorroidalis F.

È trattata la morfologia esterna dei tre stadi larvali di Copelatus haemorroidalis F. (Dytiscidae, Colymbetinae) con l'intento di studiare le variazioni che essa subisce nel corso dello sviluppo larvale e di paragonarla con quella delle specie precedentemente esaminate; viene considerato con particolare attenzione il comportamento della chetotassi delle larve neonate. Si mettono in evidenza, inoltre, i caratteri che, nell'ambito della subf. Colymbetinae, appaiono esclusivi di specie del genere Copelatus.  MORPHOLOGY OF THE THREE LARVAL INSTARS OF Copelatus haemorroidalis F. The author relates about the characters that differentiate among them the three larval instars of Copelatus haemorroidalis F. This species has been taken into consideration because it belongs to the tribe Copelatini of the subf. Colymbetinae (in the preceding papers of the author some species of the tr. Agabini and tr. Colymbetini of the same Subfamily were examined). The morphology of this species is furthermore compared with that of the previously treated species and, in comparison with this, it showes some peculiar characters mainly règarding the head appendages: antennae with two appendages at the apex of the third segment, third antennal segment with three setae, mandibules without mandibular canal, maxillae with big claw-like appendages (in addition to the galea). Within the species of subf. Colymbetinae that are treated in the papers of the consulted bibliografy none of these characters is present, except in other species of the same tribe. Comparing the chetotaxy of the first instar larva of Copelatus with the chetotaxy of the previously treated first instar larvae, it is noticed that inter- or intraspecific variability may be found in the number of setae of determinate setae groups (setae of clypeal edge, dorsal face of prelabium, pronotum and femur); in different Genera it may be also noticed a little difference in the chetotaxy of thoracic sternites and pleurites and the presence or absence of the seta V2 in the abdominal VII and VIII segments. All the other setae of the fìrst instar larva are strictly constant and homologous in the since now examined species

Dettagli di morfologia larvale su Paraphloeostiba gayndahensis (Macleay) (Coleoptera Staphylinidae Omaliinae)

SOME MORPHOLOGICAL DETAILS OF PARAPHLOEOSTIBA GAYNDAHENSIS (MACLEAY) LARVAE (COLEOPTERA STAPHYLINIDAE OMALIINAE) Observations refer to an exotic rove-beetle, which does commonly occur in masses of plant debris in Southern Italy. In every instar, mandibles of its larvae exhibit both a large laminar prostheca and a comb of denticles. Although other larvae of the subf. Omaliinae posses the same type of prostheca (4 species in the genera Phloeostiba and Phloeonomus), presence of the mandibular comb is not reported for them. In author’s view, the larvae of P. gayndahensis are outermost adapted for feeding on rotten fruits; besides the mandibular comb, they bear in front of each mandible (on the upper wall of the preoral chamber) a couple of combs, which likely compose a device for cleaning the mandibles from food remains. Key words: denticulate mandibles, prostheca, preoral chamber, cleaning device. Vengono studiate le larve fitosaprofaghe di una specie esotica della subf. Omaliinae. Si evidenzia una particolarità delle loro mandibole, in merito alla presenza, sulla loro faccia dorsale, di un pettine di spinule, che presumibilmente agevola l’ingestione del cibo. In più, esse possiedono due coppie di pettini spinulosi del palato. Coordinando i dati bibliografici, si rileva che le larve fitosaprofaghe della subf. Omaliinae (generi Phloeostiba, Phloeonomus e Paraphloeostiba) sono accomunate dal possesso di un’ampia prosteca laminare. Nel caso di P. gayndahensis, le mandibole appaiono ulteriormente adattate per l’alimentazione fitosaprofaga, grazie alla presenza del pettine mandibolare, che ricorda le denticolazioni già note per le larve carpofaghe dei nitidulidi. Inoltre, le larve di P. gayndahensis posseggono sul palato una coppia di pettini spinulosi, che sembrano costituire un organo di pulizia per le mandibole. Parole-chiave: mandibole denticolate, prosteca, camera preorale, dispositivo di pulizia

Allestimento della cella pupale e del bozzolo nei Coleotteri: qualche dettaglio etologico (Polyphaga: 7 famiglie)

BUILDING OF THE PUPAL CELL AND COCOON IN COLEOPTERA: SOME ETHOLOGICAL DETAILS (POLYPHAGA: 7 FAMILIES) Details were observed in the laboratory on larvae of Ochthebius impressipennis (Hydraenidae), Ptinella aptera (Guérin-Méneville) (Ptiliidae), Anemadus acicularis (Kraatz) (Cholevidae), Mastigus pilifer (Scydmaenidae), Micropeplus fulvus Erichson (Micropeplidae), Cafius xantholoma (Gravenhorst), Megalinus glabratus (Gravenhorst) (Staphylinidae-Staphylininae), Atheta aeneicollis (Sharp), Cordalia obscura (Gravenhorst) (Staphylinidae-Aleocharinae), Omonadus bifasciatus (Rossi), O. floralis (Linné) (Anthicidae). According to species, pupal cell is sometimes built at the end of a deep gallery; otherwise, it is assembled at the surface by using: (a) rough soil particles; (b) selected soil particles; (c) soil portions ingested and regurgitated. Main behavioural particularities were detected in larvae of Ochthebius impressipennis, which build a unique double cell, and in larvae of Micropeplus fulvus, which do regurgitate very small portions at a time. Organs engaged in cell building are: mandibles, preoral chamber, foregut, legs. Cocoon spinning organs can be: mouth parts, legs, a comb of abdominal setae, paired glandular tubercles of abdomen, pygopodium. Examined larvae of Aleocharinae spin silk by pygopodium as other of the same subfamily do; they are provided with an equipment of metameric glandular pores, which may be possible source of the silk secretion as in the larvae of certain Pselaphidae. Contribution is dedicated to the memory of the clever entomologist, Giorgio Fiori (1923-1983). Key words: soil management, spinning organs, silk glands.Sulla base di osservazioni in terrario viene illustrato il comportamento di larve di Hydraenidae, Ptiliidae, Cholevidae, Micropeplidae, Staphylinidae e Anthicidae. Le novità più rilevanti riguardano le larve di Ochthebius impressipennis (Hydraenidae), che usano fabbricare una doppia cella, e quelle di Micropeplus fulvus (Micropeplidae), che usano ingerire il terriccio e rigurgitarlo in porzioni successive molto piccole. Secondo la specie, gli organi impegnati per la costruzione della cella sono: mandibole, camera preorale, intestino anteriore e zampe. I possibili organi per la tessitura della seta sono: appendici boccali, zampe, apposite filiere addominali, urogonfi. Nel caso delle larve della subf. Aleocharinae, la fonte del secreto sericiparo è inaccertata; presumibilmente, essa consiste in una serie metamerica di ghiandole unicellulari del torace e dell’addome, come accertato in precedenza nelle larve di alcuni pselafidi. La nota è dedicata alla memoria del Prof. Giorgio Fiori (1923-1983), a 25 anni dalla scomparsa. Parole chiave: sistemazione del terriccio, organi di filatura, ghiandole della seta.

Morfologia delle uova in alcuni Pselafidi (Coleoptera)

EGG MORPHOLOGY IN SOME PSELAPHIDS (Coleoptera) On the basis of materials obtained in laboratory, eggs of 13 species, 5 tribes, have been examined, and nine egg forms have been recognized. According to species, morphological variability affects: l) egg shape (spherical, sub- spherical, ellissoidal, egg-like), 2) corion structure (smooth, wrinkled, pimpled, reticulate), 3) presence of a tubercle, 4) presence of a filament, 5) colour (milk-white, whitish, ivory- or amber-coloured). Very characteristic feature of Pselaphus heisei is a fluid droplet (? mother's secretion) that covers every egg. Both inter- and intrageneric variability has been found. Viene documentata la variabilità morfologica delle uova in tredici specie di Pselafidi di cinque tribù. Essa si esprime nella forma complessiva dell'uovo, la struttura del corion, la presenza o meno di una parte filamentosa. Di molto particolare le uova di Pselaphus heisei presentano una sorta di protezione fluida che ricopre le singole uova

Note di anatomia sui genitali interni in alcuni Pselafidi (Coleoptera)

 ANATOMICAL NOTES OF THE INTERNAL GENITALIA  IN SOME PSELAPHIDS (COLEOPTERA) By both the literature and originai observations, data were gathered from males and females of thirteen species, as shown in the following table. Sulla base di osservazioni originali, viene fatta l'anatomia comparata degli apparati genitali interni maschili e femminili nelle seguenti specie di Pselafidi: Pseudoplectus perplexus, Euplectus bonvouloiri, Trimium brevicorne, Pseudozibus crassipes, Batrisodes oculatus, Tychobythinus glabratus, Bryaxis pedator, Rybaxis longicornis, Trissemus olivieri, Brachygluta perforata, B. abrupta septentrionalis e Pselaphus heisei parvus. Si riportano, inoltre, dati bibliografici su Claviger testaceus. Le variazioni anatomiche più importanti riguardano: -  nell'apparato maschile, la presenza/assenza e numero delle ghiandole accessorie; -  nell'apparato femminile, il numero degli ovarioli, la presenza/assenza delle ghiandole accessorie, la presenza/assenza della spermateca

STUDI SULLE LARVE DEI COLEOTTERI DITISCIDI II. Morfologia dei tre stadi larvali di Melanodytes pustulatus Rossi

MORPHOLOGY OF THE THREE LARVAL STAGES OF Melanodytes pustulatus ROSSI The author relates on the characters useful to the specifìc identifìcation of Melanodytes pustulatus Rossi in his three larval stages; further characters, useful to examine in detail the morphological differences among the three larval stages, are given. Finally, some characters of Melanodytes are compared with the corresponding ones of genus Rhantus Dejean: an interesting similarity has been found between Melanodytes and Rhantus (Nartus) grapei Gyll. in the characters of antennae, maxillae and labium.  Viene trattata la morfologia dei tre stadi larvali del Melanodytes pustulatus Rossi, considerando sia i caratteri strettamente utili al riconoscimento specifico delle larve di tale specie, sia i caratteri che presentano variazioni durante lo sviluppo larvale. Vengono, inoltre, riportate alcune osservazioni derivanti da un confronto fra la morfologia del Melanodytes e la morfologia di alcune specie del genere Rhantus Dejean; una interessante affinità viene riscontrata, nei caratteri delle appendici cefaliche, fra il Melanodytes e il Rhantus (Nartus) grapei Gyll

Osservazioni sulla ovideposizione e sul ciclo larvale in Mastigus pilifer Kraatz (Coleoptera, Scydmaenidae)

 OBSERVATIONS ON OVOPOSITION AND LARVAL CYCLE IN Mastigus pilifer KRAATZ (Coleoptera, Scydmaenidae)  Full-grown larvae of Mastigus pilifer can commonly be found in forest litter without any trace of younger instars, because of their unusual larva! cycle. The discovery of eggs and the study of internai organs of adults bave led to the following observations on ovoposition, female genital system and behaviour of larvae: l) Clusters of eggs are laid in autumn under stones and are coated with a white, bright secretion (fig 1-2). 2) This secretion is composed by some hundreds of small spherical capsules, mostly 100-150 !J.m in diameter, arranged in a very long double series; each capsule consists of a thin lined shell containing both an oily and a granulous substance (figs 3-4). 3) The source of such secretion is a pocket-shaped abdominal gland of the females, deriving from the intersegmental membrane between the 7th sternite and the genital segment, and bearing glandular epithelium on the inferior wall (figs 5-11). In females bearing mature eggs the reservoir of this gland is full up with an oily substance. 4) The larvae batch few days after ovoposition and the larva! cycle includes three instars. 5) During the 1st and 2nd instar the larvae do not depart from the secretion mass (fig. 12). The first moult takes piace about 20 hours after hatching, the second nearly 3 days later. 6) The 2nd instar larvae spend part of their time in breaking the secretion capsules, and they probably swallow the secretion. 7) The larvae leave the batch piace only after the second moult; they disperse in forest litter and probably search for alive preys (fig. 13). The 3rd instar larvae differ from the younger ones in body colour and number of antenna! segments. On head discum they bear a characteristic glandular area, from which they probably get a secretion for cleaning the antennae by means of their fore legs (fig. 14). It is evident that the larval cycle spares the 1st and 2nd instar larvae the search for food. The hypodermic colouring of the young larvae, which is similar to that of the eggs, suggests that an amount of yolk substances, deposited in the midgut and/or in the fat body, remains available for the larva! development. Furthermore, it is possible that the young larvae get an additional food source from the secretion which coates the egg mass. Le femmine di Mastigus pilifer posseggono nell'addome una profonda tasca ghiandolare, derivante dalla membrana intersegmentale fra 1'8° urosternite e il segmento genitale, che si riempie di un secreto di aspetto oleoso nel periodo di maturazione delle uova. All'atto della ovideposizione, questo secreto viene emesso sotto forma di una lunghis- sima doppia collana di minuscole capsule sferiche, che si deposita irregolarmente e ricopre l'ovatura. Le uova sono deposte in autunno, in gruppi, sotto le pietre, e schiudono pochi giorni dopo. Gli stadi larvali sono tre. La prima e la seconda muta avvengono rispettivamente a circa l giorno e 4 giorni di distanza dalla schiusura. Le larve di I e II età non si allontanano dal luogo di ovideposizione, ma si soffermano sopra la masserella di secreto materno; quelle di II età si dedicano a rompere le capsule di secreto con le mandibole e presumibilmente ingeriscono il liquido oleoso che si spande. Dopo la seconda muta le larve abbandonano i resti dell'ovatura e si disperdono nella lettiera in cerca di prede. Le larve mature presentano sul capo un caratteristico raggruppamento di corte setole spiniformi, inglobate in un secreto che probabilmente viene adoperato per la pulizia delle antenne

Appunti di storia naturale su uno Ptilide partenogenetico: Ptinella mekura Kubota (Coleoptera)

SOME REMARKS OF NATURAL HISTORY ON A PARTHENOGENETIC PTILIID, PTINELLA MEKURA KUBOTA (COLEOPTERA) Many tens of Ptinella mekura specimens were collected in a garden in Southern Italy, where they mainly occurred under man-made accumulations of grass and pine needles on coniferous humus; they sustained laboratory conditions very well and led to several generations in single vessels, throughout many weeks or months, and even for more than one year. Only wingless virgin females were collected in the field, and also the individuals born in laboratory were so. Females possess a very large oviduct, where they mature a single large egg at a time. Eggs exhibit a predetermined ecclosion line and a characteristic frame to adhere at substratum. Egg development is 8-10 days long. Fecundity was regarded as the number of eggs deposited by single females within 15 days after the installation of a rearing; it was evaluated by 4 series of rearings (6 rearings per series), respectively starting from 1, 2, 5 and 10 females collected in the field. 1 egg per day was recognized as the maximum value of fecundity. The larval development is 15 days long and includes 2 instars. The number of the larval instars was evaluated on a statistic basis, by considering together the width of the head capsule and the length of the urogomphi in 25 specimens of larvae at random. Larvae pupate after they have built a spherical chamber by soil particles. The pupal development is 5 days long. Freshly emerged adults are able to ovodeposit after 10 days. Because literature does not report the presence of males in the collections from the whole world (Japan, Europe and USA), Ptinella mekura can be regarded as “obligatory and constantly parthenogenetic species”, according to the terminology of RETNAKARAN PERCY (1985), in spite of the morphological constancy of its spermatheca. Key words: Coleoptera, Ptiliidae, Ptinella mekura, rearing, parthenogenesis.Numerose informazioni sul comportamento e sul ciclo vitale di Ptinella mekura Kubota sono state raccolte sfruttando le risorse di un giardino ricco di questa specie e installando numerosi allevamenti, di cui alcuni mantenuti per più di un anno. Sono stati studiati gli organi interni, sono state ottenute le uova, è stato seguito lo sviluppo delle larve, è stata osservata la costruzione della cella pupale, è stata calcolata la fecondità massima delle singole femmine, è stata verificata per via diretta la capacità di riproduzione partenogenetica della specie. Considerando i dati delle collezioni, Ptinella mekura viene giudicata quale specie completamente e costantemente partenogenetica. Parole chiave: Coleoptera, Ptiliidae, Ptinella mekura, allevamento, partenogenesi.