Nymphal Characters Research Articles

A Revision of the Australian Ephemeroptera GenusAtalomicriaHarker (Leptophlebiidae: Atalophlebiinae)

The Australian leptophlebiid genus Atalomicria Harker is redescribed and nymphal characters are incorporated. The nymph of Atalomicria sexfasciata is described for the first time, together with four new species, one from Victoria and three from southern Queensland. Atalophlebia yugana Harker is transferred to Atalomicria. A key to male imagines and nymphs of the genus is provided.

A phylogenetic analysis of theEnchenopa binotataspecies complex (Homoptera: Membracidae) using nymphal characters

Abstract.Nymphal characters which distinguish the nine species of theEnchenopa binotatacomplex (key included) are delineated for future formal species descriptions. A phylogenetic tree using these characters is presented and compared to a tree derived from allozyme data. Three pairs of sister species are defined, two of these pairs meeting strict phylogenetic and biological criteria which suggest sympatric speciation through host shifts.

Juvenile Precocity and Maintenance of Juvenile Features in the Males of the PentastomeKiricephalus pattoni(Stephens, 1908) Sambon, 1922

Summary Male nymphs of the pentastome Kiricephalus pattoni become sexually mature in the second intermediate host, the water snake Tropidonotus piscator. Pairing of male and female nymphs, and sperm transfer, occur at the same stage. Males (but not females) retain nymphal characters within the definitive host, the rat snake Ptyas mucosus.

Newer trends in the biosystematics of Membracidae

Membracids, in general, display a very few morphological characters of taxonomic value. Many species exhibit remarkable intraspecific variations, in addition to sexual dimorphism and cornuate polymorphism that makes it difficult to allocate them to their respective taxa, unless a long series of male and female individuals belonging to the same population are available for examination. The male genitalia, although of value in the diagnosis of higher categories of the Membracidae, find limited application at the species level. The nymphal characters, especially those of the fifth immature stage, are very useful in the identification of the species, but nymphal materials are not available except for a few species, and the host plants of many species remain unknown. In recent years, it has become imperative to consider the ecophysiological aspects of these insects for a better and precise understanding of their systematics. The host plant specificity of some species of membracids, the mutual association of a particular species of membracids with a particular species of ants and the parasite-host interaction involving certain chalcidoid egg parasites of membracids are considered with a view to evaluate their role in the membracid taxonomy. The impact of differential reproductive potential in terms of host diversity, the allochronic differences in mating and initiation of oviposition, and the differences in the relative growth patterns with particular reference to the polymorphic speciesOxyrhachis tarandus (Fabricius) on 5 species is investigated.

CTENARYTAINA LONGICAUDA SP. N. (HOMOPTERA: PSYLLOIDEA) FROM LOPHOSTEMON CONFERTUS (R. BROWN) IN AUSTRALIA AND CALIFORNIA

AbstractCtenarytaina longicauda sp. n. has been collected in Queensland from Lophostemon confertus (R. Br.) and L. suaveolens (Soland. ex Gaertn.), and in 3 counties of California from ornamental trees of the former (previously Tristania conferta). Adult and nymphal characters of the genus are defined.

The adult stage of three Central American Baetodes (Ephemeroptera: Baetidae) with notes on the genus

Adults of Baetodes tritus, B. velmae and B. deflciens from Panama and eggs of & tritus and B. velmae are described and illustrated. Pseudocloeon arawak is transferred to Baetodes. Generic characters of Baetodes are discussed and additional nymphal characters are given.

Differentiation of worker-derived intercastes and precocious imagoes after queen removal in the Neo-Guinean termite Nasutitermes princeps (Desneux).

Numerous female workers underwent a beginning of sexualization in an experimentally orphaned colony of the Neo-Guinean termite N. princeps (Desneux). This led to the development of intercastes, displaying variable mosaics of worker, nymph, and soldier characteristics. The developmental pathways of these intercastes were studied with the help of multivariate techniques that revealed two main lines, one ending in a new "giant soldier" morph, the other proceeding toward the differentiation of nymphal characters, i.e., wing pads and compound eyes. It is not known whether these individuals might ultimately have become functional. Precocious adults resulting from a shortened nymphal course were also present, and one young replacement queen had already begun laying eggs.

GENERIC REVISIONS OF MAYFLY NYMPHS: II. THRAULODES IN NORTH AND CENTRAL AMERICA (LEPTOPHLEBIIDAE)

AbstractThe 26 North and Central American species of Thraulodes are discussed, and synonymies and other pertinent data are presented for all species. On the basis of nymphal gill characters two groups of related species are recognized. Thraulodes brunneus, T. speciosus, T. sp. A, T. sp. B, and T. sp. G are included in the brunneus-group, and T. gonzalesi, T. lunatus, T. packeri, T. salinus. T. zonalis, T. sp. C, T. sp. D. T. sp. E, and T. sp. F form the gonzalesi-group, The 14 species of nymphs are included in an illustrated key and on distribution maps, and the account of each includes complete synonymy, nymphal description, and collection records. Nymphs designated as Thraulodes spp. A, B, C, D, E, F, and G are described, and new descriptions are presented for nymphs of T. packeri and T. zonalis.

Influence of Farnesyl Methyl Ether on the Metamorphosis of Blattella Germanica (L.).

When farnesyl methyl ether was applied to a metathoracic trochanteral wound surface of specifically aged nymphs of Blattella germanica (L.), nymphal characters persisted after metamorphosis in the prothoracic shield, cerci, male subgenital sterna, the general facies of the abdomen, and certain structures of the male external genitalia. The juvenilising effects of treatment in the sixth (final) instar were more marked than in the fifth, and treatment in the fourth instar showed least effect. The morphology of all adult structures, with the exception of the prothoracic shield, was irrevocably committed at or slightly before the critical period for regeneration of the final nymphal instar. Aspects of the control of this commitment by endogenous hormones and the applied juvenoid are discussed.

NYMPHAL CHARACTERS AND HIGHER CLASSIFICATION ANALYSIS IN THE MIRIDAE (HEMIPTERA: HETEROPTERA) WITH A SUBFAMILY KEY BASED ON THE NYMPHS

AbstractA key to the subfamilies of Miridae based on fourth and fifth instar nymphs is provided and the value of some nymphal characters in arriving at relationships between the subfamilies is discussed. It is suggested that the reduction of parempodia to bristles most likely occurred twice in the family rather than that membranous parempodia were twice evolved. The Hyaliodes group is reviewed and the subfamily status accorded it by some authors is confirmed.

Notes on the Genus Toritrombicula (Sasa Et Al.) With Designation of Neotype, Description of Nymph and Redescription of Larva of Tori. Densipiliata (Walch), and Descriptions of Two New Species from Southeast Asia (Acarina : Trombiculidae)1

Nearly all the known species of Toritrombicula are bird-infesting parasites. A historical review of Tori. densipiliata is given and a neotype is designated to replace Walch's type of T. densipiliata which is lost. The genus is redefined on the basis of larval, nymphal and adult characters and 2 new species of Toritrombicula ( uphami and asa ) are described. Womersley & Audy's subspecies Tori. densipiliata dumbletoni is given specific rank.

NEW SPECIES OF NEW WORLD LEPTOHYPHINAE (EPHEMEROPTERA: TRICORYTHIDAE)

AbstractThe genera Leptohyphes Eaton and Tricorythodes Ulmer are confined to the New World, and the Nearctic limits of Leptohyphes has been extended from Texas to Maryland and Utah. Useful nymphal characters are presented for both genera, and descriptions and figures are included for 22 new species of Leptohyphes Eaton, and 7 new species of Tricorythodes Ulmer.

Revision of the bat-infesting chiggers of Chiroptella Vercammen-Grandjean (Acarina: Trombiculidae), with descriptions of two new larval species and a nymph.

The subgenus CHIROPTELLA Vercammen-Grandjean is elevated to generic rank on the basis of larval and nymphal characters. The subgenus Neosomia Vercammen-Grandjean & Nadchatram in the genus Riedlinia is transferred to, and retained as, a subgenus in CHIROPTELLA . The subgenus CHIROPTELLA now contain 6 previously known species and 2 new species, CHIROPTELLA ( C. ) sandoshami collectted from Hipposideros spp. in Malaysia, Thailand, and Laos, and C. ( C. ) noticola collected from Hipposideros and Emballonura spp. in Solomon Is. and New Britain. The subgenus Neosomia comprised of a single species, Chiroptella (Neosomia) audyi (Vercammen-Grandjean & Nadchatram). C. (C.) sandoshami is the only species in the genus for which the nymph is known and it is here described for the first time.

HISTOLOGY OF THE CORPORA ALLATA OF MELANOPLUS DIFFERENTIALIS (ORTHOPTERA: SALTATORIA)

1. The corpora allata of the grasshopper Melanoplus differentialis were studied histologically to determine whether these glands show changes related to their functions in the control of nymphal development and the production of ripe eggs and oviducal secretion.2. Four classes of cells were recognized in the corpora allata of this insect: a, connective tissue and tracheal cells; b, undifferentiated cells; c, normal secretory cells; and d, giant secretory or polyploid cells.3. The undifferentiated cells are small cells which divide mitotically and do not contain secretory granules or vacuoles. They show the greatest mitotic activity at the beginning of each developmental stage but occasionally divide at other times.4. The glandular cells, both normal and polyploid, show characteristic changes related to secretory activity and inactivity which are fundamentally the same in nymphs and adults and in both sexes. During inactive phases they are reduced in size and resemble undifferentiated cells. During active phases they increase in cytoplasmic and nuclear volume, the cytoplasm becomes filled with strongly acidophil granules, then intracellular and finally intercellular vacuoles appear. At the height of secretory activity the appearance of the gland suggests that materials are flowing from central regions of the gland to the periphery.5. In the fifth nymphal stage, at the end of which nymphal characters are produced, secretory material is elaborated throughout the intermolt period; active release of secretion occurs during the latter half of the stage. In the sixth stage, which terminates with the production of adult characters and metamorphosis, the glands show histological evidence of activity only during a brief period which begins on the second or third day after molting and ends around the middle of the stage.5. The corpora allata are inactive on the day the grasshopper enters the adult stage, but the histological changes which lead to the production and release of secretory material begin immediately thereafter. Full secretory activity is achieved in the corpora allata of adult females shortly before the onset of the production of oviducal secretion and yolk. It is reached at an equivalent time in adult males.

Immature Forms of the Mite, Caeculus Pettiti

Vitzthum (1933) described the larva of a new species of mite, Caeculus willmanni , from Guatemala. Both the description and the figure of this larva are so at variance with the appearance of C. pettiti that it was thought worth while to describe and to figure the larva and nymph of the latter species. Jacot (1936) compared some nymphal characters with adult characters for C. laoshanensis, C. sinensis and C. sinensis taishanicus .

Notes on Odonata of Surinam IV.1 Nine New Or Little Known Zygopterous Nymphs from the Inland Waters

The nymphs of the rich neotropical Odonate fauna are but very poorly known. In this contribution nine nymphs are described, of which seven were identified by rearing or by the study of the wing venation and the penis. These will be of importance for our knowledge of the nymphal characters in general and concerning the systematic position of some doubtfully arranged species.

The Determination of Characters at Metamorphosis in Rhodnius Prolixus (Hemiptera)

ABSTRACT Two factors have been recognized as regulating moulting and metamorphosis in Rhodnius prolixus: a “moulting hormone” and a so-called “inhibitory hormone” (Wigglesworth, 1934, 1936).

XXI.—On the Immature Stages of some Scottish and other Psyllidæ

The nymphs that are here described belong to those species the biology of which has been discussed in a previous paper (Lal, 1934 b). The plan followed was the one originally adopted by Ferris (1923), in which descriptions and illustrations of all morphological features important in the identification of the species of the nymph, apart from the adult, were prepared from careful examination of specimens mounted for microscopic observation. The importance of such a study has been increasingly appreciated in the last decade, both from the economic and the systematic points of view. Harmful species of Psyllidæ are mainly injurious because of the feeding activities of their immature stages, and there are but two species known, Psyllia pyricola Först. and Paratrioza cockerelli Sulc., in which the adults have also been found to be capable of causing injury. On the other hand, the specific determination of immature stages has been rendered difficult owing to the fact (first) that the published descriptions of individual species of nymphs are often found to be applicable to species other than those to which the particular description refers; and (second) that sometimes the nymphs of two closely allied species are distinguished by such marked differences as to warrant the adults being assigned to different genera and even subfamilies. Such cases have been mentioned by Crawford (1919), Ferris (1928 a), Husain and Nath (1927), and have been summarised by Rahman (1932) in the introductory part of his paper. The present descriptions have, therefore, been prepared with the avowed objects of facilitating the determination of individual species, where comparison with allied species is impossible owing to lack of available material, and also of assessing the value of the various nymphal characters with a view to establishing a classification based on these as contrasted with one based upon the characters of the adults.

A NEW ARCTIC BAETID (EPHEMEROPTERA)

During the month of August, 1935, Mr. W. J. Brown, who accompanied the Arctic trip of the S. S. Nascopie, was enabled to make insect collections at Lake Harbor, on the south coast of Baffin Island.The only species of Ephemeroptera obtained were two Baetids which were plentiful in both nymphal and adult state and for which definite associations between nymph and adult were secured.The one species, which occurred in both sexes, bears so much resemblance to Acentrella lapponica Bngtsson. that I am holding it under this name pending an examination of some of the material by Professor Bengtsson. The second species, a typical Baetis, could only be found in the female sex, nor could Mr. Brown, in spite of diligent searching, discover any imales amlongst the mature nymphs in the brook; it would seem that the species was parthenogenetic, at 1east as far as thecycle emerging in August was concerned. On nymphal characters it falls in the bicaudatus group, with the middle tail reduced to a stub, but can at once be separated by the much larger and relatively narrower type of gill. The following description is offered as the species appears to be undescribed.