Effects of emperor moth larval secretions, hemolymph, and components on microorganisms and predators

The biological significance of the caterpillar scolus secretions, hemolymph, and compounds of four emperor moth species (Lepidoptera, Saturniidae) has been investigated by means of different biological tests and behavioral observations: 1. Larval body fluids and several components (e.g., phenylacetaldehyde) were shown to inhibit growth of certain bacteria but not of fungi. 2. Larval body fluids deter ants from feeding, evidently due to the strong behavior-modifying activity of several compounds therein. 3. Larval body fluids and whole caterpillars produce feeding-avoidance in model bird species. The findings suggest that these defensive mechanisms effectively protect saturniid caterpillars from pathogens and predators in nature.     

Biogenic amines and phenolics characterize the defensive secretion of saturniid caterpillars (Lepidoptera: Saturniidae): a comparative study

The morphology of the scoli of Eudia pavonia, Saturnia pyri and Eupackardia calleta last instar caterpilars has been clarified. Chemical and biochemical comparisons of scolus secretions and corresponding caterpillar haemolymphs indicate two differing defensive strategies: Eudia and Saturnia contain phenolic and related compounds, whereas Eupackardia additionally synthesizes biogenic amines (e.g. neurotransmitters) in considerable amounts. For most aromatic compounds from the caterpillars a theoretical biogenetic scheme is proposed. Deterrent effects of all secretions and most haemolymphs on particular predatory ants were ascertained.Abbrevations CI chemical ionisation - EI electronimpact ionisation - GC-MS gas chromatography-mass spectrometry - GS gland secretion - HL haemolymph - PMSF phenylmethylsulphonyl fluoride - SDS-PAGF sodium dodecyl sulphate-polyacrylamide gel electrophoresis - SEM scanning electron microscope     

Molecular phylogeny of silk-producing insects based on 16S ribosomal RNA and cytochrome oxidase subunit I genes

We have examined the molecular-phylogenetic relationships between nonmulberry and mulberry silkworm species that belong to the families Saturniidae, Bombycidae and Lasiocampidae using 16S ribosomal RNA (16S rRNA) and cytochrome oxidase subunit I (coxI) gene sequences. Aligned nucleotide sequences of 16S rRNA andcoxI from 14 silk-producing species were used for construction of phylogenetic trees by maximum likelihood and maximum parsimony methods. The tree topology on the basis of 16S rRNA supports monophyly for members of Saturniidae and Bombycidae. Weighted parsimony analysis weighted towards transversions relative to transitions (ts, tv4) forcoxI resulted in more robust bootstrap support over unweighted parsimony and favours the 16S rRNA tree topology. Combined analysis reflected clear biogeographic pattern, and agrees with morphological and cytological data.     

Complete mitochondrial genome of the atlas moth, Attacus atlas (Lepidoptera: Saturniidae) and the phylogenetic relationship of Saturniidae species

Mitochondrial genome (mitogenome) can provide information for genomic structure as well as for phylogenetic analysis and evolutionary biology. In this study, we present the complete mitogenome of the atlas moth, Attacus atlas (Lepidoptera: Saturniidae), a well-known silk-producing and ornamental insect with the largest wing surface area of all moths. The mitogenome of A. atlas is a circular molecule of 15,282 bp long, and its nucleotide composition shows heavily biased towards As and Ts, accounting for 79.30%. This genome comprises 13 protein-coding genes (PCGs), two ribosomal RNA genes (rRNAs), 22 transfer RNA genes (tRNAs), and an A + T-rich region. It is of note that this genome exhibits a slightly positive AT skew, which is different from the other known Saturniidae species. All PCGs are initiated by ATN codons, except for COI with CGA instead. Only six PCGs use a common stop codon of TAA or TAG, whereas the remaining seven use an incomplete termination codon T or TA. All tRNAs have the typical clover-leaf structure, with an exception for tRNA^Ser(AGN). The A. atlas A + T-rich region contains non-repetitive sequences, but harbors several features common to the Bombycoidea insects. The phylogenetic relationships based on Maximum Likelihood method provide a well-supported outline of Saturniidae, which is in accordance with the traditional morphological classification and recent molecular works.     

The classification, evolution and biology of the Costa Rican species of Cryptophion (Hymenoptera: Ichneumonidae)

The six known Costa Rican species of the campoplegine ichneumonid genus Cryptophion Viereck are described and keyed. The distribution of species throughout Costa Rica is detailed based on data gathered by an intensive Malaise trap survey of the ichneumonids of the country. Five new species are recognized: C. espinozai. C. guillermoi, C. manueli. C. moragai and C. tickelli , and a sixth, C. inaequalipes (Cresson) redescribed. The monophyly of the genus is demonstrated and the phylogeny of the Costa Rican species reconstructed. Host relationships have been established for all species in Costa Rica; they develop as koinobiont endoparasitoids of first to third instar larvae of Sphingidae or Saturniidae. Analysis of the host relationships from a phylogenetic perspective suggested that the genus first evolved using macroglossine sphingid larvae feeding on rubiaceous understorey plants as hosts, and subsequently diversified to utilize sphingine sphingids and ceratocampine saturniids feeding on a variety of food-plants. Most species appear to be monophagous and oligophagy is apparently a derived feature of one sister-species pair, C. espinozai and C. manueli . In Santa Rosa National Park, Costa Rica, only a small proportion of the species of Saturniidae and Sphingidae present are used as hosts by Cryptophion species. No one host species is parasitized by more than one Cryptophion species. No species of Cryptophion is known to parasitize more than one host species feeding on any one plant species. The monophagous species C. inaequalipes is only known to develop in its sphingid host when that host is feeding on one of its two alternative food-plants.     

数学形态学在昆虫分类学上的应用研究.Ⅲ.在科阶元上的应用研究

在科分类阶元上对半翅目、鳞翅目和鞘翅目8个科的23种昆虫图像中提取的昆虫面积、周长等11项数学形态特征进行了统计分析。结果表明,在科的阶元上11项特征可靠性大小依次为(似圆度、偏心率)>(面积、周长、横轴长、球状性)>(纵轴长、圆形性)>(形状参数、叶状性)>亮斑数。从数学形态学角度出发,夜蛾科等3个科的亲缘关系远近为夜蛾科与粉蝶科>大蚕蛾科与粉蝶科>夜蛾科与大蚕蛾科;鳃金龟等3科的亲缘关系远近为鳃金龟科与天牛科、丽金龟科与天牛科>鳃金龟科与丽金龟科。     

Phylogenetic relationships of wild silkmoths (Lepidoptera: Saturniidae) inferred from four protein-coding nuclear genes

Abstract.  The Saturniidae, or wild silkmoths, number approximately 1861 species in 162 genera and nine subfamilies including Cercophaninae and Oxyteninae. They include some of the largest and most spectacular of all Lepidoptera, such as the moon or luna moths, atlas moths, emperor moths, and many others. Saturniids have been important as sources of wild silk and/or human food in a number of cultures, and as models for comparative studies of genetics, development, physiology, and ecology. Seeking to improve the phylogenetic framework for such studies, we estimated relationships across Saturniidae, sampling all nine subfamilies plus all five tribes of Saturniinae. Seventy-five exemplars (45 Saturniidae plus 30 bombycoid outgroups) were sequenced for four protein-coding nuclear gene regions (5625 bp total), namely CAD (the fusion protein carbamoylphosphate synthetase/aspartate transcarbamylase/dihydroorotase), DDC (dopa decarboxylase), period, and wingless. The data, analyzed by parsimony and likelihood, gave a strongly resolved phylogeny at all levels. Relationships among subfamilies largely mirrored the pre-cladistic hypothesis of Michener, albeit with significant exceptions, and there was definitive support for the morphology-based proposal that Ludiinae form a tribe (Micragonini) within Saturniinae. In the latter subfamily, the African tribe Urotini was shown to be paraphyletic with respect to Bunaeini and Micragonini, also in accord with recent morphological findings. Relationships within the New World subfamilies Arsenurinae, Ceratocampinae and Hemileucinae nearly always accord with previous morphology-based phylogenies when both are clearly resolved. Within Hemileucinae, Hemileucini are paraphyletic with respect to the monotypic Polythysanini. A preliminary biogeographical analysis supports ancestral restriction to the New World, followed by dispersal and/or vicariance splitting most of the family into a largely New World versus a largely Old World clade.     

Morphology and Molecules Reveal Unexpected Cryptic Diversity in the Enigmatic Genus Sinobirma Bryk, 1944 (Lepidoptera: Saturniidae)

The wild silkmoth genus Sinobirma Bryk, 1944 is a poorly known monotypic taxon from the eastern end of the Himalaya Range. It was convincingly proposed to be closely related to some members of an exclusively Afro-tropical group of Saturniidae, but its biogeographical and evolutionary history remains enigmatic. After examining recently collected material from Tibet, northern India, and northeastern Myanmar, we realized that this unique species, S. malaisei Bryk, 1944 only known so far from a few specimens and from a very restricted area near the border between north-eastern Myanmar and the Yunnan province of China, may in fact belong to a group of closely related cryptic species. In this work, we combined morphological comparative study, DNA barcoding, and the sequences of a nuclear marker (D2 expansion segment of the 28S rRNA gene) to unequivocally delimit three distinct species in the genus Sinobirma, of which two are described as new to science: S. myanmarensis sp. n. and S. bouyeri sp. n. An informative DNA barcode sequence was obtained from the female holotype of S. malaisei—collected in 1934—ensuring the proper assignation of this name to the newly collected and studied specimens. Our findings represent another example of the potential of coupling traditional taxonomy and DNA barcoding for revealing and solving difficult cases of cryptic diversity. This approach is now being generalized to the world fauna of Saturniidae, with the participation of most of the taxonomists studying these moths.     

The complete mitochondrial genome of the Ailanthus silkmoth, Samia cynthia cynthia (Lepidoptera: Saturniidae)

The complete mitochondrial genome (mitogenome) of the Ailanthus silkmoth, Samia cynthia cynthia (Lepidoptera: Saturniidae) was determined. The circular genome is 15,345 bp long, and presents a typical gene organization and order for sequenced mitogenomes of Bombycidea species. The nucleotide composition of the genome is highly A+T biased, accounting for 79.86%. The AT skew of the genome is slightly negative, indicating the occurrence of more Ts than As, as found in other Saturniidae species. All protein-coding genes (PCGs) are initiated by ATN codons, except for COI and COII, which are tentatively designated by CGA and GTG, respectively, as observed in other insects. Four of 13 PCGs, including COI, COII, ATP6, and ND3, harbor the incomplete termination codons, T or TA. With an exception for tRNA^Ser(AGN), all other tRNAs can form a typical clover-leaf structure of mitochondrial tRNA. The 359 bp A+T-rich region of S. c. cynthia contains non-repetitive sequences, but harbors several features common to the Bombycidea insects, including the motif ATAGA followed by a poly-T stretch of 19 bp, a microsatellite-like (AT)₇ element preceded by the ATTTA motif, and a poly-A element upstream tRNA^Met. The phylogenetic analyses support the morphology-based current hypothesis that Bombycidae and Saturniidae are monophyletic. Our result confirms that Saturniini and Attacini form a reciprocal monophyletic group within Saturniidae.     

Pteromalid parasitoids (Hymenoptera) of Oulema oryzae (Kuwayama) (Coleoptera: Chrysomelidae) from Japan, with notes on Pteromalus bifoveolatus

The present paper discusses three Japanese species of Pteromalidae reared from cocoons of the rice beetle Oulema oryzae (Kuwayama, 1929) (Coleoptera, Chrysomelidae). Pteromalus cyclostomus Ishizaki sp. nov. is described. Spaniopus monospilus (Thomson, 1878) and Usubaia liparae Kamijo, 1983 are newly recognized as parasitoid wasps of O. oryzae , and the former is also recorded from Japan for the first time. Pteromalus bifoveolatus Förster, 1861 is also newly recorded from Japan, with a new host record from Samia cynthia pryeri (Lepidoptera: Saturniidae).     

Molecular phylogeny of silk producing insects based on internal transcribed spacer DNA1

Silk moths are the best studied silk secreting insects and belong to the families Bombycidae and Saturniidae. The phylogenetic relationship between eleven silk producing insects was analyzed using the complete DNA sequence of the internal transcribed spacer DNA 1 locus. The PCR amplification and sequence analysis showed variation in length ranging from 138 bp (Antheraea polyphemus) to 911 bp (Hyalopora cecropia). Microsatellite sequences were found and was be used to distinguish Saturniidae and Bombycidae members. The nucleotide sequences were aligned manually and used for construction of phylogenetic trees based on Maximum parsimony and Maximum likelihood methods. The topology in both the approaches yielded a similar tree that supports the ancestral position of the Antheraea assama.     

Natural History and Comparative Morphology of Immatures of <Emphasis Type="Italic">Gamelia anableps</Emphasis> (C. Felder &amp; R. Felder) (Lepidoptera: Saturniidae,Hemileucinae)

Egg, larva, and pupa of Gamelia anableps (C. Felder & R. Felder, 1874) are described for the first time and the chaetotaxy of the first instar provided. Eggs and selected structures of larvae and pupae were also investigated by means of scanning electron microscopy. Eggs are laid in clusters, are ellipsoidal and laterally flat. Larvae passed through eight instars in about 78 days. Pupation occurs inside a poorly organized cocoon of yellowish silk. The dark brown pupa is cylindrical in shape with appendages firmly fused together and to the body wall. The chaeotaxy is compared with other Saturniidae species belongining to Hemileucinae, Ceratocampinae, and Saturniinae and the natural history of G. anableps compared with other Saturniidae.     

Allometric growth and adaptive value of exaggerated body parts in the larvae of Gratiana spadicea (Klug) (Coleoptera: Chrysomelidae)

1. Larvae of tortoise beetles present exaggerated body parts in association with an abdominal shield, which is made of faeces and exuviae that are deposited on the urogomphi throughout ontogeny. Growth trajectories and scaling relationships of these functional structures associated with the shield, if any, are unknown. 2. This study of Gratiana spadicea first tested, under field conditions, whether there is adaptive value associated with the shield regarding protection against predation and sunlight. Then, under laboratory conditions, the growth trajectory and allometric relationships among body parts were investigated, including scoli, individual and apparent furcae, and shield. The influence of food deprivation on the development of these structures was also determined. 3. Findings from previous studies were confirmed, suggesting that the adaptive value assigned to the shield is related to protection against predators. The present study demonstrated for the first time that the shield acts as a parasol in cassidines, decreasing the exposure of their larval body to sunlight. The scoli and apparent furca are exaggerated structures of G. spadicea, the development of which involves allometric growth and greater energetic investment (positive allometry) during ontogeny. There was proportionally less energetic investment for somatic construction of individual furca (negative allometry) due to the accumulation of the exuviae. 4. The possible consequences, in terms of developmental costs and survivorship benefits associated with the evolution of such exaggerated structures, are discussed.     

The systematics and biology of the Costa Rican species of parasitic wasps in the Thyreodon genus-group (Hymenoptera: Ichneumonidae)

This paper presents an eco‐taxonomic study of the Neotropical representatives of the Thyreodon genus‐group (Hymenoptera: Ichneumonidae) present in Costa Rica, i.e. species of the genera Thyreodon and Rhynchophion. These ichneumonids are koinobiont endoparasitoids of the larvae of Sphingidae and Saturniidae. Intensive sampling in Costa Rica, conducted over 15 years, has revealed the presence of 23 species (12 of which are described here as new –Rhynchophion woodi, Thyreodon woodleyi, T. papei, T. whitfieldi, T. deansi, T. walkerae, T. sharkeyi, T. zitaniae, T. delvarei, T. schauffi, T. darlingi and T. carmeani), whereas earlier studies recognized only nine species in the same area. Several of the additional species we found are simply very scarce and thus unlikely to be encountered except by the type of intensive survey that, in the tropics, has only been conducted in Costa Rica. In some other cases, it has become apparent that more than one species has previously been confused under a single name. Thyreodon rufothorax Cameron is shown to be morphologically and biologically distinct from T. atriventris (Cresson), with which it has long been synonymized, and the relatively well‐known, chromatically distinctive species ‘T. laticinctus Cresson’ and ‘T. morosus Smith’ are both shown to be complexes of sibling species. Reared series have been essential in facilitating the separation of the species in these complexes. An illustrated key is provided to separate all taxa using simple morphological characters. Fourteen of the 23 species have been reared, and all have been found to be restricted to one or a few species of hosts, species of Thyreodon primarily on macroglossine Sphingidae (with one species on Saturniidae) and species of Rhynchophion on sphingine sphingids of the genus Manduca. No two species of these ichneumonids attack the same host caterpillar species, and not all species of macroglossines present in the study area are attacked by species in this genus‐group. Most species are apparently rather rare. Many have only been collected by rearing on a few occasions, other species have been collected at light (six in total) or in Malaise traps (ten in total), or by hand‐netting (20 in total), but no one method collected all of the species present in the principal study area, the Area Conservacion de Guanacaste. The two New World genera Rhynchophion and Thyreodon are found to be related to the Old World genera Dictyonotus and Euryophion, the former of which comprises species that are also sphingid parasitoids, whereas species of the latter attack the caterpillars of other large bombycoid moths, Saturniidae and Eupterotidae. A cladistic analysis shows that Thyreodon is the sister‐lineage to Dictyonotus, and Euryophion is the most basal lineage in the genus‐group. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society, 2004, 141 , 297–351.     

Sauropod haemal arches: morphotypes,new classification and phylogenetic aspects

Sauropod haemal arches are caudal bony structures that have been traditionally incorporated into two different types observed in different anatomical views: Y-shaped (anterior view) and forked (lateral view). This research proposes a classification combining information observed in anterior and lateral views. Four types of ‘Y-shaped’ and six types of ‘V-shaped’ chevrons were recognised. Complete chevron series in some eusauropods allows the comparison of topological equivalent structures along the tail and also among taxa. A basal titanosaur from Argentina exhibits mid-caudal chevron morphology in which more than one cranial and caudal process is present, arising from the distal blades as well as from the proximal rami, a condition not seen before in a sauropod dinosaur. The morphological variability seen in sauropod chevrons along the tail is in close relationship with the development and distribution of muscle. caudofemoralis longus, as seen in extant crocodiles and as previously proposed for non-avian theropods and for caudal centra and transverse processes of sauropod dinosaurs. Two new characters related to middle chevrons are proposed here, in which the transitional morphology is described.     

Phylogeny of the major tetrapod groups: Morphological data and divergence dates

Summary The phylogeny of the major groups of tetrapods (amphibians, reptiles, birds, and mammals) has until recently been poorly understood. Cladistic analyses of morphological data are producing new hypotheses concerning the relationships of the major groups, with a focus on the identification of monophyletic groups. Molecular phylogenies support some of these views and dispute others. Geological dates of the major evolutionary branching points are recalculated on the basis of the cladograms and new fossil finds.     

Complete mitochondrial genome of Saturnia jonasii (Lepidoptera: Saturniidae): Genomic comparisons and phylogenetic inference among Bombycoidea

The complete mitochondrial genome (mitogenome) of Saturnia jonasii (Lepidoptera: Saturniidae) was sequenced and compared to those of 19 other bombycoid species. Furthermore, the mitogenome sequences were used to infer phylogenetic relationships among bombycoid species. The 15,261-bp Saturnia jonasii mitogenome contained the typical sets of genes and gene arrangements found in majority of Lepidoptera. All Bombycoidea species, including Saturnia jonasii, have a 15–33-bp spacer sequence at the trnS₂-ND1 junction. The phylogenetic reconstruction of bombycoid species consistently and strongly supported monophylies of the families, Saturniidae, Bombycidae, and Sphingidae, based on Bayesian inference (BI) and maximum-likelihood (ML) methods. Among these families, the Bombycidae and Sphingidae species consistently showed a sister relationship, regardless of data partitions; the BI method strongly supported this relationship, whereas it was moderately supported using the ML method.     

The complete mitochondrial genome of the Chinese oak silkmoth, Antheraea pernyi (Lepidoptera: Saturniidae)

We determined the complete nucleotide sequence of the mitogenome from Chinese oak silkmoth, Antheraea pernyi (Lepidoptera: Saturniidae). The 15,566 bp circular genome contains atypical gene organization and order for lepidopteran mitogenomes. The mitogenome contains the lowest A+T content (80.16%) among the known lepidopteran mitogenome sequences. An unusual feature is the occurrence of more Ts than As, with a slightly negative AT skewness (−0.021), in the composition of the major genome strand. All protein-coding genes are initiated by ATN codons, except for cytochrome oxidase subunit I, which is proposed by the TTAG sequence as observed in other lepidopterans. All transfer RNAs (tRNAs) have a typical clover-leaf structure of mitochondrial tRNA, except for tRNA ^Ser (AGN) , the DHU arm of which could not form a stable stem-loop structure. Two aligned sequence blocks with a length of more than 50 bp and 90% of the sequence identity were identified in the A+T-rich region of the Saturniidae and Bombycoidae species.     

Comparative and experimental studies on the relationship between body size and countershading in caterpillars

Countershading is a gradient of colouration in which the illuminated dorsal surfaces are darker than the unilluminated ventral surface. It is widespread in the animal kingdom and endows the body with a more uniform colour to decrease the chance of detection by predators. Although recent empirical studies support the theory of survival advantage conferred by countershading, this camouflage strategy has evolved only in some of the cryptic animals, and our understanding of the factors that affect the evolution of countershading is limited. This study examined the association between body size and countershading using lepidopteran larvae (caterpillars) as a model system. Specifically, we predicted that countershading may have selectively evolved in large-sized species among cryptic caterpillars if (1) large size constrains camouflage which facilitates the evolution of a trait reinforcing their crypsis and (2) the survival advantage of countershading is size-dependent. Phylogenetic analyses of four different lepidopteran families (Saturniidae, Sphingidae, Erebidae, and Geometridae) suggest equivocal results: countershading was more likely to be found in larger species in Saturniidae but not in the other families. The field predation experiment assuming avian predators did not support size-dependent predation in countershaded prey. Collectively, we found only weak evidence that body size is associated with countershading in caterpillars. Our results suggest that body size is not a universal factor that has shaped the interspecific variation in countershading observed in caterpillars.