Analysis of insect distribution in the Northern Hemisphere by the example of the subfamily Arctiinae (Lepidoptera,Arctiidae). 2. Species level

An attempt is made to apply cluster analysis to comparison of local faunas in the Northern Hemisphere at the species level by the example of the subfamily Arctiinae (Lepidoptera, Arctiidae). A total of 200 North African, Eurasian (New Guinea inclusive), and North American (north of the United Mexican States) local faunas have been considered. It is found that the circumarctic fauna is clearly separated from the Palearctic and Nearctic ones, being closer to the former only at the level of genera. Therefore, it is not reasonable to recognize the united European-Canadian subprovince of the boreal belt according to the tiger moth faunas. The Palearctic tiger moth fauna is characterized by relatively smooth variations within the boreal, subboreal, and western subtropical belts. The fauna gradually changes from the Amur catchment area to South China, Himalayas, and India so that all fauna types of these regions are closely related to one another and, to a lesser extent, to equatorial fauna types of Southeast Asia islands. The boundary between the Palearctic and Oriental (Indo-Malayan) provinces should be drawn north of the Yangtze catchment area. The most dramatic fauna change at the species level takes place between North China and the Yangtze catchment, and at the genus level, between Northern and Northeastern China. It is reasonable to establish a broad transition area between the two zoogeographic provinces in Eastern Asia. On the grounds of the nonuniform tiger moth fauna, the South Chinese-East Himalayan subprovince should be assigned to the Oriental (Indo-Malayan) province rather than the Palearctic one, as was repeatedly proposed. The Southwest-Asian fauna (Arabian Peninsula and southern Iran) is transitional between the Palearctic, African, and Oriental ones. Many African taxa penetrate to the west and south of the Arabian Peninsula, whereas Oriental and Paleotropical species penetrate to southern Iran. It is reasonable to elevate considerably the rank of the Quinghai-Tibet highland fauna by distinguishing its habitat as a separate zoogeographic subprovince, because the similarity between this fauna type and any other Palearctic fauna at the species level is much less than between temperate faunas of the Palearctic and Nearctic. The assignment of this fauna to the Palearctic is confirmed only at the genus level.     

Systematics and origin of moths in the subfamily Arctiinae (Lepidoptera,Erebidae) in the Neotropical region

The availability of standard protocols to obtain DNA sequences has allowed the inference of phylogenetic Hypotheses for many taxa, including moths. We here have inferred a phylogeny using maximum‐Likelihood and Bayesian approaches for a species‐rich group of moths (Erebidae, Arctiinae), with strong emphasis on Neotropical genera collected in different field campaigns in the Atlantic Forest of Brazil, eastern Amazon and southern Ecuador. A total of 277 species belonging to 246 genera were included in the analysis. Our main objectives were to shed light on the relationships between suprageneric groups, especially subtribes, and hypothesize colonization events in and out of the Neotropics. The monophyly of Arctiinae and its four tribes (Lithosiini, Amerilini, Syntomini and Arctiini) was recovered in the ML and Bayesian trees. Three Lithosiini subtribes previously found and two additional species groups were recovered monophyletic in both phylogenetic estimation methods. In Arctiini, the monophyly of Spilosomina and Arctiina was highly supported in the ML and Bayesian trees, but the monophyly of Ctenuchina and Echromiina was weakly supported in the ML tree and absent in the Bayesian tree; the remaining subtribes were paraphyletic and, in the case of Phageopterina, formed several species groups. The mapping of species occurrence in our ML tree suggests that Arctiinae have an Old World origin and that the Neotropical region was colonized at least six times independently. Our analysis also suggests that a number of species that occur in Neotropical and other zoogeographic regions may have originated in the Neotropics, although further taxon sampling is required to support this hypothesis. To our knowledge, this is the first time that a highly speciose group of tropical moths is well covered in a phylogeny, and it seems plausible that the results reported here may be extendable to other species‐rich tropical undersampled moth taxa.     

Description of two new Lophocampa Harris from the Dominican Republic (Arctiidae, Arctiinae)

Two new species of Lophocampa Harris are described from the Dominican Republic, Lophocampa lineatasp. n. based on two males, and Lophocampa albitegulasp. n. based on three females. The habitus and genitalia are illustrated. The following nomenclatural changes are also proposed: Lophocampa albiguttata Boisduval, 1870, stat. rev. and Lophocampa brunnea Vincent, nom. n.     

Survey of the native insect natural enemies of Hyphantria cunea (Drury) (Lepidoptera: Arctiidae) in China

The fall webworm, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), is an invasive and important pest in China. Investigations on insect natural enemies have been conducted from 1996 to 1999 in five provinces and one municipality of China in order to select effective species for biological control. Two carabid predators (Coleoptera) and 25 parasitoid species were found, among which 23 were parasitic wasps (Hymenoptera), including five hyperparasitic species and two tachinid flies (Diptera). The two carabids preyed on young larvae inside webs, two braconid wasps parasitized larvae, and 18 parasitoid species attacked the fall webworm during the pupal and/or 'larval-pupal' stages. Among these parasitoids, there were one genus and nine species that are new to science and four species new to China, which were described and published by the senior author Yang. The average parasitism rates of fall webworm pupae were 25.8% and 16.1% in the overwintering generation and the first generation (summer generation), respectively. These findings reveal that these natural enemies play an important role in the natural control of the pest. Chouioia cunea Yang (Hymenoptera: Eulophidae), a gregarious pupal endo-parasitoid, was recommended as a promising biological control agent against the fall webworm in China.     

The population ecology of the Cinnabar Moth,Tyria jacobaeae L. (Lepidoptera,Arctiidae)

Summary This paper describes the results of a study of the factors determining the abundance and distribution of the Cinnabar Moth in Britain. The main part of the study was on a population of the moth at Weeting Heath in Norfolk. This is an area of sandy heath which is heavily overgrazed by rabbits. Here the moth fluctuates violently in number and periodically it completely defoliates its food plant (ragwort, Senecio jacobaea L.) over large areas. This happened in 1960, 1961, 1967, and 1968.Since 1966, the numbers of the moth have been studied in detail and Life Tables are presented for five years.Adult fecundity varies considerably between years. This is due mainly to fluctuations in adult size resulting from changes in larval density. By comparison adult mortality and dispersal have little effect on fecundity; although there is some evidence to suggest that dispersal is density dependent. Because the number of eggs laid in one generation depends on the size of the previous generation, fecundity tends to be acting as a delayed density dependent factor.Mortality is low during the egg stage, but is high amongst young larvae, due mainly to arthropod predation. As the caterpillars grow they become immune from this predation. They are distasteful to vertebrate predators.A larval parasite, Apanteles popularis, kills many of the fully grown larvae. The highest rates of parasitism have coincided with the lowest densities of the moth, however, so that over the five years it has acted as an inverse density dependent factor.In 1967, the population became so large that the ragwort was completely defoliated, and about 20% of the caterpillars died from starvation. In the following year the population was still large and the ragwort plants were small, owing to the effects of defoliation in the previous year. Food ran out early in the season and about 50% of the larvae starved. Because of the overriding effect of starvation, total larval mortality tends to be density dependent.Mortality is high at, or immediately after, pupation and this is thought to be due primarily to predation by moles (Talpa europaea). Pupal mortality does not appear to be density dependent.The upward growth of the population is limited by food supply. Starvation led to a population crash, so that in 1969 only 62 eggs/150 m² were laid compared with 17110 and 16493 in the previous two years. The rate of recovery of the population after this crash was dependent upon the rapid recovery of the ragwort plants. Owing to the wet summer in 1968, plant numbers actually increased after defoliation, due to regeneration from root buds. This was in spite of the fact that no seed was produced in the area in either 1967 or 1968.The only factor which appears to buffer the population against extinction in years when food runs out early in the season, is the heterogeneity within the moth and ragwort populations. The earliest individuals manage to obtain sufficient food in those patches of ragwort which survive longest.Large fluctuations in number only occur in some localities. Other populations of the moth persist at low density and never eat out their food supply. Some data are presented from such a population at Monks Wood. This site is on a heavy clay soil, rabbit grazing is less marked than at Weeting, and ragwort occurs only at a low density. The lusher vegetation supports a very large population of arthropod predators and these take a higher percentage of the young caterpillars than was found at Weeting. Pupal survival is also low due probably to waterlogging of the soil. Pupae can withstand considerable desiccation, but excessive moisture soon leads to their death.The distribution of the moth in Britain and its use for the biological control of ragwort are discussed.     

The neuroethology of sound production in tiger moths (Lepidoptera,Arctiidae)

When stimulated either acoustically or tactually, certain species of arctiid moths rhythmically emit trains of clicks from metathoracic tymbals. The purpose of the experiments presented here was to determine the location within the central nervous system (CNS) of the proposed tymbal central pattern generator (CPG) in Cycnia tenera. Motor neuron impulses that underlie tymbal activation were recorded extracellularly from the tymbal nerve while moths were subjected to selective severing of the suboesophageal, prothoracic, pterothoracic and abdominal ganglia connectives. Motor output evoked by either acoustic or tactile stimulation originates from a common CPG because tymbal nerve spikes in both cases are similar in amplitude, waveform and rhythmicity. Our results showed: (1) removal of the CNS posterior of the second abdominal neuromere had no effect, (2) removal of the head decreased the responsiveness of the animal to acoustic stimulation and, (3) severing the connectives between the prothoracic and pterothoracic ganglia abolished responses to acoustic stimuli and diminished responses to tactile stimuli. We conclude that although the minimal circuitry sufficient for activating the tymbals resides in the pterothoracic ganglion, the prothoracic and cephalic ganglia are required for the normal, and in particular, auditory-evoked operation of the tymbal CPG.Abbreviations ASR acoustic startle response - CNS central nervous system - CPG central pattern generator - dB peSPL decibel peak equivalent sound pressure level (rms re 20 Pa) - ISI inter-spike interval     

Changes in spatial distribution pattern during the larval stage of the fall webworm,Hyphantria cunea drury (Lepidoptera: Arctiidae)

Summary The changes in spatial distribution pattern during larval stage of the fall webworm,Hyphantria cunea were quantitatively investigated in the field experimental populations. The female adult deposits eggs as a cluster and the hatchlings make a compact colonial-web. In this period, the all-or-none type mortality which is characteristic in gregarious insect species was occasionary recognized before spinning a compact colonial-web. Once making a compact colonial-web, the larvae feed the leaves in the colonial-web up to about 5th instar. In this period, the movement of larvae occurred due to the local food shortage in a colonial-web and the expansion of colonial-web. As the larvae developed, the colonial-web was separated into several small groups. These larvae began to disperse about 5th instar. In this period, the local food shortage seems to be an important trigger for the larval dispersal. The mean concentration of larvae on leaves abruptly decreased, and finally the larvae became solitary at the 6th or 7th instars. The dispersal process in later larval stage is not necessarily due to the complete food shortage. The dispersal prior to the occurrence of food shortage may be a safety mechanism to protect the larvae from the food shortage.     

Development of a phylogenetic model for the tribe Micrarctiini (Lepidoptera, Arctiidae) by the SYNAP method

A phylogenetic model for all the 18 genera of Micrarctiini (Lepidoptera, Arctiidae) of the World fauna is discussed. The SYNAP method was used for development of the model. For these purposes, 47 characters of the general appearance, male and female genitalia, and wing pattern were used. Based on these characteristics, an evolutionary trend from the plesiomorphic to apomorphic states was revealed. The genera Apantesis and Amurrhyparia, as well as Notarctia, differ from the other genera to the greatest extent. The other genera have formed two the main clades: Grammia + (Diacrisia + (Rhyparia + Rhyparioides)). Neoarctia + (Palearctia + Holoarctia + Chelis) and all the other genera have occupied separate positions. The latter group was divided into two clades: Ebertarctia + Tancrea + Divarctia with brachypterous females and Centrarctia + (Sibirarctia + (Micrarctia + Hyperborea)).     

Presence of IL-1- and TNF-like molecules in Galleria mellonella (Lepidoptera) haemocytes and in an insect cell line Fromestigmene acraea (Lepidoptera).

In this study the authors give immunocytochemical evidence for the presence of interleukin (IL)-1alpha- and tumour necrosis factor (TNF) alpha-like molecules in the haemocytes of last instar larvae from the greater wax moth Galleria mellonella. Similar results are demonstrated in a continuous haemocyte line (BTI-EA-1174-A) from the salt marsh caterpillar Estigmene acraea. In Galleria mellonella larvae granular cells show a strong positive reaction with both primary antibodies, whereas plasmatocytes are stained to a lesser extent. Cell line haemocytes also react positively with both antibodies. After activating the cells with lipopolysaccharide (LPS) staining of Estigmene acraea cells is decreased, whereas Galleria mellonella haemocytes show no visible reaction in comparison to non-activated cells.     

Transmembrane ion distribution during recovery from freezing in the woolly bear caterpillar Pyrrharctia isabella (Lepidoptera: Arctiidae)

During extracellular freezing, solutes in the haemolymph are concentrated, resulting in osmotic dehydration of the cells, which must be reversed upon thawing. Here, we used freeze tolerant Pyrrharctia isabella (Lepidoptera: Arctiidae) larvae to examine the processes of ion redistribution after thawing. To investigate the effect of the intensity of cold exposure on ion redistribution after thawing, we exposed caterpillars to −14 °C, −20 °C or −30 °C for 35 h. To investigate the effect of duration of cold exposure on ion redistribution after thawing, we exposed the caterpillars to −14 °C for up to 6 weeks while sampling several time points. The concentrations of Na⁺, K⁺, Mg²⁺ and Ca²⁺ were measured after thawing in the haemolymph, fat body, muscle, midgut tissue and hindgut tissue. Being frozen for long durations (>3 weeks) or at low temperatures (−30 °C) both result in 100% mortality, although different ions and tissues appear to be affected by each treatment. Both water distribution and ion content changes were detected after thawing, with the largest effects seen in the fat body and midgut tissue. Magnesium homeostasis appears to be vital for post-freeze survival in these larvae. The movement of ions during thawing lagged behind the movement of water, and ion homeostasis was not restored within the same time frame as water homeostasis. Failure to regain ion homeostasis after thawing is therefore implicated in mortality of freeze tolerant insects.     

Development of the male scent organ ofCreatonotos transiens (Lepidoptera,Arctiidae) during metamorphosis

Summary (1) The male abdominal scent organ (corema) of the arctiid mothCreatonotos transiens consists of a basal bladder and four tubes. It can be everted from the sternal intersegmental membrane 7/8. Its scent hairs (scales) produce and release the pheromone hydroxydanaidal, which attracts both sexes. Pyrrolizidine alkaloids (PA) ingested by the larva with its food are not only precursors of the pheromone but also a morphogen, which quantitatively controls the growth of the pupal corema and, thus, its final size and number of hairs. (2) The coremata arise from epidermalanlagen at the anterior border of the 8th abdominal sternite. If male larvae are fed 1 mg PA these organs begin to develop from small vesicles, and four tubes then arise during the first 3 pupal days. The corresponding mitoses reach their peak at 36 h. During the next 2 days the tubes shorten, while the walls become thin and doubly folded. The total surface of the corema increases about 20 times because of the shape transformation of the epidermal cells from prismatic to very flat. (3) The scent hairs originate from trichogen cells, which arise together with their associated tormogen cells during the 1st pupal day by way of differential mitoses. As the trichogen cells grow, their nuclei enlarge by way of endomitoses, elongate distally, and thus produce the hairs that extend into the lumen of the corema. Tormogen cells degenerate by the 8th day at latest. The hairs in each tube form a thick, caudally oriented bundle. The hair cells are finally bottle-shaped and at day 6 they extend freely into the hemolymph space. They are probably also the pheromoneproducing cells in later pupal and early imaginal life. Mitoses that produce trichogen cells stop after the 1st day, those producing epithelial cells 2 days later. This delay shifts the ratio of the two cell types from about 111 (18 h) to 140. (4) The processes hitherto described refer to normogenesis with ample PA supply. Control coremata in PA-free or PA-deficient specimens develop in principle in the same way, but at a slower rate, with minimal hair cell numbers barely 1/10th of normal, or at any rates between, depending upon the earlier PA supply. The size of control coremata varies from very small to small; even the hair cells and the hairs are smaller. (5) PA regulates corema development quantitatively through the number of mitoses of its cells and of endomitotic steps of the hair cells. In PA-treated specimens the coremaanlage is already advanced prior to pupation, at about the time when its sensitivity to PA influence terminates, in the early prepupa. Since PA only affects the anlagen of the corema and not that of any other body part (not even the basal coremal bladder), we postulate a selective interaction of PA with the presumptive corema cells. We found earlier that ecdysone is also involved, since the respective cell numbers can only be realized if this hormone is present.     

Gustatory responsiveness to pyrrolizidine alkaloids in the Senecio specialist, Tyria jacobaeae (Lepidoptera, Arctiidae)

Abstract.  Electrophysiological recordings from taste sensilla of the caterpillar Tyria jacobaeae with the pyrrolizidine alkaloids, characteristic compounds from their host plants, demonstrated sensitivity of a pyrrolizidine alkaloid-sensitive cell in the lateral galeal sensilla at concentrations as low as 1 × 10⁻¹¹ M. Another pyrrolizidine alkaloid-sensitive cell in the medial galeal sensilla responded at higher concentrations. Both pyrrolizidine alkaloid-cells were maximally sensitive to seneciphylline N -oxide and senecionine N -oxide. Seven other pyrrolizidine alkaloids were less stimulating. Monocrotaline N -oxide was the least stimulating. Observation experiments demonstrated that differences in sensitivity to different pyrrolizidine alkaloids at the electrophysiological level were correlated with differences in feeding behaviour; the first feeding bout was of longer duration on diet containing seneciphylline N -oxide than on diet containing monocrotaline N -oxide, and a plain diet was generally not accepted.     

Variability of gustatory responsiveness to phenylalanine in the generalist caterpillar, Grammia geneura (Lepidoptera, Arctiidae)

Electrophysiological recordings were made from maxillary taste sensilla of the caterpillar Grammia geneura, stimulated with the deterrent amino acid, phenylalanine. High levels of variability were noted and different potential causes examined. Little variation was detected with respect to standardized intra-individual tests, phenylalanine concentration, previous food type or time of day. Some changes were observed in relation to age, but could not account for the overall variation found. Major differences in responsiveness depended on cohort and the possibility of important genetic differences is discussed.     

The complete mitochondrial genome of the fall webworm,Hyphantria cunea (Lepidoptera: Arctiidae)

The complete mitochondrial genome (mitogenome) of the fall webworm, Hyphantria cunea (Lepidoptera: Arctiidae) was determined. The genome is a circular molecule 15 481 bp long. It presents a typical gene organization and order for completely sequenced lepidopteran mitogenomes, but differs from the insect ancestral type for the placement of tRNA^Met. The nucleotide composition of the genome is also highly A + T biased, accounting for 80.38%, with a slightly positive AT skewness (0.010), indicating the occurrence of more As than Ts, as found in the Noctuoidea species. All protein-coding genes (PCGs) are initiated by ATN codons, except for COI, which is tentatively designated by the CGA codon as observed in other lepidopterans. Four of 13 PCGs harbor the incomplete termination codon, T or TA. All tRNAs have a typical clover-leaf structure of mitochondrial tRNAs, except for tRNA^Ser(AGN), the DHU arm of which could not form a stable stem-loop structure. The intergenic spacer sequence between tRNA^Ser(AGN) and ND1 also contains the ATACTAA motif, which is conserved across the Lepidoptera order. The H. cunea A+T-rich region of 357 bp is comprised of non-repetitive sequences, but harbors several features common to the Lepidoptera insects, including the motif ATAGA followed by an 18 bp poly-T stretch, a microsatellite-like (AT)₈ element preceded by the ATTTA motif, an 11 bp poly-A present immediately upstream tRNA^Met. The phylogenetic analyses support the view that the H. cunea is closerly related to the Lymantria dispar than Ochrogaster lunifer, and support the hypothesis that Noctuoidea (H. cunea, L. dispar, and O. lunifer) and Geometroidea (Phthonandria atrilineata) are monophyletic. However, in the phylogenetic trees based on mitogenome sequences among the lepidopteran superfamilies, Papillonoidea (Artogeia melete, Acraea issoria, and Coreana raphaelis) joined basally within the monophyly of Lepidoptera, which is different to the traditional classification.     

Note on the life history of the magpie moth,Nyctemera annulata (Lepidoptera: Arctiidae)

Nyctemera annulata Boisduval was reared in the laboratory at 26±1°C and 50 ±5% RH on a host plant, ragwort (Senecio jacoboea L.), and on an artificial diet. On ragwort the average life cycle of 34 days embraced a larval period of 24 days, with up to 6 larval instars, and a pupal period of 9–11 days, depending on whether pupation occurred at the 5th or 6th instar. On the artificial diet the larval period of 56 days, involving up to 10 instars, was followed by a pupal period of 9 days, for an average life cycle of 65 days.     

Catoptinae subfam. n., a new subfamily of carpenter-moths (Lepidoptera,Cossidae)

The new subfamily of Cossidae; Catoptinae Yakovlev, subfam. n., well distinguished from other representatives of the family, is described. The new subfamily includes two genera: Catopta Staudinger, 1899 (type genus) and Chiangmaiana Kemal et Koçak, 2006. A catalogue of the subfamily is presented. One new synonym Catopta hyrcanus (Christoph, 1888) = Catopta brandti Bryk, 1947, syn. n., is established. The new subfamily has the following distinguishing features: short valvae; reduced processes of transtilla; vesica with numerous cornuti; pearshaped bursa copulatrix; and very short ductus bursae.     

Metamorphic changes in the neurosecretory cells of Diacrisia obliqua Walker (Lepidoptera: Arctiidae)

4 PF-positive NSC appear for the first time in each brain hemisphere on 4th day of exclosion. B-, C- and D-cells appear in the pars intercerebralis region on the second day in the 2nd instar. 3 lateral NSC appear for the first time in this instar. 2 A4-cells appear in the tritocerebral region of the 4th instar. An increase in the number and size of the NSC is noted in the successive instars. A3-cells appear for the first time in 5th instar. The secretory phases in the pupal period are completed in three "stages" which last for 3.3 and 4 days respectively. Adults lack PF-positive cells in the lateral and tritocerebral regions. Females show accumulation of NSM before mating which depletes gradually as the mating time reaches.