Tiger Moth Research Articles

TO CLICK OR NOT TO CLICK?

When a bat is cruising around looking for its next meal it sends out its ultrasonic pulses and listens carefully to the tell-tale echoes of a moth fluttering by. Despite the sophistication of a bat's echolocation system,moths have a few defences of their own. The dogbane tiger moth responds to a bat's attacking clicks with clicks of its own when the bat gets too close,either interfering with the bat's echolocation or warning the bat that it faces a bitter mouthful. However the moth has to choose very carefully when to click at a bat; too early draws unnecessary attention to itself, and leaving it too late is very risky. James Fullard and colleagues at the University of Toronto and Cornell University investigated which aspects of a bat's calls the moths use to decide whether to defend themselves or not (p. 2481).A bat can vary many of the characteristics of its echolocating calls, such as the frequency or intensity of the calls. It also alters the duration of the individual pulses or the time between the start of each pulse, known as pulse period, which in turn affect the duty cycle, which is the percentage of the total time a calling bat is making a sound. A moth could use any of these characteristics to identify an attacking bat, but the question is, which one?First the team recorded from the moths' auditory neurons to test their response to different frequency sounds, and find their auditory threshold. They found while moths' auditory neurons are sensitive between 30 and 50 kHz,they didn't show any difference in their clicking behaviour to different frequencies, showing that moths are essentially tone deaf.Having ruled out frequency, they turned to a technique which allowed them to test if moths could tell the difference between two sets of bat calls. They attached the moths to a pin with wax and suspended them above a speaker in a dark room, before repeatedly playing a sequence of bat pulses to them and recording their clicking response. Once the moths had habituated –stopped responding to the bat signals – they changed one or more aspects of the signal to see whether the moths could tell the difference and start clicking again.They found that once the moths had habituated to a particular signal, they had to change the duty cycle by 60% or more before the moths started responding again. Next they tested to see how the moths responded to varying duty cycles, and found that they were most sensitive to pulse periods of 20 ms. They were less sensitive to longer and shorter pulse periods, showing that the response was tuned.Finally to show that pulse period was the primary parameter that the moths were responding to, they habituated the moths to `searching' bat signals and then tested them with `attacking' bat signals. Both signals had the same duty cycle, but the pulse period changed as the bats switched from searching to attacking. They found that the moths responded very strongly to the switch between a searching and attacking bat, showing that pulse period is the defining feature they use to identify when they are in danger. However they also found that their response was influenced by the intensity of the signal. If an attacking bat is pulsing to another insect 30 m away, then the moth is not going to respond because the intensity is too low, and it doesn't want to draw attention to itself. But if the intensity is right, and the bat is bearing down on the moth and bombarding it with high intensity, short period signals, it will click to avoid being snatched and eaten.

Acoustic mimicry in a predator–prey interaction

Mimicry of visual warning signals is one of the keystone concepts in evolutionary biology and has received substantial research attention. By comparison, acoustic mimicry has never been rigorously tested. Visualizing bat-moth interactions with high-speed, infrared videography, we provide empirical evidence for acoustic mimicry in the ultrasonic warning sounds that tiger moths produce in response to echolocating bats. Two species of sound-producing tiger moths were offered successively to naïve, free-flying red and big brown bats. Noctuid and pyralid moth controls were also offered each night. All bats quickly learned to avoid the noxious tiger moths first offered to them, associating the warning sounds with bad taste. They then avoided the second sound-producing species regardless of whether it was chemically protected or not, verifying both Müllerian and Batesian mimicry in the acoustic modality. A subset of the red bats subsequently discovered the palatability of the Batesian mimic, demonstrating the powerful selective force these predators exert on mimetic resemblance. Given these results and the widespread presence of tiger moth species and other sound-producing insects that respond with ultrasonic clicks to bat attack, acoustic mimicry complexes are likely common components of the acoustic landscape.

Tiger moth responses to a simulated bat attack: timing and duty cycle

Many night-flying insects perform complex, aerobatic escape maneuvers when echolocating bats initiate attack. Tiger moths couple this kinematic defense with an acoustic reply to a bat's biosonar-guided assault. The jamming hypothesis for the function of these moth sounds assumes that tiger moth clicks presented at high densities, temporally locked to the terminal phase of the bat attack will produce the greatest jamming efficacy. Concomitantly, this hypothesis argues that moths warning bats of bad tasting chemicals sequestered in their tissues should call early to give the bat time to process the meaning of the warning signal and that moths calling at low duty cycles are more likely to employ such an aposematic strategy. We report here the first investigation of a tiger moth assemblage's response to playback of a bat echolocation attack sequence. This assemblage of arctiid moths first answered the echolocation attack sequence 960+/-547 ms (mean +/- s.d.) from the end of the bat attack. The assemblage reached a half-maximum response shortly after the first response, at 763+/-479 ms from the end of the terminal buzz. Tiger moth response reached a maximum at 475+/-344 ms from the end of the sequence; during the approach phase, well before the onset of the terminal buzz. In short, much of tiger moth response to bat attack occurs outside of the jamming hypotheses' predictions. Furthermore, no relationship exists between the duty cycle of a tiger moth's call (and thus the call's probability of jamming the bat) and its temporal response to bat attack. These data call into doubt the assumptions behind the jamming hypothesis as currently stated but do not directly test the functionality of arctiid sounds in disrupting echolocation in bat-moth aerial battles.

Ratcliffe, J. M. and Fullard, J. H. (2005). The adaptive function of tiger moth clicks against echolocating bats: an experimental and synthetic approach. J. Exp. Biol. 208, 4689-4698

Ratcliffe, J. M. and Fullard, J. H. (2005). The adaptive function of tiger moth clicks against echolocating bats: an experimental and synthetic approach. J. Exp. Biol. 208, 4689-4698

Review of generic limits of the tiger moth genera Virbia Walker and Holomelina Herrich-Schäffer (Lepidoptera: Arctiidae: Arctiinae) and their biogeography

A phylogeny for Holomelina and Virbia was constructed based on adult morphology. This study included 42 of the 70 recognized species in Holomelina and Virbia, two new species, and two elevated synonyms (H. marginata Druce and V. inversia Edwards). The following outgroups were chosen from the Arctiini: Arachnis picta Packard, Hypercompe permaculata Packard, Paracles fusca Walker, Phragmatobia fuliginosa (Linneaus), Pyrrarctia isabella (J. E. Smith), and Spilosoma virginica (Fabricius). Fifty-eight characters (195 states) were described and scored, including several newly discovered characters of the male and female abdomen and genitalia. Three male character systems, the shape and orientation of the basiphallus; the shape, orientation and ornamentation of the endophallus; and the pattern of sclerotization of the eighth male sternite, were important diagnostic characters for smaller clades and species. The maximum parsimony analysis of all taxa with 100 randomized repetitions yielded 779 trees with a length (L) of 1698, a consistency index (CI) of 0.41 and a retention index (RI) of 0.65. Holomelina species were placed in two clades, an H. aurantiaca clade and an H. opella clade that was paraphyletic with respect to Virbia. The ingroup clade comprised of Holomelina and Virbia species was supported by eleven synapomorphies and a Bremer index higher than fifteen. The decay of this node was greater than 10. Taxon jack-knife analyses revealed that results were sensitive to the inclusion of two outgroup species, A. picta and P. fuliginosa. When either was removed the relationships of ingroup taxa became unresolved. When the analysis was restricted to species which represented by both males and females, we recovered an ingroup consisting of Holomelina and Virbia species, but the strict consensus of 123 trees (L = 1356, CI = 0.47, RI = 0.65) resulted in a polytomy of smaller clades. Neither analysis recovered a reciprocally monophyletic Holomelina and Virbia. We place Holomelina as a junior generic synonym of Virbia and provide a species checklist for Virbia. Biogeographic areas were scored from distribution information in a specimen-level database consisting of over 12,000 specimens. The following eight areas were recognized: A. western USA and Canada, B. central USA and Canada, C. eastern USA and Canada, D. southwestern USA and Mexico, E. central America, F. western South America, G. eastern and central South America, and H. highlands of northern South America. A weighted ancestral area analysis was used to determine ancestral areas for five major ingroup clades. We propose replacing the name “probability index” (PI) of Bremer with the term “Weighted Area Index (WAI)” because the PI of Bremer is not based on a statistical distribution and the term is misleadingWe determined that the ancestral area for Virbia was most likely the southwestern United States and Mexico. The species distributed in North America north of Mexico represent a composite fauna with a minimum of two dispersal events from Mexico into the northern latitudes. In contrast, the South American fauna appears to have a single origin.

Large-Scale Temporal Changes in Spatial Pattern During Declines of Abundance and Occupancy in a Common Moth

We examined the changes in spatial pattern that accompanied the population decline of the garden tiger moth, Arctia caja (L.) in Britain between 1968 and 1999 using Spatial Analysis by Distance Indices (SADIE) techniques. A principal co-ordinate analysis of all pair-wise spatial associations between years indicated three groupings of years: 1969–1978,1979–1990,1991–1999, which revealed three phases during the population decline: an early period with highly structured spatial pattern; a middle period with nearly random distribution overall; and a recent period with highly structured spatial pattern but small abundance overall. The change in spatial structure in the early 1980’s accompanied rapid changes in abundance but preceded a sharp decline in occupancy and confirms that the sharp decline in abundance included decreases from widespread high-density sites. Perhaps unusually, A. caja varied from spatially aggregated to randomly distributed and back to spatially aggregated, all while its abundance declined sharply. Present distribution pattern may reflect past abundance changes poorly in this species. Areas showing the greatest variation in abundance displayed the greatest range in spatial structure, but also the greatest stability of spatial pattern, indicating changes between extremes of spatial pattern occurred slowly. SADIE techniques are a powerful method to quantify temporal changes in spatial pattern and relate them to temporal changes in abundance.

Caterpillars of Eastern North America: a guide to identification and natural history

This lavishly illustrated guide will enable you to identify the caterpillars of nearly 700 butterflies and moths found east of the Mississippi. The more than 1,200 color photographs and two dozen line drawings include numerous exceptionally striking images. The giant silk moths, tiger moths, and many other species covered include forest pests, common garden guests, economically important species, and of course, the Mescal Worm and Mexican Jumping Bean caterpillars. Full-page species accounts cover almost 400 species, with up to six images per species including an image of the adult plus succinct text with information on distribution, seasonal activity, foodplants, and life history. These accounts are generously complemented with additional images of earlier instars, closely related species, noteworthy behaviors, and other intriguing aspects of caterpillar biology. Many caterpillars are illustrated here for the first time. Dozens of new foodplant records are presented and erroneous records are corrected. The book provides considerable information on the distribution, biology, and taxonomy of caterpillars beyond that available in other popular works on Eastern butterflies and moths. The introductory chapter covers caterpillar structure, life cycles, rearing, natural enemies, photography, and conservation. The section titled Caterpillar Projects will be of special interest to educators. Given the dearth of accessible guides on the identification and natural history of caterpillars, Caterpillars of Eastern North America is a must for entomologists and museum curators, forest managers, conservation biologists and others who seek a compact, easy-to-use guide to the caterpillars of this vast region. * A compact guide to nearly 700 caterpillars east of the Mississippi, from forest pests to garden guests and economically important species *1,200 color photos and 24 line drawings enable easy identification * Full-page species accounts with image of adult insect for almost 400 species, plus succinct text on distribution and other vital information * Many caterpillars illustrated here for the first time * Current information on distribution, biology, and taxonomy not found in other popular works * A section geared toward educators, Caterpillar Projects * An indispensable resource for all who seek an easy-to-use guide to the caterpillars of this vast region

Isolation and characterization of highly polymorphic microsatellite loci for the garden tiger moth Arctia caja (Lepidoptera: Arctiidae)

AbstractA set of microsatellite markers was isolated from Arctia caja, a species that has been declining in UK for several decades. As has been found with other Lepidoptera species, this proved to be a difficult task. Eight enriched libraries identified 103 positive clones, and these yielded only seven polymorphic microsatellites. Allelic diversity ranged from 10 to 23 alleles per locus in a population of 30 individuals. Significant heterozygosity deficits were shown by three of these loci, presumably due to null alleles. The remaining four loci were in Hardy–Weinberg equilibrium and will be used to investigate the population genetic structure of A. caja.

Arctiid moth ensembles along a successional gradient in the Ecuadorian montane rain forest zone: how different are subfamilies and tribes?

AbstractAim We examined changes in the species diversity and faunal composition of arctiid moths along a successional gradient at a fine spatial scale in one of the world's hot spots for moths, the Andean montane rain forest zone. We specifically aimed to discover whether moth groups with divergent life histories respond differentially to forest recovery.Location Southern Ecuador (province Zamora‐Chinchipe) along a gradient from early successional stages to mature forest understorey at elevations of 1800–2005 m a.s.l.Methods Moths were sampled with weak light traps at 21 sites representing three habitat categories (early and late succession, mature forest understorey), and were analysed at species level. Relative proportions were calculated from species numbers as well as from specimen numbers. Fisher's α was used as a measure of local diversity, and for ordination analyses non‐metric multidimensional scaling (NMDS) was carried out.Results Proportions of higher arctiid taxa changed distinctly along the successional gradient. Ctenuchini (wasp moths) contributed more strongly to ensembles in natural forest, whereas Lithosiinae (lichen moths) decreased numerically with forest recovery. Arctiid species diversity (measured as Fisher's α) was high in all habitats sampled. The three larger subordinated taxa contributed differentially to richness: Phaegopterini (tiger moths) were always the most diverse clade, followed by Ctenuchini and Lithosiinae. Local species diversity was higher in successional habitats than in forest understorey, and this was most pronounced for the Phaegopterini. Dominance of a few common species was higher, and the proportion of species represented as singletons was lower, than reported for many other tropical arthropod communities. NMDS revealed a significant segregation between ensembles from successional sites and from forest understorey for all larger subordinated taxa (Phaegopterini, Ctenuchini, Lithosiinae). Abandoned pastures held an impoverished, distinct fauna. Faunal segregation was more pronounced for rare species. Ordination axes reflected primarily the degree of habitat disturbance (openness of vegetation, distance of sites from mature forest) and, to a lesser extent, altitude, but not distance between sampling sites.Main conclusions Despite the geographical proximity of the 21 sites and the pronounced dispersal abilities of adult arctiid moths, local ecological processes were strong enough to allow differentiation between ensembles from mature forest and disturbed sites, even at the level of subfamilies and tribes. Differences in morphology and life‐history characteristics of higher arctiid taxa were reflected in their differential representation (proportions of species and individuals) at the sites, whereas patterns of alpha and beta diversity were concordant. However, concordance was too low to allow for reliable extrapolation, in terms of biodiversity indication, from one tribe or subfamily to the entire family Arctiidae. Phaegopterini (comprising more putative generalist feeders during the larval stages) benefited from habitat disturbance, whereas Ctenuchini (with host‐specialist larvae) were more strongly affiliated with forest habitats.

The adaptive function of tiger moth clicks against echolocating bats: an experimental and synthetic approach

We studied the efficiency and effects of the multiple sensory cues of tiger moths on echolocating bats. We used the northern long-eared bat, Myotis septentrionalis, a purported moth specialist that takes surface-bound prey (gleaning) and airborne prey (aerial hawking), and the dogbane tiger moth, Cycnia tenera, an eared species unpalatable to bats that possesses conspicuous colouration and sound-producing organs (tymbals). This is the first study to investigate the interaction of tiger moths and wild-caught bats under conditions mimicking those found in nature and to demand the use of both aerial hawking and gleaning strategies by bats. Further, it is the first to report spectrograms of the sounds produced by tiger moths while under aerial attack by echolocating bats. During both aerial hawking and gleaning trials, all muted C. tenera and perched intact C. tenera were attacked by M. septentrionalis, indicating that M. septentrionalis did not discriminate C. tenera from palatable moths based on potential echoic and/or non-auditory cues. Intact C. tenera were attacked significantly less often than muted C. tenera during aerial hawking attacks: tymbal clicks were therefore an effective deterrent in an aerial hawking context. During gleaning attacks, intact and muted C. tenera were always attacked and suffered similar mortality rates, suggesting that while handling prey this bat uses primarily chemical signals. Our results also show that C. tenera temporally matches the onset of click production to the ;approach phase' echolocation calls produced by aerial hawking attacking bats and that clicks themselves influence the echolocation behaviour of attacking bats. In the context of past research, these findings support the hypotheses that the clicks of arctiid moths are both an active defence (through echolocation disruption) and a reliable indicator of chemical defence against aerial-hawking bats. We suggest these signals are specialized for an aerial context.

An Acquired Taste for Toxins

The tiger moth caterpillars Grammia geneura and Estigmene acrea defend themselves against parasites by feeding on plants containing phytochemicals toxic to the parasites: E. acrea eats and sequesters pyrrolizidine alkaloids; G. geneura eats and sequesters iridoid glycosides as well. The caterpillars detect these compounds by means of specialized chemoreceptor gustatory cells that stimulate feeding behavior. Bernays and Singer showed that, compared with control caterpillars, the increase in taste cell firing rate in response to the iridoid catalpol and the pyrrolizidine alkaloid seneciphylline N -oxide was greater in parasitized G. geneura . In contrast, the response of a gustatory cell sensitive to the feeding deterrent caffeine was decreased. There was no difference in the response to sucrose, which is detected through the same gustatory cells as iridoids, indicating that the change affected the iridoid receptor or the subsequent signaling pathway rather than being cell-wide. Similarly, gustatory cells in parasitized E. acrea showed an enhanced response to seneciphylline N -oxide compared with unparasitized caterpillars, a reduced response to the feeding deterrent protocatechuic acid, and an inconsistent response to sucrose. Thus, parasitization appears to alter the sensitivity of caterpillar gustatory cells to promote the ingestion of substances toxic to the parasites and to inhibit the response to substances that inhibit feeding behavior. E. A. Bernays, M. S. Singer, Insect defences: Taste alteration and endoparasites. Nature 436 , 476 (2005). [PubMed]

Phylogeny and classification of Callimorphini (Lepidoptera: Arctiidae: Arctiinae)

A preliminary phylogeny for the Callimorphini and related tribes was constructed based on adult morphology. The data matrix, consisting of 91 taxa and 116 characters (299 states), was analyzed using maximium parsimony. To test the monophyly of the Callimorphini s.s. and determine the placement of the Euchaetes group, 49 ingroup species and 42 outgroup species were included. Callimorphini was represented by 23 species (11 genera), and the Euchaetes group was represented by 26 species (6 genera). Outgroup taxa include both root genera from the Arctiini (10 genera, 12 species) and representative genera from related tribes as “internal outgroups.” Internal outgroups included representatives from Phaegopterini (6 genera, 9 species), Nyctemerini (1 genus, 9 species), and Pericopini (7 genera, 12 species). The data matrix included both nongenitalic and genitalic characters as follows: 7 head (17 states), 5 leg (10 states), 22 wing (57 states), 12 thoracic (29 states), 39 male abdominal and genitalic characters (95 states) and 31 female abdominal and genitalia (91 states). Of these, 36 were multistate and were treated as unordered. Heuristic searches with 20, 100, and 1000 random–taxon additions were performed to sample multiple tree islands. This study also assessed the utility of adult genitalic character systems for confident resolution of older divergences. The resulting cladistic analysis demonstrated that phylogenetic relationships among closely related genera were recovered; however, genitalic characters do not fully replace information from immature stages. Relationships among major clades remained poorly supported as determined by taxon and character jackknifes. Based on these results, a revised concept for Callimorphini is proposed based on well–supported relationships. A checklist of callimorphine genera also is provided. The Old World genus Nyctemera is placed in the Pericopini rev. placement and Euchaetes and allied genera are placed in the Phaegopterini rev. placement.KEY WORDS: Arctiidae, Callimorphini, phylogenyCallimorphini (Lepidoptera: Arctiidae: Arctiinae), like many tiger moths, are cosmopolitan in distribution and most diverse in the tropics. Adults frequently are brightly colored with orange, pink, yellow, and red scales on the wings and abdomen (Ferguson 1985, Holloway et al. 2001). Some members of the Callimorphini, a small tribe of approximately 108 species, resemble butterflies in that they are diurnal (e.g., Utetheisa Hübner) or have large wings and “slender” bodies characteristic of butterflies (e.g., Haploa Hübner, Callimorpha Latreille) (Figs. 1, 2). Callimorphini, and tiger moths more generally, have captured the attention of scientists because of their coloration and their intriguing biology. In general, arctiid larvae and adults defend themselves from predators with biogenic amines, often in combination with host–plant derived chemicals such as pyrrolizidine alkaloids (PAs), cardiac glycosides (CGs), or sesquiterpenes (reviews: Weller et al. 1999; Conner & Weller 2004). These compounds can be found in all life stages in several species. Callimorphini is pivotal for understanding the evolutionary transitions among the different defense strategies within the subfamily Arctiinae (Fig. 3; Weller et al. 1999). Most callimorphines use pyrrolizidine

Diversity and composition of Arctiidae moth ensembles along a successional gradient in the Ecuadorian Andes

ABSTRACTAndean montane rain forests are among the most species‐rich terrestrial habitats. Little is known about their insect communities and how these respond to anthropogenic habitat alteration. We investigated exceptionally speciose ensembles of nocturnal tiger moths (Arctiidae) at 15 anthropogenically disturbed sites, which together depict a gradient of forest recovery and six closed‐forest understorey sites in southern Ecuador. At weak light traps we sampled 9211 arctiids, representing 287 species. Arctiid abundance and diversity were highest at advanced succession sites, where secondary scrub or young forest had re‐established, followed by early succession sites, and were lowest, but still high, in mature forest understorey. The proportion of rare species showed the reverse pattern. We ordinated moth samples by non‐metric multidimensional scaling using the chord‐normalized expected species shared index (CNESS) index at various levels of the sample size parameter m. A distinct segregation of arctiid ensembles at succession sites from those in mature forest consistently emerged only at high m‐values. Segregation between ensembles of early vs. late succession stages was also clear at high m values only, and was rather weak. Rare species were responsible for much of the faunal difference along the succession gradient, whereas many common arctiid species occurred in all sites. Matrix correlation tests as well as exploration of relationships between ordination axes and environmental variables revealed the degree of habitat openness, and to a lesser extent, elevation, as best predictors of faunal dissimilarity. Faunal differences were not related to geographical distances between sampling sites. Our results suggest that many of the more common tiger moths of Neotropical montane forests have a substantial recolonization potential at the small spatial scale of our study and accordingly occur also in landscape mosaics surrounding nature reserves. These species contribute to the unexpectedly high diversity of arctiid ensembles at disturbed sites, whereas the proportion of rare species declines outside mature forest.

Effectiveness of tiger moth (Lepidoptera, Arctiidae) chemical defenses against an insectivorous bat (Eptesicus fuscus)

Adult tiger moths exhibit a wide range of palatabilities to the insectivorous big brown bat Eptesicus fuscus. Much of this variation is due to plant allelochemics ingested and sequestered from their larval food. By using a comparative approach involving 15 species from six tribes and two subfamilies of the Arctiidae we have shown that tiger moths feeding on cardiac glycoside-containing plants often contain highly effective natural feeding deterrents. Feeding on pyrrolizidine alkaloid-containing plants is also an effective deterrent to predation by bats but less so than feeding on plants rich in cardiac glycosides. Moths feeding on plants containing iridoid glycosides and/or moths likely to contain biogenic amines were the least deterrent. By manipulating the diet of several tiger moth species we were able to adjust their degree of palatability and link it to the levels of cardiac glycosides or pyrrolizidine alkaloids in their food. We argue that intense selective pressure provided by vertebrate predators including bats has driven the tiger moths to sequester more and more potent deterrents against them and to acquire a suite of morphology characteristics and behaviors that advertise their noxious taste.

Sound strategy: acoustic aposematism in the bat–tiger moth arms race

The night sky is the venue for an ancient arms race. Insectivorous bats with their ultrasonic sonar exert an enormous selective pressure on nocturnal insects. In response insects have evolved the ability to hear bat cries, to evade their hunting maneuvers, and some, the tiger moths (Arctiidae), to utter an ultrasonic reply. We here determine what it is that tiger moths "say" to bats. We chose four species of arctiid moths, Cycnia tenera, Euchaetes egle, Utetheisa ornatrix, and Apantesis nais, that naturally differ in their levels of unpalatability and their ability to produce sound. Moths were tethered and offered to free-flying naive big brown bats, Eptesicus fuscus. The ability of the bats to capture each species was compared to their ability to capture noctuid, geometrid, and wax moth controls over a learning period of 7 days. We repeated the experiment using the single arctiid species E. egle that through diet manipulation and simple surgery could be rendered palatable or unpalatable and sound producing or mute. We again compared the capture rates of these categories of E. egle to control moths. Using both novel learning approaches we have found that the bats only respond to the sounds of arctiids when they are paired with defensive chemistry. The sounds are in essence a warning to the bats that the moth is unpalatable-an aposematic signal.

Comparing the effects of genetic drift and fluctuating selection on genotype frequency changes in the scarlet tiger moth

One of the recurring arguments in evolutionary biology is whether evolution occurs principally through natural selection or through neutral processes such as genetic drift. A 60-year-long time series of changes in the genotype frequency of a colour polymorphism of the scarlet tiger moth, Callimorpha dominula, was used to compare the relative effects of genetic drift and variable natural selection. The analysis showed that most of the variation in frequency was the result of genetic drift. In addition, although selection was acting, mean fitness barely increased. This supports the 'Red Queen's hypothesis' that long-term improvements in fitness may not occur, because populations have to keep pace with changes in the environment.

Description of Sphecosoma pattiannae, new species, with comments on its novel male androconia (Lepidoptera: Arctiidae: Arctiinae: Euchromiini)

A new species of the mimetic tiger moth genus Sphecosoma, S. pattiannae Simmons sp. nov., is described and illustrated. The presumed sister species, S. tarsalis (Walker), is redescribed with illustrations of the male and female genitalia. These two species bear a novel androconial structure, which is a dorsal pouch at the base of the genitalia; this structure is described and illustrated. Phylogenetic placement of S. tarsalis and S. pattiannae within Sphecosoma Butler is discussed, with male and female genital comparisons to S. cognatum (Walker).

Fascinated by the beauty of Tiger Moth (1)

Fascinated by the beauty of Tiger Moth (1)

Fascinated by the beauty of Tiger Moth (2)

Fascinated by the beauty of Tiger Moth (2)

Inventory of tiger moths of Sikkim (Lepidoptera: Arctiidae: Arctiinae)

1143 Abstract A total number of 24 species of Tiger moths belonging to subfamily Arctiinae of family Acrtiidae have been collected from nine localities i.e., Gangtok, Mangan, Ranipul, Chungthang, Lachen, Lachung, Namchi, Singtam, Phodong in the Sikkim state. A list of these species including their first reference, synonmy, material examined and distribution have been given in this manuscript. Spilarctia coma (Walker) has been reported for the first time from this state.