Geometrid moths were collected on Mt. Kinabalu (Sabah, Malaysia) along two habitat gradients, ranging from primary rain forest to cultivated areas. During 135 nights' trapping in 1997, 4585 individuals representing 500 species were attracted by light. Primary forest samples and those from old-grown regenerated forest exhibited high diversity (Fisher's α = 75–128), while agricultural areas as well as most secondary forests had a significantly lower diversity (α = 34–61). One 15-y-old secondary forest with a rich undergrowth vegetation also housed a diverse geometrid community (α = 89). In three paired samples, diversity of geometrid moths in the canopy was equal to or lower than in the understorey. Of six habitat variables tested, only undergrowth plant species diversity emerged as a significant predictor of geometrid diversity. The NESS index, in combination with multi-dimensional scaling, was used to investigate patterns of between-habitat diversity. Of two dimensions extracted, one represented the degree of habitat disturbance, while the other separated the two study areas. Geometrid samples of strongly disturbed habitats did not converge between sites, indicating that apart from the degree of human interference the regional species pool was also important in determining similarity among local communities.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S026646740200202X

From forest to farmland: diversity of geometrid moths along two habitat gradients on Borneo

Moths are frequently used as indicators of biodiversity or habitat quality. Light traps are the most effective and widely used method for gathering data on moth communities. Knowing the distance from which moths are drawn to a light trap is therefore essential for the ecological interpretation of such data. Two community-wide mark-release-recapture experiments were carried out in forest habitats in central Europe in order to investigate whether the percentage of marked moths recaptured at weak artificial light sources (2 × 15 W UV-light tubes) is dependent on the distance they were released from the light source. Altogether 2,331 moths belonging to 167 species were caught at light traps and released at distances of 2-100 m. Of these moths 313 returned to the light trap within 5 min of release. Percentage recapture was generally low (gross rate 13.4%) and strongly decreased with increase in the distance at which they were released. Percentage recapture was not significantly affected by ambient temperature or the sex of the moths. Only for the Geometroidea was the percentage recaptured slightly greater for the larger species. We found no significant dif- ferences between moth super-families with regard to the distance dependence of their attraction to light. Our data confirm that the radius of attraction of low powered light traps for moths is very small often even below 10 m. Thus, moths are good indicators of habitat quality and fragmentation as they are rarely attracted from distant habitats to such light traps.

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Attraction to light - from how far do moths (Lepidoptera) return to weak artificial sources of light?

Aim The objective of this study was to describe and interpret the changes in faunal composition in the moth family Geometridae (Lepidoptera) along a small-scale elevational gradient in a tropical montane rain forest. This gradient was compared with a large-scale latitudinal gradient in Europe.



Location Investigations were carried out in the province Zamora-Chinchipe in southern Ecuador along a gradient ranging from 1040 to 2677 m above sea level at twenty-two sites.



Methods  Moths were sampled with light-traps in three field periods in 1999 and 2000 and subsequently sorted and determined to species or morphospecies.



Results  We analysed 13,938 specimens representing 1010 species of geometrid moths. The proportional contribution of subtaxa to the local geometrid fauna changes along the elevational gradient at all systematic levels considered. While proportions of species of the subfamilies Ennominae, Sterrhinae and Geometrinae significantly decrease, the proportion of Larentiinae increases with increasing altitude. Changes also occur within the subfamilies Ennominae and Larentiinae. The host–plant specialist ennomine tribes Cassymini, Macariini and Palyadini completely vanish, and the proportion of the tribe Boarmiini decreases at high altitudes. In contrast, the remaining tribes (mostly comprising polyphagous species) either do not show proportional changes (Azelinini, Nacophorini, Nephodiini, Ourapterygini) or even increase (Caberini, ‘Cratoptera group’). Within Larentiinae, the species proportion of the genus Eois decreases, whereas concomitantly the proportion of Eupithecia increases. There is a remarkable similarity between the altitudinal patterns in Ecuador and those found along the latitudinal gradient in Europe.



Main conclusions  Species of the subfamily Larentiinae seem to be particularly well-adapted to harsh environmental conditions, towards both high altitudes and latitudes. They might disproportionately profit from lower predation at higher altitudes. Many changes in the faunal composition can be explained by expected host–plant requirements of the species involved. Our results show that diversity estimates based on taxon ratios which are assumed to be constant must be regarded with caution because such ratios can change rapidly along environmental gradients.

Resumen

Objetivo  La meta de este estudio era describir e interpretar los cambios y la composicion faunistica en la familia de mariposas Geometridae (Lepidoptera) a lo largo de un gradiente altitudinal de escala pequena en un bosque de montana en los tropicos. Este gradiente fue comparado con un gradiente latitudinal de escala grande en Europa.



Localidad  Las investigationes fueron realizadas en la provincia Zamora-Chinchipe en el sur del Ecuador a lo largo de un gradiente elevandose de 1.040 a 2.677 m.s.n.m. en veintidos sitios.



Metodos Las mariposas fueron colectadas con trampas de luz en tres periodos de campo en 1999 y 2000. Despues fueron ordenadas y determinadas como especies o morfoespecies.



Resultados  Se analizaron 13.938 especimenes representando 1.010 especies de geometridos. La contribucion proporcional de los subtaxa para la fauna local cambia a lo largo del gradiente altitudinal en todos los niveles sistematicos considerados. Mientras las proporciones de especies de las subfamilias Ennominae, Sterrhinae y Geometrinae disminuyen significantemente con la altura, la proporcion de Larentiinae incrementa. Tambien hay cambios dentro de las subfamilias Ennominae y Larentiinae. Las tribus ennominas Cassymini, Macariini y Palyadini, que son especialistas acerca de plantas huespedes, desaparecen completamente y la proporcion de la tribu Boarmiini disminuye en altitudes grandes. Por el contrario, las demas tribus (mayormente especies polifagas) no demuestran cambios proporcionales (Azelinini, Nacophorini, Nephodiini, Ourapterygini) o incluso incrementan (Caberini, grupo ‘Cratoptera’). Dentro de los Larentiinae la proporcion de especies del genero Eois disminuye, mientras la de Eupithecia crece concomitantemente. Hay una similitud notable entre los resultados de Ecuador de un gradiente altitudinal y aquellos encontrados a lo largo de un gradiente latitudinal en Europa.



Conclusiones principales  Las especies de la subfamilia Larentiinae parecen ser particularmente bien adaptadas a condiciones ambientales desfavorables, tanto hacia altitudes como latitudes grandes. Podrian beneficiarse desproporcionadamente de una depredacion mas baja en altitudes mas grandes. Muchos cambios en la composicion faunistica pueden explicarse con demandas esperadas a plantas huespedes de las especies involucradas. Nuestros resultados muestran que estimados de diversidad basados en relaciones entre los taxa supuestas constantes deben de considerarse con cuidado ya que tales relaciones pueden cambiar rapidamente a lo largo de gradientes ambientales.

Faunal composition of geometrid moths changes with altitude in an Andean montane rain forest

Fall armyworm is a significant agricultural pest in the United States, affecting most notably sweet corn and turf grass. While infesting much of North America, fall armyworms invading the eastern United States arise from annual migrations of populations wintering in southern Florida. It has long been noted that this seasonal geographical localization represents an opportunity for controlling this pest prior to its annual migration. However, such efforts have been hindered by the presence of two genetically distinct but morphologically identical strains that differ physiologically and behaviorally. The biology of the host strains is poorly understood and this lack of knowledge precludes accurate predictions of fall armyworm population behavior in the field. This paper reviews recent studies examining strain behavior and discusses the potential relevance of these results to the development of effective regional management strategies that can be used proactively to mitigate the economic impact of this pest.

/pdf/behavior-and-distribution-of-the-two-fall-armyworm-host-5xf8r6cgha.pdf

Behavior and distribution of the two fall armyworm host strains in Florida

Male fall armyworm moths( Spodoptera frugiperda (J. E. Smith)) were captured in pheromone traps over a 16- to 24-mo period in selected sites in southern Florida. Molecular markers were used to determine whether individuals were of one of two host strains (historically designated "rice-strain" and "corn-strain"). Trapsplaced in agricultural areass howed a population peak in the spring (MarchÐMay) and fall (OctoberÐDecember), with a prolonged decline in numbers in summer (JulyÐOctober) and a smaller reduction in mid-winter (January). The host strain distribution during these periods varied signiÞcantly, suggesting strain-speciÞc and seasonal population patterns. Both strains were captured in substantial numbers during the spring peak, but surprisingly, only the rice-strain showed an increase in capture rates during the fall, despite the presence of sweet corn throughout this period. Trap captures in a sod (turfgrass) farm were composed almost entirely of the rice-strain and showed a bimodal seasonal distribution similar to that seen in the agricultural areas, with peaks in the spring and fall. These results represent the Þrst indication that the two host strains might have substantially different population dynamics in the overwintering agricultural areas of Florida and suggest that the rice-strain is the predominant fall armyworm pest during the fall and winter growing periods. It further indicates that the two strains can display a markedly different response to seasonal environmental cues. The implications of these Þndings on our understanding of fall armyworm migration are discussed.

https://bioone.org/journals/Environmental-Entomology/volume-33/issue-4/0046-225X-33.4.881/Seasonal-Distribution-of-Fall-Armyworm-Lepidoptera--Noctuidae-Host-Strains/10.1603/0046-225X-33.4.881.pdf

Seasonal Distribution of Fall Armyworm (Lepidoptera: Noctuidae) Host Strains in Agricultural and Turf Grass Habitats

In a 3-yr study (1991–1993), we compared blacklight and Townes-style Malaise traps for assessing richness and abundance of forest macrolepidoptera in 4 small watersheds in the Fernow Experimental Forest in West Virginia. From early May through mid-August each year, sampling was conducted by one 8-W blacklight trap and 5 Townes-type Malaise traps in each watershed. Light traps were operated 1 night each week; Malaise traps operated continuously with the samples collected every 10 d. Over all years, macrolepidopteran species richness and abundance were 343 and 36,160 and 273 and 28,246 for light trap and Malaise trap samples, respectively. Percentage of total macrolepidopteran species per family was similar in both collecting methods although both diurnal and nocturnal lepidopterans were represented in Malaise samples. Differences were noted in percentage of total abundance by family. For example, geometrid abundance was similar in both sample types and represented the highest overall abundance, whereas the proportion of arctiids and notodontids was higher in light trap samples, and proportional abundance of noctuids was higher in Malaise trap samples. There were 135 and 65 species unique to light trap and Malaise trap samples, respectively. Abundance of macrolepidopterans sampled by both methods was highest in 1991 (a warm, dry year) and lowest in 1992 (a cool, wet year). Minimum ambient temperature and rainfall significantly affected the sizes of samples from blacklight traps, based on multiple-regression analysis. Moonlight in the absence of cloud cover reduced moth catch in blacklight traps. Mean ambient temperature, but not total rainfall, during trapping periods significantly affected the sizes of Malaise-trap samples based on a multiple autoregression analysis.

Linda Butler

Papers

Effects of weather conditions and trap types on sampling for richness and abundance of forest macrolepidoptera