Phylogeny and palaeoecology of Polyommatus blue butterflies show Beringia was a climate-regulated gateway to the New World

Transcontinental dispersals by organisms usually represent improbable events that constitute a major challenge for biogeographers. By integrating molecular phylogeny, historical biogeography and palaeoecology, we test a bold hypothesis proposed by Vladimir Nabokov regarding the origin of Neotropical Polyommatus blue butterflies, and show that Beringia has served as a biological corridor for the dispersal of these insects from Asia into the New World. We present a novel method to estimate ancestral temperature tolerances using distribution range limits of extant organisms, and find that climatic conditions in Beringia acted as a decisive filter in determining which taxa crossed into the New World during five separate invasions over the past 11 Myr. Our results reveal a marked effect of the Miocene-Pleistocene global cooling, and demonstrate that palaeoclimatic conditions left a strong signal on the ecology of present-day taxa in the New World. The phylogenetic conservatism in thermal tolerances that we have identified may permit the reconstruction of the palaeoecology of ancestral organisms, especially mobile taxa that can easily escape from hostile environments rather than adapt to them.     

Shiny wing scales cause spec(tac)ular camouflage of the angled sunbeam butterfly,Curetis acuta

The angled sunbeam butterfly, Curetis acuta (Lycaenidae), is a distinctly sexually dimorphic lycaenid butterfly from Asia. The dorsal wings of female and male butterflies have a similar pattern, with a large white area in the female and an orange area in the male, framed within brown–black margins. The ventral wings of both sexes are silvery white, which is caused by stacks of overlapping, non‐pigmented, and specular‐reflecting scales. With oblique illumination, the reflected light of the ventral wings is strongly polarized. We show that the silvery reflection facilitates camouflage in a shaded, foliaceous environment. The ecological function of the silvery reflection is presumably two‐fold: for intraspecific signalling in flight, and for reducing predation risk at rest and during hibernation. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 279–289.     

Contemporary habitat loss reduces genetic diversity in an ecologically specialized butterfly

Aim This study investigated the influence of contemporary habitat loss on the genetic diversity and structure of animal species using a common, but ecologically specialized, butterfly, Theclinesthes albocincta (Lepidoptera: Lycaenidae), as a model. Location South Australia. Methods We used amplified fragment length polymorphism (AFLP) and allozyme datasets to investigate the genetic structure and genetic diversity among populations of T. albocincta in a fragmented landscape and compared this diversity and structure with that of populations in two nearby landscapes that have more continuous distributions of butterflies and their habitat. Butterflies were sampled from 15 sites and genotyped, first using 363 informative AFLP bands and then using 17 polymorphic allozyme loci (n = 248 and 254, respectively). We complemented these analyses with phylogeographic information based on mitochondrial DNA (mtDNA) haplotype information derived from a previous study in the same landscapes. Results Both datasets indicated a relatively high level of genetic structuring across the sampling range (AFLP, F_ST = 0.34; allozyme, F_ST = 0.13): structure was greatest among populations in the fragmented landscape (AFLP, F_ST = 0.15; allozyme, F_ST = 0.13). Populations in the fragmented landscape also had significantly lower genetic diversity than populations in the other two landscapes: there were no detectable differences in genetic diversity between the two continuous landscapes. There was also evidence (r² = 0.33) of an isolation by distance effect across the sampled range of the species. Main conclusions The multiple lines of evidence, presented within a phylogeographic context, support the hypothesis that contemporary habitat fragmentation has been a major driver of genetic erosion and differentiation in this species. Theclinesthes albocincta populations in the fragmented landscape are thus likely to be at greater risk of extinction because of reduced genetic diversity, their isolation from conspecific subpopulations in other landscapes, and other extrinsic forces acting on their small population sizes. Our study provides compelling evidence that habitat loss and fragmentation have significant rapid impacts on the genetic diversity and structure of butterfly populations, especially specialist species with particular habitat preferences and poor dispersal abilities.     

Absence of cuticular alkenes allows lycaenid larvae to avoid predation by Formica japonica ants

Chemical mimicry and camouflage based on cuticular hydrocarbons (CHCs) are adaptive strategies that are frequently observed in myrmecophilous insects. The larvae of several lycaenid butterfly species that exhibit obligate associations with specific ant species have been reported to use chemical mimicry. However, little is known about the strategies used by the larvae of species that have facultative associations with multiple ant species. We attempted to reveal the effects of larval CHC profiles on interactions with Formica japonica workers, using three lycaenid species, two facultative ant‐associated (Lycaeides argyrognomon and Zizeeria maha) and one non‐ant‐associated (Lycaena phlaeas), which commonly possess n‐alkanes as the major CHCs. In field bioassays, the lycaenid larvae were attacked by ant workers less often than larvae of Papilio polytes (Papilionidae), the CHCs of which were rich in 7‐alkenes. Treating the lycaenid larvae with 7‐heptacosene and 9‐heptacosene significantly activated ant aggression (biting), whereas treating them with n‐heptacosane, n‐octacosane and 13‐methylheptacosane had little effect. Furthermore, larvae of Pieris rapae (Pieridae), possessing n‐alkanes as the dominant CHCs, suffered an intermediate level of ant biting between the lycaenid and Pa. polytes larvae. However, treatments of the P. rapae larvae with 7‐heptacosene and 9‐heptacosene significantly affected the frequency of ant biting. These findings suggest that the absence of alkenes in larval CHC profiles is an effective means of circumventing predation by ants and allows lycaenid larvae to inhabit the foraging territory of predaceous ants, at least to some extent.     

On Hypolycaena from Maluku, Indonesia, including the first description of male Hypolycaena asahi (Lepidoptera, Lycaenidae)

The taxonomy and distribution of the five species of Hypolycaena in Maluku are discussed and new locality records given. Corrections are made to the published taxonomy and distribution of Hypolycaena phorbas (Fabricius, 1793). This clarification enables a better understanding of the biogeography of the genus. Hypolycaena asahi Okubo, 2007, was originally described from a single female from Ambon and is here recorded from Seram. The male is described for the first time.     

长白山区眼灰蝶属(鳞翅目,灰蝶科)研究和中国一新纪录种

记述长白山区眼灰蝶属4种,其中兹眼灰蝶Polyommatus tsvetaevi(Kurentzov,1970)为中国新纪录种,编制分种检索表,提供成虫照片和外生殖器特征图。因阿眼灰蝶Polyommatus amanda和酷眼灰蝶Polyommatus semiargus在长白山的亚种名均为amurensis,因此,amurensis Tutt,1909就成为amurensis(Staudinger,1892)的次同名,需要提出替代名Polyommatus semiargus changbaishanensis nom.nov.     

Analysis of Transect Counts to Monitor Population Size in Endangered Insects The Case of the El Segundo Blue Butterfly, Euphilotes Bernardino Allyni

Before, during and after habitat restoration from 1984 to 1994, we monitored population size of the federally listed endangered El Segundo blue butterfly, Euphilotes bernardino allyni (Shields). In the subsequent formalization of a recovery plan for the species, the U.S. Fish and Wildlife Service established several recovery criteria, including a requirement of a scientifically credible monitoring plan to track population size annually. To avoid detrimental effects of the extensively used mark-release-recapture method on the delicate El Segundo blue butterfly, which would conflict with protection afforded by the Endangered Species Act, we chose instead to perform transect counts to estimate relative population size. Herein, we analyze the results of our transect counts by three different methods, developed by or modified from Pollard, Watt et al. and Zonneveld. Qualitatively, the three methods, which have different assumptions, produced similar results when applied to the same data. Zonneveld's model estimates death rate in addition to an index of population size, thus providing more information than the other two methods. The El Segundo blue butterfly's sedentary nature and the close relationship of its adult and early stages to one foodplant permits extrapolation of the index of population size based on transect counts, to an estimate of actual population size. Our data document butterfly numbers increasing from 1984 to 1989, but then declining until the end of our observations in 1994. Based on analysis of our El Segundo blue butterfly data, we propose an implementation of a scientifically credible monitoring plan.     

中国何华灰蝶属一新种（鳞翅目：灰蝶科）

本文记述产自我国广东省的何华灰蝶属Ｈｏｗａｒｔｈｉａ１新种,即陈氏何华灰蝶ＨｏｗａｒｔｈｉａｃｈｅｎｉＣｈｏｕｅｔＷａｎｇ,ｓｐ．ｎｏｖ,种名以采集者姓氏命名。陈氏何华灰蝶ＨｃｗａｒｔｈｉａｃｈｅｎｉＣｈｏｕｅｔＷａｎｇ,新种（图１）前翅长１８ｍｍ,触角长８ｍｍ。新种与四川产的柯氏何华灰蝶Ｈｏｗａｒｔｈｉａｃｏｕｒｖｏｉｓｉｅｒｉ（Ｏｂｅｒｔｈｕｒ）相近似,但前翅正面蓝色斑小,后翅只在中部有一极小的蓝斑,后翅反面ＣｕＡ２室内的眼状斑的黑色瞳孔大,覆盖有银灰色鳞片,并向外缘扩散,前翅反面ＣｕＡ２及１Ａ＋２Ａ室内的亚缘线内侧各有一大而显著的黑斑。正模♂,广东乳源,１９９４—Ⅴ—３,陈锡昌采。标本存西北农业大学昆虫博物馆。     

The effect of host-plant quality on the survival of larvae and oviposition by adults of an ant-tended lycaenid butterfly, Jalmenus evagoras

Abstract.

• 1 Juveniles of the Australian lycaenid butterfly, Jalmenus evagorus (Donovan), secrete to ants a solution of sugars and amino acids, primarily serine. The attendant ants protect the larvae and pupae from parasites and predators.
• 2 The effect of caterpillar nutrition on the defence provided by ants was investigated. Potted food plants of Acacia decurrens were either given water containing nitrogenous fertilizer or were given water alone. Fertilized plants had a higher nitrogen content than unfertilized plants.
• 3 Fifth instar larvae of J.evagoras feeding on fertilized plants attracted a larger ant guard than those feeding on unfertilized plants. In the absence of caterpillars, ants were not differentially attracted to fertilized and unfertilized plants.
• 4 In the presence of ants, over a 10-day period, larvae on fertilized plants survived better than larvae on unfertilized plants. In the absence of ants larvae survived equally on fertilized and unfertilized plants. It is concluded that larvae on fertilized plants attracted a larger ant guard, and thereby survived better, than larvae on unfertilized plants.
• 5 Adult females of J. evagoras preferred to lay egg batches on fertiized, rather than unfertilized plants, but they did not lay larger egg batches.

     

Associations between lycaenid butterflies and ants in Australia

A comprehensive and critical review of all available literature on associations between Australian lycaenid butterflies and ants was undertaken to establish an accurate database of the partners involved. Collections and observations of lycaenids and ants were used to augment this review, resulting in a significant number of newly documented association (and non-association) records. Twenty published records considered to be erroneous or doubtful are noted, with justifications given for their deletion from the association database. In total, 265 different associations between lycaenids and ants, plus 65 non-attendance records are documented for Australia. Nearly 80% of the lycaenid species in Australia, for which the early stages are known, are recorded associating with ants and half of these are obligately ant-associated. Patterns of association are examined from the perspective of both lycaenids and ants, with a focus on ant systematics and ecology. Lycaenids are recorded with five ant subfamilies, including the first record of an association with the Pseudomyrmecinae. The Dolichoderinae, and to some extent the Formicinae, have a disproportionately high percentage of genera that associate with lycaenid butterflies. All ant species that tend lycaenids spend at least some portion of their time foraging on vegetation to collect plant and insect nectar. There is a robust relationship between the competitive status of ants within a community, and their frequency and degree of association with lycaenids. Obligate ant-association is accompanied by a high degree of specificity for ant partner, but two notable exceptions, Ogyris aenone and O. amaryllis are discussed. Facultative myrmecophiles tend to associate with a broad range of ants, although interactions with ecologically dominant ants are less frequent than might be expected based on the abundance of dominant ant species in Australian communities.