Effects of predation risks of bats on the growth, development, reproduction, and hormone levels of Spodoptera litura

Predation is a powerful selection pressure that shapes predator–prey interactions. Due to long-term interactions, moths have developed hearing to detect the echolocation calls of bats. This allows bats to impose the non-consumptive effects of predation on moths. However, information on the changes in the growth, development, reproduction, and hormones of moths that are vulnerable to bat predation is limited. In this study, we used Spodoptera litura (Lepidoptera: Noctuidae) to determine the effects of the predation risks of bats on their growth, development, reproduction, and hormone titers. Our results showed that the larvae of S. litura increased food intake, accelerated the development of the larval stages, increased mortality and metamorphosis failure, and had a smaller body size under the risk of predation by bats. Additionally, the reproductive activity and fecundity decreased in the adults of S. litura, but the juvenile hormone titers and 20-Ecdydysone hormone titers increased. These results suggested an adaptive response in S. litura under bat predation risks at the cost of lower survival and reproduction. Finally, we found that S. litura moths showed different responses to different predation risk cues, which suggested that they might assess the magnitude of different predation risks to make the most suitable decision for survival and reproduction. Our results highlight the importance of the predation risk imposed by bats to negatively regulate the population dynamics of moths. Our findings indicated that the biological control of bugs using bats is a promising strategy

Pleistocene glacial cycle effects on the phylogeography of the Chinese endemic bat species, Myotis davidii

<p>Abstract</p> <p>Background</p> <p>Global climatic oscillations, glaciation cycles and the unique geographic topology of China have profoundly influenced species population distributions. In most species, contemporary distributions of populations cannot be fully understood, except in a historical context. Complex patterns of Pleistocene glaciations, as well as other physiographic changes have influenced the distribution of bat species in China. Until this study, there had been no phylogeographical research on <it>Myotis davidii</it>, an endemic Chinese bat. We used a combination of nuclear and mitochondrial DNA markers to investigate genetic diversity, population structure, and the demographic history of <it>M. davidii</it>. In particular, we compared patterns of genetic variation to glacial oscillations, topography, and environmental variation during the Pleistocene in an effort to explain current distributions in light of these historical processes.</p> <p>Results</p> <p><it>M. davidii </it>comprises three lineages (MEP, SWP and SH) based on the results of molecular variance analysis (AMOVA) and phylogenetic analyses. The results of a STRUCTURE analysis reveal multi-hierarchical population structure in <it>M. davidii</it>. Nuclear and mitochondrial genetic markers reveal different levels of gene flow among populations. In the case of mtDNA, populations adhere to an isolation-by-distance model, whereas the individual assignment test reveals considerable gene flow between populations. MDIV analysis indicate that the split of the MEP and SWP/SH lineages, and from the SWP and SH lineages were at 201 ka BP and 158 ka BP, respectively. The results of a mismatch distribution analysis and neutrality tests indicate a population expansion event at 79.17 ka BP and 69.12 ka BP in MEP and SWP, respectively.</p> <p>Conclusions</p> <p>The complex demographic history, discontinuous extant distribution of haplotypes, and multiple-hierarchy population structure of <it>M. davidii </it>appear associated with climatic oscillations, topography and eco-environmental variation of China. Additionally, the three regions are genetically differentiated from one another in the entire sample set. The degree of genetic differentiation, based on the analysis of mtDNA and nDNA, suggests a male-mediated gene flow among populations. Refuges were in the MEP, SH and the lower elevations of SWP regions. This study also provides insights for conservation management units (MEP, SWP and SH).</p

Sex ratio potentially influence the complexity of social calls in Himalayan leaf-nosed bat groups

Animals living in a complex social environment emit diverse acoustic signals and thus serve as excellent subjects for understanding the evolution of acoustic communication. Previous studies have focused on the complexity of social calls in some group-living animals, yet the determinants of vocal complexity at the intraspecific level remain unclear. Here, we aimed to assess the influence of group composition on social call complexity in Himalayan leaf-nosed bats (Hipposideros armiger) in the non-breeding season. The bats divided into three groups with the same number of individuals but with different sex ratio compositions. We monitored social vocalizations for the all-male group, the all-female group, the mixed group, and also quantified vocal complexity for each group based on multiple acoustic metrics, including vocal repertoire, call sequences, the diversity index, and information capacity. The results showed that there were significant differences in the composition of call sequences among the three bat groups. The number of vocalizations was the highest in the mixed group, while the social call complexity was the highest in the all-male group, followed by the all-female group, and was the lowest in the mixed group. The results suggest that sex ratio potentially influence the vocal repertoire in Himalayan leaf-nosed bats. Our findings might provide a cue for vocalization research to investigate sex ratio in social groups as a potential driver for vocal complexity

Myotis flavus Shamel 1944

&lt;i&gt;Myotis flavus&lt;/i&gt; Shamel 1944 &lt;p&gt; &lt;i&gt;Myotis flavus&lt;/i&gt; Shamel 1944; type specimen, National Museum of Natural History (NMNH) 239908; adult &female;, remainder in fluid, skull removed. The type specimen was collected under a grove of trees with large leaves and lilac-like flowers in Jul 1923 at Enri in Formosus.The bat hanged head downwards from the stem of a leaf. Its colour was light yellow, the wing being variegated with orange and brown (Shamel 1944).&lt;/p&gt; &lt;p&gt; &lt;b&gt;New materials.&lt;/b&gt; JX- 07X-20, adult, male, collected at Shiyan cave (114&deg;12΄E, 26&deg;36΄N; 1058 m) in Liping village of Jinggangshan Natural Reserve of Jiangxi Province in mainland China by TingLei Jiang and KePing Sun in September 2006. Fur specimen (No. JX- 07X-20) was deposited at Northeast Normal University, China.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Description and taxonomic notes.&lt;/b&gt; For &lt;i&gt;Myotis&lt;/i&gt; species from mainland China, this is a medium to large size &lt;i&gt;Myotis&lt;/i&gt; with a forearm length of 48.5 mm (Table 3)(52.5 mm in Shamel 1944), which is within the range (45 &ndash; 55 mm) given by Lin &lt;i&gt;et al.&lt;/i&gt; (2005). The bases of the dorsal and ventral pelage are grayish white with their tips golden yellow and pale yellow, respectively (Fig. 2 a). Light brown bands exist around the digits of the wings. There are no black edges on the upper margin of the auricles, around the nostrils, thumbs, toes and the end of the tail (Fig. 2 a and Fig. 2 b). This clearly differs from &lt;i&gt;M. rufoniger&lt;/i&gt; (Bates &amp; Harrison 1997), &lt;i&gt;M. watasei&lt;/i&gt; (Lin &lt;i&gt;et al.&lt;/i&gt;, 2005) and &lt;i&gt;M. tsuensis&lt;/i&gt; (Yoshiyuki 1989). The tragus is narrow and tapering towards a bluntly-pointed tip. The nose and chin are bare of long hairs for a distance of about 5 mm from tip, but the remainder of the face is well haired (Fig. 2 b), which corresponds to those specimens described in Shamel (1944). Metacarpals are considerably shorter than the forearm, and the third, fourth, fifth metacarpals were 91.2%, 88.6% and 90% of forearm length, respectively (Table 3). The wings are attached to the base of the phalanx of the outer metatarsal of each foot. Tail vertebrae extend 2.5 mm beyond the interfemoral membrane.&lt;/p&gt; &lt;p&gt; The greatest antero-posterior length of the skull is 18.3 mm (Table 3)(19.5 mm in Shamel, 1944). The skull has the forehead region strongly concave (Fig. 3 c). The sagittal crest is well defined anteriorly but the lambdoid crest is inconspicuous (Fig. 3 a). The joint between the supraoccipital and foramen magnum is round and protruding downwards. The supraoccipital is slightly orbicular and plump (Fig. 3 c). The upper incisors become gradually larger from the inner to the outer teeth, and the canine is well developed (Fig. 3 b). The upper middle premolar (P3) site is completely within the upper tooth row, whereas in &lt;i&gt;M. rufoniger&lt;/i&gt; and &lt;i&gt;M. watasei&lt;/i&gt;, P3 is usually only partially within the tooth row of the upper jaw (Shamel, 1944). The upper anterior premolar (P2) and the upper posterior premolar (P4) are not in contact with each other; P3 is not visible when the tooth row is viewed externally, but is visible from a buccal view, which is same included in Shamel (1944). P3 extends its tip barely above the level of the cingulum on P2 (Fig. 3 c). The anterior and middle upper molars have distinct W- shaped ridges, and the posterior upper molar is half reduced (Fig. 3 b). The crowns of the second and third lower incisors divide into four leaflets. The first lower incisor is prolate, and the incisors are aligned forming a convex arch (Fig. 3 d). P3 is set inward, but visible from the outside of the tooth row, and the cusp is more slender and pointed than in P2 and about half its height (Fig. 3 c).&lt;/p&gt; &lt;p&gt; The baculum of the sample JX- 07X-20 is generally Y-shaped, but slightly (Fig. 4 a). Proximal and distal ends concave at its central portion, and its ventral surface is not deeply fluted. Total length is 0.975 mm and maximum basal width is 0.575 mm. However, the baculum of &lt;i&gt;M. formosu&lt;/i&gt; s from Jilin province clearly differs from that of the sample JX- 07X- 20 in having a concavity only in its proximal end and showing a deeply fluted ventral surface (Fig. 4 b). In addition, the size of the baculum of &lt;i&gt;M. formosu&lt;/i&gt; s (total length 0.8 mm, maximum basal width 0.575 mm.) is slightly smaller than that of JX- 07X-20.&lt;/p&gt; &lt;p&gt;Definitions follow those given in Bates and Harrison(1997).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Echolocation.&lt;/b&gt; The echolocation calls of individual JX- 07X-20 are short, broadband frequency modulated signals with a dominant fundamental harmonic. The mean value for the frequency containing the maximum energy is 43.91 kHz, with a range of 41.0 &ndash; 46.2 kHz (n = 22).&lt;/p&gt; &lt;p&gt; &lt;b&gt;Discussion.&lt;/b&gt; When describing &lt;i&gt;M. flavus&lt;/i&gt;, Shamel (1944) indicated that from &lt;i&gt;M. rufoniger&lt;/i&gt; and &lt;i&gt;M. watasei&lt;/i&gt; in body size and dental characteristics. Chou (2004) also distinguished &lt;i&gt;M. flavus&lt;/i&gt; from &lt;i&gt;M. watasei&lt;/i&gt;. In the present study, &lt;i&gt;M. flavus&lt;/i&gt; is found to be different from &lt;i&gt;M. formosus&lt;/i&gt; in coloration, skull and dental characteristics. In addition, differences in baculum morphology indicate a potential for the occurrence of reproductive isolation between &lt;i&gt;M. flavus&lt;/i&gt; and &lt;i&gt;M. formosus&lt;/i&gt; (Wu &lt;i&gt;et al.&lt;/i&gt;, 2008).&lt;/p&gt; &lt;p&gt; Relatively inexpensive and rapid DNA sequencing techniques have given biologists a new tool for detecting and differentiating morphologically similar species (Bickford, &lt;i&gt;et al.&lt;/i&gt;, 2007). We took advantage of this by analyzing the mtDNA cytb gene, which showed that our specimen JX- 07X-20 differed by 0.61% from &lt;i&gt;M. flavus&lt;/i&gt; from Taiwan (Table 2) which most likely corresponds to a divergence of intraspecific level. This genetical similarity supported the result of our morphological identification of this specimen. In contrast, it was surprising to see that the divergence values between &lt;i&gt;M. flavus&lt;/i&gt; and other &lt;i&gt;M. formosus&lt;/i&gt; specimens were so much larger (15.53&ndash;16.67 %) and even higher than the other interspecific divergences (Table 2). Genetic distances over 5% at cytb are generally considered to indicate the existence of cryptic taxonomic diversity, and values exceeding 10% in bats are indicative of species-level divergence (Baker &amp; Bradley 2006). Moreover, our phylogenetic analysis shows that &lt;i&gt;M. formosus&lt;/i&gt; and &lt;i&gt;M. flavus&lt;/i&gt; are not sister taxa (Fig. 1). Hence, we consider &lt;i&gt;M. flavus&lt;/i&gt; to be a distinct species and different from &lt;i&gt;M. formosus&lt;/i&gt;. In addition, the phylogenetic grouping of and sequence similarity between &lt;i&gt;M. watasei&lt;/i&gt; and &lt;i&gt;M. formosus&lt;/i&gt; from mainland China strongly suggests that &lt;i&gt;M. watasei&lt;/i&gt; is synonymous with &lt;i&gt;M. formosus&lt;/i&gt;.&lt;/p&gt; &lt;p&gt; &lt;b&gt;Distribution and ecological notes.&lt;/b&gt; So far, &lt;i&gt;M. flavus&lt;/i&gt; is only known from Taiwan (Lin &lt;i&gt;et al.&lt;/i&gt;, 2005; Shamel 1944). The present report gives the first confirmed account of this species from mainland China. Our specimen JX- 07X-20 was captured at Shiyan cave in Liping village of Jinggangshan Natural Reserve of Jiangxi Province in China where the average temperature and mean rainfall are 14 &deg;C and 1865 mm per year, respectively, resulting in a subtropical wet climate. The collection site is dominated by a forest consisting of &lt;i&gt;Phyllostachys heterocycla&lt;/i&gt;, &lt;i&gt;Cunninghamia lanceolata&lt;/i&gt;, &lt;i&gt;Schima uperba&lt;/i&gt; and &lt;i&gt;P. heterocycla&lt;/i&gt;. The other bat species roosting in the same cave were &lt;i&gt;Rhinolophus affinis&lt;/i&gt;, &lt;i&gt;R. pearsoni&lt;/i&gt;, &lt;i&gt;R. macrotis&lt;/i&gt;, &lt;i&gt;Hipposideros armiger&lt;/i&gt;, &lt;i&gt;M. davidii&lt;/i&gt; and &lt;i&gt;M. formosus&lt;/i&gt;.&lt;/p&gt;Published as part of &lt;i&gt;Jiang, Tinglei, Sun, Keping, Chou, Chenghan, Zhang, Zhenzhen &amp; Feng, Jiang, 2010, First record of Myotis flavus (Chiroptera: Vespertilionidae) from mainland China and a reassessment of its taxonomic status, pp. 41-51 in Zootaxa 2414&lt;/i&gt; on pages 46-50, DOI: &lt;a href="http://zenodo.org/record/194368"&gt;10.5281/zenodo.194368&lt;/a&gt

The Geographical Differences in the Bird Prey of the Great Evening Bat (<i>Ia io</i>)

Geographic variation in diet can indicate if species have unique ecological roles or feeding strategies in different environments. Bats have a unique nocturnal ecological niche and a diverse diet, making them an ideal model for studying changes in feeding. Some bats have adapted to reduced food resources caused by environmental changes and human disturbances by expanding their dietary ecological niche. As one of the typical species whose dietary niche has expanded from invertebrates (insects) to vertebrates (birds), the feeding habits of the great evening bat (Ia io) have attracted much attention from researchers. Unfortunately, little is known about how the diet of Ia io varies in different regions. Therefore, in this study, the diversity and composition of the bird prey of the great evening bat from two populations were examined using cytochrome C oxidase subunit I (COI) amplicon sequencing. The results showed that the great evening bat in both populations preyed on a variety of passerine birds, with the Phylloscopidae being the dominant family. Although most birds preyed upon by these two populations are the same, there are significant differences in predation on Cettiidae between the two populations. Both populations prey on migratory birds more than resident birds. Both populations of bats can prey on finch birds weighing more than 15 g, but they preyed on more birds weighing less than 10 g. The results of this study provide an important addition to the study of changes in bat diets under the conditions of expanding dietary ecological niches

The Consumption and Diversity Variation Responses of Agricultural Pests and Their Dietary Niche Differentiation in Insectivorous Bats

Insectivorous bats are generalist predators and can flexibly respond to fluctuations in the distribution and abundance of insect prey. To better understand the effects of bats on arthropod pests, the types of pests eaten by bats and the response of bats to insect prey need to be determined. In this study, we performed DNA metabarcoding to examine prey composition and pest diversity in the diets of four insectivorous species of bats (Hipposideros armiger, Taphozous melanopogon, Aselliscus stoliczkanus, and Miniopterus fuliginosus). We evaluated the correlation between bat activity and insect resources and assessed dietary niche similarity and niche breadth among species and factors that influence prey consumption in bats. We found that the diets of these bats included arthropods from 23 orders and 200 families, dominated by Lepidoptera, Coleoptera, and Diptera. The proportion of agricultural pests in the diet of each of the four species of bats exceeded 40% and comprised 713 agricultural pests, including those that caused severe economic losses. Bats responded to the availability of insects. For example, a higher abundance of insects, especially Lepidoptera, and a higher insect diversity led to an increase in the duration of bat activity. In areas with more abundant insects, the number of bat passes also increased. The dietary composition, diversity, and niches differed among species and were particularly significant between H. armiger and T. melanopogon; the dietary niche width was the greatest in A. stoliczkanus and the narrowest in H. armiger. The diet of bats was correlated with their morphological and echolocation traits. Larger bats preyed more on insects in the order Coleoptera, whereas the proportion of bats consuming insects in the order Lepidoptera increased as the body size decreased. Bats that emitted echolocation calls with a high peak frequency and duration preyed more on insects in the order Mantodea. Our results suggest that dietary niche differentiation promotes the coexistence of different bat species and increases the ability of bats to consume insect prey and agricultural pests. Our findings provide greater insights into the role of bats that prey on agricultural pests and highlight the importance of combining bat conservation with integrated pest management

Using sounds for making decisions: greater tube-nosed bats prefer antagonistic calls over non-communicative sounds when feeding

Bats vocalize extensively within different social contexts. The type and extent of information conveyed via their vocalizations and their perceptual significance, however, remains controversial and difficult to assess. Greater tube-nosed bats, Murina leucogaster, emit calls consisting of long rectangular broadband noise burst (rBNBl) syllables during aggression between males. To experimentally test the behavioral impact of these sounds for feeding, we deployed an approach and place-preference paradigm. Two food trays were placed on opposite sides and within different acoustic microenvironments, created by sound playback, within a specially constructed tent. Specifically, we tested whether the presence of rBNBl sounds at a food source effectively deters the approach of male bats in comparison to echolocation sounds and white noise. In each case, contrary to our expectation, males preferred to feed at a location where rBNBl sounds were present. We propose that the species-specific rBNBl provides contextual information, not present within non-communicative sounds, to facilitate approach towards a food source