Characterization of polymorphic microsatellites in the castration parasite plant‐ant Allomerus octoarticulatus cf. demerarae (Formicidae: Myrmicinae)

Fifteen microsatellite loci were isolated from the Peruvian tropical plant‐ant Allomerus octoarticulatus cf. demerarae (Hymenoptera: Myrmicinae) and their polymorphism was characterized. High levels of within‐population variation were observed at most loci, with number of alleles ranging from one to 21, and heterozygosity from 0 to 1 per population sample. Cross‐species amplification of these loci was also tested in one other species of the ant genus Allomerus (Allomerus decemarticulatus), displaying similar life history.     

中国红蚁属一新种记述(膜翅目,蚁科)

描述陕西佛坪红蚁属1新种,即郑氏红蚁Myrmica zhengi sp.nov.。新种体色极浅;头部正面观方形;前中胸背板刻纹横形,但极不规则;并胸腹节刺粗壮,基部宽;后腹第1节背板基侧具明显细纵刻纹与近似种类相区别。模式标本保存于陕西师范大学动物研究所,副模标本分存于广西师范大学生命科学学院、西北农林科技大学昆虫博物馆、东北师范大学生命科学学院和西南林业大学标本馆昆虫标本室。     

Correlates of ecological dominance within Pheidole ants (Hymenoptera: Formicidae)

1. In any group of organisms, one can almost invariably find some species that are ecologically dominant (i.e. disproportionately more abundant and widespread), whereas others are comparatively less prevalent. Understanding of the causes of variation in ecological dominance has been elusive, particularly given that dominant and subordinate species often lack obvious features that could predict their abundance in nature. 2. In this study, physiological, behavioural, morphological, and phylogenetic information is integrated in an effort to understand the mechanisms underlying ecological dominance in ants using the hyperdiverse ant genus Pheidole (Formicidae: Myrmicinae) as a model system. Field estimates of the relative abundance of 10 Pheidole species were compared with potential correlates, which included behavioural (walking velocity), physiological (tolerance to high and low temperatures and desiccation), and morphological traits (body size and degree of dimorphism in the worker caste). A molecular phylogeny of the tested species was also generated to account for potential confounding effects of phylogenetic non‐independence. 3. Dominant Pheidole species were characterised by higher environmental tolerance with respect to temperature and humidity, as well as faster walking speeds. On the other hand, no morphological correlates of ecological dominance were detected. Interestingly, subordinate species showed no evidence of trade‐off in performance, being both more fragile to environmental challenges and slower in their walking speeds. 4. These results provide important insights into the mechanisms involved in local species coexistence in Pheidole.     

Association between the African lycaenid,Anthene usamba,and an obligate acacia ant,Crematogaster mimosae

The African lycaenid butterfly, Anthene usamba, is an obligate myrmecophile of the acacia ant, Crematogaster mimosae. Female butterflies use the presence of C. mimosae as an oviposition cue. The eggs are laid on the foliage and young branches of the host plant, Acacia drepanolobium. Larvae shelter in the swollen thorns (domatia) of the host tree, where they live in close association with the acacia ants, and each larva occupies a domatium singly. Anthene usamba are tended by ants that feed from the dorsal nectary organ at regular intervals. Larvae also possess tentacle organs flanking the dorsal nectary organ and appear to signal to ants by everting these structures. Larvae were observed to spend most of their time within the domatia. Stable isotope analysis of matched host plant–ant–butterfly samples revealed that Anthene usamba are δ¹⁵N enriched relative to the ants with which they associate. These data, based on the increase in δ¹⁵N through trophic levels, indicate that the caterpillars of these butterflies are aphytophagous and either exploit the ant brood of C. mimosae within the domatia, or are fed mouth to mouth by adult workers via trophallaxis. This is the first documented case of aphytophagy in African Anthene. Pupation occurs inside the domatium and the imago emerges and departs via the hole chewed by the larva. The adult females remain closely associated with their natal patch of trees, whereas males disperse more widely across the acacia savannah. Females prefer to oviposit on trees with the specific host ant, C. mimosae, an aggressive obligate mutualist, and avoid neighbouring trees with other ant species. Adult butterflies are active during most months of the year, and there are at least two to three generations each year. Observations made over a 5‐year period indicate that a number of different lycaenid species utilize ant‐acacias in East Africa, and these observations are summarized, together with comparisons from the literature. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013 , 109 , 302–312.     

Monomorium dryhimi sp. n., a new ant species (Hymenoptera, Formicidae) of the M. monomorium group from Saudi Arabia, with a key to the Arabian Monomorium monomorium-group

A new ant species, Monomorium dryhimi, is described based on workers from a single colony collected in Al Bahah, Asir Province, Saudi Arabia. This is the fourth species of the Monomorium monomorium-group collected from Arabian Peninsula, and appears to be closely related to Monomorium holothir Bolton, 1987, from Kenya. It can be distinguished by the following characters: head in profile with a weakly convex dorsal surface and a clearly convex ventral surface; eyes of moderate size with maximum diameter EL 0.19-0.25 × HW and with 6 ommatidia in the longest row; body colour yellow to light brownish yellow. In some individuals, head and gaster slightly but conspicuously darker than rest of body. Second halves of first and second gastral tergites with two characteristic brownish transverse bands. An identification key to the workers of the Arabian species of the Monomorium monomorium-group is presented. Scanning electron micrographs are given to illustrate the new species.     

切叶蚁亚科蚂蚁的防御性生物碱

蚂蚁(蚁科)有显著的群居特性,个体间分工明确,并具有复杂的合作策略,以保护巢穴不受捕食者、病原微生物、蚂蚁竞争者的侵害,以及捕食猎物等。切叶蚁亚科是蚁科的最大类群,共有147个现生属,主要通过喷洒富含生物碱的毒液分泌物进行防御和捕猎。本文综述了该亚科防御性生物碱的组分及属种分布特征,其结构类型包括哌啶、吡啶、吡咯、吲哚里西啶、吡咯里西啶和脂肪胺等,并对其功能及应用进行了概述和展望。哌啶类生物碱是火蚁属Solenopsis毒液的典型特征,而吡咯烷、吡咯啉和吡咯里西啶类生物碱是小家蚁属Monomorium毒液的主要成分。吲哚里西啶类生物碱是脊红蚁属Myrmicaria蚂蚁和火蚁属贼蚁毒液的主要成分。除此之外,脂肪胺也是小家蚁属蚂蚁的毒液成分。这些毒液生物碱成分具有显著的生物活性,在农药和生物医药领域具有重要的应用前景。     

Molecular phylogeny of the ant tribe Myrmicini (Hymenoptera: Formicidae)

The interrelationships within ant subfamilies remain elusive, despite the recent establishment of the phylogeny of the major ant lineages. The tribe Myrmicini belongs to the subfamily Myrmicinae, and groups morphologically unspecialized genera. Previous research has struggled with defining Myrmicini, leading to considerable taxonomic instability. Earlier molecular phylogenetic studies have suggested the nonmonophyly of Myrmicini, but were based on limited taxon sampling. We investigated the composition of Myrmicini with phylogenetic analyses of an enlarged set of taxa, using DNA sequences of eight gene fragments taken from 37 representatives of six of the seven genera (Eutetramorium, Huberia, Hylomyrma, Manica, Myrmica, and Pogonomyrmex), and eight outgroups. Our results demonstrate the invalidity of Myrmicini as currently defined. We recovered sister‐group relationships between the genera Myrmica and Manica, and between Pogonomyrmex and Hylomyrma. This study illustrates that to understand the phylogeny of over 6000 myrmicine species, comprehensive taxon sampling and DNA sequencing are an absolute requisite. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 482–495.     

Life history,damage assessment and control of Trioza hopeae (Hemiptera: Psylloidea), a serious pest on Hopea odorata (Malvales: Dipterocarpaceae) in Vietnam

Young plants of the commercially important timber species Hopea odorata Roxb. are seriously damaged by the psyllid Trioza hopeae Burckhardt & Vu in nurseries in South Central and Southern Vietnam. Farmers routinely use Class 1 toxic insecticides to control the psyllids but these pose serious health risks in the urban environment. As a precursor to developing a pest management strategy, we studied the life cycle of T. hopeae and trialed several control measures. Trioza hopeae is polyvoltine with overlapping generations peaking in mid wet season. Females laid approximately 135 eggs; however, there was a natural attrition rate of about 80% in first‐instar nymphs due to the nymph's inability to find a suitable feeding site. Feeding nymphs induced pit galls on young H. odorata leaves and were present on all trees examined during the study. The pre‐adult life cycle lasted approximately 13 days and adult life span approximately seven days. Several toxic insecticides were found to be effective for controlling T. hopeae, but a novel non‐toxic alternative was equally as effective. We discuss these methods and potential biological control measures.     

Volatile components from the mandibular glands of the turtle ants, Cephalotes alfaroi and Cephalotes cristatus

GC–MS analysis of whole head extracts from the turtle ants, Cephalotes alfaroi and Cephalotes cristatus, showed that 4-heptanone and 4-heptanol were the major volatile components in the mandibular glands. 4-Heptanone and 4-heptanol have rarely been identified in mandibular gland secretions from other ant genera. Thus, these compounds may be chemotaxonomic markers for the genus Cephalotes, since they have been identified in the mandibular glands from all members of this genus that have been investigated to date. Minor components identified in the whole head extracts of these ants were 3-methyl-1-butanol, 3-heptanone, 3-hexanol, 2- and 3-methylbutanoic acids, 2-methyl-4-heptanone, 2-phenylethanol and phenol. To our knowledge, this is the first time that 2-methyl-4-heptanone and phenol have been reported in the mandibular gland secretion from any Formicid.