有翅型与无翅型棉蚜发育及繁殖能力比较研究

在室内采用网罩盆栽苗研究有翅型与无翅型棉蚜若虫及成虫发育历期、繁殖能力、成虫寿命、产仔能力、体重.有翅型与无翅型棉蚜若虫发育历期之间无显著差异.二者成虫寿命、第一次产仔数量、平均每次产仔数差异不显著,而生殖前期、产仔次数、净增殖率与内禀增长率均存在极显著差异(P<0.01).有翅型棉蚜的产仔次数极显著小于无翅型,而有翅型棉蚜生殖前期显著长于无翅型棉蚜.无翅型棉蚜净增殖率显著大于有翅型棉蚜.无翅型棉蚜可能可以将用于翅发育和飞行的能量转而用于繁殖.     

桃蚜鞣化激素基因克隆与表达分析

Bursicon是调节昆虫表皮硬化及展翅的激素类蛋白,它在昆虫表皮硬化和翅伸展过程中起着关键作用。本研究克隆获得桃蚜Bursicon基因(burs-α和burs-β)全长,分别命名为Mpburs-α(GenBank登录号:MF083566)和Mpburs-β(GenBank登录号:MF083567)。Mpburs-α开放阅读框长483bp,编码160个氨基酸。其相对分子量为17.59kDa,分子式为C_(759)H_(1204)N_(210)O_(232)S_(19);理论等电点为7.96,Mpburs-β开放阅读框长417bp,编码138个氨基酸。其相对分子量为15.45kDa,分子式为C672H1072N180O212S12;理论等电点为4.84。分子系统进化树分析表明,桃蚜与豌豆蚜Acyrthosiphon pisum和麦双尾蚜Diuraphis noxia具有较近的亲缘关系。RT-qPCR结果表明:Mpburs-α和Mpburs-β在桃蚜各龄期均有表达,以1龄若蚜期表达量最高;成蚜有翅个体中表达量显著高于无翅个体。推测Bursicon在桃蚜翅的形成中发挥着重要作用。研究结果可为续研究Bursicon在桃蚜蜕皮后表皮的骨化、翅的形成方面相关的功能机制奠定基础。     

红火蚁不同虫态个体对辛硫磷的敏感性研究

用点滴法分别测定了红火蚁不同虫态个体对辛硫磷的敏感性。处理后24 h的毒力测定结果为:小工蚁、大工蚁、雄蚁、有翅雌蚁和蚁后的LC50分别为1.04,2.06,7.38,9.39和7.81μg/mL,表明不同虫态个体对药剂的敏感性差异很大,毒力相差9.0倍之多。     

The evolution of agriculture in ants

Cultivation of fungi for food by fungus-growing ants (Attini: Formicidae) originated about 50 million years ago. The subsequent evolutionary history of this agricultural symbiosis was inferred from phylogenetic and population-genetic patterns of 553 cultivars isolated from gardens of "primitive" fungus-growing ants. These patterns indicate that fungus-growing ants succeeded at domesticating multiple cultivars, that the ants are capable of switching to novel cultivars, that single ant species farm a diversity of cultivars, and that cultivars are shared occasionally between distantly related ant species, probably by lateral transfer between ant colonies.     

Nothomyrmecia macrops: A Living-Fossil Ant Rediscovered

The Australian Nothomyrmecia macrops is the most primitive living ant. Until recently rediscovered, it was known only from two 46-year-old specimens, both workers. All developmental stages and adult castes are now known. Adults have stridulatory organs placed ventrally, between abdominal sternites III (with plectrum) and IV (with stridulitrum), differing from all other Hymenoptera, where these organs are dorsal. The chromosome number is the highest recorded for Hymenoptera (2n = 92). Virgin queens are brachypterous. Other anatomical and behavioral features are reviewed. Most are primitive for ants, many being shared with Myrmecia, another primitive Australian genus. Fundamental differences in abdominal structure place Myrmecia near the base of the poneroid phylad of ant subfamilies, while Nothomyrmecia is a primitive formicoid.     

Genetic compatibility affects queen and worker caste determination

The development of queen and worker phenotypes in ants has been believed to be largely determined from environmental effects. We provide evidence that the production of discrete phenotypes is also influenced by genetic interaction effects. During the development of eggs into adults, some patrilines among offspring of multiply mated Pogonomyrmex rugosus ant queens became more common in workers while others became overrepresented in queens. Controlled crosses showed that these changes stem from some parental genome combinations being compatible for producing one phenotype but less compatible for the other. Genetic interaction effects on caste may be maintained over evolutionary time because the fitness of an allele depends on its genetic background.     

Evolutionary history of the symbiosis between fungus-growing ants and their fungi

The evolutionary history of the symbiosis between fungus-growing ants (Attini) and their fungi was elucidated by comparing phylogenies of both symbionts. The fungal phylogeny based on cladistic analyses of nuclear 28S ribosomal DNA indicates that, in contrast with the monophyly of the ants, the attine fungi are polyphyletic. Most cultivated fungi belong to the basidiomycete family Lepiotaceae; however, one ant genus, Apterostigma, has acquired a distantly related basidiomycete lineage. Phylogenetic patterns suggest that some primitive attines may have repeatedly acquired lepiotaceous symbionts. In contrast, the most derived attines have clonally propagated the same fungal lineage for at least 23 million years.     

Leg patterning driven by proximal-distal interactions and EGFR signaling

wingless and decapentaplegic signaling establishes the proximal-distal axis of Drosophila legs by activating the expression of genes such as Distalless and dachshund in broad proximal-distal domains during early leg development. However, here we show that wingless and decapentaplegic are not required throughout all of proximal-distal development. The tarsus, which has been proposed to be an ancestral structure, is instead defined by the activity of Distalless, dachshund, and a distal gradient of epidermal growth factor receptor (EGFR)-Ras signaling. Our results uncover a mechanism for appendage patterning directed by genes expressed in proximal-distal domains and possibly conserved in other arthropods and vertebrates.     

Ancestral developmental potential facilitates parallel evolution in ants

Complex worker caste systems have contributed to the evolutionary success of advanced ant societies; however, little is known about the developmental processes underlying their origin and evolution. We combined hormonal manipulation, gene expression, and phylogenetic analyses with field observations to understand how novel worker subcastes evolve. We uncovered an ancestral developmental potential to produce a "supersoldier" subcaste that has been actualized at least two times independently in the hyperdiverse ant genus Pheidole. This potential has been retained and can be environmentally induced throughout the genus. Therefore, the retention and induction of this potential have facilitated the parallel evolution of supersoldiers through a process known as genetic accommodation. The recurrent induction of ancestral developmental potential may facilitate the adaptive and parallel evolution of phenotypes.     

Coevolved crypts and exocrine glands support mutualistic bacteria in fungus-growing ants

Attine ants engage in a quadripartite symbiosis with fungi they cultivate for food, specialized garden parasites, and parasite-inhibiting bacteria. Molecular phylogenetic evidence supports an ancient host-pathogen association between the ant-cultivar mutualism and the garden parasite. Here we show that ants rear the antibiotic-producing bacteria in elaborate cuticular crypts, supported by unique exocrine glands, and that these structures have been highly modified across the ants' evolutionary history. This specialized structural evolution, together with the absence of these bacteria and modifications in other ant genera that do not grow fungus, indicate that the bacteria have an ancient and coevolved association with the ants, their fungal cultivar, and the garden parasite.     

Postsecretory hydrolysis of nectar sucrose and specialization in ant/plant mutualism

Obligate Acacia ant plants house mutualistic ants as a defense mechanism and provide them with extrafloral nectar (EFN). Ant/plant mutualisms are widespread, but little is known about the biochemical basis of their species specificity. Despite its importance in these and other plant/animal interactions, little attention has been paid to the control of the chemical composition of nectar. We found high invertase (sucrose-cleaving) activity in Acacia EFN, which thus contained no sucrose. Sucrose, a disaccharide common in other EFNs, usually attracts nonsymbiotic ants. The EFN of the ant acacias was therefore unattractive to such ants. The Pseudomyrmex ants that are specialized to live on Acacia had almost no invertase activity in their digestive tracts and preferred sucrose-free EFN. Our results demonstrate postsecretory regulation of the carbohydrate composition of nectar.     

Traditional knowledge and rationale for weaver ant husbandry in the Mekong delta of Vietnam

The weaver ant, Oecophylla smaragdina Fabricius (Hymenoptera: Formicidae), has long been known as perhaps the first example of human manipulation of a natural predator population to enhance the natural biological control of insect pests. The practice of ant husbandry in Vietnamese citrus orchards and the knowledge associated with the use of weaver ants in the Mekong delta are described. In contrast to other regions of Asia, where weaver ants are noted for their role in the protection of citrus from insect damage, citrus farmers in the Mekong delta explain the benefits of ant husbandry in terms of an improvement in fruit quality, likened to the influence of fertilizers, that occurs in direct response to excretory products deposited by the weaver ants as they patrol the fruit. A series of tests, carried out in 1993–94, rated the external shine, sweetness, juiciness, and overall appeal, as characteristics of fruit quality, for paired comparisons of sweet orange, mandarin, and pummelo fruit that had been grown in the presence of weaver ants or from which ants had been excluded. The tests indicate a strong influence of the presence of the weaver ant on external shine, juiciness, and overall appeal for each of the citrus fruits, but particularly for mandarin. The significance of these results and ant husbandry practices in the Mekong delta are discussed in relation to the development of citrus production in Vietnam.     

氟虫腈饵剂防控红火蚁的田间药效试验

以含0.05％氟虫腈为有效成分与多种天然物质配制饵剂,撒于红火蚁(SolenopsisinvatBuren)蚁巢上,药剂中的引诱剂吸引红火蚁取食,将饵剂带入巢内,并通过红火蚁在巢内交哺喂食行为将药剂传递给其它各品级个体,引起全巢红火蚁中毒死亡.结果表明,0.05％氟虫腈杀蚁饵剂对红火蚁具有良好的控制效果,药后15d开始进入防效高峰期,25～30d防效达到最佳.0.05％氟虫腈杀蚁饵剂药后30d对工蚁的防治效果达93.39％～100.00％;灭巢效果达95.84％～100.00％;药后50d,蚁群级别降低率达83.33％～100.00％,显著优于对照药剂.     

广东红火蚁多个生境中诱饵对蚂蚁诱集作用比较

研究了荔枝园、荒草地和绿化带3种红火蚁Solenopsis invicta入侵生境中火腿肠、沙丁鱼、黄粉虫和蜂蜜4种诱饵及其组合对蚂蚁的引诱作用.结果表明,火腿肠、火腿肠 蜂蜜、沙丁鱼 蜂蜜这3种诱饵不仅能诱到较多的蚂蚁种类,也能诱到较多的蚂蚁数量;红火蚁对火腿肠的趋性最强,而火腿肠诱集其他蚂蚁的数量最少;通过对3种生境中不同诱饵诱集其他蚂蚁数量占所诱蚂蚁总数的百分比的分析发现,蜂蜜和加蜂蜜的诱饵诱集其他蚂蚁的数量最多;综合多方面的因素,在红火蚁发生区进行蚂蚁群落调查,火腿肠 蜂蜜和沙丁鱼 蜂蜜是最好的诱饵选择.     

Tandem calling: a new kind of signal in ant communication

Leptothorax acervorum, L. muscorum, and L. nylanderi recruit nest mates to a new food source by tandem running, with only one nest mate being recruited at a time. This technique is initiated by a special "tandem calling" behavior; the recruiter slants its gaster upward and discharges poison gland secretions from the extruded sting. Nest mates are attracted, and as soon as one of them touches the calling ant, tandem running starts. Further details of the full recruitment sequence are provided. Evidence is presented to suggest that tandem running is the evolutionary precursor of odor-trail communication and sex attraction within certain phylogenetic lines of myrmicine ants.     

Bivoltinism as an antecedent to eusociality in the paper wasp genus Polistes

To learn the evolutionary trajectories of caste differentiation in eusocial species is a major goal of sociobiology. We present an explanatory framework for caste evolution in the eusocial wasp genus Polistes (Vespidae), which is a model system for insect eusocial evolution. We hypothesize that Polistes worker and gyne castes stem from two developmental pathways that characterized the bivoltine life cycle of a solitary ancestor. Through individual-based simulations, we show that our mechanistic framework can reproduce colony-level characteristics of Polistes and, thereby, that social castes can emerge from solitary regulatory pathways. Our explanatory framework illustrates, by specific example, a changed perspective for understanding insect social evolution.     

Caste in a primitive ant: absence of age polyethism in amblyopone

Polyethism, the divison of labor among members of a colony, is based on worker age and size in ants. In the ponerine species Amblyopone pallipes worker behavior is independent of age, therefore temporal castes, or groups of age-related task specialists, do not exist. This primitive caste system, previously unknown in ants, appears to be correlated with the peculiar characteristics of the life history and ecology of Amblyopone.     

Sex-linked genetic influence on caste determination in a termite

The most ecologically successful and destructive termite species are those with both a nymph caste and an irreversibly wingless worker caste. The early developmental bifurcation separating these castes is widely accepted to be strictly environmentally determined. We present evidence that genotype also influences this process. Offspring from four different crosses of nymph- and worker-derived secondary reproductive individuals had strongly differentiated caste and sex ratios, despite uniform rearing conditions. These data fit an X-linked, one-locus-two-allele model. Of five possible genotypes, one was lethal, two resulted in workers, and two resulted in either nymphs or environmentally determined workers. Caste is thus controlled both by environment and by a complex genetic inheritance pattern.