Gene flow in the green mirid,Creontiades dilutus (Hemiptera: Miridae), across arid and agricultural environments with different host plant species

Creontiades dilutus (Stål), the green mirid, is a polyphagous herbivorous insect endemic to Australia. Although common in the arid interior of Australia and found on several native host plants that are spatially and temporally ephemeral, green mirids also reach pest levels on several crops in eastern Australia. These host‐associated dynamics, distributed across a large geographic area, raise questions as to whether (1) seasonal fluctuations in population size result in genetic bottlenecks and drift, (2) arid and agricultural populations are genetically isolated, and (3) the use of different host plants results in genetic differentiation. We sequenced a mitochondrial COI fragment from individuals collected over 24 years and screened microsatellite variation from 32 populations across two seasons. The predominance of a single COI haplotype and negative Tajima D in samples from 2006/2007 fit with a population expansion model. In the older collections (1983 and 1993), a different haplotype is most prevalent, consistent with successive population contractions and expansions. Microsatellite data indicates recent migration between inland sites and coastal crops and admixture in several populations. Altogether, the data suggest that long‐distance dispersal occurs between arid and agricultural regions, and this, together with fluctuations in population size, leads to temporally dynamic patterns of genetic differentiation. Host‐associated differentiation is evident between mirids sampled from plants in the genus Cullen (Fabaceae), the primary host, and alternative host plant species growing nearby in arid regions. Our results highlight the importance of jointly assessing natural and agricultural environments in understanding the ecology of pest insects.     

遗传不育技术在蚊媒疾病防控中的应用

疟疾、登革热等重大传染性蚊媒疾病严重危害人类健康,且目前缺乏有效的药物和疫苗,防治埃及伊蚊、冈比亚按蚊等媒介昆虫是控制和消除这些疾病的有效手段。化学杀虫剂的大规模使用在一定程度上控制了疾病的传播,但其抗药性和环境污染等问题也随之而来。分子生物学的飞速发展为昆虫不育技术(SIT)的更新及害虫防治提供了新的策略,由此发展起来的以释放携带显性致死基因昆虫(RIDL)为代表的一系列遗传不育技术为蚊虫种群防控提供了更加有效的选择。本文概述了遗传技术在蚊虫防控中的应用进展,包括蚊虫遗传防治的历史和策略,阐述了RIDL技术体系的原理,同时介绍了相关遗传控制品系和已经开展的田间释放研究,展示了遗传修饰不育技术在蚊媒疾病防治中的巨大潜力。     

Effect of elevated CO2 on tropical soda apple and its biological control agent Gratiana boliviana (Coleoptera: Chrysomelidae)

Rising atmospheric CO₂ levels could have drastic effects on the performance of invasive weeds and their insect herbivores. Despite the importance of biological control as an effective management tool for environmental weeds, there have been few studies on the potential impact of climate change on the future efficacy of biological control. The objective of the present study was to evaluate the effect of elevated CO₂ on the performance of tropical soda apple Solanum viarum (Solanaceae) and its biological control agent Gratiana boliviana (Coleoptera: Chrysomelidae). We established three levels of CO₂ in environmental growth chambers: ambient (400 ppm), medium (580 ppm) and high (780 ppm). Plants growing at the high level had greater biomass compared to those growing at the ambient and medium levels of CO₂. Leaf water content and the amount of leaf nitrogen were reduced at high compared to ambient or medium CO₂ levels. G. boliviana immature survival and developmental time were negatively affected at high CO₂ but not at medium or ambient levels. Adults were lighter and smaller when reared at the high CO₂ level compared to ambient and medium treatments, while adult fecundity was higher at the medium CO₂ level. Leaf area consumed by fifth instars was lower when feeding on plants grown at the high CO₂ level either inside a Petri dish or on potted plants. These results suggest that beetle performance may be diminished under future climate. However, further studies should incorporate other factors such as temperature and precipitation as well as the evolutionary potential of herbivores and plants to adapt to a changing climate.     

Successional patterns of the insect fauna on a pig carcass in southern Italy and the role of Crematogaster scutellaris (Hymenoptera,Formicidae) as a carrion invader

The sarcosaprophagous fauna plays a key role in organic matter decomposition. Moreover, the biological, ecological and behavioral specificities of the taxa are useful to reconstruct the decay history of a corpse or carcass, often back to the lethal event. Here we report the seasonal succession of the insect fauna on a pig carcass exposed in a rural area in Calabria (southern Italy) during summer 2007 and 2008. The aim is to identify and qualitatively assess the major taxa of forensic importance in this region. The principal fly invaders were Lucilia caesar (L.), L. sericata (Meigen, 1826), Chrysomya albiceps (Wiedemann, 1819), Sarcophaga (Meigen, 1826) spp. and Amobia (Robineau‐Desvoidy, 1830) spp., Musca domestica (L.) and Muscina stabulans (Fallen, 1817). The primary beetle species collected in summer belonged to Dermestidae, Dermestes maculatus (De Geer, 1774) and Cleridae, Necrobia rufipes (De Geer, 1775). This paper also examined the ecological role of ants in the insect succession and describes the evidence of skin injuries directly inflicted by the acrobat ant Crematogaster (Acrocoelia) scutellaris (Olivier, 1791) (Hymenoptera Formicidae) while feeding on pig carrion. Ants belonging to two other species were also collected: Camponotus aethiops (Latreille, 1798) and Tetramorium semilaeve (André, 1881). Ants can invade carcasses and corpses directly, disrupting blowfly egg laying or preying on their larvae. Our data on the carrion faunal composition and role of ants as invaders should be useful for further forensic cases in Calabria (southern Italy). This is among the few reports of ants as forensically relevant species.     

Changes in phenology and abundance of suction-trapped Diptera from a farmland site in the UK over four decades

1. Recently documented insect declines have caused major concerns and an increased interest in studies using long-term population-monitoring data. 2. Samples from a 12.2-m suction trap were used to examine trends in phenology and abundance of Diptera over four decades. 3. The timing of peak flight has advanced by an average of 17 days, from 23 July in 1974 to 6 July in 2014. 4. The abundance of flies has decreased by 37% over the studied period (from April to September), and peak abundance has decreased by 48%. The flight period has started earlier in recent years, and in 2014, the number of flies was higher in spring until the 31st of May than in 1974. Possible causes and impacts of these changes are discussed.     

Incipient speciation in the Anastrepha fraterculus cryptic species complex: reproductive compatibility between A. sp.1 aff. fraterculus and A. sp.3 aff. fraterculus

Reproductive isolation among biological strains can be detected by analyzing reproductive barriers between populations. The Anastrepha fraterculus Wiedemann (Diptera: Tephritidae) cryptic species complex comprises eight morphotypes defined by morphometric characteristics. The present study analyzed the existence of pre‐ and post‐zygotic isolation among populations of A. sp.1 aff. fraterculus (A. sp.1) and A. sp.3 aff. fraterculus (A. sp.3) determined by tests of sexual compatibility, analyses of the temporal pattern of calling behavior, and the reproductive performance of the offspring of homotypic and heterotypic crosses. Pre‐zygotic tests indicated asymmetric matings with preferences for homotypic crosses. The A. sp.3 population demonstrated distinct characteristics, including low copulation percentages and a high proportion of homotypic copulations under crowded conditions. The females of the A. sp.1 population demonstrated lower copulation latency. The analyzed morphotypes demonstrated two peaks in pheromone emission activity, at the beginning and at the end of the morning and were differentiated in the abundance of males. The calling behavior of the hybrids between A. sp.1 male and A. sp.3 female crosses had an intermediate pattern compared to either parental type. Post‐zygotic compatibility tests indicated low viability of the cross between A. sp.3 males and A. sp.1 females. Pronounced asymmetries were found in the sex ratios of the offspring of heterotypic crosses, and only hybrids from A. sp.1 male vs. A. sp.3 female crosses produced descendants. The observed pre‐ and post‐zygotic incompatibilities reflect the probable occurrence of incipient speciation between A. sp.1 and A. sp.3. A more adequate taxonomic classification of this species complex that considers the distinct characteristics of each morphotype will be needed to improve environmentally wise control methods against this insect pest.     

中国植物区系的鸟类传粉现象

概述了分布于中国的传粉鸟类类群和鸟类传粉的植物类群,并分析了这些植物的分布区类型和花部特征.中国的传粉鸟类几乎全部属于雀形目;鸟类传粉现象广泛存在于30余科的植物中,其花部特征表现出对非专性嗜蜜鸟类的适应.这些植物类群在中国的植物区系中主要表现出热带成分的特征,但其中也有温带成分.结合植物类群的系统发育研究以及对其鸟类传粉现象的认识,可以系统地了解鸟类传粉在旧世界温带地区的起源与演化,以及鸟-花协同进化的过程.     

吉林黑土区不同施肥处理对农田土壤昆虫的影响

为研究不同施肥处理与农田土壤昆虫群落之间的关系,对吉林黑土区不同施肥处理对农田土壤昆虫群落的影响进行了研究.在12个处理小区内,即（1）撂荒（不施肥、不耕作、不种植,ABAND）、（2）对照（种植、不施肥,CK）、（3）施氮肥（N）、（4）施氮磷肥（NP）、（5）施氮钾肥（NK）、（6）施磷钾肥（PK）、（7）施氮磷钾化肥（NPK）、（8）施氮磷钾化肥＋有机肥处理（有机N 和化肥N 的比例为2：1）（M1NPK）、（9）增加50 %用量化肥配施有机肥（1.5 MNPK）、（10）化肥配施秸秆（SNPK）、（11）玉米、大豆2：1轮作,施肥量同处理8（Rot）、（12）施氮磷钾化肥＋有机肥处理（有机N 和化肥N 的比例为1：1）（M2NPK）,共采集144个定点土壤样品.通过手捡法和改良干漏斗法（Modified Tullgren ）共获得土壤昆虫9922只（未知标本187只）,隶属9目48科.调查结果显示,12种施肥小区内,大型土壤昆虫个体数和类群数依次是：ABAND＞NP＞N＞1.5MNPK＞Rot.＞PK＞NK＞NPK＞M2NPK＞CK＞M1NPK＞SNPK,N＞NK＞ABAND=1.5MNPK＞NP=NPK＞PK＞CK=Rot.＞M2NPK=M1NPK＞SNPK;中小型土壤昆虫数依次是ABAND＞1.5MNPK＞PK＞M2NPK＞CK＞Rot.＞NPK＞SNPK＞NK＞NP＞N＞M1NPK,Rot.＞NPK＞ABAND=NP=1.5MNPK=PK=NK=M2NPK=CK=M1NPK=SNPK＞N.大型土壤昆虫个体数和类群数撂荒中分布最多,中小型土壤昆虫则分别在撂荒和轮作中分布最多.多样性分析表明,1.5MNPK处理中大型农田土壤昆虫组成最丰富,M1NPK处理中小型农田土壤昆虫组成最丰富;CK处理与其他11处理之间群落相似程度最小,Rot.与其他处理之间的群落相似程度较大.Kruskal- Wallis检验法分析表明,施肥对农田土壤昆虫分布影响极显著（X0.05（11）=10.25,p〈0.05）,反映出不同施肥对土壤生态系统内部环境,进而对土壤动物群落产生的影响.多元统计分析表明,轮作对土壤昆虫优势类群具有负向作用,而M2NPK则具正向作用.各种施肥对农田土壤昆虫影响不平衡,其中对农田土壤昆虫个体数影响最大,对中小型土壤昆虫均匀性影响最小.