The relationship of egg size and incubation temperature to embryonic development time in univoltine and multivoltine aquatic insects

1. We used published data to investigate the combined influence of egg size and incubation temperature on embryonic development time for a broad assortment of aquatic insects at four different incubation temperatures (10, 15, 20 and 25 °C).
2. Embryonic development time (EDT) was positively correlated with egg size at each of the four temperatures, but with different relationships for univoltine and multivoltine aquatic insects. The relationships of embryonic development time to egg size expressed in degree-days did not significantly differ in slope ( P >0.50) or intercept ( P >0.05) for either univoltine or multivoltine aquatic insects at each of the four temperatures.
3. The relationship of embryonic development time (degree-days) to egg mass in multivoltine aquatic insects (EDT=885×0.19, P <0.0001, r 2=0.48) is similar in slope and intercept to that for other oviparous animals (i.e., zooplankton, fish, amphibians and reptiles), and to the relationship of embryonic development time to neonate mass in mammals. Univoltine species on average require 3–5 times longer to develop (EDT=14190×0.29, P <0.001, r 2=0.29) than most other animals of equivalent egg mass, but the relationship of embryonic development time to egg mass is similar in slope to that of most other animals. Together, these relationships provide a basis for evaluating differences in embryonic development time among aquatic insects.     

Photoperiodic and temperature control of nymphal development and induction of reproductive diapause in two predatory Orius bugs: interspecific and geographic differences

Abstract The effects of day‐length and temperature on pre‐adult growth and induction of reproductive diapause are studied in Orius sauteri and Orius minutus (Heteroptera: Anthocoridae) from northern (43.0°N, 141.4°E) and central (36.1°N, 140.1°E) Japan. In the north, at 20 °C, pre‐adult growth is slower under an LD 14 : 10 h photoperiod than under shorter or longer photophases. At 24 and 28 °C, the longer photophases result in shorter pre‐adult periods. Acceleration of nymphal growth by short days in autumn appears to be adaptive. In the central region, this response is less pronounced, suggesting that timing of adult emergence is less critical than in the north. Day length also influences the thermal requirements for pre‐adult development. The slope of the regression line representing temperature dependence of pre‐adult development is significantly smaller and the lower development threshold (LDT) is significantly lower under an LD 12 : 12 h photoperiod than under long‐day conditions. The weaker dependence of nymphal growth on temperature and the lower LDT in autumn might be adaptive. In the north, increased temperature shifts the critical day length of diapause induction and suppresses the photoperiodic response in O. sauteri but not in O. minutus. Further south, the incidence of diapause in both species is low even under short‐day conditions but the same interspecific difference is observed (i.e. increase of temperature affects the response in O. sauteri but not in O. minutus). This suggests seasonally earlier diapause induction with weaker temperature dependence in O. minutus than in O. sauteri.     

Vulnerability of stream community composition and function to projected thermal warming and hydrologic change across ecoregions in the western United States

Shifts in biodiversity and ecological processes in stream ecosystems in response to rapid climate change will depend on how numerically and functionally dominant aquatic insect species respond to changes in stream temperature and hydrology. Across 253 minimally perturbed streams in eight ecoregions in the western USA, we modeled the distribution of 88 individual insect taxa in relation to existing combinations of maximum summer temperature, mean annual streamflow, and their interaction. We used a heat map approach along with downscaled general circulation model (GCM) projections of warming and streamflow change to estimate site‐specific extirpation likelihood for each taxon, allowing estimation of whole‐community change in streams across these ecoregions. Conservative climate change projections indicate a 30–40% loss of taxa in warmer, drier ecoregions and 10–20% loss in cooler, wetter ecoregions where taxa are relatively buffered from projected warming and hydrologic change. Differential vulnerability of taxa with key functional foraging roles in processing basal resources suggests that climate change has the potential to modify stream trophic structure and function (e.g., alter rates of detrital decomposition and algal consumption), particularly in warmer and drier ecoregions. We show that streamflow change is equally as important as warming in projected risk to stream community composition and that the relative threat posed by these two fundamental drivers varies across ecoregions according to projected gradients of temperature and hydrologic change. Results also suggest that direct human modification of streams through actions such as water abstraction is likely to further exacerbate loss of taxa and ecosystem alteration, especially in drying climates. Management actions to mitigate climate change impacts on stream ecosystems or to proactively adapt to them will require regional calibration, due to geographic variation in insect sensitivity and in exposure to projected thermal warming and hydrologic change.     

Muscular connections between the gut and thoracic exoskeleton in some orthopteroid insects

Muscle and connective tissue strands linking the prothoracic cuticle to the posterior foregut and anterior midgut are described for 17 species of orthopteroid insects: Dinocras cephalotes (Plecoptera); Forficula aurkularia (Dermaptera); Acheta domesticus, Gryllus bimaculatus, Brachytrupes sp. and Phaeophyllacris spectrum (Gryllidae); Schizodactylus monstrosus (Schizodactylidae); Hemideina crassidens (Stenopelmatidae); Ephippiger ephippiger, Tettigonia viridissima, Conocephalus dorsalis and Pholidoptera griseoaptera (Tetligoniidae); Schislocerca gregaria, Omocestus viridulus and Chorthippus brunneus (Acrididae), and Carausms morosus (Phasmida). Of the 18 species examined, only the Gryllotalpa sp. (Gryllotalpidae) lacked extrinsic strands to the post-cephalic gut. The arrangement of the strands in the various species is compared, and the possible evolution and function of the strands are briefly discussed.     

植食性昆虫学习行为与害虫治理的关系

植食性昆虫的学习行为一般具有习惯性反应、厌恶性学习、联系性学习、敏感性反应、嗜好性诱导几种类型,它们对害虫防治方法的效果具有重要影响。害虫通过嗜好性诱导对栖境中大面积单作农作物造成更大的危害,通过联系性学习可对诱虫植物的效果产生积极或消极的影响。害虫对驱避剂或杀虫剂等产生习惯性反应可降低其防治效果。害虫对寄主植物驱避抗性产生习惯性学习就会加重对作物的为害,产生厌恶性学习则有利于对作物的保护。利用害虫的联系性学习行为,释放前让不育雄虫学习自然交配场所的环境刺激,可增强通过释放不育雄虫控制害虫的防治效果。了解植食性昆虫学习行为对害虫治理的影响有助于研究和发展有效的栖境调控、行为调控等策略和方法。     

中国半翅目昆虫多样性和地理分布数据集

全球生物多样性逐渐丧失已成为最严重的环境问题之一, 探究各地生物多样性资源及形成机制是生态学和生物地理学领域关注的重要科学问题。生物多样性数据的整合和共享可以为相关研究的开展提供科学依据。昆虫是地球上多样性最高的生物类群, 但是由于目前关于昆虫多样性数据的整理不足, 相关研究较为缺乏。为了促进昆虫类群的多样性数据整理和共享工作的发展, 本研究选取昆虫纲中重要且多样的半翅目作为对象, 通过广泛的数据检索和收集, 系统整理了截至2017年已发表的中国半翅目昆虫的多样性及地理分布信息。数据集中共收集了102科2,090属7,822种半翅目昆虫的分类信息及其39,298条地理分布记录。该数据集可以为今后开展生物多样性格局、生物区系演化和害虫防治等方面的研究工作提供帮助。     

Gross mismatch between thermal tolerances and environmental temperatures in a tropical freshwater snail: Climate warming and evolutionary implications

The relationship between acute thermal tolerance and habitat temperature in ectotherm animals informs about their thermal adaptation and is used to assess thermal safety margins and sensitivity to climate warming. We studied this relationship in an equatorial freshwater snail (Clea nigricans), belonging to a predominantly marine gastropod lineage (Neogastropoda, Buccinidae). We found that tolerance of heating and cooling exceeded average daily maximum and minimum temperatures, by roughly 20 °C in each case. Because habitat temperature is generally assumed to be the main selective factor acting on the fundamental thermal niche, the discordance between thermal tolerance and environmental temperature implies trait conservation following ‘in situ’ environmental change, or following novel colonisation of a thermally less-variable habitat. Whereas heat tolerance could relate to an historical association with the thermally variable and extreme marine intertidal fringe zone, cold tolerance could associate with either an ancestral life at higher latitudes, or represent adaptation to cooler, higher-altitudinal, tropical lotic systems. The broad upper thermal safety margin (difference between heat tolerance and maximum environmental temperature) observed in this snail is grossly incompatible with the very narrow safety margins typically found in most terrestrial tropical ectotherms (insects and lizards), and hence with the emerging prediction that tropical ectotherms, are especially vulnerable to environmental warming. A more comprehensive understanding of climatic vulnerability of animal ectotherms thus requires greater consideration of taxonomic diversity, ecological transition and evolutionary history.     

温度对红珠凤蝶小斑亚种发育的影响

室内研究了红珠凤蝶小斑亚种Pachliopta aristolochiae adaeus(Rothschild)在19～31℃范围内5个恒温条件下的发育.结果表明,成虫在19℃时不能交配和产卵,而卵、幼虫和蛹在19～31℃范围内均能完成发育,且发育历期随温度而变化.各温度下,预蛹期最短,幼虫期最长,幼虫龄期随虫龄的增加...     

红棕象甲发育起点温度及有效积温的测定

在室内恒温条件下,观察了不同温度对棕榈红棕象甲Rhynchophorus ferrugineus Fabricius生长发育的影响,并用直线回归法测得产卵前期、卵、幼虫、蛹和全世代的发育起点温度分别为(16.11±1.44)、(14.10±0.56)、(15.28±0.21)、(14.89±0.24)和(14.15±0.54)℃;有效积温分别为(31.86±1.65)、(748.60±15.79)、(417.94±20.80)和(1215.50±28.56)日·度。红棕象甲的各虫态和全世代发育历期随温度的升高而缩短,在测定的温度范围内,全世代发育历期与温度的关系符合指数函数:y=3343e-0.1279x。     

Role of ageing and temperature in shaping reaction norms and fecundity functions in insects

The existing energy partitioning models assume that fecundity is constant throughout adult life. In insects, however, fecundity is a triangular function of time: after maturation, it initially sharply increases and after reaching its maximum it slowly declines as the mother ages. These models also fail to explain that empirical data generally indicate an increase in juvenile growth rate caused by improvement in food quality results in larger adults, whereas that caused by an increase in ambient temperature results in smaller adults. This ‘life history puzzle’ has worried many biologists for a long time. An energy‐partitioning model for insects is presented with soma and gonads as its components, which – contrary to other models – assumes ageing of soma. This model explains the triangular shape of the fecundity function, and also offers an explanation of the ‘life history puzzle’. The differential response in adult size to changes in food quality and temperature in nature may result from the differential responses of our model’s parameters to changes in these environmental parameters. Better food quality results in bigger adults, because food quality affects the assimilation rate, but not the rate of conversion of gonadal biomass into offspring, or the rate of senescence. In contrast, an increase in temperature speeds up all the processes. That is, temperature affects the assimilation rate, the conversion rate of gonadal biomass into offspring, and the rate of senescence equally. Therefore, an increase in temperature results in larger or smaller adults, depending on the shape of the senescence function.     

On the biology and thermal developmental requirements of the cotton mealybug,Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) in Egypt

This study evaluated the thermal requirements for development of the cotton mealybug Phenacoccus solenopsis depending on different biological parameters on Okra leaves Abelmoschus esculentusat under two constant temperatures (20 and 30 °C) at (RH 65%, 12:12 h. light/dark). The effect of temperature on eggs was ineffective since it hatched shortly to first nymphal instars after deposition. While the tested temperature caused significant effects on nymphal durations, pupation rate (pre-male stage), females emergence %, pre-oviposition, longevity, post-oviposition periods and fecundity in females (egg deposition, ovisacs numbers and hatchability %). The thermal constant and developmental zero were calculated to be 7.29 °C and 79.9 degree-days (DDs) for eggs, 11.67 °C and 272.9 DDs for nymphal stages, 11.06 °C and 46.4 DDs for males and then 3.31 °C and 554.1 DDs for females, respectively. The duration of the life cycle was 65.6 ± 10.36 days at 20 °C; this was shortened to 35.51 ± 1.12 days at 30 °C. The thermal requirements to complete the insect development for one generation was 8.2 °C for the developmental zero and 774.1 DDs for the thermal constant. Based on the thermal requirements values, the average life cycle duration from January to December 2016 was 61.78 days and the number of annual generations was 7.143 when the average annual temperature was 23.29 °C.     

Both cell‐autonomous mechanisms and hormones contribute to sexual development in vertebrates and insects

The differentiation of male and female characteristics in vertebrates and insects has long been thought to proceed via different mechanisms. Traditionally, vertebrate sexual development was thought to occur in two phases: a primary and a secondary phase, the primary phase involving the differentiation of the gonads, and the secondary phase involving the differentiation of other sexual traits via the influence of sex hormones secreted by the gonads. In contrast, insect sexual development was thought to depend exclusively on cell‐autonomous expression of sex‐specific genes. Recently, however, new evidence indicates that both vertebrates and insects rely on sex hormones as well as cell‐autonomous mechanisms to develop sexual traits. Collectively, these new data challenge the traditional vertebrate definitions of primary and secondary sexual development, call for a redefinition of these terms, and indicate the need for research aimed at explaining the relative dependence on cell‐autonomous versus hormonally guided sexual development in animals.     

铜污染对昆虫生长发育及繁殖影响的研究进展

铜(Cu)是生物体生长发育所必需的微量营养元素,参与或构成许多含铜酶及含铜生物活性蛋白质,但是过度摄入Cu会对生物体产生危害。Cu中毒由许多因素而定,如物种、遗传、年龄和食物等。在生态系统中昆虫种类多,数量大,分布广,往往会取食、转移和代谢环境中的Cu,从而对自身生长发育及繁殖造成影响。通常表现为发育历期延长,体重下降,体长变短,化蛹率、羽化率、产卵率、孵化率、存活率降低,种群数量减少等。本文以近几年Cu2+胁迫对昆虫生长发育及繁殖影响的研究进行综述。     

The physiology and biochemistry of cold tolerance in arctic insects

Nine species of insects from three different geographical regions of Canada were examined for freezing tolerance, supercooling capacity, water content and changes in biochemical characteristics during acclimation to subzero temperatures. Six species proved to be freezing tolerant, the remaining three freezing susceptible. The majority of species in each category conformed to the generally recognized profiles of overwintering response. There were enough specific variations within each category, however, to indicate that cold tolerance mechanisms have evolved independently on a number of different occassions. Specific physiological and biochemical anomalies in these insects were discussed.     

大气CO_2浓度升高对植物-植食性昆虫的作用机制

大气二氧化碳浓度升高及其伴随的全球变暖引起国内外科学家的极大关注。CO2浓度升高主要通过改变植物的初级和次级代谢产物,影响以之为食的昆虫。本文结合作者近年来的研究成果,着重于以CO2浓度升高为作用因子,以植物和植食性昆虫的相互关系为对象,比较了咀嚼式口器昆虫与刺吸式口器昆虫对大气CO2浓度升高的响应特征,分析了不同取食类型昆虫-植物对大气CO2浓度升高的响应机制。     

乙酰胆碱酯酶性质改变与昆虫抗药性的关系

乙酰胆碱酯酶是生物神经传导中的一种关键性酶,同时又是有机磷和氨基甲酸酯杀虫剂的靶标,因此一直是人们研究的热点。就近年来昆虫乙酰胆碱酯酶(AChE)在生化和分子生物学方面的研究进展、昆虫AChE基因结构及表达的变化对动力学参数、昆虫抗药性的影响机制以及害虫与天敌AChE的比较研究进行了简要综述。     

济南地区蟋蟀总科种类组成与栖息生境的关系

采用野外调查、分类鉴定及数量统计方法 ,对济南地区蟋蟀总科的种类组成、栖境选择、数量动态等生态特征进行了分析。调查共获 4科 9属 17种 ,其中 8种为该地区新记录种。讨论了优势类群及其形成原因     

多异瓢虫的发育与温度的关系

测定多异瓢虫Hippodamia variegata(Goeze)在13,17,21,25,29和33℃下各虫态的发育历期。结果表明,在不同温度梯度下,多异瓢虫全世代历期依次为:(62.23±3.42)d,(48.31±2.96)d,(25.01±2.53)d,(20.78±1.83)d,(13.68±0.67)d和(10.92±0.58)d。利用最小二乘法确定出多异瓢虫各虫态的发育起点温度和有效积温,其全世代的分别为10.85℃和249.79日.度;由微分法求出Logistic曲线方程中的最大发育速率K,进而由最小二乘法求出a、r,从而确定出多异瓢虫各虫态的发育速率与温度的Logistic曲线关系,其全世代的为:V=0.101156/[1+exp(3.905041-0.183509T)];由Lagrangc中值定理求出各虫态的发育最适温度、适宜温区,其全世代的分别为:Tmid(最适温度)=21.28℃、Tmin(适宜温区下限)=11.55℃、Tmax(适宜温区上限)=31.01℃。