Life history traits of Pseudasphondylia rokuharensis (Diptera: Cecidomyiidae) affecting emergence of adults and synchronization with host plant phenology

To identify adaptive strategies of gall-inducing cecidomyiids, we studied the life history traits of Pseudasphondylia rokuharensis (Diptera: Cecidomyiidae), a univoltine species inducing fruit galls on a deciduous shrub, Viburnum dilatatum. Although univoltine gall midges that are associated with trees or shrubs are usually difficult to rear from immature stages under artificial conditions, we successfully reared P. rokuharensis from first instar to adult. Mature larvae entered diapause in autumn, and the diapause terminated after low temperature treatment (4 mo of incubation at 5 degrees C). The adults emerged within a shorter period of time than those without low temperature treatment. Thus, the diapause provides better synchronization of adult emergence in the spring. Because adults live for only a few days, this synchronization improves the chances of adults finding a mate. This is the first report on the mechanism of larval diapause termination for univoltine and tree- or shrub-associated gall midges. The numbers of days needed for adults to emerge under laboratory conditions after low temperature incubation were significantly different between two different localities. This result might suggest the possible existence of ecoclines in their life history parameters.     

Biology of Hylobitelus xiaoi (Coleoptera: Curculionidae), a new pest of slash pine, Pinus elliottii

The biology of the weevil Hylobitelus xiaoi Zhang was studied in both field and laboratory in Shangyou, Jiangxi Province, China. This species required 2 yr to complete one generation with overwintering by adults in pupal chambers and larvae in galleries in the bark of host trees. Adults emerged from early March to early April and fed on the inner bark of branches of the trees. Adults fly little. Adults exhibited a diel periodicity, climbing up the trees around sunset and returning to the tree base the next morning. The mean preovipostion period was 46 d. Oviposition commenced in early May and ended in late August. The average fecundity per female was 36 eggs. Overwintered adult females and males lived 208 and 227 d, respectively. At 25 degrees C, the mean egg incubation period was 13 d. In the field, egg hatch occurred in 12-15 d with 83% survival. There were five to seven instars. At 25 degrees C, duration of the larval stage averaged 129 d. Pupation commenced in late August. At 25 degrees C, pupation averaged 20 d. In the field, pupation required 20-26 d. Transformation to adults occurred from late September to October. New adults remained in the pupal chambers until the next year. Infection by Beauveria bassiana Vuill. occurred in 0.8% of the pupae and 8.8% of the overwintered adults.     

Life-history traits in insect inclusions associated with bamboo galls

We examined the life-history traits of insect inclusions in bamboo galls induced by the gall maker, Aiolomorphus rhopaloides Walker (Hymenoptera: Eurytomidae) in a bamboo stand. Eight hymenopteran and one dipteran species were detected using soft X-ray photography of the galls and insect emergence from the galls. Aiolomorphus rhopaloides was the gall maker and Diomorus aiolomorphi Kamijo (Torymidae) was its inquiline.Homoporusjaponicus Ashmead (Pteromalidae) and Eupelmus sp. (Eupelmidae) are likely to be primary parasitoids of the larva ofA. rhopaloides. Eurytoma sp. (Eurytomidae),Sycophila sp. (Eurytomidae) and Norbanus sp. (Pteromalidae) are thought to be facultative hyperparasitoids. Cecidomyiidae sp. is thought to be the inquiline ofA. rhopaloides galls.Leptacis sp. (Platygastridae) probably parasitizes the larvae of Cecidomyiidae sp. Larvae of A. rhopaloides appeared in galls in July with the percentage of larvae decreasing in September, before overwintering as pupae. The growth ofD. aiolomorphi larvae within galls may be faster than that ofA. rhopaloides. The percentage of parasitoids in galls was low in July, but increased until winter. Aiolomorphus rhopaloides and D. aiolomorphi emerged from mid-April to early May, and from late April to early June, respectively. From overwintering galls, six other hymenopteran species emerged between late May and late June; one dipteran Cecidomyiidae sp. emerged between mid-April and early May.     

Mating and diapause in hibernating adults ofMenida scotti puton (Heteroptera: Pentatomidae)

InMenida scotti aduts which mate during hibernation, we examined the effect of photoperiod on diapause induction in terms of the developmental degree of reproductive organs and corpora allata. In a hibernating population, mating season and physiological changes related to dipause were investigated. When newly emerged adults were reared under long- or short-day conditions, reservoir of the ectodermal accessory gland and corpora allata in males developed, while the developments of ovary and corpora allata in females were suppressed under both conditions. This suggests that diapause of this species is induced only in females independently photoperiodic conditions during adult stage. In a hibernating population, mating was observed from early to late November and from late March to early May. Observations of the development of reproductive organs and corpora allata suggest that diapause is induced only in females in the former period, while both sexes are not in diapause in the latter period.     

Life history strategy and taxonomic position of gall midges (Diptera: Cecidomyiidae) inducing leaf galls on Styrax japonicus (Styracaceae)

Four gall midge species (Diptera: Cecidomyiidae) that induce leaf galls on Styrax japonicus (Styracaceae) were identified to generic level based on larval morphology. Three of these gall midges, which induce whitish hemiglobular galls, flattened subglobular galls, and purple globular galls, respectively, were identified as three genetically distinct species of Contarinia, and the remaining species, which induces globular galls with dense whitish hairs, was identified as a species of Dasineura. Field surveys in Fukuoka, Japan, revealed that adults of these gall midges emerged and oviposited in late March to mid‐April at Mount Tachibana (approximately 200 m a.s.l.) and in late April to early May at Mount Sefuri (about 1050 m a.s.l.), coinciding with the leaf‐opening season of S. japonicus. Larvae of these gall midges mostly developed into third instars by June and then left their galls and dropped to the ground. These species therefore have a life history strategy that differs from that of another S. japonicus‐associated gall midge, Oxycephalomyia styraci, which overwinters as the first instar in ovate swellings, matures rapidly in spring, and emerges directly from the galls.     

Photoperiodic control of larval development in the semivoltine cockroachPeriplaneta japonica (Blattidae: Dictyoptera)

Periplaneta japonica is semivoltine, entering early diapause in any (except the first) larval instar before the last, and late diapause in the last instar. Early diapause was induced under a short day of 13 h or less at 28°C, and under both short and long daylength (12–16 h) at 20°C. The shorter the daylength and the lower the temperature, the younger the instar was entering early diapause. Early diapause was terminated by a long day (16 h) or a high temperature (28°C), after which larvae grew faster in short days than in long days until the last instar, when they again entered diapause, always in short days and frequently in long days. This late diapause was terminated also by an increase in daylength and was always followed by adult emergence. In this case, 13 and 14 h daylengths after exposure to 12 h daylength were as effective as 16 h daylength. Ourdoor samples collected in late autumn, winter and early spring at Hirosaki (40.5°N) comprised two distinct size groups, corresponding with the early and late diapause instars. Based on these results, the seasonal development strategy and intriguing aspects of the photoperiodic response in this cockroach are discussed.     

Dogwood borer (Lepidoptera: Sesiidae) infestation of horned oak galls

Pin oak, Quercus palustris Muenchhausen, is the primary host for the gall wasp Callirhytis cornigera (Osten Sacken). Woody stem galls formed by C. cornigera may be infested by the dogwood borer, Synanthedon scitula (Harris), an important pest of flowering dogwood, Cornus florida L. Previous research has shown that S. scitula has a bimodal seasonal flight pattern, with peaks in late spring and midsummer. We tested the hypothesis that moths emerging from dogwoods largely account for the first flight pulse, whereas emergence from stem galls contributes disproportionately to the second pulse. Seasonal flight activity of S. scitula was monitored with pheromone traps baited with Z,Z-3,13-octadecadien-1-ol acetate. Traps were hung near plantings of dogwoods in suburban landscapes or near heavily galled pin oaks. Borer emergence from dogwood was monitored by sampling infested trees for pupal exuviae, and from galls that were collected and held in outdoor rearing cages. The impact of S. scitula on C. cornigera larvae was assessed by weighing, measuring, and dissecting galls. Flight activity of S. scitula began on 5 May and ended on 13 October 1999, with peaks in late May and in late July to early August. The flight pattern was similar for the two types of trapping sites, and moths emerged from both hosts during both flight periods. Proportionately more moths emerged from dogwoods during the first flight pulse than during the second, but emergence from galls was nearly evenly divided between the two flight peaks. We therefore reject the hypothesis that emergence of borers from galls contributes disproportionately to the second flight period. Approximately 12-15% of stem galls (2-3 yr old) contained S. scitula larvae. Feeding and tunneling by borers contributed to gall desiccation and reduced horn development, but rarely killed C. cornigera larvae. This study has implications for management of S. scitula because borers emerging from horned oak galls may represent a threat to dogwood.     

Juvenile hormone changes associated with diapause induction, maintenance, and termination in the beet webworm, Loxostege sticticalis (Lepidoptera: Pyralidae)

At 22°C and under a long-day photoperiod of L:D 16:8, all the last fifth instar Loxostege sticticalis larvae undergo prepupal stage and pupate without diapause. Under a short-day photoperiod of L:D 12:12, in contrast, they all enter diapause with approximately 36 days diapause maintenance and then terminate diapause spontaneously, although only 44% of the larvae terminated diapause successfully. Changes in hemolymph juvenile hormone (JH I) titers of diapause-destined larvae across diapause induction, maintenance and termination were examined using HPLC, and were compared with those of non-diapause-destined larvae from the fifth instar through pupation. JH I titer of the earliest fifth instar diapause-destined larvae remained at a high level with a peak of 220.4 ng/ml, though it decreased continuously to a minimum of 69.0 ng/ml on day 5 in the fifth instar when the larvae stopped feeding to enter diapause. During the diapause maintenance, JH I titer of the mature larvae increased significantly and maintained a high level until day 31 in prepupae. JH I titer declined and fluctuated at low level from 5 days before pupation. In contrast, JH I titer of both the fifth instar non-diapause-destined larvae and prepupae remained and fluctuated at low level consistently, as well as decreased before pupation. These results indicate that diapause induction and maintenance in this species might be a consequence of high JH, whereas diapause termination can be attributed to low JH titer, which was in agreement with the hormonal regulation observed in many other larval-diapausing insects.     

Diapause in a Glasgow strain of the flour moth, Ephestia kuehniella

ABSTRACT. The incidence of diapause in Ephestia kuehniella Zeller from an unhealed granary in Scotland was influenced by both photoperiod and temperature. At 25°C, nearly 50% of larvae entered diapause when reared in continuous darkness (DD) and up to 30% did so in short photoperiods. Little diapause was detected around LD 14:10 but a second, smaller peak of about 20% occurred at LD 16:8 and LD 18:6, falling away again to nearly zero in continuous light. More larvae entered diapause when reared continuously at 15 or 20°C than at 25 and 30°C. However, when larvae reared from hatch at 25°C in LD 16:8 were transferred after 1 week to 15°C in LD 9:15, almost twice as many entered diapause as did those reared at 15°C throughout. The sensitive phase for diapause induction occurred near the start of the final instar. The mean duration of diapause was between 2 and 3 months in most photoperiods at 20 and 25°C, and was shorter at 15°C. However, in DD at 25°C, it lasted about 7 months. Termination of diapause was hastened in larvae reared at 25°C in DD by transferring them to LD 14:10, and also by chilling them at 7.5°C for 6 weeks before returning to 25°C in DD. In an unhealed store in southern England, viable adults emerged from May to July and originated from larvae which terminated diapause relatively late. It would appear from the results of transferring larvae back to the laboratory at various times during the winter that some phases of diapause development were completed quite early after exposure to low temperatures, although no further development took place in the store until temperatures rose again in April.     

火红拟孔蜂的生物学特性

首次报道了火红拟孔蜂除雌性成虫以外的各虫态形态特征、生活史、生殖发育及性行为等生物学特性。该蜂在西鄂尔多斯地区一年发生一代。越冬幼虫翌年4月中旬开始化蛹;预蛹约d左右;蛹期约15d。成虫5月上旬陆续羽化出茧;雄蜂早于雌蜂数日出现,雄蜂交尾后不久死去,寿命约为10d左右。雌蜂寿命约30d。卵期约3d左右。老熟幼虫多数在6月中下旬结茧后进入滞育状态,幼虫期长达300d左右。滞育幼虫通过人工控制温度可提前打破滞育或推迟其羽化的时间。     

Over-wintering stage polymorphism of a bruchine beetle: geographical variation in optimal diapause strategy

Abstract.  1. Most temperate insects undergo diapause at a specific developmental stage to overcome severe winters. The bruchine beetle Bruchidius dorsalis in a warmer region in Japan, however, has diverse over-wintering stages – non-diapausing larvae, diapausing larvae, and diapausing adults, whereas in a cooler region, it over-winters only as the final instar larva or adult in diapause.
2. The geographical pattern of over-wintering stages in 12 populations was investigated over a wide range along the mainland of Japan. It revealed that a distinct geographical pattern of over-wintering stages exists in relation to temperature conditions. In regions with warmer climates, the proportion of non-diapausing larvae increased and B. dorsalis had a more complex over-wintering stage structure.
3. Life cycles were also compared between two areas of Japan by field experiments. In the cooler area, the first generation over-wintered in the diapausing larval or adult stage. Conversely, in the warmer area, diapause was induced later and some of the first-generation adults produced second-generation offspring before over-wintering.
4. Based on the geographical cline of climates and the differences in cold hardiness among stages, we can demonstrate that the over-wintering stage variation among and within populations results from an adaptive timing of diapause induction in each region, because the late larval or adult diapauses protect pupae or eggs – which unlike other stages are not cold hardy – from being produced late in the season.     

黑脉蛱蝶的生物学特性与生境调查

通过野外观察、室内饲养、野外调查等方法研究黑脉蛱蝶Hestina assimilis(L.)的生物学特性以及生境状况。该蝶幼虫以榆科朴属(Celtis spp.)植物为食,在南京地区1年发生3代,10月下旬以4龄或5龄幼虫在寄主植物的落叶中越冬,翌年4月初越冬幼虫眠起活动。越冬代成虫5月上旬始见、中旬为高峰期;第1代7月上旬始见、中旬为高峰期;第2代9月上旬始见、中旬为高峰期。幼虫共5龄,在室内饲养的条件下,卵期为4～5d,幼虫期为28～42d,蛹期为7～8d。     

Synthesis of the same two proteins prior to larval diapause and pupation in the spruce budworm,Choristoneura fumiferana

Spruce budworm larvae produce large quantities of two proteins (Choristoneura fumiferana diapause associated proteins 1 and 2, CfDAP1 and CfDAP2) that are diapause related. These proteins appeared soon after hatching and increased in abundance, reaching maximum levels by four days into the 1st instar, and they remained at high levels until three days after the termination of diapause. These two proteins were purified to homogeneity and their NH2-terminal sequences were obtained. Oligonucleotide primers designed on the basis of these NH2-terminal sequences were used in RT-PCR to isolate the cDNA fragments coding for these proteins. These PCR fragments were then used as probes to isolate the cDNAs that contained the complete coding region. The 2.5kb mRNAs coding for these proteins started to appear 24hr after hatching and large quantities of these mRNAs were detected in 1st instar and 2nd instar larvae until the 2nd instar larvae entered diapause. Low levels of these mRNAs were detected in the 2nd instar larvae that were preparing to enter diapause, in those that were in diapause as well as in those that terminated diapause. Low levels of CfDAP1 mRNA were also detected on days 1 and 2 after ecdysis to the 3rd instar. However, no CfDAP1 and CfDAP2 mRNAs could be detected during the 4th and 5th instar larval stages. The mRNAs reappeared 24hr after the 5th instar larvae molted into the 6th instar and increased to reach maximum levels by 60hr after ecdysis. The mRNA levels remained high until 156hr after ecdysis into the 6th instar (36-48hr before pupal ecdysis), after which they disappeared once again. Immunocytochemical analyses showed that CfDAP1 protein was present in 2nd and 6th instar larval fat body but not in 5th instar larval fat body. Thus, the same two genes were expressed for the first time before C. fumiferana larvae entered diapause and for a 2nd time before pupation.     

Seasonal susceptibility of 'Bartlett' pears to codling moth (Lepidoptera: Tortricidae) infestation and notes on diapause induction

Seasonal susceptibility of 'Bartlett' pear, Pyrus communis L., to codling moth, Cydia pomonella (L.), infestation, successful completion of larval development after infestation, and the induction of C. pomonella diapause was studied from 1992 through 1995. The seasonal variation in C. pomonella infestation and larval survival were effected by changes in fruit maturity. In late May through mid-June, pears were hard and were not as successfully infested by C. pomonella and produced less larvae compared with fruit later in the season. In late June to mid-July, pears became more suitable for infestation and a greater percentage of the larvae completed their development. In late July through mid-August, pears were susceptible to infestation, but the larvae were less likely to successfully complete development than in the late June to mid-July period due to pear tissue breakdown. From mid-August through September, pears are unsuitable for infestation, and few larvae were produced. When fruit were infested with neonate larvae in late May and mature larvae emerged from the fruit in July, a low percentage of the larvae entered diapause. However, when fruit were infested with neonate larvae in early July and mature larvae emerged from the fruit in early August, the majority of the larvae entered diapause. When fruit were infested with neonate larvae in late July through September and mature larvae emerged from the fruit after mid-August, nearly all C. pomonella larvae had entered diapause.     

The evolution of gall parasitism accompanied by a host shift in the gall aphid, Eriosoma yangi (Homoptera: Aphidoidea)

Eriosoma aphids form leaf-roll galls on various elm species. Eriosoma yangi occurring on the Japanese elm is an obligatory "cuckoo" parasite, invading and usurping galls of other Eriosoma species. But another host race of E. yangi induces its own galls on the Chinese elm. Multivariate morphometries show that the two host races differ significantly in quantitative characters. Overwintering eggs of the parasitic form were experimentally transferred to the Chinese elm. The resultant larvae still exhibited a parasitic habit and developed into adults, which multivariate morphometries classified as the parasitic form. This form is considered different enough from the gall maker to be given a species rank. Eriosoma aphids facultatively invade other Eriosoma galls, where they sometimes deposit offspring. It is hypothesized that the parasitic form on the Japanese elm originated from a founder population which had migrated from the Chinese elm. On this new host, only those fundatrices that invade other species' galls will be able to leave offspring, because aphid fundatrices cannot gall plants other than their primary hosts. It is assumed that the parasitic form was established under intense selective pressure following a population bottleneck. This hypothesis was corroborated by field investigations at sites where the two forms occur sympatrically.     

Asymmetric intraspecific competition among larvae of the damselfly Ischnura elegans (Zygoptera: Coenagrionidae)

Abstract. 1. A laboratory competition experiment is described in which the growth and development rates of larvae of the damselfly Ischnura elegans (Lind.) were measured over an entire instar.
2. Two larval instars which commonly occur together in the field were used in the experiment; they were maintained with a superabundance of prey and either larvae from the same or the larger/smaller instar.
3. Small larvae suffered increased development times and decreased size increases at the moult in the presence of large larvae but similar interference effects were not evident when these smaller larvae were in the presence of other small larvae.
4. Development time and size increases of large larvae were not significantly affected by the presence of small larvae.
5. Irrespective of the instar combinations investigated, interference effects were reduced when there were more perches available, although in only a few cases was this reduction significant.
6. The consequences of the asymmetric competition reported in the experiment for the study of lifetime reproductive success in damselflies are discussed. Late emerging adults may incur reduced reproductive success.     

An introduction experiment of an herbivorous lady beetle: Characteristics of the adult population

In May 1971, 45 adults of an herbivorous lady beetleEpilachna niponica (Coleoptera: Coccinellidae) from Asiu Experimental Forest were introduced into a botanical garden of Kyoto University, where is 10 km south of the southern limits of its distribution with being 3–5°C warmer than the original site. The introduced population of the lady beetle was thus investigated from 1975 to 1981. Mark-release-recapture experiments were applied to individual adult beetles, to estimate population size and daily survival rate. Overwintering adults emerged from hibernation around early April, reaching peak numbers in late April to early May, then gradually declined to late June. No adults remained at the end of June. Adult survival was maintained at a high level to early May, and declined consistently until late in the reproductive season. New adults began to emerge in late June and quickly reached a peak in early July; thereafter they decreased in number and had entered hibernation by late October. In spite of seasonally deteriorating food resources and heat stress in summer, new adults showed moderately high survival during the inimical period. New adults which emerged later in the season tended to be smaller in body size than those that emerged early. The proportion of females in the new adult population gradually increased throughout the pre-hibernating period, suggesting that male-biased mortality occurred during this period. When compared to the source population, the introduced population had a higher rate of population growth. Coupled with the improved population growth, heavy leaf damage during the larval period suggested that intensive intraspecific competition was most likely to occur among larvae in the introduced population.     

Diapause in a large aggregation of a tropical beetle

Abstract. 1_˜ Diapause is described for adults of Stenotarsus rotundus Arrow (Endomychidae, Coleoptera) in the tropical lowland forest on Barro Colorado Island, Panama.
2 . Diapause lasted up to 10 months each year, covering some 6 months of the wet season plus 4 months of the dry season. When in diapause the beetles clustered in an aggregation of up to 70 ,000 individuals on the stem of a palm tree, the same individual palm tree in at least four successive years.
3. The habitat and habits of the beetle when not in diapause are unknown, but one or two generations may be produced during this period. Beetles returned to the diapause site from June until late August.
4. Soon after arrival at the diapause site the flight muscles degenerated and did not develop again until February/March. The ovaries were undeveloped when the beetles arrived at the site and remained in that condition until the onset of yolk deposition in March. At the beginning of the rainy season in April the beetles mated and dispersed.
5. Lean dry weight of the beetles did not decrease noticeably during diapause, but fat content did. It is suggested that the beetles do not feed, or feed very little, while in diapause. During diapause, the metabolic rate is surprisingly low considering a mean ambient temperature of 25° C.
6. Juvenile hormone analogue (ZR515) stimulated flight muscle and ovary development. Daylength, when different from LD 12: 12 , initiated a partial flight muscle development, but there was no effect on the ovaries. Field observations suggest that neither temperature nor humidity had an effect on the termination of diapause.
7. Although the development of both flight muscles and ovaries were stimulated by juvenile hormone analogue and both developed around March of each year, it is suggested that the mechanisms causing this development are different.     

小麦吸浆虫保幼激素酯酶和保幼激素环氧水解酶基因的克隆及在滞育和变态发育过程中的表达动态

【目的】保幼激素(juvenile hormone, JH)在小麦吸浆虫Sitodiplosis mosellana滞育诱导及滞育后静息状态的维持中发挥着重要作用。保幼激素酯酶(hormone esterase, JHE)和保幼激素环氧水解酶(juvenile hormone epoxide hydrolase, JHEH)是调控JH滴度的重要降解酶。本研究旨在探讨JHE和JHEH在小麦吸浆虫滞育和变态发育中潜在功能。【方法】通过RT-PCR和RACE技术从小麦吸浆虫滞育前幼虫克隆JHE和JHEH全长cDNA序列;利用生物信息学软件分析其核苷酸及编码蛋白特性;采用qPCR技术分析其在小麦吸浆虫滞育不同时期(滞育前、滞育期、滞育后静息期和滞育后发育)3龄幼虫及1龄幼虫到成虫不同发育阶段(1-2龄幼虫、预蛹、初蛹、中蛹、后蛹、雌成虫和雄成虫)中的表达水平。【结果】克隆获得了cDNA全长分别为3 102和1 980 bp的小麦吸浆虫SmJHE和SmJHEH基因(GenBank登录号分别为MG876768和MG876769),其开放阅读框分别长1 740和1 371 bp,分别编码579和45...     

麦红吸浆虫3-羟基-3-甲基戊二酰辅酶A还原酶基因SmHMGR的克隆及在滞育与发育变态过程中的表达动态

【目的】3-羟基-3-甲基戊二酰辅酶A还原酶(HMGR)是保幼激素(JH)合成途径的限速酶。麦红吸浆虫Sitodiplosis mosellana是一种典型的专性幼虫滞育昆虫。本研究旨在探讨HMGR基因在麦红吸浆虫滞育和发育变态过程中的作用。【方法】通过RT-PCR和RACE技术克隆麦红吸浆虫滞育前幼虫HMGR基因全长cDNA序列;利用生物信息学软件分析HMGR基因核苷酸和其编码的蛋白氨基酸序列特性;采用qPCR技术测定其在麦红吸浆虫滞育不同时期3龄幼虫及不同发育阶段(1-2龄幼虫、预蛹、初蛹、中蛹和后蛹以及雌雄成虫)中的mRNA表达水平。【结果】克隆获得一条麦红吸浆虫HMGR基因全长cDNA序列,命名为SmHMGR(GenBank登录号: MG876766)。该基因全长2 548 bp,其中开放阅读框长2 328 bp,编码775个氨基酸,预测的蛋白分子量为84.16 kD,理论等电点为8.29。序列分析发现该基因编码的蛋白具有HMGR蛋白家族典型的HMG-CoA-reductase-classⅠ催化功能域及其他保守功能基序;序列比对和系统发育分析表明,SmHMGR与达氏按蚊Anopheles darling等长角亚目(Nematocera)昆虫HMGR的相似性最高、亲缘关系最近。SmHMGR在麦红吸浆虫滞育前的3龄早期幼虫中表达量显著升高,进入滞育后一直维持较高水平,并在滞育后静息阶段的当年12月至翌年1月达到最高。SmHMGR在蛹期表达量低于幼虫期,预蛹期表达量最低;在雌成虫中表达量显著高于在蛹和雄成虫中的表达量。【结论】SmHMGR的表达与麦红吸浆虫发育密切相关,可能在滞育诱导、维持及滞育后静息状态的维持及生殖中发挥作用,其表达量的降低可能参与了幼虫到蛹的变态。