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1.
Summary The Formosan subterranean termite, Coptotermes formosanus Shiraki is the most destructive, difficult to control and economically important species of termite in the southern United States. At present, no information is available on the genetic relatedness of primary Formosan subterranean termite reproductives that establish new colonies. Information on survivorship and fitness components of primary reproductives from different sibships (sibling or nonsibling) is helpful to our understanding of biological and ecological characteristics of different breeding generations in C. formosanus. The present study examined the effects of sibship and colony origin on growth and mortality of incipient colonies of C. formosanus. Seven stock colonies of C. formosanus were collected in 1996 through 1997 in New Orleans and Lake Charles, La, USA. A total of 338 incipient colonies of sibling pairs or nonsibling pairs of C. formosanus were set up. The study indicated that mate relatedness significantly affected mortality and fitness. Nonsibling mates suffered significantly higher mortality than sibling mates originated from New Orleans. However, the decreased success of outbred mates was offset by an increased fecundity compared to inbred colonies over time. Both sibling- and nonsibling-founded colonies from Lake Charles had a significantly higher survival rate than did colonies from New Orleans. Colonies from Lake Charles also produced a significantly higher number of larvae/workers than colonies from New Orleans. The mismatch of habits by mates from different locations and the potential for greater disease risks may be associated with higher mortality in outbred pairs. However, heterozygous offspring of outbred pairs probably have increased genetic variation, which provides greater adaptation potential, thus making the colony more robust in the face of environmental fluctuations.Received 11 March 2002; revised 26 February 2003; accepted 14 March 2003.  相似文献   

2.
Cover Caption     
《Insect Science》2021,28(1):3-3
Swarming behaviour is critical for the dispersal and distribution of the termite Reticulitermes chinensis Snyder, which can cause severe damage to wooden structures and trees. After dispersal flight of termite alates, their flight muscles perform degeneration in structure and energetic function, which should facilitate the followed establishment of incipient colony (see pages 77-92). The cover photo shows that termite alates are preparing for flight away from the wooden stake. The photo provided by Dr. Qiu-Ying Huang (Huazhong Agricultural University, China).  相似文献   

3.
The Formosan subterranean termite, Coptotermes formosanus is recognized as one of the most important invasive pest species. Originating from China, C. formosanus has spread to many tropical and subtropical regions around the globe in the last 400 years, including Japan, Hawaii and the continental USA. Although the current distribution is well documented, information about the patterns of invasion and effects of introduction on the population genetics of this species is largely lacking. We analyzed the genetic structure of populations from two native populations (Guangdong and Hunan provinces, China) and two introduced populations (Maui and Kauai, Hawaii) using microsatellite genotyping. We also reanalyzed published data of additional populations from China, Japan, Hawaii, and the continental USA. The population from Hunan, the earliest introduction outside of China (Japan) and the first introduction to the continental USA (South Carolina) showed little genetic similarity with any of the native or introduced populations investigated. However, populations from Oahu (HI), New Orleans (LA) and Rutherford County (NC) showed close similarity. In general, genetic patterns suggest multiple introductions to the USA, with, for example, two separate introductions to the island of Maui. Bottleneck effects were detected in almost all recent introductions (after 1940). All populations in the introduced range showed lower genetic diversity than those in the native range. However, this low genetic diversity did not result in the formation of polygynous supercolonies as has been described for other invasive termite and ant species.  相似文献   

4.
Summary. Termite workers from all families examined had no arolia (=adhesive pads) on their tarsi and are unable to climb smooth vertical surfaces such as glass or polypropylene plastic. This contrasts with ants where both workers and alates of most species possess arolia and are able to climb these surfaces. Arolia were present in alates of the majority of species investigated from three of the four most basal termite families (Mastotermitidae, Termopsidae and Kalotermitidae), though absent from the basal family Hodotermitidae that contains only three genera. Alates in the two kalotermitid species tested readily climbed glass walls. The complete evolutionary loss of arolia from alates in the specious two most apical termite families (Rhinotermitidae and Termitidae) suggests paedomorphosis. Very smooth surfaces probably cannot be used to completely prevent entry of rhinotermitid termites into buildings because these termites can eventually build galleries of feces and soil over these surfaces. However, an experiment with Coptotermes formosanus showed that a smoother surface significantly slows down the rate of gallery building.Received 12 February 2004; revised 17 June 2004; accepted 29 June 2004.  相似文献   

5.
The trail-following pheromone and sex pheromones were investigated in the Indomalayan termite Hodotermopsis sjoestedti belonging to the new family Archotermopsidae.Gas chromatography coupled to mass spectrometry (GC–MS) after solid phase microextraction (SPME) of the sternal gland secretion of pseudergates and trail-following bioassays demonstrated that the trail-following pheromone of H. sjoestedti was syn-4,6-dimethylundecan-1-ol, a new chemical structure for termite pheromones. GC–MS after SPME of the sternal gland secretion of alates also allowed the identification of sex-specific compounds. In female alates, the major sex-specific compound was identified as (5E)-2,6,10-trimethylundeca-5,9-dienal, a compound previously identified as the female sex pheromone of the termite Zootermopsis nevadensis. In male alates, the major sex-specific compound was identified as syn-4,6-dimethylundecanal, a homolog of syn-4,6-dimethyldodecanal, which has previously been confirmed as the male sex pheromone of Z. nevadensis. The presence of sex-specific compounds in alates of H. sjoestedti strongly suggests for this termite the presence of sex-specific pairing pheromones which were only known until now in Z. nevadensis. Our results showed therefore a close chemical relationship between the pheromones of the taxa Hodotermopsis and Zootermopsis and, in contrast, a clear difference with the taxa Stolotermes and Porotermes, which is in total agreement with the recent creation of the families Archotermopsidae and Stolotermitidae as a substitute for the former family Termopsidae.  相似文献   

6.
Swarming by alates of the Formosan subterranean termite, Coptotermes formosanus Shiraki, occurs around dusk during April–June in Louisiana and adjoining states. Dispersal is the primary purpose for swarming. We studied the premating behavior, following swarming. Loss of wings, especially in females, was essential for successful formation of tandem pairs between the two sexes. No calling was observed and apparently a long-range volatile sex pheromone, reported in some other species of termites, may not be involved in mate attraction in C. formosanus. Males moving randomly use their antennae to detect a female, and, together with maxillary and labial palps, contact is maintained with her while in tandem. Previously mated males paired with virgin females showed tandem behavior. The incidence was very low when both males and females were previously mated and then paired. Males with complete ablation of antennae did not form tandem pairs. Ablation of 10 terminal antennal segments or the labial palps caused a significant increase in the time to initiate tandem behavior. Electrophysiological recordings from gustatory sensilla on both antennae and maxillary palps revealed increased neural activity in response to female abdominal tip extracts compared to activity elicited by a solvent control. Analysis of extracts of male and female abdominal tips using high-performance liquid chromatography showed a peak unique to the female extract. We discuss the presence of a nonvolatile chemical in female C. formosanus and its involvement in the specific premating behavior.  相似文献   

7.
The success of all insect societies relies on their ability to maintain optimal levels of different castes. Here we report on an apparent free-running circannual rhythm that optimizes the developmental time of the soldier caste of Coptotermes formosanus Shiraki. Over a 3 year period, bioassays were conducted each month (except June) with groups of 100 termite workers in a 28°C incubator in total darkness. The number of days needed for C. formosanus soldiers to develop varied depending on the time of the year (month). In March, just prior to the major swarming exodus for alates (April to June), 9 days were required before a worker molted to a presoldier. Longer times were required for such a molt in all other months, with an increasing trend from April to December (from 13 to 30 days) and a decreasing trend from January to February (from 25 to 12 days). Colony origin or the length of time that termites were kept in the laboratory under constant conditions (26 – 28°C, 70 – 80% RH) before testing (7 days – 1 year) did not affect this rhythm. This is the first demonstrated evidence of a free-running circannual rhythm in a social insect. Received 23 July 2007; revised 9 and 21 August 2007; accepted 23 August 2007.  相似文献   

8.
Behavioral responses to vibrational stimuli were examined in two subterranean termite species, Coptotermes formosanus Shiraki and Reticulitermes flavipes (Kollar). Termites habituated to vibrational stimulation when in social groups, but failed to do so individually, indicating that habituation is a collective action. In assays on termite groups, both species demonstrated a similar pattern of behavioral responses to vibrational stimuli: evanescent cessation of activity and movement, followed by withdrawal from the vibration source. Groups of both species then gradually moved back toward the vibration source as a consequence of continuous exposure. However, it took a significantly shorter period for C. formosanus to return (57 s) to the test arena and to resume (80 s) normal foraging activities in the test arena compared with R. flavipes, which took 97 and 227 s, respectively, when exposed to the vibration frequency of 120 bmpm. High vibration frequency (240 bmpm) increased the time required to return (C. formosanus, 80 s; R. flavipes, 153 s) and to resume regular locomotion (C. formosanus, 186 s; R. flavipes, 263 s). Our experiments demonstrate that workers play a crucial part in adjusting groups of termites to distressful vibrations. Soldiers of R. flavipes demonstrated similar behavioral responses as workers, however, C. formosanus soldiers exhibited a transient positive response before withdrawal. An erratum to this article is available at .  相似文献   

9.
Fungus‐growing termites (subfamily Macrotermitinae) cultivate the symbiotic basidiomycete fungus Termitomyces in their fungus comb to digest cellulosic materials and to supply nitrogen‐rich fungal diet. In Japan, the fungus‐growing termite Odontotermes formosanus is found on the Yaeyama Islands and Okinawa Island, Okinawa Prefecture. Odontotermes formosanus is thought to have been recently and artificially introduced to Okinawa Island as its distribution is discontinuous and restricted to small areas. Previous DNA analyses revealed that two types of Termitomyces, namely Termitomyces sp. Type A and Termitomyces sp. Type B, whose fruiting bodies correspond to Termitomyces microcarpus‐like pseudorhiza‐lacking small mushroom and Termitomyces intermedius, respectively, are cultivated by O. formosanus on the Yaeyama Islands. However, information about the Termitomyces types cultivated by O. formosanus on Okinawa Island is limited. To define the fungal types cultivated by O. formosanus on Okinawa Island, I developed a diagnostic polymerase chain reaction method using primer sets specific to the nuclear ribosomal DNA sequences consisting of the internal transcribed spacers (ITS1 and ITS2) and 5.8S rDNA of Termitomyces not using fungal mycelium, but using the termite gut metagenome including fungal DNA as a template. The results indicated that the same two Termitomyces types from Iriomote Island are cultivated by O. formosanus on Okinawa Island. The distribution pattern of Termitomyces types on Okinawa Island showed that Termitomyces sp. Type A is limited to the mountainous side of Sueyoshi Park, despite Termitomyces sp. Type B being widely distributed in the area in which O. formosanus is found. This finding implies that O. formosanus on Okinawa Island was recently introduced from Iriomote Island to Sueyoshi Park.  相似文献   

10.
Termite alates are thought to be poor active flyers, and this should lead to considerable genetic differentiation on small spatial scales. However, using four microsatellite loci for the termite Macrotermes michaelseni we found low values of genetic differentiation (FST) across a spatial scale of even more than 50 km. Genetic differentiation between populations increased with spatial distance up to 50 km. Furthermore, up to this distance, the scatter around the linear regression of genetic differentiation versus spatial distance increased with spatial distance. This suggests that across such spatial distances gene flow and genetic drift are of about equal importance, and near equilibrium. Using a regional FST as well as the distance between populations with non-significant FST-values (up to 25 km), gene flow is sufficiently high so that populations may be regarded as panmictic on spatial scales of 25 to 50 km. The apparent contradiction between dispersal distances observed in the field and estimates of gene flow from genetic markers may be due to the masses of swarming alates. Assuming a leptokurtic distribution of dispersal distances, atleast some alates are expected to travel considerable distances, most likely by passive drift. Received 25 January 2005; revised 11 April 2005; accepted 26 April 2005.  相似文献   

11.
Many aphid species possess wingless (apterous) and winged (alate) stages, both of which can harbor parasitoids at various developmental stages. Alates can either be parasitized directly or can bear parasitoids eggs or larvae resulting from prior parasitism of alatoid nymphs. Winged aphids bearing parasitoid eggs or young larvae eventually still engage in long-distance flights, thereby facilitating parasitoid dispersal. This may have a number of important implications for biological control of aphids by parasitoids. In this study, we determined the effect of parasitism by Aphelinus varipes (Hymenoptera: Aphelinidae) on wing development and flight of the soybean aphid, Aphis glycines (Hemiptera: Aphididae). We also quantified the influence of aphid flight distance on subsequent A. varipes development. Parasitism by A. varipes was allowed at different A. glycines developmental stages (i.e., alatoid 3rd and 4th-instar nymphs, alates) and subsequent aphid flight was measured using a computer-monitored flight mill. Only 35% of aphids parasitized as L3 alatoid nymphs produced normal winged adults compared to 100% of L4 alatoids. Flight performance of aphids parasitized as 4th-instar alatoid nymphs 24 or 48 h prior to testing was similar to that of un-parasitized alates of identical age, but declined sharply for alates that had been parasitized as 4th-instar alatoid nymphs 72 and 96 h prior to testing. Flight performance of aphids parasitized as alate adults for 24 h was not significantly different from un-parasitized alates of comparable ages. Flight distance did not affect parasitoid larval or pupal development times, or the percent mummification of parasitized aphids. Our results have implications for natural biological control of A. glycines in Asia and classical biological control of the soybean aphid in North America.  相似文献   

12.
Coptotermes formosanus Shiraki is a wood‐feeding termite which secretes a series of lignolytic and cellulolytic enzymes for woody biomass degradation. However, the lignin modification mechanism in the termite is largely elusive, and the characteristics of most lignolytic enzymes in termites remain unknown. In this study, a laccase gene lac1 from C. formosanus was heterogeneously expressed in insect Sf9 cells. The purified Lac1 showed strong activities toward hydroquinone (305 mU/mg) and 2,6‐dimethoxyphenol (2.9 mU/mg) with low Km values, but not veratryl alcohol or 2,2’‐azino‐bis (3‐ethylbenzothiazoline‐6‐sulfonic acid). Lac1 could function well from pH 4.5 to 7.5, and its activity was significantly inhibited by H2O2 at above 4.85 mmol/L (P < 0.01). In addition, the lac1 gene was found to be mainly expressed in the salivary glands and foregut of C. formosanus, and seldom in the midgut or hindgut. These findings suggested that Lac1 is a phenol‐oxidizing laccase like RflacA and RflacB from termite Reticulitermes flavipes, except that Lac1 was found to be more efficient in phenol oxidation, and it did not require H2O2 for its function. It is suspected that this kind of termite laccase might only be able to directly oxidize low redox‐potential substrates, and the high redox‐potential groups in lignin might be oxidized by other enzymes in the termite or by using the Fenton reaction.  相似文献   

13.
The life of a colony of subterranean termites, such as Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), has natural inbreeding and outbreeding cycles. Reproductives of mature colonies can be replaced by their offspring, which increases the degree of inbreeding in each generation. High degrees of inbreeding may lead to inbreeding depression. In this study we focused on mechanisms for inbreeding avoidance during swarming that do not require kin recognition. We investigated genetic differentiation between swarm aggregations (isolation by distance), genetic diversity within swarm aggregations (multiple colony origin) and genetic differentiation between sexes. Alates were collected from five swarm aggregations in New Orleans, La. The genetic make-up of each swarm aggregation was then described by microsatellite genotyping. Alates from the different swarm aggregations were genetically differentiated; however, no isolation by distance up to at least 1000 m was detected. The dispersal distance of alates was sufficient to guarantee mixing of an average of 13 colonies within swarm aggregations. On average, eleven percent of all possible pairs of alates in each swarm aggregation were putative full siblings. Genotypic frequencies differed significantly between males and females. This could not be explained by sex-biased dispersal. We hypothesize sex-biased investment at the colony level to account for this difference. Genetic differentiation between the sexes and dispersal distances sufficient to promote high genetic diversity within swarm aggregations each facilitate inbreeding avoidance. These observations are consistent with the results of previous studies demonstrating that the majority of simple family colonies in Louisiana populations are headed by unrelated and outbred pairs of reproductives. Received 11 August 2005; revised 5 December 2005; accepted 20 December 2005.  相似文献   

14.
The Formosan termite Coptotermes formosanus Shiraki is a well-known invasive pest that causes severe damage to wooden structures in many parts of the world. Although several studies examined its phylogeographic patterns using a few mitochondrial genes, the phylogenetic relationships among C. formosanus are poorly understood because of the small number of mutations known among its mitochondrial genes. To provide a useful genetic tool for further analyses, we analyzed the complete mitochondrial genome sequence of C. formosanus using specimens collected from three isolated islands in the Ryukyu Archipelago of Japan. The circular mitogenome of these termites consisted of genes encoding 22 transfer RNAs, two ribosomal RNAs, and 13 mitochondrial proteins, as is the case for most animal mitochondrial genomes. The G + C content was 34.1%, and the total length varied slightly between 16,234 and 16,236 base pairs. The complete mitochondrial genomes of the three populations were more than 99.9% identical to each other and showed differences at six nucleotide positions. The COII, 12S rRNA, and 16S rRNA genes that are commonly used for phylogenetic analyses revealed only one substitution or no substitutions. The mitogenome sequences determined here should contribute to the design of new molecular markers for the clarification of the historical distribution process of C. formosanus and for further phylogenetic analyses with this and related termite species.  相似文献   

15.
Experiments were conducted to examine competitive interactions between the Formosan subterranean termite, Coptotermes formosanus Shiraki (FST), and the eastern subterranean termite, Reticulitermes flavipes (Kollar) (EST), using groups of termites with different worker:soldier proportions. Experiments were conducted using three connected test chambers: an FST chamber, an unoccupied center chamber, and an EST chamber. When groups of FST were comprised of 20% soldiers versus 2% EST soldiers, only 8% of center chambers were occupied exclusively by EST. When groups of FST were comprised of 10% soldiers versus 1% EST soldiers, 44% of center chambers were occupied exclusively by EST. When the only food source was located in the center chamber, 60% of center chambers were occupied by both species. FST did not completely displace EST in any of these experiments.  相似文献   

16.
Summary. We studied the dealation of a subterranean termite Reticulitermes speratus Kolbe from three different angles; mechanism, induction factors, and adaptive significance. During nuptial flight alates prevent the wings from breaking off by holding the wings in a 3-dimensional configuration. In the process of dealation, the alates hold the wings in a 2-dimensional configuration, half spread the wings in a lowered position, and bend the abdomen back toward the wings, thereby exerting high pressure at the basal sutures. This separates the wings from the body. The primary factor determining the timing of dealation appears to be isolation from other alates: It induces alates to shed their wings, whereas pairing has no effect on dealation in this species. Alates of termites are especially vulnerable to ant predation during the period between flight and colony foundation. An experiment designed to compare the risk of alates and dealates to predation by a termite-hunting ant, Brachyponera chinensis Emery, showed that dealation reduced the predation risk during the period spent running on the ground.  相似文献   

17.
An extensive monitoring and survey program in Mississippi was conducted from 2000 to 2004 to investigate the distribution of the Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). Seventy-two towns from 22 counties in southern Mississippi were monitored with a total of 3914 traps that catch alates during the swarming season. In addition, 259 licensed pest management professionals in Mississippi were surveyed to determine the locations of termite infestations treated. The alates of C. formosanus were recovered in 12 counties with light traps, and termite infestations were documented in an additional 13 from data collected in the termite survey. Infestations of C. formosanus have been documented in urban, urban cluster, rural, and forested areas of Mississippi. However, the distribution in mean total capture of alates for 4 yr differed significantly among the four ecological areas with the highest percentage in forested areas (31%) and the lowest percentage in urban cluster areas (17%). Most of the infestations of C. formosanus were geographically distributed along the coastal areas of southern Mississippi from Gulfport to Pascagoula. The greatest total number of alates captured in light traps was documented in Pearl River County. Mass swarming of C. formosanus occurred primarily in May or June, depending on weather conditions. The number of documented counties with the evidence of large and widely dispersed swarms of C. formosanus in different ecological areas, and the increase in total annual alate captures from 2000 to 2003, suggest that this invasive termite species is now firmly established in Mississippi.  相似文献   

18.
Sexual specialization and skewed sex ratios of the altruistic castes, especially soldiers, are common in many termite taxa. However, no theoretical or empirical studies have explained the origin of the sexual division of labor in termites. In most termite species, female alates are larger than male alates, and mature queens are much larger than kings, with females under consistent selection for high fertility. Therefore, females usually have the potential to be larger than males. Here, I present a novel preadaptation hypothesis that potential sexual differences in the suitability for the caste give rise to the sexual division of labor, and I provide the first evidence in support of this hypothesis in termites. Defense in Reticulitermes is typically performed by soldiers via mandibular and phragmotic defense in which soldiers with pluglike heads block openings, thus preventing enemies from invading the nest. Phragmotic defense requires that soldiers have heads wide enough to plug nest openings. Therefore, a size threshold for workers that develop into soldiers is a likely adaptation for effective defense. I show that sexual size dimorphism (SSD) and a size threshold for soldiers promote skewed sex ratios. A female-biased soldier sex ratio was observed in species with SSD, whereas there was no bias in soldier sex ratio in species without SSD. Thus, SSD and soldier sex ratio data from several Reticulitermes species support the preadaptation hypothesis.  相似文献   

19.
The longevity, daily fecundity, degree of gravidity and lipid content of alates of varied ages, and lipid utilisation during sustained tethered flight of the corn leaf aphid, Rhopalosiphum maidis, were studied. Alates had a mean longevity of 9.7 days and a mean fecundity of 14.9 nymphs. A significant increase in the lipid content of alates before emerging as adults was observed. Newly emerged and half-day-old alates had more lipid reserve and embryos than 1-, 2-, 4-, 8-, and 16-day-old specimens. The lipid content of alates decreased significantly with age. The alates' degree of gravidity and lipid content had a low but significant correlation. Half- to 1-day-old alates flew readily and could fly for much longer durations than 2- and 4-day-old. Eight-day-old alates were not capable of flight. R. maidis utilised lipid during prolonged tethered flight. Our data suggest that there is a threshold point when alates cease utilising stored lipid as the energy source and start utilising non-lipid sources as flight fuel energy.  相似文献   

20.
Members of the termitophilous subtribe Termitozyrina (Aleocharinae: Lomechusini) associated with Hodotermopsis sjostedti are taxonomically treated. The genera Hodotermophilus Naomi & Terayama and Termophidoholus Naomi & Hirono, and each type species (monotypic) are redescribed. Termophidoholus formosanus, originally described from Taiwan, and its host termite H. sjostedti are newly recorded from Laos. Yakuus iwatai Kanao & Maruyama gen. & sp. nov. and H. gloriosus were collected sympatrically in the same nests in Yaku‐shima, Japan. All of the above species, belonging to the three genera, share the presence of a batch of spurs at the tibial apex of fore and mid legs. Habitus photographs and illustrations of diagnostic features are provided for these species, and their phylogenetic relationships are discussed based on morphological similarities and the extant distribution of the host termite species.  相似文献   

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