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1.
A poorly known chrysomelid beetle, Chrysolina fastuosa (Scopoli) has been found in a strikingly great number on black horehound (Ballota nigra L.), a soft caulescent plant belonging to the Lamiaceae family. B. nigra can be found from April to August commonly on roadsides, along walls or at the border of gardens and orchards in Hungary and continental Europe. It can be called a minor weed. The glistering tiny adults that feed voraciously on leaves cause apparently significant damage. The subsequent investigation, which focuses on the number of feeding individuals and the loss of plant tissue, showed 1–24 beetles on a plant and the consumed leave surface which amounted to 8–94%. The repeated damage assessment, a week later showed a significantly unimportant increase in the number of individuals but a significant 20–31% increase in the plant surface loss. According to the literature, Ch. fastuosa has been found in association with other Labiatae plants such as Galeopsis pubescens Besser, Lamium album L. and Urtica dioica L. (Urticaceae). Thus, considering its efficiency mentioned above, it could be used to augment and maintain its populations as a biological control agent for these weeds. However, taking into consideration the growing importance of the production of medicinal plants among which Lamiaceae species are numerous, Ch. fastuosa can cause damage that cannot be neglected.  相似文献   

2.
This study examined the frequency of infection by an unidentified pathogenic fungus of oak logs bored into by males alone or by both males and females ofPlatypus quercivorus (Murayama) in the field. The fungus, which is associated with mass mortality of oak trees in Japan, was not isolated from logs bored into by males alone, which bored only short entrance galleries. However, it was isolated from logs bored into by both males and females, which together bored longer galleries and reproduced successfully. This suggests that it is difficult for the fungus to colonize logs bored into by males alone. The fungus was not isolated from a log in which the beetles failed to reproduce, and in which the galleries were significantly shorter than in logs where reproduction succeeded, but it was unclear whether the shortness of the galleries prevented colonization of the log by the fungus. The study also revealed that some gallery-initiating males survived for at least 2 months in the absence of females, and that females elongated entrance galleries that had been bored by the gallery-initiating males.  相似文献   

3.
Both cDNA and DNA clones of PtDof1 (GenBank Accession No. FJ402844 and FJ402845) were isolated from plants grown in tissue culture of Populus tomentosa. The DNA sequence is 1597 bp including two exons and one intron. The cDNA is 969 bp in length with a 765 bp open reading frame which is capable of encoding 255 amino acids. The deduced amino acids sequence of the PtDof1 protein shares 65%, 56% and 55% identity with Vitis vinifera (CAO48618), Nicotiana tabacum (CAA08755) and Glycine max (ABI16022) Dof protein by blast analysis in GenBank. Phylogenic analysis suggests PtDof1 gene could belong to the Dof gene family. PtDof1 protein contains an unusual conserved single zinc finger with the pattern of C-X2-C-X21-C-X2-C, which may play a functional role in tissue-specific expression and possibly the auxin response of endogenous plant genes.  相似文献   

4.
Abtract The system Vicia faba–Aphis fabae fabae was studied under the influence of Ocimum basilicum (basil) and Satureja hortensis, in a wind tunnel, in the greenhouse and in field experiments. In the wind tunnel at 20°C both Lamiaceae were deterrent for A. fabae, and S. hortensis proved to be more deterrent than O. basilicum. In experiments in the greenhouse at low temperatures (average minimum 14.6°C, average maximum 24.1°C), A. fabae colonised first and significantly more intense Vicia fabae (field beans) not surrounded by O. basilicum or S. hortensis. At high temperatures (average minimum 18.0°C, average maximum 38.5°C) this relation was inverted: Vicia faba surrounded by the two Lamiaceae were preferred for colonisation (Ocimum basilicum significantly). It showed that pots with Lamiaceae were no obstacle for the aphids to reach Vicia faba. In strip cropping in the field, the repellent effect of Ocimum basilicum proved to be stronger than of Satureja hortensis. In 2002 there was observed only a tendency of lower aphid attack of field beans intercropped with Lamiaceae, while in 2004 and 2005 the infestation of Vicia faba by Aphis fabae was significantly lower in plots intercropped with basil. In plots with Satureja hortensis as intercrop, Vicia faba were significantly lower infested, after 3 weeks. The differences between the results of the wind tunnel/greenhouse at low temperatures, and the field experiments concerning the deterrence by Satureja hortensis cannot be explained. But basing on our results with Ocimum basilicum and those published by other authors, it is recommended to follow up intercropping, after a sincere analysis in every case, in favour of agronomists.  相似文献   

5.
The period between 2000 and 2002 repeated outbreaks of the web spinning sawfly Cephalcia lariciphila (Wachtl 1898) around the village of Větrny Jeníkov, Czech Republic. The impact of defoliation, caused by C. lariciphila feeding, on tree-ring formation of European larch (Larix decidua Mill.) was studied using dendrochronological methods. Heavy defoliation resulted in much less growth in the years of insect attack, the average incremental loss being 67% for the 2000–2002 period. Also, defoliation resulted in the formation of latewood with fewer cells and reduced cell-wall thickness.  相似文献   

6.
In a study of the parasitoid complex of the locust leaf miner Phyllonorycter robiniella (Clemens, 1859), 23 species of its parasitoids were recorded at 18 localities in Serbia. The parasitoid species included 2 species of the family Braconidae, 1 of the family Eupelmidae, and 20 of the family Eulophidae. The recorded species of parasitoids are polyphagous; in addition to Ph. robiniella, they also develop on other species of leaf miners as primary; primary and secondary; or primary, secondary, and tertiary parasitoids. Among the recorded species of parasitoids, the most significant were the species Pholetesor bicolor, Pholetesor nanus, Sympiesis sericeicornis, Sympiesis acalle, Minotetrastichus frontalis, Pediobius saulius, and Baryscapus nigroviolaceus. The parasitoids were found to have a strong effect on the abundance of Ph. robiniella because they reduced more than 50% of its larvae and pupae in the majority of study samples.  相似文献   

7.
The major bioecological characteristics of Bracon intercessor Nees (Hymenoptera: Braconidae), a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lepidoptera: Sesiidae), were studied from 1987 to 2003. Poplar shoots infested with P. tabaniformis larvae were collected in 11 localities in Bulgaria and examined in the laboratory, and infestations were also studied in the field. B. intercessor was recorded in seven localities and was found to be a gregarious external larval parasitoid of P. tabaniformis. Two generations of the parasitoid developed on the host. The first (summer) generation was associated with early and mid-stage (up to third instar) host larvae, and the second (overwintering) generation with third- to fifth-instar larvae. The average number of parasitoid individuals feeding on a host was 4.5 and 12.4 in summer and overwintering generations, respectively. The maximum number recorded was 25 individuals per host in the overwintering generation. B. intercessor overwintered as a mature larva on the host and completed its development in early spring. The adults from the overwintering generation appeared in April, about 1 month prior to emergence of P. tabaniformis. The life cycle of B. intercessor was not in close synchrony with the development of P. tabaniformis in the spring, but the parasitoid adults which fed on honey-sugar solution lived for up to 31 days (males) and 86 days (females), respectively. This suggests that, in the field, B. intercessor females eclosing in the spring could survive until the host larvae appear if nectar is available. Adults of the summer generation emerge from July to September when sufficient suitable host larvae are available. B. intercessor was responsible for 1.5% of the average mortality of the P. tabaniformis overwintering larvae. The host mortality caused by the summer generation of the parasitoid ranged from 3.2% to 5.8%.  相似文献   

8.
白蜡虫孵化行为的研究   总被引:2,自引:0,他引:2       下载免费PDF全文
白蜡虫卵孵化主要受温度的影响,湿度和光照对其孵化行影响不大。白蜡虫卵在温度12℃温度范围内卵都能孵化,以20-25℃条件下孵化率较高,达95%左右。  相似文献   

9.
We estimated fine root biomass in a Japanese cedar (Cryptomeria japonica) plantation using a min-irhizotron technique. Since data obtained from minirhizo-trons are limited to the length and diameter of fine roots observed on minirhizotron tubes, data conversion is necessary to determine the fine root biomass per unit soil volume or unit stand area. We first examined the regression between diameter squared and weight per unit length of fine roots in soil core samples, and calculated the fine root biomass on minirhizotron tubes from their length and diameter. Then we determined conversion factors based on the ratio of the fine root biomass in soil core samples to that on minirhizotron tubes. We examined calculation methods, using a single conversion factor for total fine root biomass in the soil for depths of 0–40cm (Cal1), or using four conversion factors for fine roots in the soil at 10-cm intervals (Cal2). Cal1 overestimated fine root biomass in the lower soil or underestimated that in the upper soil, while fine root biomass calculated using Cal2 better matched that in soil core samples. These results suggest that minirhizotron data should be converted separately for different soil depths to better estimate fine root biomass.  相似文献   

10.
In the present study, the suitability of different predatory bug species, such as Dicyphus tamaninii Wagner, Macrolophus pygmaeus (Rambur), Orius albidipennis Reuter, Orius majusculus Reuter and Orius sauteri Poppius, for the biological control of Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), were investigated. Development of the predatory bug species, their reproduction as well as their daily and total prey consumption over a 18-day period with F. occidentalis larvae or various stages of Tetranychus urticae Koch (Acari: Tetranychidae) individuals as prey species were studied during the experiments in the laboratory. In further experiments, the efficiency of D. tamaninii, M. pygmaeus, O. albidipennis and O. majusculus in controlling F. occidentalis under glasshouse conditions was investigated. Results showed that all the predators could develop under the experimental conditions with either F. occidentalis larvae or different stages of T. urticae as prey. When F. occidentalis larvae were offered as prey, the shortest duration of development was observed for O. albidipennis with a mean of 17.7 days, while D. tamaninii took the longest to develop with a mean of 36.3 days. With different stages of T. urticae as prey, the duration of development ranged from 19.3 days in O. albidipennis to 42.9 days in M. pygmaeus. Mean daily fecundity ranged from 0.8 eggs/female for O. majusculus to 2.2 eggs/female for O. sauteri with F. occidentalis larvae as prey and from 0.6, O. majusculus, to 2.3 eggs/female/day, O. sauteri, when different stages of T. urticae were offered as prey. Over the 18-day reproduction period, O. sauteri was the most fecund predatory species, laying a mean total of 31.6 and 31.3 eggs/female with F. occidentalis and T. urticae as prey, respectively. Daily consumption from F. occidentalis larvae ranged between 5.5 individuals consumed per day by O. majusculus and 29.1, by O. sauteri. When different stages of T. urticae were offered as prey, maximal consumption was observed in D. tamaninii with a mean of 29.0 individuals/day, while O. albidipennis consumed the least with an average of 8.1 preys/day. Over the 18-day prey consumption period, D. tamaninii consumed the highest mean number of 422.8 F. occidentalis larvae, while O. majusculus only consumed 98.8 larvae. Also, D. tamaninii had the maximum consumption of different stages of T. urticae with a mean of 522.4, while M. pygmaeus and O. albidipennis consumed the least, with an average of 146.1 and 146.0, respectively. The predatory bugs D. tamaninii, M. pygmaeus, O. albidipennis and O. majusculus significantly reduced the density of F. occidentalis on hybrids of Euphorbia milii, Serissa foetida and Saintpaulia ionantha in the glasshouse, which confirms their efficiency against this pest on different hosts under controlled climatic conditions.  相似文献   

11.
The incidence and severity of resinous stem canker disease were investigated in hinoki (Chamaecyparis obtusa) and sawara (C. pisifera) at a progeny test located in Yamatsuri Town, Fukushima Prefecture, Japan. Symptoms of the disease were observed in 307 trees out of 933 investigated trees (32.9%). The damage was more severe on lower slopes than on upper slopes, indicating that micro-environmental factors are causally associated with the occurrence of the disease. The severity of the disease varied both among nine open-pollinated progenies derived from hinoki plus-tree clones and among 13 progenies derived from pollination between hinoki plus-tree clones and the mixed-pollen of hinoki plus-tree clones. The severity of the disease also varied with height above the ground. This tendency was most obvious where the disease was most severe. An estimation of the narrow sense heritability,h 2, of 0.214, was obtained from analysis of the 13 progenies derived from pollination with mixed-pollen. The heritability derived from material that had not been subjected to selection against the disease, indicated that breeding to enhance resistance would be possible to control the disease. The interaction between environments and progenies in relation to severity of the disease is also discussed. Ms. Setsuko Chiba and Mr. Mamoru Ueta gave us vigorous supports, and Mr. Haruki Orita, Dr. Tomiyasu Miyaura, and Dr. Shinichiro Ito gave us many helpful comments. We deeply appreciated their cooperation. The study was supported by a grant from the Ministry of Agriculture, Forestry. and Fisheries of Japan.  相似文献   

12.
A 2-year study on the preference and performance of Lipaphis erysimi on different Brassica species in the field and under greenhouse conditions revealed that rapeseed (B. campestris var. BSH-1, B. campestris var. YSPB-9) and mustard (B. juncea RH-30) were better hosts for this aphid than other Brassica species (B. napus, B. nigra, Eruca sativa, B. carinata). On the first group of plants, the rate of nymphal development, longevity and fecundity of this pest were significantly less than on the second group of plants. Development was significantly prolonged when the aphid was reared on second group of plants.  相似文献   

13.
This study investigated the number of adults ofPlatypus quercivorus (Murayama) captured on host oak (Quercus spp.) trees, the attack density (the number of entry holes per 100 cm2), and the number of emerging adults to clarify the relationships between the beetle’s colonization on trees in oak stands and tree mortality. The initial attack ofP. quercivorus, which was the most intense attack, was observed on most living trees simultaneously. Although some attacked trees died within the year of the attack or in the next year, a high density of attack did not usually cause the death of host trees. Surviving trees suffered low levels of consecutive attack after the initial attack. BecauseP. quercivorus successfully produced broods only in the dead trees, the population of the insect seems to be maintained only in stands where oak mortality occurs. However, the adults that landed on most of the surviving trees appeared unable to reproduce probably due to degradation of host quality. Thus, oak mortality probably ceases within 3 or 4 years after the start of infestation in a stand, with subsequent reductions in population density of the borer.  相似文献   

14.
An ongoing expansion of Myzocallis (L.) walshii (Monell) in the NE Iberian Peninsula was detected. The aphid species was recorded in Catalonia, Andorra and Navarra. Adaptation of local native parasitoids (at least Trioxys pallidus Haliday and T. tenuicaudus Stary) to the new immigrant was documented, together with background information on their host range in the native environments. The detection of parasitoids of M. walshii is the first published evidence in Europe. The new evidence for M. walshii in the NE Iberian Peninsula also supports the warning of the expansion of the aphid as a pest of Quercus rubra over Europe.  相似文献   

15.
Bursaphelenchus mucronatus Mamiya et Enda has been recovered for the first time from adults of the cerambycid beetle, Monochamus urussovi (Fischer), in Hokkaido, Japan. The nematode was also recovered from the inner bark of Picea jezoensis (Siebold et Zuccarini) Carrière and Abies sachalinensis (Fr Schmidt) Masters infested with M. urussovi larvae. PCR–RFLP analysis indicated that B. mucronatus in Hokkaido is the European type.  相似文献   

16.
The decline of virgin fir (Abies firma) forest at Mt. Oyama has been reported. Related field observations suggest that high acidity fog is linked with its decline. However, cedar (Cryptomeria japonica) in the same area shows no symptoms of decline. For assessing effects of acid fog on membrane-bound calcium (mCa) of the leaf mesophyll cells, 9-year-old seedlings of fir (Abies firma) and 8-year-old seedlings of cedar (Cryptomeria japonica) were exposed twice a week to simulated acid fog (SAF at pH 3 with pH 5 as control) for 2 h per day in a chamber during May–December 2007 (except August). Current and 1-year-old needles were collected from seedlings and analyzed at 1-month intervals. For current-year needles of fir, mCa levels in cells exposed to SAF at pH 3 were significantly lower than in cells exposed to pH 5, especially during September 2007–March 2008. In contrast, it is noteworthy that mCa levels of cedar were maintained as virtually constant irrespective of SAF acidity, indicating that fir is more sensitive to acid fog than is cedar. Based on these results, mCa loss by acid fog might also be caused in the declining virgin fir forest at Mt. Oyama.  相似文献   

17.
[目的]日本学者Kosaka与Ogura发现松褐天牛成虫除携带松材线虫外,雌成虫卵巢内还携带有另一种线虫,他们将其命名为卵巢线虫,并认为这种线虫是松褐天牛成虫的寄生性线虫。我国对该种线虫的研究迄今未见报道。为了证明这种线虫在我国是否存在和分布,开展了本项研究。[方法]分期分批捕获刚羽化的松褐天牛雌雄成虫,采用解剖松褐天牛成虫松树木质部及感病的松褐天牛幼虫等方法,调查卵巢线虫的存在与分布。[结果]通过调查研究,发现我国的松褐天牛成虫体内有该卵巢线虫存在,分布于松褐天牛成虫、幼虫体内和松树木质部3个部位;在松褐天牛成虫体内的卵巢线虫通过松褐天牛雌成虫产卵而接种、进入寄主树木木质部中。同时,木质部的卵巢线虫也有一部分进入松褐天牛幼虫体内寄生,另一部分仍在木质部生活,当松褐天牛幼虫再次发育为成虫时,在木质部中的卵巢线虫和已被寄生的松褐天牛幼虫体内的卵巢线虫再次进入松褐天牛成虫体内,完成循环。卵巢线虫在松褐天牛雌、雄虫体内均有分布,携带率为44.4%,其中松褐天牛雌成虫携带率为43.8%,松褐天牛雄成虫携带率为45.0%,两者间无显著差异;每头松褐天牛成虫平均携带卵巢线虫574条,其中雌成虫平均携带816条,雄成虫平均携带308条,具显著差异。初步研究表明,卵巢线虫在松褐天牛成虫体内只能完成产卵到1~4龄的幼虫阶段,不能完成一个完整的世代;在松褐天牛幼虫体内寄生和在木质部生活的卵巢线虫能完成一个完整世代,但具体过程尚不清楚;调查中未观察到卵巢线虫对松褐天牛成虫有寄生致病或致死的现象,但对松褐天牛幼虫有寄生致死的能力;卵巢线虫常与松材线虫同时存在,而且侵入松树及离开松树的方式与松材线虫相同。[结论]我国松褐天牛体内也发现有卵巢线虫存在;目前尚不能证明该线虫对松褐天牛成虫具有寄生致死性,但对松褐天牛幼虫具有一定的寄生致死性;卵巢线虫的生活史与松材线虫相似,是否与松材线虫一样对松树具有危害性以及其病理作用还有待于进一步研究。  相似文献   

18.
Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae) is recorded as a new factitious host for the solitary egg-larval parasitoid, Chelonus oculator Panzer (Hymenoptera: Braconidae). A short biology and rearing method of the parasitoid on the new host were studied at 30±1°C, 60–70% relative humidity, with a photoperiod of 16:8 (L: D). Chelonus eclosed from 74.60% of parasitized hosts. No significant difference was found between development times of male and female parasitoids. Development of the parasitoid was completed in 28.14±0.47 days in male, and 28.87±0.58 days in female. However, a significant difference was found between adult sizes of male and female parasitoids. Adult dry mass was found 0.88±0.04 mg in male, and 1.99±0.11 mg in female. In addition, C. oculator was successfully reared from P. interpunctella in twenty generations with the explained method. Significant knowledge about biology of C. oculator is still lacking. However, the parasitoid can be candidate for future research as a biological control agent against some important lepidopteran pests, and P. interpunctella may be suitable factitious host for mass rearing of C. oculator.  相似文献   

19.
The hemispherical soft scale, Saissetia coffeae (Walker) (Homoptera: Coccidae), is one of the most important pests attacking olive trees in Egypt. During the period 2001–2003, a total of about 300,000 individuals of the parasitoid Coccophagus cowperi Girault (Hymenoptera: Aphelinidae), obtained from India, was released at 35 sites for the biological control of S.coffeae on olive trees in Egypt. The maximum parasitism rates reached 53 and 62%, while average parasitism rates were 17.2 and 30.8% in the Marsy Mattrouh and El-Arish locations, respectively. These results indicate establishment of this parasitoid on this important economic plant in Egypt.  相似文献   

20.
The effectiveness of natural enemies against arthropod herbivores can depend on the characteristics of the plant on which they are found. The influence of the plant on the egg-laying behaviour of the promising whitefly predator, Serangium parcesetosum Sicard (Col., Coccinellidae) was examined in order to be able to use it effectively in biological control programs. The present work investigated the possible influence of the portion of the leaf on the number of eggs laid as well as the effect of plant species on the way in which eggs are deposited by S. parcesetosum. The experiments were conducted on cucumber and cotton leaves with Bemisia tabaci (Genn .) (Hom., Aleyrodidae) as prey in the absence and presence of a natural enemy, the lacewing, Chrysoperla carnea (Stephens) (Neur., Chrysopidae) at two different temperatures. The results showed that at 18°C, S. parcesetosum females significantly preferred to lay their eggs between the veins and close to the veins of cucumber leaves, mean of 10.1 and 7.5 eggs, in the absence of C. carnea, respectively, while in its presence significantly more eggs were deposited close to the veins and close to the petiole. On cotton leaves, close to the petiole, a mean of 8.4 eggs in the absence of the lacewing, as well as close to the veins, mean of 6.3 eggs in the presence of the lacewing, were found to be the most suitable leaf portions for egg-laying. At 30° C, the females laid their eggs preferentially close to the veins of cucumber leaves in the absence and presence of C. carnea. On cotton leaves, S. parcesetosum females significantly preferred to lay their eggs close to the petiole, mean of 7.6 and 6.1 eggs, as well as close to the veins, mean of 6.2 and 8.7 eggs, in the absence and presence of the lacewing, respectively. At both temperatures, the ladybird females laid their eggs singly on cucumber leaves in the absence and presence of C. carnea. While on cotton leaves, the females had a tendency to deposit their eggs together in the absence and presence of the lacewing, except at 30°C in its absence. Within the same plant species, significant differences were found in the total number of eggs laid by S. parcesetosum females on cotton leaves at 18°C as well as on cucumber leaves at 30°C in the absence and presence of the natural enemy. In addition to the effects of presence and absence of C. carnea, and where eggs were laid, some significant differences due to plant species was found at both temperatures.This article is dedicated to Prof. Dr Wolfgang Schwenke on his 84th birthday.  相似文献   

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