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1.
The species complex of Schizotetranychus celarius (Banks) has been thought to involve three morphologically distinct species, S. celarius, Schizotetranychus longus Sait and Schizotetranychus miscanthi Sait. Furthermore, the former species includes at least three morphs which have not yet been examined taxonomically. In the present study, the protein differences of these species and morphs were examined using two-dimensional electrophoresis. In comparison of protein spot patterns between 11 populations of the S. celarius complex and Schizotetranychus recki Ehara, the former group appeared to be very different to S. recki. The phenogram made based on genetic distance suggested that the species complex includes at least two subgroups: S. miscanthi and S. longus. These results are consistent with the previous taxonomic study. On the other hand, the morphs which had been categorized as S. celarius did not form a distinct cluster.This study was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education. Science and Cultures, Japan (No. 02640501) and from the Ministry of Agriculture, Forestry and Fisheries (Bio Cosmos Program, BCP-93-I-B-14), and it is the contribution No. E-163 of the Fruit Tree Research Station.  相似文献   

2.
Spider mites inhabiting Sasa bamboo show considerable variation in traits believed to be the result of coevolution between predator and prey. In Schizotetranychus recki Ehara inhabiting the hairy leaves of a dwarf bamboo, Sasa senanensis, all quiescent stages, including eggs, appear within web boxes in the leaf hairs of their host plant, and this habit is thought to be a trait involved in predator avoidance. To test this hypothesis, the survival rates of S. recki eggs inside a web box and those freed of a web box were assessed in relation to six predator species that co-occur with the spider mite in the field. The results clearly show that the webbing behavior (web box) of S. recki has a function in avoiding five predator species. However, one predator species, Agistemus summersi Ehara, preyed more on eggs protected by a web box. This suggests that this predator species has a special trait to overcome the nest barriers.  相似文献   

3.
Success of counter-attack by the spider mite,Schizotetranychus celarius (Banks), against its specific phytoseiid predator,Typhlodromus bambusae Ehara, was examined under experimental conditions. The success of counter-attack by prey females (mothers) against a predaceous larva depended upon the former's density per nest. About 30% of the predaceous larvae were killed when they intruded into a nest containing eight females and their offspring. On the other hand, the prey males (fathers) effectively killed the predators, i.e. one male in the nest killed ca. 40% of the predators while two or three males destroyed up to 80%.The presence of prey parents in a nest considerably enhanced the success of the counter-attack. One male and two young females could kill 70% of the predator's larvae, while two males and two females killed 90% of such larvae. This suggests a kind of cooperative brood defence amongstS. celarius parents.Although more robust, protonymphs of the predator also suffered damage by the prey's counter-attack. However, prey male and female could not destroy the predator's eggs and adult females, whilst the latter often killed spider mite adults.From these as well as previous experiments, it is concluded thatS. celarius has evolved some kind of biparental care for its offspring. It is further proposed that the predator—prey interactions observed in this study provide a unique contribution towards understanding predator—prey coevolution.  相似文献   

4.
The seasonal cycle and population dynamics of Schizotetranychus nanjingensis Ma and Yuan, Aponychus corpuzae Rimando (Tetranychidae), Aculus bambusae Kuang (Eriophyidae) and their natural enemy Typhlodromus bambusae Ehara (Phytoseiidae) were studied during 1996–1998 in moso bamboo forests in Nanping, Fujian, China. Damage to bamboo leaves was often caused by mixed populations of the three phytophagous species, which displayed different seasonal dynamics: S. nanjingensis fed actively and reproduced in May and from late July to late October (aestivating from June to mid July), Ap. corpuzae was active and reproduced from mid July to late November, and Ac. bambusae from July to next February. During Spring S. nanjingensis was the dominant species with the greatest niche width, but in Summer Ac. bambusae and Ap. corpuzae became dominant and had greater niche widths. In Autumn, Ac. bambusae decreased but both S. nanjingensis and Ap. corpuzae mites increased and the latter became dominant. In winter all species decreased sharply in number. The two spider mite species (S. nanjingensis and Ap. corpuzae) had high niche overlaps in all four seasons. Niche overlaps between the eriophyid Ac. bambusae and the two spider mites were similarly high except during the spring when Ac. bambusae was absent. The predatory mite (T. bambusae) had higher niche overlap with Ap. corpuzae than with others during Autumn and Winter, but during Spring and Summer niche overlap was higher with S. nanjingensis.  相似文献   

5.
1. A type of arms race that includes predation, counterattacks and cross‐counterattacks occurs between the phytophagous mite Stigmaeopsis nanjingensis (Ma et Yuan), which lives in self‐woven nests and exhibits cooperative sociality, and its specialised phytoseiid mite predator, Typhlodromus bambusae Ehara. 2. First, the efficiency of the S. nanjingensis (prey) counterattacking T. bambusae (predator) was observed. The prey females frequently locked the immature predators out of their nests using silk web, and the predators subsequently died of starvation. Furthermore, the prey males often killed immature T. bambusae mites after they invaded the nests. 3. This reversal of roles in the predator–prey system was then re‐reversed (returned to a normal state) by the behaviour of T. bambusae females. Immature predators could maintain their predacious natures due to the presence of attending adult females, which are able to cope with the prey counterattack behaviours.  相似文献   

6.
The influence of feeding and temperature on life table parameters ofEuseius stipulatus (Athias-Henriot) andTyphlodromus phialatus Athias-Henriot was determined in laboratory tests. Both phytoseiids developed and reproduced readily when fed onCarpobrotus edulis (L.) pollen andPanonychus citri (McGregor) Intrinsic rates of increase (r m ) at 25°C forE. stipulatus andT. phialatus were 0.197 and 0.126, and, when fed onP. citri, 0.129 and 0.144, respectively.Tetranychus urticae Koch offered as prey allowed normal development and oviposition ofT. phialatus, but no eggs were laid byE. stipulatus when fed on this spider mite. Eggs and honeydew ofAleurothrixus floccosus Mask. furnished sufficient nutrition for development of immatures ofE. stipulatus. Larvae ofPlanoccocus citri Risso, and honeydew and eggs ofA. floccosus, allowed adult survival but no egg-laying of the predaceous mites.Lorryia formosa Cooreman was not a favoured prey species.Life tables were calculated forE. stipulatus fed on pollen andT. phialatus fed onP. citri at constant temperatures of 18, 25, and 32°C. Maximum development was reached at 32°C, withr m values of 0.225 forE. stipulatus and 0.179 forT. phialatus. In general, both phytoseiids showed medium to high total number of eggs per female and long oviposition periods when compared with other phytoseiid species.When mating took place at 32°C,E. stipulatus females were not able to lay eggs, thus suggesting an interference of high temperatures with fertilization in this species. No hatching was observed in eggs of either species when kept at relative humidities of 50% or lower. The possible significance of these responses is discussed in relation to population trends observed in the field.  相似文献   

7.
The predatory miteTyphlodromus talbii Athias-Henriot occurs in European vineyards and is often associated with economically important species. Neither its role in vineyards nor the factors affecting its population dynamics and relationships with other phytoseiid species are well known. The development and the reproduction ofT. talbii were studied in the laboratory by rearing the predator on different kinds of food (Panonychus ulmi, Eotetranychus carpini, Colomerus vitis, Tydeus caudatus, Mesembryanthemum criniflorum pollen). Overwintered females reared on tydeids survived for long periods and laid eggs, but they died after a few days when spider mites or pollen were provided. Development occurred on all mite species but not on pollen. Developmental times on tydeids were shorter than on the other prey. Oviposition was recorded on tydeids and, to a lesser extent, on eriophyids but not on spider mites or pollen. Experiments on tydeids, which resulted as being the best food, were conducted at two temperatures (20° and 27°C). The highest temperature affected the duration of development and oviposition rates positively, but total fecundity was similar. Predators reared at 27°C consumed more prey than those reared at 20°C. The life table parameters of the species were evaluated onT. caudatus (at 20° and 27°C) and onC. vitis. The highest rm ofT. talbii was found for individuals reared onT. caudatus at 27°C (0.165). Lower values were obtained on the same prey at 20°C (0.089) or onC. vitis (0.030). The feeding habits ofT. talbii may explain why the species coexists with the generalistAmblyseius aberrans orTyphlodromus pyri.  相似文献   

8.
Observations were made on the feeding behavior of the two main phytoseiid species in Spanish Citrus orchards,Euseius stipulatus (Athias-Henriot) andTyphlodromus phialatus Athias-henriot. The experiences were carried out by rearing the predatory mites on excised orange leaves, and always with an excess of the prey the Citrus Red Mite (=CRM)Panonychus citri (McGregor). In experiments with all stages of CRM, the number of prey killed per hour was 5.12 and 2.00, the percentage of successful attacks, 58% and 21%, and the mean time spent feeding on each prey was 5.1 and 12.2 minutes for starving females ofE. stipulatus andT. phialatus respectively.E. stipulatus feeds on all stages of the prey except eggs, andT. philatus, on all stages, except males. Both species attack much less successfully females ofP. citri rather than immatures. In experiments with adult females and eggs ofP. citri as prey, the mean number of prey killed daily was 4.51 females forE. stipulatus, and 2.01 females and 2.12 eggs forT. philatus. Considering this killing rate and the number of eggs laid by the predators in the same period, it can be concluded thatE. stipulatus consumes only 30% of the content of the preys killed, whereasT. philatus consumes a percentage of prey variable between individuals and ranging from 40% to 100%. These differences in feeding behavior between the two species could partly explain differences in their efficiency as biocontrol agents ofP. citri observed in the field.   相似文献   

9.
Amblyseius idaeus (Denmark & Muma) andA. anonymus Chant & Baker are morphologically very similar species of phytoseiids inhabiting areas in South America that have very different levels of humidity. Above 60% RH, nearly all eggs of both species hatch successfully, but below 60% RH the egg hatching rate ofA. anonymus is very poor, whereas eggs ofA. idaeus hatch at humidities as low as 30% RH. The mobile stages ofA. idaeus are better able to survive in absence of food and water than those ofA. anonymus. Water availability promotes survival of both species, but its effect onA. idaeus exceeds that onA. anonymus. These differences in low-humidity tolerance and survival ability are consistent with the climatic origin of these phytoseiid species;Amblyseius ideaus has been reported from very dry and humid areas, andA. anonymus from humid areas only.In comparison with other phytoseiid species, the eggs ofA. idaeus have the highest tolerance to low humidities reported to date, and, among the phytoseiids that are shown to be capable of controllingTetranychus spp., this tolerance appears to be exceptionally high. The impact of this result on the scope of biological control ofTetranychus spp. is discussed.  相似文献   

10.
Experimental observations on the arrenotokous reproductive patterns of two spider mite species (Acari: Tetranychidae), the long-seta form of Schizotetranychus celarius (Banks ) and Tetranychus urticaeKoch , revealed that reproduction of unfertilized females of the former is very differnt from that of the latter. Unfertilized females of S. celarius, which has a subsocial life, laid a few eggs and then became inactive. In contrast, the fecundity of unfertilized T. urticae females was only slightly reduced as compared with fertilized females. Mother-son matings may thus sometimes occur in natural S. celarius populations. A two-year field survey revealed that, in the absence of males, overwintering females of S. celarius occasionally remain unfertilized until early spring. Furthermore, nest foundation observed in late spring indicated that most of the season's first nests were founded by single females. These two sets of observations strongly suggest that motherson mating takes places in nature, corresponding to the reproductive trait seen in the experiment. Mother-son mating inevitably increases the relatedness between nest members. The estimated father's relatedness to its offspring is extraordinarily high under such condition. The possibility that kin-selection in the long seta-form of S. celarius led to subsociality, especially paternal care, is suggested.  相似文献   

11.
The effect of prey species and the different stages of prey on the predatory efficiency and biology of the phytoseiid mites,Amblyseius gossipi Elbadry andTyphlodromus mangiferus sp. n. was studied. It was found that feeding either predator onTetranychus cucurbitacearum (Sayed) promoted faster development and a higher rate of oviposition than rearing on the twospotted spider mite,T. urticae (Koch). Different stages of both prey species also produced different responses in the biological activities of these predaceous mites.
Résumé On a étudié l'effet de l'espèce de la proie et de ses différents stades sur l'efficacité et la biologie des acariens phytoseiides,Amblyseius gossipi Elbadry etTyphlodromus mangiferus sp. n. Il a été constaté que l'alimentation des 2 prédateurs avecTetranychus cucurbitacearus (Sayed) assure un dévelopment plus rapide et une fécondité plus élevée que leur élevage surT. urticae (Koch). Les différents stades de ces 2 proies produisent des réponses différentes dans les activités biologiques des 2 acariens prédateurs.
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12.
The responses of 3 phytoseiid mite speciesPhytoseiulus persimilis Athias-Henriot,Phytoseius finitimus Ribaga andAmblyseius gossipi Elbadry to allelochemics emitted by prey mite speciesTetranychus urticae Koch,Brevipalpus pulcher (Canestrini & Fanzago) andEriophyes dioscoridis Soliman & Abou-Awad were studied using a test of two-choice assays. The repellent effect elicited by the tenuipalpid mite,B. pulcher and the eriophyid mite,E. dioscoridis againstP. persimilis could be an evidence for the existence of allomones produced by these 2 prey species. The negative response ofP. persimilis to the different stadia ofB. pulcher and the attraction ofP. finitimus toward the same prey suggest that the volatile semiochemicals produced by this prey act as kairomones forP. finitimus and as allomones forP. persimilis. The strong attraction ofP. finitimus andA. gossipi to the different stadia ofT. urticae and the considerable attraction of either predator toB. pulcher compared to the neutral response toE. dioscoridis reveal that both predators show a hierarchy of preference for the kairomones of the 3 prey species studied.   相似文献   

13.
The prey selection of the phytoseiid miteTyphlodromus pyri Scheuten was studied by using polyacrylamide gel electrophoresis to analyse the diet of field-collected predators. The predators were obtained from an orchard where the phytophagous prey mitesPanonychus ulmi (Koch) andAculus schlechtendali (Nalepa) were present in various density ratios.Esterases of both prey species were identified in the predators, but on all sampling datesP. ulmi esterases were discovered much more frequently than those ofA. schlechtendali. The data show thatT. pyri hardly fed onA. schlechtendali over a range of prey density ratios. It is therefore concluded thatT. pyri prefersP. ulmi toA. schlechtendali.  相似文献   

14.
The developmental times and the reproduction of two resistant Italian strains ofTyphlodromus pyri Scheuten andAmblyseius andersoni (Chant) were studied in the laboratory by rearing them on the spider mitesPanonychus ulmi (Koch) andEotetranychus carpini (Oud.), on the eriophyidColomerus vitis (Pgst.) and on pollen ofMesembryanthemum criniflorum. The response ofT. pyri andA. andersoni females to a spider mite supply (P. ulmi orE. carpini) of 4, 8 and 16 adult female prey per female predator per day was also studied.Development ofT. pyri onE. carpini andC. vitis required a shorter period than onM. criniflorum pollen, while intermediate values were recorded forP. ulmi. When the highest number of prey was offered, the influence of different foods on oviposition rates ofT. pyri was not significant. An increase in spider mite supply favoured a shorter pre-oviposition period and higher oviposition rates.Development ofA. andersoni was faster on pollen than on spider mites, while intermediate values were found concerningC. vitis. Differences statistically significant were recorded for development onP. ulmi andC. vitis. Colomerus vitis proved to be the more suitable food in terms of oviposition. The oviposition rate decreased when feeding uponP. ulmi, but reached intermediate values onE. carpini andM. criniflorum. Increasing spider mite densities caused shorter pre-oviposition times and higher oviposition rates. Using a given number ofE. carpini females, rather than those ofP. ulmi, resulted in higher oviposition rates and shorter pre-oviposition times.For both predators, the results suggest a higher intrinsic rate of population increase onE. carpini orC. vitis than onP. ulmi.The research was supported by a grant from Regione Veneto (Lotta biologica ed integrata nel controllo di insetti ed acari dannosi).The general lines of the research have been planned by C. Duso. The authors contributed equally to the experimental work.  相似文献   

15.
New species of Alternaria from Marathwada (India)   总被引:1,自引:0,他引:1  
Summary The paper deals with two new species ofAlternaria, Alternaria nyctanthi onNyctanthes arbortristis Linn. andAlternaria tropaeoli onTropaeolum majus L.  相似文献   

16.
A survey was conducted of the predator fauna occurring in and around the nests of the two forms (LW: low male aggression and HG: high male aggression) of Stigmaeopsis miscanthi (Saito) that occur in Japan. Two phytoseiid species, Neoseiulus womersleyi (Schicha) and Typhlodromus bambusae Ehara predominated in S. miscanthi nests and their respective occurrence frequencies were the same in LW form nests as in HG form nests. We examined the counterattack success of S. miscanthi LW form males against these two phytoseiid predators. It was shown that while LW form male(s) could kill or effectively drive the larvae of both predator species out of their nests, there were no significant differences in the male counterattack success rate between 1-male and 2-male defended nests, or against the two predator species. On the other hand, there was a significant difference between the two predator species’ behavioral response to male-defended nests.  相似文献   

17.
The life history ofPanonychus akitanus Ehara was studied in two Hokkaido populations on dwarf bamboos. The Sapporo population overwintered both as egg and female adult onSasa senanensis, and the Tomakomai population overwintered as egg onSasa apoiensis. Mites of the Sapporo population produced four or five generations from late April to late November or early December. The eggs that had overwintered began to hatch in mid-May, and this hatching period overlapped with that of eggs laid in late April by females that had overwintered. Therefore, mites with different overwintering stages would interbreed. Most eggs that had overwintered in the Tomakomai population hatched in mid-May, and about four generations were produced before early December, when only eggs were found. The density of mites per leaf of the Sapporo population reached a maximum in early May on old leaves and in late June on new leaves, and thereafter gradually decreased. The Tomakomai population initially decreased in density after hatching in the spring, but rapidly dispersed to new leaves, reached a peak in early September, and then gradually decreased. The maximal density was about 10 times higher and the distribution was less clumped (lower values of the aggregation index,m/m) than that of the Sapporo population. This was probably because the Sapporo mites could utilize only the underside of sporadically distributed leaves which were curled by spiders, whereas the Tomakomai mites inhabited any part of the leaf undersurface of the hairy host plant. Predators observed were phytoseiid mites and larvae of gall midges. The predatory effect on the Sapporo population was not clear. In the Tomakomai population, the number of gall midges correlated with the number of spider mites better than that of phytoseiid mites.  相似文献   

18.
Zusammenfassung Im zweiten Beitrag zur Flora Ionica werden folgendeSilene-Arten (Caryophyllaceae) behandelt:S. cephallenia Heldr.,S. congesta Sm. in S. &Sm.,S. ungeri Fenzl inUnger,S. behen L. undS. reinholdii Heldr. Die Chromosomenzahlen vonS. cephallenia, congesta, behen, reinholdii, holzmannii undgraeca werden mitgeteilt. Alle Arten besitzen 2n=24 Chromosomen.S. cephallenia ist näher mitS. paeonensis Bornm. aus Mazedonien als mitS. congesta verwandt. Die Stellung vonS. cephallenia in der SektionBrachypodae (Chowdhuri, 1957) erscheint nicht berechtigt und die Untergliederung der Sektion stimmt nicht mit unseren Beobachtungen anS. cephallenia undS. congesta überein. Abbildungen (S. cephallenia, congesta, paeonensis, behen, reinholdii) und Chromosomenbilder ergänzen den Text. FürS. cephallenia, congesta, ungeri, reinholdii undbehen (nur Griechenland) wird die Verbreitung in Punktkarten dargestellt.
Summary In this second contribution to the Flora Ionica the followingSilene-species (Caryophyllaceae) are treated:S. cephallenia Heldr.,S. congesta Sm. in S. &Sm.,S. ungeri Fenzl inUnger,S. behen L. undS. reinholdii Heldr. The chromosome numbers ofS. cephallenia, congesta, behen, reinholdii, holzmannii andgracea were reported. All species investigated have 2n=24 chromosomes.S. cephallenia is more related toS. paeonensis Bornm. from Macedonia than toS. congesta. The position ofS. cephallenia in the sectionBrachypodae (Chowdhuri, 1957) seems to be not justified and the subdivision of the section is not in accordance with our observations onS. cephallenia andS. congesta. Drawings of plants (S. cephallenia, congesta, paeonensis, behen, reinholdii) and of chromosomes (S. graeca, holzmannii, reinholdii, congesta, cephallenia) complete the text. The distribution ofS. cephallenia, congesta, ungeri, reinholdii andbehen (only for Greece) is given on two dot maps.
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19.
Using a Y-tube olfactometer, a study has been made of the response of females of the predatory miteTyphlodromus pyri Scheuten (Acarina: Phytoseiidae) to volatile kairomones of three prey species: the European red spider mite (Panonychus ulmi (Koch)), the two-spotted spider mite (Tetranychus urticae Koch) and the apple rust mite (Aculus schlechtendali (Nalepa)).Predators that had been reared onT. urticae responded only to the volatile kairomone ofP. ulmi. In contrast, when reared onVicia faba L. pollen, they responded to the kairomones of all three prey species. Pollen-reared predators, offered a choice between kairomones of two different prey species, prefer theP. ulmi kairomone to those ofA. schlechtendali orT. urticae.The difference in response between predators reared onV. faba pollen andT. urticae seems to be caused by the low carotenoid content ofV. faba pollen. Predators that had been reared onV. faba pollen mixed with crystalline -carotene behaved in a way similar to conspecific that had been reared on the carotenoid-rich prey miteT. urticae. Obviously, pollen-rearedT. pyri females are in need of carotenoids, which can be obtained from, e.g.,P. ulmi, T. urticae orA. schlechtendali. This may explain why pollen-reared predators respond to more prey species thanT. urticae-reared predators.WhyT. pyri females need carotenoids has not been established. The only known function of carotenoids in mites is involvement in diapause induction. However, as pollen-rearedT. pyri enter reproductive diapause under short-day conditions, they either extract sufficient amounts of carotenoids fromV. faba pollen, or do not need carotenoids for diapause induction.Apart from the effect of dietary requirements on prey selection, food deprivation also affects the predator's response to kairomones. All the data mentioned above have been obtained for predators that had been starved for 20 h. Predators that had been reared onT. urticae and starved for 48 h before the experiment did respond to the volatile kairomone ofT. urticae in contrast to predators from the same culture that had been starved for 20 h. Thus foraging decisions byT. pyri are affected by both starvation time and specific hunger for carotenoids.  相似文献   

20.
The effects ofOstrinia nubilalis(Hübner) (Lepidoptera: Pyralidae) eggs andAcyrthosiphon pisum(Harris) (Homoptera: Aphididae), when provided as single prey species and in combination, on life history characteristics ofColeomegilla maculataDeGeer (Coleoptera: Coccinellidae) larvae and adults were quantified. Preimaginal development was not influenced by the larval prey regime; development at 26 ± 1°C was completed in approximately 13.5 days onO. nubilaliseggs,A. pisum,orA. pisumalternated daily withO. nubilaliseggs. The resulting adults weighed 13.0, 10.7, and 12.5 mg when reared onO. nubilaliseggs,A. pisum,andA. pisumalternated daily withO. nubilaliseggs, respectively. Eighteen percent of the individuals died when reared onA. pisum,28% died when reared onO. nubilaliseggs, and 22% died when fedA. pisumalternated daily withO. nubilaliseggs. Seven adult diet combinations, based on diet regimes of larvae and adults, did not cause significant differences in preoviposition period, interoviposition period, and the number of days on which eggs were laid. Total fecundity was influenced both by larval and adult diet. The diet that resulted in highly fecund females wasA. pisumalternated daily withO. nubilaliseggs for larvae andO. nubilaliseggs for adults. FemaleC. maculatafedO. nubilaliseggs had the highest intrinsic rate of increase and net reproductive rate.  相似文献   

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