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1.
The external and internal morphological characteristics of the predator Rhyzobius lophanthae Blaisdell (Coleoptera, Coccinellidae) were studied. The head, antenna, thorax elytra, hind wings, legs and abdomen are described. The adult has an average length of about 2.5?mm and width of 1.8?mm. The flagellum of the antenna consists of 9 segments. The whole surface of thorax and elytra is covered by setae. The tarsus of the 3 legs is 3-segmented. An external morphological difference between male and female is the outline of the 5th sternite. The alimentary canal, the central nervous system, and the reproductive system of both male and female are also described. The testes consist of 10 follicles and the ovaries of 10 ovarioles. The life cycle of R. lophanthae was studied by rearing the predator on the diaspidid Chrysomphalus aonidum (Linnaeus). The duration of the development of the embryo, 1st, 2nd, 3rd, 4th larval instars, pupa and preoviposition period of adults were measured at 15, 20, 25 and 30?°C.  相似文献   

2.
In the coastal regions of the Southern Ukraine adults ofLixus albomarginatus Boh. feed onCakile euxina Pobed. (Brassicaceae). Preimaginal development occurs in the same plants.  相似文献   

3.
The fungal genera associated with larvae ofStromatium fulvum were isolated externally, internally and also those from larval galleries and exit holes. They belonged to six genera:Penicillium, Trichoderma, Helminthosporium, Aspergillus, Rhizopus andChaetomium. Based on the antagonistic effect,Trichoderma andChaetomium were used in the mortality studies. Isolation of fungi from inoculated dead larvae proved thatCheatomium spp. are non pathogenic. The genera ofTrichoderma spp.,Aspergillus spp. andPenicillium spp. were pathogenic and are recommended as biological control agents forStromatium fulvum larvae.  相似文献   

4.
Adults of the histeridTeretriosoma nigrescens Lewis, a predator of the Larger Grain BorerProstephanus truncatus (Horn), were captured under field conditions in Costa Rica within the same pheromone traps as the stored product pest. Neither insect could be found in unbaited traps. The possible kairomonal importance of the prey's pheromone is discussed.  相似文献   

5.
In a laboratory study, it was tried to measure the extent of olfactory responses of two predators namelyCryptolaemus montrouzieri Mulsant andChrysoperla carnea (Stephens) to their respective preys at varied levels of their starvation. Results indicated that both the predators, irrespective of their developmenta stage, oriented more positively to their preys odour when they were deprived of food for certain period of time than they did so when tested directly without subjecting them to starvation. The first, second, third and fourth instar larvae and adults ofC. montrouzieri showed maximum response at 4 h, 8 h, 12 h, 12 h and 24 h of starvation, respectively. Similarly, the larvae ofC. carnea responded maximum with 4 h, 8 h and 12 h of hunger in first, second and third instar, respectively. However it was also evident that the continued starvation for more than certain ideal period affected the predators olfactory orientation negatively. But the adults ofC. montrouzieri differed slightly in their behavior as they could respond positively for comparatively longer period of starvation.
Zusammenfassung In Laborversuchen wurde das Ausmaß der olfaktorischen Reaktionen der beiden PrädatorenCryptolaemus montrouzieri Mulsant undChrysoperla carnea (Stephens) auf deren BeuteinsektenPlanococcus citri Risso respektiveAcyrthosiphon pisum (Harris) und in Abhängigkeit von der Dauer einer vorangegangenen Hungerperiode, namentlich 2, 4, 8, 12, 16, 20 und 24 Stunden, ermittelt. Wie die Ergebnisse belegen, reagieren beide Prädatoren-Arten unabhängig vom jeweiligen Entwicklungsstadium stärker auf den Geruch ihrer Beute, wenn sie zuvor eine bestimmte Zeit unter Ausschluß von Nahrung gehalten worden waren. Dabei zeigte sich bei den Larven beider Arten ein typischer Verlauf der Attraktivität durch die Beute, nach dem diese mit zunehmender Dauer der Hungerperiode zunächst zunahm, um nach einem Maximum wieder deutlich abzufallen. Dieser Verlauf erwies sich für die einzelnen Larvenstadien als unterschiedlich. So wurde fürC. montrouzieri das Maximum bei den L1-Larven mit durchschnittlich 9,33 von 15 durch die Beute angelockten Individuen bereits nach einer Hungerperiode von 4 h erreicht, für die L2 jedoch mit 9,50 Individuen erst nach 8 und für die L3 sowie L4 erst nach 12 h mit 8,83 respektive 9,17 Individuen. Lediglich bei denC. montrouzieri-Adulten war eine kontinuierliche Zunahme der Attraktivität der Beute während des Untersuchungszeitraums von 24 h festzustellen, wobei das Maximum bei 10,00 Individuen lag. Analog wurde für das ersteC. carnea-Larvenstadium bei einer 4stündigen Hungerperiode mit 55,5% attrahierten Individuen das Maximum erreicht, wohingegen das zweite Stadium mit 61,1% bei der 8- und das dritte mit 65,5% bei der 12stündigen Hungerperiode die maximale Attraktion durch die Beute aufwies.


With one table and one figure  相似文献   

6.
The function of the Hastisetae (typical for Megatominae) has not been clarified exactly. The observations of several workers make probable a defensive function. Others interpret the Hastisetae as a contrivance to the passive dispersion of the species. The present observations show that the Hastisetae have an only defensive character.  相似文献   

7.
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   

8.
Lady beetles are among the most successful predators of aphids in different environments. The functional responses of different life stages of Hippodamia variegata (Goeze) towards cotton aphids were examined in two different set-ups, a two-dimensional Petri dish set-up with detached leaves and a three-dimensional set-up with whole plants. In addition, the functional responses in two-dimensional set-ups towards cotton aphids and the pea aphids were compared. H. variegata exhibited a functional type II response to both cotton aphids and pea aphids irrespective of life stage and spatial scale of the set-up. Females and fourth instars generally had higher search rates than third instars whereas handling times were consistently lower for the fourth instar stage compared with the preceding juvenile stage and with females. The spatial dimensions did not have any significant influence on the functional responses towards cotton aphids, except for third instars which in the three-dimensional set-up reduced their search rate and increased their handling time. Fourth instars reacted in the same way to both Aphis gossypii and Acyrthosiphon pisum whereas the functional response parameters for third instars and females were significantly different on the two prey species. Our study, a part of this first-step evaluation of H. variegata as a biocontrol agent against A. gossypii and A. pisum under field condition, suggest that the voracity of all tested stages of H. variegata towards both aphid species hold good promises for a use of especially fourth instars and females in inundative biocontrol.  相似文献   

9.
An outbreak on apple permitted a closer look at Coenorhinus pauxillus (Germar) (Col.: Attelabidae). The adult weevils emerge from mid-March onwards and attack the first unfolding leaves. Infested leaves drop when the larvae are in the 1st or 2nd instar, and it takes a further 4 weeks before the larvae are ready to pupate. Rearing of field-collected eggs and larvae is described. Leaf decomposition is an essential condition for pupation, as the fully-grown larvae do not leave their mine actively. Part of the population pupates more or less immediately and produces adult weevils in autumn. However, up to 70?% of the weevils remain in prolonged diapause; their pupation does not take place before the summer of the following year. Damage by the weevil involves not only the loss of leaves of flower clusters and shoots, but also feeding damage to young fruits. Two parasitoids were found. Observations indicate that 3?–?4 subsequently more abundant generations of Anaphes brachygaster Debauche (Hym.: Mymaridae) develop in eggs of C. pauxillus. Probles brevicornis Horstmann (Hym.: Ichneumonidae, Tersilochinae) emerges in May and oviposits in young weevil larvae on the tree. The parasitoid does not develop into a pupa until its host starts pupating. The outbreak of apple leaf cutter did not decline over three years, but did not spread into adjacent plantings.  相似文献   

10.
11.
Journal of Pest Science - This study sought to provide relevant information for developing effective programs to manage Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) resistance to...  相似文献   

12.
The data on natural enemies of 19 species of Cleoninae (generaCleonis, Chromoderus, Cyphocleonus, Rhinocyllus, Lixus, Larinus) are given. They were parasitized by Ichneumonidae, Braconidae (Hymenoptera), Erythraeidae (Acariformes) and fungi. Weevils fell victim of ants (Formicidae), beetles (Tenebrionidae, Elateridae, Scarabaeidae) and probablyOrius bugs (Anthocoridae).
Zusammenfassung Es werden Beobachtungen von 56 Stellen der Ukrainischen Steppe mitgeteilt über natürliche Feinde von 19 Rüsselkäfer-(Cleoninae-) Arten der GattungenCleomis, Chromoderus, Cyphocleonus, Rhinocyllus, Lixus undLarinus. Die Rüsselkäfer und ihre Stadien werden vor allem von Ichneumonidae, Braconidae (Hymenoptera), Erythraeidae (Acariformes) und Pilzen angegriffen. Des weiteren werden sie auch zu Opfern von Ameisen (Formicidae), Käfern (Coleoptera) und wahrscheinlich Wanzen (Orius spp., Anthocoridae).


With one table  相似文献   

13.
This study was carried out to determine the development, survival and reproduction responses of Adalia fasciatopunctata revelierei (Mulsant) (Coleoptera: Coccinellidae) feeding on Hyalopterus pruni (Geoffroy) (Homoptera: Aphididae), using 20, 40, 80, 160 and 250 prey densities. All experiments were conducted at 25±1°C, 60±5% relative humidity, 16:8 light:dark under laboratory conditions. The average daily prey consumption of A. fasciatopunctata revelierei immatures and adults increased with increasing prey densities. Predation was not different for the larval stages at 80, 160 and 250 prey densities. The longevities of adult females were 35.67, 35.33, 49.00, 58.33 and 57.16 days when 20, 40, 80, 160 and 250 H. pruni were provided, respectively. The mean daily and total fecundity of A. fasciatopunctata revelierei increased with increasing prey densities. Females of A. fasciatopunctata revelierei feeding on H. pruni laid 89 eggs at 20 prey density and 301.67 eggs at 160 prey density. The search rate of females was higher than that of all larval instars; and the search rate of the fourth-instar larvae was higher than that of younger instars. Handling time decreased with development from larval stages to adult.  相似文献   

14.
Leaf beetle occurrence and abundance on certain shrubs and bushes were surveyed during 2002–2003 in several natural habitats of Isparta. The 34 leaf-beetle species collected are listed and classified according to their relative percentage of the total caught and to their associated host plants. In all habitats sampled, leaf beetles showed a preference for plants from the genera Quercus and Crataegus. Some abundant species causing serious damage to their food plants are discussed.  相似文献   

15.
The ambrosia beetle Gnathotrichus materiarius, which originally came from North America, was discovered in southern Finland in 1996. In 1997, using Norwegian drainpipe traps baited with pheromones of Gnathotrichus retusus and G. sulcatus, we collected beetles in the region where the first specimen had been caught in order to determine whether this potential pest species had become established in the area. Samples from a total of 16 traps included 79 species of beetles and 719 individuals, but no specimens of G. materiarius. The most abundant species in the samples were the ambrosia beetles Xyleborus dispar and Trypodendron lineatum. Several predators and other associates of bark beetles were also captured. The majority of the beetles caught were saproxylic species.  相似文献   

16.
Aromatic spice crops such as coriander, Coriandrum sativum L., and fennel, Foeniculum vulgare L., are among the major seeds exported to the international market. Observations on the stores of these crops revealed differences in their susceptibility to the cigarette beetle, Lasioderma serricorne (F.) (Col., Anobiidae). Coriander seeds proved to be the most appropriate diet for the beetle. The population dynamics of L. serricorne (F.) was determined, showing 3 generations during the period from May to October.  相似文献   

17.
BLETCHLY  J. D.; WHITE  M. G. 《Forestry》1962,34(2):139-163
Following damage to saw-logs in Argyllshire forests methodsof controlling attack by the ambrosia (pinhole borer) beetleTrypodendron lineatum (Oliv.) have been studied. Attack beginsin April, reaches a peak in May but then declines rapidly, beingof negligible importance after August. Trees felled betweenNovember and January are more susceptible but few logs leftat stump are attacked. Damage is much more widespread in logsstacked in the forest or at the milt. Good protection can be provided economically by spraying stackedtimber with an emulsion of 0?75 per cent, gamma BHC. A freshtreatment is advisable if logs are restacked or the outsideones removed from a stack between April and August. These treatments,combined with rapid extraction and conversion of logs duringthe summer, should reduce the incidence of damage. Suspensionof felling during this period appears unjustified if these measuresare followed; moreover, freshly felled timber is less susceptibleto attack. Although the Lymexylid beetle Hylecoetus dermestoides L. isalso widespread, damage is less apparent due to the absenceof associated staining. The control measures recommended forTrypodendron appear suitable for Hylecoetus.  相似文献   

18.
Relating to the frequency of occurrenceAmblyseius finlandicus Oud. is the dominating species of the family Phytoseiidae in Austria. Series of experiments have been made in the laboratory to investigate the influence of the predator population density on the rate of oviposition. In spite of sufficient food supply the rate of reproduction decreased with an increasing number of mites per rearing unit. Single kept females had rates of oviposition (1.9 eggs/day/female) significantly different from females kept in groups (2, 5 or 8 mites per unit with 1.6, 1.2 and 1.1 eggs/day/female).  相似文献   

19.
Acyrthosiphon gossypii is a widespread, major pest of cotton in central Asia. Effects of specific temperatures on A. gossypii development and survival are unknown and would be useful in helping interpret population dynamics and devising management tactics for this pest. In this paper, the effect of temperature on the life table of A. gossypii reared on cotton was evaluated under laboratory conditions using temperatures of 18, 21, 24, 27, and 30 °C. The developmental rate of immatures increased exponentially from 18 to an optimum around 27 °C and then declined. The estimated lower developmental threshold was 8.0 °C, and 107.5 degree days were required for development from the first instar to adult. The percentage survival of immature stages varied from 81 to 91 % within the range of 18-27 °C. Survival declined to 27 % at 30 °C. The average longevity of adult females was 15.7, 11.7, 8.2, 5.2, and 2.8 days, and the average number of offspring produced per female was 46, 38, 20, 14, and 0, at temperatures of 18, 21, 24, 27, and 30 °C, respectively. From 21-27 °C, the intrinsic rate of increase of A. gossypii was significantly higher than at 18 °C, indicating that 21–27 °C was within the optimal range for the growth of A. gossypii, and that 30 °C constant is beyond the upper limit for reproduction. The observations will form the basis of a forecasting system and could account for the decline of the species on cotton in central Asia as well as other regions during hot summer months.  相似文献   

20.
2000年5月至2001年5月,研究了云南切梢小蠹与横坑切梢小蠹蛀梢期的种间竞争,比较了2种松小蠹在其寄主云南松树冠的垂直分布规律.结果表明,不同月份2种松小蠹在云南松树冠的垂直分布的存在差异,并随着月份的变动而发生变化.横坑切梢小蠹多危害较细的松梢,而云南切梢小蠹多危害较粗大的松梢.2种松小蠹的其它蛀梢习性(危害梢的年龄、攻击部位、蛀道长度等)文中也进行了比较.结论,云南切梢小蠹对云南松树梢的攻击能力强于横坑切梢小蠹.  相似文献   

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