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1.
Plant and surrogate stems exhibiting specific combinations of physical cues were used to determine which plant‐related stimuli influence the oviposition of Busseola fusca (Fuller) (Lepidoptera: Noctuidae). The number of eggs and egg batches laid per female increased with an increase in diameter of both natural and artificial stems. Direct observations of the oviposition behaviour (walking, antennating, and sweeping with the ovipositor) indicated that the female moths preferred oviposition supports with a large diameter and non‐pubescent or smooth surfaces over pubescent or rough ones. Pubescence and rough surfaces significantly affected the behavioural steps leading to oviposition by interfering with the ovipositor sweep process necessary to find a suitable oviposition site. Furthermore, more eggs and egg batches were laid on soft than rigid supports. The rigidity of the support affected the proper insertion of the ovipositor for egg deposition. Our results underline the importance of physical stimuli in B. fusca's choice of an oviposition site, which may facilitate the identification of potential host plants or preferred oviposition sites on a plant for this species.  相似文献   

2.
Mutualisms such as the fig–fig wasp mutualism are generally exploited by parasites. We demonstrate that amongst nonpollinating fig wasps (NPFWs) parasitic on Ficus citrifolia, a species of Idarnes galls flowers and another species feeds on galls induced by other wasps killing their larvae. The galling wasp inserts its ovipositor through the fig wall into the fig cavity. The ovipositor then follows a sinuous path and is introduced through the stigma and style of the flower. The egg is deposited between the integument and nucellus, in the exact location where the pollinating mutualistic wasp would have laid its egg. Gall induction is a complex process. In contrast, the path followed by the ovipositor of the other species is straightforward: attacking a larva within a developed gall poses different constraints. Shifts in feeding regime have occurred repeatedly in NPFWs. Monitoring traits associated with such repeated evolutionary shifts may help understand underlying functional constraints. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 114–122.  相似文献   

3.
The reproductive ecology of two endangered subspecies of the bitterling Rhodeus atremius was investigated in two rivers in Okayama and Fukuoka Prefectures, Japan. Several other bitterling species, R. ocellatus, Tanakia limbata, T. lanceolata, Acheilognathus tabira and A. rhombeus, are also found in these rivers. Spawning of both R. atremius subspecies was recorded between late March and August 2007, peaking between April and July. Females of R. atremius began to mature at small body size (minimum 25 mm). They had small clutch sizes (maximum 16 eggs) and developed a short ovipositor (mean 13.6 mm), which was used to deposit a bulb-shaped egg of comparatively large size (3.2 mm3, major and minor axes 2.8 and 1.5 mm). Clutch size, ovipositor length and egg size appear to be a function of female body size. Both the body size and ovipositor length of R. atremius with ripe ova and the size and shape of the eggs varied seasonally. Rhodeus a. suigensis achieved maturity at a smaller body size, had a longer ovipositor and produced smaller eggs, with the minor axis being wider relative to the major axis than those of R. a. atremius. Rhodeus atremius may be adapted for depositing small numbers of eggs in a much shallower position inside the gills of smaller host mussels than other bitterling species.  相似文献   

4.
The tachinid Celatoria compressa, a parasitoid of adult Diabrotica species in North America has been studied as a candidate classical biological control agent for the western corn rootworm, Diabrotica virgifera virgifera, in Europe. Prior to its potential importation, a thorough understanding of the parasitoid's reproductive biology is essential, and is an important component in the evaluation of a species as a biological control agent. In this study it has been clarified that C. compressa belongs to a group of a few tachinid species characterised by having eggs that contain fully developed larvae which are laid directly into the host. After mating, the egg load of females increased steadily from day 1 to a maximum egg load on day 4. Thereafter eggs containing fully developed first instar larvae reached a maximum of 31 in 69 eggs. At the first day of larviposition, females laid on average only five eggs into multiple hosts, which is in contrast to the availability of 18 eggs containing fully developed first instars in the uterus per female at that time. During a mean female's larviposition period of 23 days, a total of 33 first instars were larviposited into the hosts, which is only half of the female's egg load. Lifetime fecundity of C. compressa was significantly correlated with longevity. However no relationship was found between body size and either lifetime fecundity or longevity. In this study, an inverse host density-dependent pattern of percent parasitism was shown for C. compressa under 24-h fixed-time laboratory conditions, reflecting a Holling type II response. The number of host parasitized per C. compressa female reached an upper limit of 10 hosts with an increasing host density, which can be explained by the long host handling time of C. compressa.  相似文献   

5.
Abstract

The Canterbury knobbled weevil, Hadramphus tuberculatus (Coleoptera: Curculionidae: Molytini), was once widespread in the Canterbury plains, foothills and fringing ranges, ranging from Oxford in the north to Waimate in the south. Habitat degradation, reduction in host plant numbers through grazing and predation by rodents are thought to be responsible for the decline in its numbers and distribution. In December 2004, more than 80 years since the last sighting of H. tuberculatus in 1922, a single individual was found at Burkes Pass Scenic Reserve. This paper records the rediscovery of H. tuberculatus, reviews the historical distribution records for H. tuberculatus, discusses them with respect to changes in host plant habitat in the eastern South Island, and suggests conservation strategies to protect this and other relictual populations that might be found in future.  相似文献   

6.
The development from egg to pupation is followed for the wasp Eretmocerus mundus, parasitizing the whitefly Bemisia tabaci. We elucidate and describe structural details, histological developments and changes that the different parasitoid and host tissues have undergone during parasitism. These include the presence and apparent function of very large salivary glands, which probably produce substances that help to regulate the host's decomposition and parasitoid nutrition. Moreover, the gut of all instars is devoid of both peritrophic membrane and microvilli and, in the early instars, it has squamous rather than columnar epithelial cells. Differing from many other parasitoids, the E. mundus larva usually does not come into contact with the host tissues and does not devour the entire host during its development.The possible reasons for the developmental mechanisms, as well as the functions of the host capsule that envelopes the parasitoid, are discussed.  相似文献   

7.
Abstract.
  • 1 Gastrophysa viridula Degeer (Coleoptera: Chrysomelidae) and the pathogenic rust fungus Uromyces rumicis (Schum.) Wint. both occur on leaves of Rumex crispus L. and R.obtusifolius L. Individual stages of beetle development, and egg laying, were compared on healthy and infected leaves of each plant species in the laboratory. Oviposition choice was investigated in the field and laboratory.
  • 2 Beetles reared on infected leaves of each species had greater larval mortality and slower development than those reared on healthy leaves. Although larvae feeding on infected leaves consumed up to 2.5 times more dry weight than those reared on healthy leaves, they had a lower relative growth rate and pupated at a lower weight. These changes were consistent with the reduced nutritive quality of rust-infected Rumex leaves.
  • 3 Fecundity of beetles reared on infected leaves of both species was considerably reduced. Eggs laid by beetles feeding on infected R.crispus leaves also had a reduced viability.
  • 4 The beetle developed consistently poorer on healthy R.crispus than on healthy R.obtusifolius throughout its life-cycle. Differences in larval performance were greater between host species than between infected and healthy leaves.
  • 5 Oviposition was similar on infected and healthy R.crispus in both the laboratory and field. However, adults consumed less, and laid fewer eggs on infected than on healthy R.obtusifolius. The pattern of egg laying on different aged leaves was affected by rust infection: a greater proportion of eggs was laid on the older, infected leaves, than on the equivalent aged leaves on the healthy plants. Few larvae survived from eggs laid on rusted leaves in the field.
  相似文献   

8.
M. G. BROOKER  L. C. BROOKER 《Ibis》1989,131(4):528-547
The breeding behaviour of two similarly sized sympatric cuckoos, Horsfield's Bronze-Cuckoo Chrysococcyx basalts and the Shining Bronze-Cuckoo C. lucidus, was studied over four breeding seasons at Gooseberry Hill, Western Australia. Both cuckoos usually began laying in late August; Shining Bronze-Cuckoos laid for up to 13 weeks and Horsfield's Bronze-Cuckoos for up to 15 weeks. Four host species were parasitized and major hosts were parasitized throughout most of their laying periods. The frequency of parasitism varied between hosts and between years, but Splendid Fairy-wrens Malurus splendens and Yellow-rumped Thornbills Acanthiza chrysorrhoa (major hosts) were always parasitized more heavily than Western Thornbills A. inornata and Scarlet Robins Petroica multicolor. Western Thornbills were parasitized by both cuckoos. Horsfield's and Shining Bronze-Cuckoos laid monomorphic eggs; those of Horsfield's Bronze-Cuckoos were highly mimetic whereas those of Shining Bronze-Cuckoos were non-mimetic and dark in colour. Both cuckoos laid one egg per host nest, deposited eggs directly into the nest, laid very quickly in the early morning, removed at least one host egg at laying, laid eggs small for the size of the birds, hatched after 12 days and evicted nest companions shortly after hatching. Laying was well synchronized with the start of incubation by hosts. Field observations and experiments with egg models indicated that neither of the major hosts, nor the secondary host in common, discriminate against foreign eggs. The nestling period for Horsfield's Bronze-Cuckoo was 17 days, and for the Shining Bronze-Cuckoo 20 days. There was a corresponding difference in nestling growth rate between the cuckoo species. About 50% of cuckoo eggs produced fledglings. Reproductive success for both cuckoos was highest in nests of the secondary host in common, the Western Thornbill. Young cuckoos reached independence 5–6 weeks after hatching. The adaptive significance of competition between cuckoos as a selective agent for cuckoo egg morphology and host specificity is discussed.  相似文献   

9.
The present study investigates morphological differentiation among host races of the fruit fly Tephritis conura Loew (Diptera: Tephritidae) for two fitness‐related traits and whether these traits are host induced or genetically determined. Flies were analyzed from independent sympatric regions, and from one syntopic site where parental host plants [Cirsium heterophyllum (L.) Hill. and Cirsium oleraceum (L.) Scop. (Cardueae)] and hybrid plants (C. heterophyllum×C. oleraceum) co‐occur. As both host races may oviposit on hybrid plants and hybrid plants provide an identical environment for larvae of both host races, flies emerging from C. heterophyllum×C. oleraceum hybrids were used to assess whether host‐race morphological differences are genetically determined or due to phenotypic plasticity. No significant size (wing length) differences were found among host races, whereas flies emerging from C. heterophyllum had on average 8.4% longer ovipositors than flies emerging from C. oleraceum. The mean size‐corrected ovipositor length (i.e., the ratio ovipositor/wing length) was 10.3% longer. These proportions were repeated among host races emerging from hybrid plants. Although flies of the C. heterophyllum host race from hybrid plants were smaller than on parental host plants, the ratio ovipositor/wing length was constant. Hybrid flies (which emerged only on hybrid plants) were intermediate in relative and absolute ovipositor length. Thus, ovipositor‐length differences among T. conura host races most likely have a genetic basis. This suggests that host‐related differences in ovipositor length reflect adaptations to the respective host‐plant species, most likely to the host's flower‐head size, whereas both host races experience similar selection regimes on body size.  相似文献   

10.
Species in the Polysphincta genus group, as far as is known, are exclusively koinobiont ectoparasitoids of spiders. These wasps attack their hosts, inflicting a temporary paralysis, and then lay one egg on the host’s abdomen or prosoma. Parasitoid attack behavior is highly variable among species, including occasions where the wasp darts directly and holds the spider, as well as instances involving complex behavioral sequences. In the present study, we describe the attack behavior of Polysphincta sp. nr. purcelli and P. janzeni on Cyclosa fililineata and C. morretes, respectively. All attacks occurred at night. Initially, the female wasp landed on the web hub at the position occupied by the spider, with the spider always escaping from this initial attack. Subsequently, the wasp waited for up to 14 h at the web hub for the spider’s return. The wasp then inserted its ovipositor into the mouth of the spider, after which the spider became paralyzed and remained motionless for at least 30 min. The wasp laid one egg on the surface of the host’s abdomen and remained on the web for at least 1 h thereafter. The lie-in-wait and attack only after the return of the host to the web hub, as well as the permanence of the wasp on the web after the attack are not frequent behaviors described for polysphinctines. Behavioral idiosyncrasies, such as those observed here, are common among polysphinctines, suggesting a high level of specific adaptive matching of polysphinctine parasitoid behavior to their hosts’ biological characteristics.  相似文献   

11.
When brood parasites exploit multiple host species, egg rejection by hosts may select for the evolution of host‐specific races, where each race mimics a particular host's egg type. However, some brood parasites that exploit multiple hosts with the ability to reject foreign eggs appear to have only a single egg type. In these cases, it is unclear how the parasite egg escapes detection by its hosts. Three possible explanations are: 1) host‐specific races are present, but differences in egg morphology are difficult for the human eye to detect; 2) the brood parasite evolves a single egg type that is intermediate in appearance between the eggs of its hosts; 3) or the parasite evolves mimicry of one of its hosts, which subsequently allows it to exploit other species with similar egg morphology. Here we test these possibilities by quantifying parameters of egg appearance of the brood‐parasitic Pacific koel Eudynamys orientalis and seven of its hosts. Koel eggs laid in the nests of different hosts did not show significant differences in colour or pattern, suggesting that koels have not evolved host‐specific races. Koel eggs were similar in colour, luminance and pattern to the majority of hosts, but were significantly more similar in colour and luminance to one of the major hosts than to two other major hosts, supporting hypothesis 3. Our findings suggest that mimicry of one host can allow a brood parasite to exploit new hosts with similar egg morphologies, which could inhibit the evolution of host defences in naïve hosts.  相似文献   

12.
Intraspecific interactions among ectosymbionts may occur when suitable attachment sites are limited to specific parts of their hosts. In this study, we examined attachment site selection by the ectosymbiotic chironomid Nanocladius (Plecopteracoluthus) asiaticus. Larvae and pupae of this chironomid attach to larvae of the megalopteran Protohermes grandis: they feed on algae and detrital materials caught on the chironomid's silken nets and on the body surface of the host. Sampling at approximately monthly intervals in central Japan revealed that the proportion of hosts with chironomids was relatively high and stable during the 2 year study period. When attached singly, larvae were usually found on the ventral side of the host's mesothorax. However, when two or more larvae were attached to a host, the mesothorax was occupied by only one larva (usually a large individual) and the other(s) were attached to the ventral side of the abdomen. Density dependent shifts in attachment sites were confirmed by a reattachment experiment in which a larva was removed from its host and released onto a new host with or without symbiosis by another individual. All of the larvae released singly on a host devoid of symbionts attached to the thoracic region and survived, whereas those released in pairs and not occupying this site were frequently lost. Thus, the thorax (particularly the mesothorax) is the most suitable attachment site, and there is a possibility that chironomid larvae compete for this site.  相似文献   

13.
《Journal of Asia》2019,22(1):296-307
Pseudoligosita yasumatsui Viggiani and Subba Rao 1978 (Hymenoptera: Trichogrammatidae) is a common egg parasitoid of rice insect pests. The surface morphology of the antenna and ovipositor on P. yasumatsui was examined using scanning electron microscopy. The antenna of P. yasumatsui is geniculate in shape, hinged at the scape-pedicel joint, approximately 190 μm in length and consists of seven antennomeres. In total, the male and female antennae have ten different types of sensilla: trichoid sensilla type 1, 2, 3, 4, 5, 6, campaniform sensilla, basiconic sensilla, and placoid sensilla type 1 and 2. The flagellum of the female antenna is covered with cuticular pores, which are absent on the male antennal flagellum. The distal extremity of its ovipositor stylet has campaniform sensilla and styloconic sensilla. Trichoid sensilla found on its apical abdomen part may play a role in the host detection and egg placement. The types and distribution of antennal and ovipositor sensilla on the parasitoid were discussed.  相似文献   

14.
Two species of the genus Probles Förster, P. interruptor sp . nov . and P. segaza sp . nov ., from South Korea and Russian Far East, are described. Probles interruptor differs from its congeners by occipital carina mediodorsally narrowly interrupted and polished occipital surface extending partly on the vertex. Probles segaza differs from other species of Euporizon by its robust ovipositor with a deep and narrow dorsal subapical notch.  相似文献   

15.
The occurrence of the epiphyte alga Pseudendoclonium submarinum Wille (Ulvophyceae) on Rhodymenia pseudopalmata (Lamouroux) Silva (Rhodophyta) is reported. The present study describes a first line of evidence of an epidemiological study conducted with the purpose of comparing both the prevalence and effects of algal epiphytic organisms in R. pseudopalmata in the Patagonian coasts of Argentina. P. submarinum infected approximately 80% of R. pseudopalmata thalli and the frequency of infection was variable in connection with different areas of the host's thalli: 42% of R. pseudopalmata fronds presented P. submarinum thalli in the basal region, which presented a severity degree of infection from low to high. The median region presented an average frequency of infection of 30% and minor susceptibility to colonization. The covering varied from 1% to 70% representing a low to moderate degree of colonization. The apical region presented a cover frequency of 28% and the level of infection varied between low to moderate. The developmental morphology and the growth dynamics of the epiphyte were also investigated under unialgal as well as bialgal culture conditions. In nature, thalli of P. submarinum on R. pseudopalmata never invaded internal tissues of the host. Vegetative thalli of P. submarinum were inoculated on fronds R. pseudopalmata. Experimental infections confirmed that P. submarinum thalli did not penetrate the host's fronds. P. submarinum swarmers showed the capacity of settlement on a host's fronds and developed an epiphytic monostromatic thallus. The results allowed us to suggest that P. submarinum uses the R. pseudopalmata thalli as a proper substrate, since Pseudendoclonium thalli complete the entire life cycle. Culture experiments revealed that P. submarinum could develop without the presence of the host and evidenced the nutritional independence, being the relationship in nature, probably triggered by an ecological advantage since fronds of R. pseudopalmata offer a suitable substratum.  相似文献   

16.
The host plant, oviposition behavior and larval ecology of Profenusa japonica Togashi are reported for the first time. Adults of P. japonica mated and oviposited on a polyantha rose, Rosa multiflora (Rosaceae), in April. Each female adult laid an egg on the edge of a leaflet. Hatched larvae consumed the parenchymatous layer of leaflets and in so doing created a mine. The larval stage comprised five instars. On average, 70.6% of the total area of a leaflet was consumed by one larva. Female adults of P. japonica laid eggs singly, probably to avoid larval competition for food.  相似文献   

17.
1. The chief objectives were: (i) to describe quantitatively the life cycles of four species of Elmidae, Elmis aenea, Esolus parallelepipedus, Oulimnius tuberculatus and Limnius volkmari; (ii) to use life tables to identify critical periods for survival in the life cycle of each species; (iii) to evaluate the immediate and longer‐term effects of a severe spate on densities of the four species. Monthly samples were taken over 63 months at two contrasting sites in a small stream: one in a deep section with macrophytes abundant, and the other in a shallow stony section. 2. There were five larval instars for O. tuberculatus, seven for L. volkmari and six for the other two species. The life cycle of each species took 1 year from egg hatching (chiefly in June for E. aenea and O. tuberculatus, and July for the other species) to pupation in the stream bank and a further year before the adults in the stream matured and laid their eggs. Mature adults were present in most months, but were rare or absent in January and February and attained maximum densities in April for O. tuberculatus and May for the other species. 3. Laboratory experiments provided data on egg hatching and pupation periods and the number of eggs laid per female. Life tables compared maximum numbers per square metre for key life‐stages. Within each species, mortality rates between adjacent life‐stages were fairly constant among six cohorts and between sites, in spite of large differences in numbers. The only exception for all species was the high adult, but not larval, mortality during a severe spate. 4. Standardised life tables, starting with 1000 eggs, identified key life‐stages with the highest mortality, namely the early life‐stages for E. aenea (36% mortality), start of the overwintering period to pupation for O. tuberculatus (41%) and L. volkmari (51%), start of pupation to the maximum number of immature adults for E. parallelepipedus (41%) and between the maximum numbers of immature and mature adults for O. tuberculatus (41%). Therefore, critical periods for survival in the life cycle differed between species, presumably because of their different ecological requirements. Similarly, the effects of the spate on adult mortality, and hence egg production, varied between species, being most severe and long‐term for E. aenea and O. tuberculatus, less severe for E. parallelepipedus and least severe with a rapid recovery for L. volkmari. Possible reasons for these discrepancies are discussed, but more data are required on the food and microhabitat requirements of the elmids before satisfactory explanations can be found.  相似文献   

18.
Abstract The present paper describes two new species of Microgaster Latreille, 1804, viz: M. longiterebra sp. nov. (♂) and M. longicaudatus sp. nov. (♂). M. longiterebra sp. nov. is described from Kunming, Yunnan Prov. in China closely related to M. subcompletus, but differs from the latter in the combination of the following features: 1) APOL as long as OD; 2) Mesonotum strongly punctate on anterior 2/ 3) r shorter than width of stigma; 4) cu‐a of hind wing medially curved; 5) Apex of hypopygium ending far beyond apex of abdomen. M. longicaudatus sp. nov. is described from Tianmushan, Zhejiang Prov. in China closely related to M. ductilis, but differs from the latter in the combination of the following features: 1) middle and hind femora reddish yellow only with apical 1/4 blackish; 2) 1‐SR 0.5 times as long as 1‐M; 3) the hairy part of ovipositor sheath 0.5 times as long as hind tibia; 4) tergite 3 with slightly weaker rugosity. The type specimens are deposited in Zhejiang University, Hangzhou, China.  相似文献   

19.
C. Peter  B. V. David 《BioControl》1991,36(3):403-407
Goniozus sensorius Gordh (Hymenoptera: Bethylidae) was recorded as a major parasite of the pumpkin caterpillar,Diaphania indica (Saunders) (Lepidoptera: Pyralidae). This paper provides detailed information on the oviposition behaviour ofG. sensorius. Prior to oviposition, the parasite temporarily paralyses the host larva. The paralysed condition lasts for about 2 h. The egg laying process on each larva requires 30 to 60 min. The maximum number of eggs are laid on the 6th and 7th segment, and none in the terminal segments. Generally, oviposition is restricted to 1 segment of the host larva and occasionally on 3 segments. The maximum number of eggs are laid on the 2nd and 3rd day after emergence and the mean number of eggs laid on each host larva was 7.1.  相似文献   

20.
Relation of the ovipositor structure and the egg-laying habit with the larval biology in the family Scathophagidae was investigated. The ovipositor was examined and illustrated for 29 species including Phrosia albilabris (F.), Cordilura umbrosa (Lw.), Spathephilus breviventris (Lw.), Scathophaga stercoraria (L.), Chaetosa punctipes (Mg.), Pogonota barbata (Ztt.), Cochliarium cuneiventris (Ztt.), and Delina nigrita (Fll.). Species with different bionomics and different larval feeding tissues, i.e., different substrates for oviposition, were distinguished. Comparative morphological analysis of the author’s and literature data on 29 species belonging to 15 genera has shown the constancy of the ovipositor structure within the genera examined. Two principal types of the ovipositor structure were distinguished: (a) the elongate ovipositor with the distal position of the terminal part of the abdomen (the proctiger), this type is characteristic of phytophagous species (the delinine type); and (b) the shortened ovipositor with the proctiger shifted dorsally (the scathophagine type), this type is typical of predatory and saprophagous species. The delinine type of the ovipositor is adapted to inserting eggs into hard plant tissues. Changes in the feeding habits of the larvae were found to be associated with changes in the ovipositor structure. The dependence of the ovipositor structure on the egg-laying habit and on the larval biology enables hypothesizing biological features of those species for which the relevant data are not available yet. The morphogenesis of the ovipositor is speculated based on the data on its structure.  相似文献   

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