Juveniles stick to adults: recruitment of the tube-dwelling polychaete Lanice conchilega (Pallas, 1766)

Juveniles of the tube-dwelling polychaete L. conchilega were found attached to adult tubes at an exposed beach in South Wales (U.K.). They attached to the upper part of tubes protruding above the sediment. The aim of this study was to determine the timing of juvenile settlement on to adult tubes, their abundance and size distribution, and the time of detachment and densities in the sediment after re-settlement. Furthermore, to establish whether the sediment composition of juvenile tubes differed from those of adults and the surrounding sediment. In 1998, 1999 and 2000, tubes of adult L. conchilegawere sampled and numbers of attached juveniles were quantified and their sizes measured. Densities of solitary L. conchilega in the sediment were estimated, as well as the size distribution of solitary tubes. On average, 5–13 juveniles were attached to single adult tubes in spring, but numbers varied greatly with up to 72 juveniles on a single tube in April 1998. Availability of a hard substratum and chemical cues are discussed as potential factors triggering the attachment of juveniles to adult tubes. Juveniles started to detach and re-settle in the sediment 1 month after attachment. Once settled in the sediment, juvenile numbers decreased steeply, but the size distribution of solitary L. conchilega suggested that some juveniles survived in the population. However, the extent to which numbers of juvenile recruits contribute to the density of adults remained unclear. Juveniles used a smaller mean particle size for tube building than adults, but both actively selected particles.     

Role of Diadegma semiclausum (Hymenoptera: Ichneumonidae) in controlling Plutella xylostella (Lepidoptera: Plutellidae): Cage exclusion experiments and direct observation

We evaluated the role of the larval parasitoid, Diadegma semiclausum Hellén (Hymenoptera: Ichneumonidae), in controlling Plutella xylostella (L.) (Lepidoptera: Plutellidae) by cage exclusion experiments and direct field observation during the winter season in southern Queensland, Australia. The cage exclusion experiment involved uncaged, open cage and closed cage treatments. A higher percentage (54–83%) of P. xylostella larvae on sentinel plants were lost in the uncaged treatment than the closed (4–9%) or open cage treatments (11–29%). Of the larvae that remained in the uncaged treatment, 72–94% were parasitized by D. semiclausum, much higher than that in the open cage treatment (8–37% in first trial, and 38–63% in second trial). Direct observations showed a significant aggregation response of the field D. semiclausum populations to high host density plants in an experimental plot and to high host density plots that were artificially set-up near to the parasitoid source fields. The degree of aggregation varied in response to habitat quality of the parasitoid source field and scales of the manipulated host patches. As a result, density-dependence in the pattern of parasitism may depend on the relative degree of aggregation of the parasitoid population at a particular scale. A high degree of aggregation seems to be necessary to generate density-dependent parasitism by D. semiclausum. Integration of the cage exclusion experiment and direct observation demonstrated the active and dominant role of this parasitoid in controlling P. xylostella in the winter season. A biologically based IPM strategy, which incorporates the use of D. semiclausum with Bt, is suggested for the management of P. xylostella in seasons or regions with a mild temperature.     

Growth rates of arctic juvenile Scolelepis squamata (Polychaeta: Spionidae) isolated from Chukchi Sea fast ice

In spring, Arctic coastal fast ice is inhabited by high densities of sea ice algae and, among other fauna, juveniles of benthic polychaetes. This paper investigates the hypothesis that growth rates of juveniles of the common sympagic polychaete, Scolelepis squamata (Polychaeta: Spionidae), are significantly faster at sea ice algal bloom concentrations compared to concurrent phytoplankton concentrations. Juvenile S. squamata from fast ice off Barrow, Alaska, were fed with different algal concentrations at 0 and 5?°C, simulating ambient high sea ice algal concentrations, concurrent low phytoplankton concentrations, and an intermediate concentration. Growth rates, calculated using a simple linear regression equation, were significantly higher (up to 115?times) at the highest algal concentration compared to the lowest. At the highest algal concentration, juveniles grew faster at 5?°C compared to those feeding at 0?°C with a Q ₁₀ of 2.0. We conclude that highly concentrated sea ice algae can sustain faster growth rates of polychaete juveniles compared to the less dense spring phytoplankton concentrations. The earlier melt of Arctic sea ice predicted with climate change might cause a mismatch between occurrence of polychaete juveniles and food availability in the near future. Our data indicate that this reduction in food availability might counteract any faster growth of a pelagic juvenile stage based on forecasted increased water temperatures.     

An Evidence to Use Cotes/a plutellae (Kurdjumov) (Hymenoptera: Braconidae) as a Field Control Agent against Diamondback Moth,Plutella xylostella L (Lepidoptera: Plutellidae)

The parasitic effectiveness of Cotesia plutellae Kurdjumov for the control of diamondback moth (DBM), Plutella xylostella L., was investigated without spraying pesticides in the greenhouse, and the damage degrees of Brassica rapa cv. Pakchoi grown in parasitoid-applied plot and control plot were evaluated. Among the 961 fourth instar DBM larvae collected in the common cabbage fields at Kwanshan region in Taiwan, 336 cocoons of C. plutellae were harvested from DBM larvae, which showed a parasitism rate of 35.0%. A total of 650 DBM adults and 600 C. plutellae adults were released according to the releasing scheme in the experiment plot. As a result, 56.7% of the DBM larvae were parasitized by C. plutellae adults 12 days before harvest, and the parasitism reached 80.8% at six days before harvest. At the harvest time, a population density of C. plutellae cocoons in the experiment plot was 2.2/plant, and that of normal DBM larvae was 0.5/plant. The density of DBM in the control plot was much higher than in the parasitoid-released plot by 7.7/plant. In the first survey, the density of DBM larvae on a Pakchoi plant was quite low, 0.3 ∼ 0.8 larvae. However, the DBM population increased dramatically after six days later, 5.7-10.1 larvae/plant. The population density of DBM larvae showed clear difference between the parasitoid-released plot and control plot. The parasitism increased to nearly two fold within a week after the release of DBM adults. As a further study, a combining use of two or more species para-sitoids could be considered to improve a parasitism against DBM in the fields.     

Interference interactions among tube-dwelling polychaetes in a dense infaunal assemblage

Interactions involving contact between the feeding organs of the tube building polychaetes Pseudopolydora paucibranchiata Okuda, Streblospio benedicti Webster, and Fabricia limnicola Hartman were observed through a dissecting microscope and quantified for frequency of occurrence and effects on foraging time and withdrawal. These surface feeding species form a dense intertidal assemblage ( > 100000 individuals · m^?2) and can be readily transferred to the laboratory and observed in undisturbed sediment cores. Interspecific contact with Pseudopolydora often resulted in withdrawal and consequently a 4 to 7% loss of foraging time for individuals of other species, while intraspecific interactions among Pseudopolydora did so rarely. Larger individuals of all three species experience more interaction. The probability and duration of withdrawal due to contact with Pseudopolydora is size dependent in Fabricia and Streblospio: juvenile Fabricia and adult Streblospio show the greatest interference. The observation that Pseudopolydora interferes with individuals of other species more than with conspecifics contradicts the small-scale dispersion of these species as well as previous reports of interference behavior. A possible explanation is the relatively recent coexistence of these three species, two of which were introduced to the eastern Pacific since 1900.     

Short-term response of deposit-feeders to an increase of the nutritive value of the sediment through seasons in an intertidal mudflat (Western Mediterranean, Italy)

In coastal intertidal flats, assemblages of deposit-feeders often vary seasonally and according to the availability of food in sediments. In the mudflat where this study has been done, the deposit-feeder assemblage changed after a sharp increase of fresh detritus, which occurred in summer 1997. The number of the animals increased and abundances of some worms (Streblospio shrubsolii, Desdemona ornata and Capitella cf. capitata) were correlated with the nutritive value of the sediment. In addition, there was evidence that increasing food in summer would increase recruitment of juveniles and adults of S. shrubsolii.In this paper, the concentration of food was manipulated in situ in sediments of an intertidal mudflat in different seasons. Food of high nutritive value was added to small plots of sediments to test hypotheses about effects on the distribution of deposit-feeders. It was predicted that addition of food would change composition and abundance of the assemblage and densities of the deposit-feeders that were correlated to the availability of food. Furthermore, it was tested whether juveniles and adults of S. shrubsolii were affected by the availability of food consistently through seasons.Densities of deposit-feeders increased in plots where the sediment was organically enriched. The composition of the assemblage, however, was not affected. S. shrubsolii, D. ornata and C. cf. capitata responded to the addition of food. However, the nutritive value of the sediment affected the dynamics of these animals variably through seasons. Abundances increased in the experimental treatment E in winter and spring for D. ornata and in winter and autumn for C. cf. capitata. Furthermore, in summer and autumn juveniles and adults of S. shrubsolii were more abundant in plots where food was added.     

Effects of the gastropod,Ilyanassa obsoleta(Say) and the bivalve,Mercenaria mercenaria (L.), on larval settlement and juvenile recruitment of infauna

Densities of a deposit-feeding gastropod, Ilyanassa obsoleta(Say) and a suspension-feeding bivalve, Mercenaria mercenaria (L.), were manipulated to test the importance of interactions between adults and settling larvae in affecting abundance patterns of infaunal invertebrates. Abundance of postlarvae and juveniles was significantly lower in the presence of Ilyanassa obsoleta than in snail-free controls. I. obsoleta caused a reduction in abundance of as much as 45%. Surface-dwelling tubiculous polychaetes, gastropods, harpacticoid copepods, and mobile subsurface-dwelling infauna all declined in abundance with increasing I. obsoleta density. Mercenaria mercenaria had little or no effect upon larval settlement. The effect of Ilyanassa obsoleta and Mercenaria mercenaria combined was equivalent to the sum of the effects of each species separately. Disturbance and ingestion of newly settled larvae by Ilyanassa obsoleta, larval settlement selectivity, and disturbance-induced emigration are probable mechanisms causing differences in abundance between I. obsoleta treatments.     

Proteomic analysis during larval development and metamorphosis of the spionid polychaete Pseudopolydora vexillosa

Background  

While the larval-juvenile transition (metamorphosis) in the spionid polychaete Pseudopolydora vexillosa involves gradual morphological changes and does not require substantial development of juvenile organs, the opposite occurs in the barnacle Balanus amphitrite. We hypothesized that the proteome changes during metamorphosis in the spionids are less drastic than that in the barnacles. To test this, proteomes of pre-competent larvae, competent larvae (ready to metamorphose), and juveniles of P. vexillosa were compared using 2-dimensional gel electrophoresis (2-DE), and they were then compared to those of the barnacle.     

Tyrosine metabolism for cuticle tanning in the tobacco hornworm, Manduca sexta (L.) and other Lepidoptera: identification of beta-D-glucopyranosyl-O-L-tyrosine and other metabolites

When [${}^{14}\text{C}$]tyrosine and [${}^{14}\text{C}$]glucose were fed or injected into feeding fifth-instar larvae of the tobacco hornworm, Manduca sexta (L.), they were incorporated into a conjugate identified in hemolymph and carcass extracts as β-d-glucopyranosyl-O-l-tyrosine. In wandering larvae and pupae, the conjugate was hydrolyzed, and tyrosine was hydroxylated and decarboxylated to dihydroxyphenylalanine and 2-(dihydroxyphenyl)ethylamine. None of these metabolites were formed in fourth-instar larvae or in adults. [${}^{14}\text{C}$]Phenylalanine was hydroxylated to tyrosine in all stages of insect development. β-d-Glucopyranosyl-O-l-tyrosine was also detected in 18 other species of Lepidoptera but not in species from other insect orders. This conjugate appears to be the major tyrosine storage metabolite for production of tanning diphenol substrates in Lepidoptera.     

Reflex ovulation in light-induced persistent estrus (LLPE) rats: Role of sensory stimuli and the adrenals

Penile intromissions have been thought to be the primary stimulus for reflex ovulation in light-induced persistent estrus (LLPE) rats, even though other stimuli also trigger reflex ovulation. To clarify the nature of these noncoital stimuli, intact (nonadrenalectomized) LLPE rats were briefly exposed to a variety of environmental stimuli, other than intromissions, and checked for ova 19–22 hr later. Summary of results (number of rats ovulating/number of rats tested): (A₁) home cage ($\text{3}\text{10}$); (B₁) home cage + vaginal taping ($\text{2}\text{9}$); (C₁) home cage + male-soiled bedding ($\text{15}\text{28}$); (D₁) novel cage ($\text{2}\text{11}$); (E₁) novel cage + vaginal taping ($\text{2}\text{11}$); (F₁) novel cage + vaginal taping + male-soiled bedding ($\text{9}\text{19}$); (G₁) novel cage + vaginal taping + male-soiled bedding + male mounts without intromissions ($\text{14}\text{26}$). The percentage of LLPE rats that ovulated in the last-mentioned test condition was related to the degree of proceptivity/receptivity of the LLPE females. Eight of eight proceptive LLPE females ovulated, but only $\text{6}\text{18}$ nonproceptive females ovulated. To account for reflex ovulation in the absence of intromission it has been suggested that adrenal progesterone (P) stimulates release of an ovulatory quota of luteinizing hormone. This study demonstrates no significant differences in percentage of LLPE females ovulating in corresponding groups of adrenalectomized (ADX) and adrenal-intact females. Summary of results: A₂ = $\text{0}\text{6}$, B₂ = $\text{5}\text{15}$, C₂ = $\text{4}\text{16}$, D₂ = $\text{2}\text{14}$, E₂ = $\text{5}\text{13}$, F₂ = $\text{7}\text{19}$, G₂ = $\text{10}\text{21}$. Conclusion: (a) Exposure to a factor in male-soiled bedding induces reflex ovulation in a significant proportion of adrenal-intact LLPE animals while exposure to a novel cage and/or vaginal taping does not, (b) penile intromissions are not the primary stimulus for reflex ovulation in intact proceptive LLPE rats, and (c) adrenal P is not required for reflex ovulation after tests with noncoital stimuli.     

The oxygen consumption of non-dormant and dormant larvae of Chironomus plumosus (Diptera)

The physiological expression of a short-day-induced dormancy (Oligopause) of 4th-instar Chironomus plumosus larvae was investigated by measuring the oxygen consumption. By means of a polarographic continuous-flow respirometer the oxygen consumption of single larvae or groups of larvae (up to 5) could be measured continuously over a period of several hours. The oxygen consumption of dormant larvae is lower than in non-dormant larvae: in relation to the individual it is reduced by about $\text{1}\text{3}$, in relation to 1 g of dry weight by about $\text{1}\text{2}$. Dormant larvae are heavier than non-dormant larvae. In the dormant larvae, the proportion of dry weight to total weight is higher than in the non-dormant larvae. The increased proportion of dry weight is composed of a size-specific (dormancy-independent) and a dormancy-specific component. Independent of the sex and dormancy state, the larger larvae have a lower oxygen consumption per weight unit than the smaller larvae. A sex-specific difference can be observed: when animals with identical oxygen consumption per weight unit are compared, the females are considerably heavier than the males.     

Trichinella spiralis: Genetics of worm expulsion in inbred and F1 mice infected with different worm doses

The nematode Trichinella spiralis is rejected from the intestine at a time that is characteristic for each inbred strain of mouse. Previous work (R. G. Bell et al. 1982a) had empirically identified strong, intermediate, and weak phenotypes (NFR, $\text{C}\text{H}\text{He}$, and $\text{C57}\text{10}$ mice, respectively) in mice infected with 400 muscle larvae. It is shown that this classification applies to another eight inbred strains: SWR, $\text{DBA}\text{2}$, $\text{DBA}\text{1}$, LP, $\text{Bub}\text{Bn}$—all intermediate, and $\text{NZB}\text{BIN}$, C57L, A, and Mus molossinus—all weak. This phenotypic classification consistently applies with infections of 400–800 muscle larvae. Below doses of 300 muscle larvae, the strain designation of phenotype does not consistently apply. By this it is meant that the relative rejection rate changes for certain strains so that eventually some strains that were strong (NFR) or intermediate (AKR) responders to 400 muscle larvae become weak responders to 50 muscle larvae. Other strains increase their relative rejection time (B10 · BR, B10 · Q) while many do not change (NFS, $\text{C}\text{3}\text{Heb}\text{Fe}$, $\text{DBA}\text{2}$, $\text{DBA}\text{1}$). The phenomenon is most apparent in inbred parental strains rather than in F₁ crosses, and it represents a phenotypic variation in rejection time that is dependent on dose. It is also demonstrated that time of rejection is directly proportional to dose in all inbred and F₁ mouse strains that we have examined. Analysis of F₁ crosses shows that most have the rejection time of the strongest responding parental line, suggesting simple genetic control of strong, intermediate, and weak responses. Two F₁ crosses invalidated this theory. The $\text{DBA}\text{1}\text{×}\text{C3}\text{H}\text{He}$ (intermediate × intermediate) showed a strong response. The additive effects of parental rejection phenotype indicated that these lines could not be genetically identical for intermediate responsiveness. Similarly, the NFR (strong) × B10 · BR (weak) F₁ showed intermediate rejection, indicating partial dominance of $\text{C}\text{57}\text{B}\text{1}\text{10}$ genes over the strong responder NFR strain. Neither the primary expulsion time phenotype, phenotypic variation to low doses, or the rejection characteristics of F₁ crosses could be ascribed to genes linked to the major histocompatibility complex.     

Effects of the Brachyury (T) mutation on morphogenetic movement in the mouse embryo

$\text{T}\text{T}$ embryos have been first distinguishable at 8 days post coitum by their gross morphological abnormalities. By quantitative morphometry of histological sections, anomalies in the homozygotes were expressed numerically. At 8 days p.c., morphologically identifiable T-homozygotes had an increased number of ectodermal and a reduced number of mesodermal cells compared to the wild type. At 7 days p.c., embryos with a low mesoderm/ectoderm ratio were found only in litters of $\text{T}\text{+}\text{×}\text{T}\text{+}$ matings at the expected frequency. At 6 days p.c., one-fourth of the embryos in $\text{T}\text{+}\text{×}\text{T}\text{+}$ litters showed a delay in the transition from cuboidal to squamous endoderm. No such embryos were found in the +/+ × +/+ matings. In 6-, 7-, and 8-day mutant embryos, cells proliferated at statistically normal rates. Therefore, it may be said that advanced morphological irregularities of 8-day homozygotes cannot be accounted for by anomalies in cell proliferation. When the total cell number was 5 × 10⁴/embryo (8 days), a sudden change was observed in the regional distribution of mesodermal and ectodermal cells along the anteroposterior axis of $\text{T}\text{T}$ embryos. Since no regional difference in the cell cycle time was observed, these abnormalities may best be explained by anomalies in cell migration. These results strongly suggest abnormal morphology of $\text{T}\text{T}$ mutants resulting from defects in morphogenetic movement.     

Le grégarisme chez Blaberus craniifer: Isolement et identification de la phéromone

In the gregarious cockroach, Blaberus craniifer, an aggregation pheromone is produced by all individuals (larvae and adults) except at ecdysis. The pheromone, secreted by the mandibular glands, was analysed by thin-layer and gas chromatography and by mass spectrometry. The mandibular glands secrete three major volatile products: undecane, tetradecane, and ethyl-caproate. The last component is of unknown significance, but a mixture of undecane and tetradecane ($\text{1}\text{1}$) reproduces all the effects of the natural pheromone. The distance of perception is short: 40 cm for the adults and old larvae and 10 cm for the first instar larvae. The threshold is about 0·2 ng for the adults and 0·4 ng for the first instar larvae. The mixture undecane and tetradecane is specific: it is not attractive for other gregarious cockroaches (many of which are devoid of mandibular glands), and other straight-chain saturated hydrocarbons are not attractive for B. craniifer.     

Biosynthesis of the bile pigment sarpedobilin from [14C]pterobilin by Papilio sarpedon (lepidoptera)

Sarpedobilin $\text{3}$, the main blue-green tetrapyrrolic bile pigment of the butterfly $\text{Papilio sarpedon}$, is present at the different larval instars and in the adults. Using labelled pterobilin $\text{1}$, it is established that this compound is the precursor of sarpedobilin in larvae of the 4th instar.     

Predation by small mobile aquatic predators regulates populations of the intertidal limpet Patella vulgata (L.)

Highly mobile aquatic predators are known to forage in the intertidal during periods of immersion. There is limited quantitative information, however, on the extent to which these predators influence the abundance of grazing molluscs which are known to have a key role in structuring intertidal assemblages. Our preliminary video observations revealed that crabs and small fish were abundant on shores in southwest England during high-tide. We then used manipulative experiments to quantify the effect of small mobile aquatic predators on the abundance of limpets (Patella vulgata L.). On the lower shore at two moderately sheltered rocky shores three treatments were established: complete cage, partial cage (cage control) and uncaged (natural condition). The complete cages excluded all predators. The partial cage treatment allowed full access to small predators and the uncaged treatment allowed access to all predators. After two months, limpet abundance in uncaged and partial cage treatments had declined by around 50% compared to the complete cage treatment. Population structure also changed with survival of larger individuals being greater than smaller individuals in the open and partial cage treatments compared to the complete cage treatment. The effects of excluding predators were consistent at small (meters) and large spatial scales (kilometres) and hence, it would appear that the outcomes of our research are generally applicable to similar shores in the region.To explore the mechanism behind the differential effects of predators according to prey size, we compared the detachment force required to remove limpets of differing sizes from the shore. This was around four times greater for larger individuals than for smaller ones indicating that smaller limpets were more vulnerable to predation. These effects were also consistent between locations. Subsequent laboratory observations showed that the crabs Carcinus maenas (L.), Necora puber (L.) and Cancer pagurus (L.) which are locally abundant predators of limpets, had differing handling behaviour but were all highly efficient at removing limpets from substratum. Hence, shell width and attachment force appeared to be critical factors influencing the vulnerability of limpets to predation by these crabs. Limpets are known to control the abundance of macroalgae on shores in the North-east Atlantic and so our conclusions about the role of mobile predators in regulating the abundance of these grazers are important to our broader understanding of the ecology of these shores.     

Experimental studies on a mutant gene (e) preventing the differentiation of eye and normal hypothalamus primordia in the axolotl

The phenotype of axolotls (Ambystoma mexicanum) homozygous for the mutant gene e (“eyeless”) is different from normal in that (1) no optic vesicles develop in $\text{e}\text{e}$ embryos, (2) $\text{e}\text{e}$ larvae from posthatching onward are darker than normal white larvae, and (3) fully grown $\text{e}\text{e}$ animals are sterile.Experiments reported here show that eyelessness in $\text{e}\text{e}$ embryos results from a direct effect of the gene on presumptive forebrain ectoderm; not on the mesoderm that induces the ectoderm to form eyes. Homotopic grafts of normal presumptive ectoderm on $\text{e}\text{e}$ blastula hosts differentiated complete eyes, but reciprocally grafted embryos were always eyeless. Similarly, grafts of either $\text{e}\text{e}$ or normal presumptive prechordal mesoderm into normal hosts gave normal eyes, but in the mutant hosts no eyes developed. Thus the e gene affects only the ectodermal component of the inductive system for eye formation.Genetically eyeless (pigmented) cells, when interspersed prior to gastrulation among genetically eyed (albino) cells in the eye preprimordium, are induced to form clones of pigmented retinal epithelium in the albino host eye.The sterility of $\text{e}\text{e}$ larvae appears also to be due to a direct effect of the e gene on the ectodermal (neural plate) primordium of the hypothalamus. Grafts of normal cells which included the hypothalamic, but not the optic or anterior pituitary primordia, always restored fertility to $\text{e}\text{e}$ recipients.The mutant pigmentation phenotype was demonstrated to be a consequence of eyelessness and, therefore, an indirect effect of the gene. The pigment pattern of normal embryos from which both optic vesicles were removed resembles that of the mutants. In addition, implantation of a single full-sized, functional eye was able to restore the normal pigmentation, but not fertility, to $\text{e}\text{e}$ recipients.     

Pollen and seed flow patterns of Carapa guianensis Aublet. (Meliaceae) in two types of Amazonian forest

Various factors affect spatial genetic structure in plant populations, including adult density and primary and secondary seed dispersal mechanisms. We evaluated pollen and seed dispersal distances and spatial genetic structure of Carapa guianensis Aublet. (Meliaceae) in occasionally inundated and terra firme forest environments that differed in tree densities and secondary seed dispersal agents. We used parentage analysis to obtain contemporary gene flow estimates and assessed the spatial genetic structure of adults and juveniles. Despite the higher density of adults (diameter at breast height ≥ 25 cm) and spatial aggregation in occasionally inundated forest, the average pollen dispersal distance was similar in both types of forest (195 ± 106 m in terra firme and 175 ± 87 m in occasionally inundated plots). Higher seed flow rates (36.7% of juveniles were from outside the plot) and distances (155 ± 84 m) were found in terra firme compared to the occasionally inundated plot (25.4% and 114 ± 69 m). There was a weak spatial genetic structure in juveniles and in terra firme adults. These results indicate that inundation may not have had a significant role in seed dispersal in the occasionally inundated plot, probably because of the higher levels of seedling mortality.     

Responses of the cinnabar moth Hypocrita jacobaeae to various temperature/photoperiod régimes

Subjecting larvae of Hypocrita jacobaeae to temperatures of 21 and 28°C and photoperiods of $\text{0}\text{24}$, $\text{10}\text{14}$, $\text{12}\text{12}$, and $\text{18}\text{6}$ does not interfere with the phenomenon of diapause. The last larval instar is particularly affected by the higher temperature. Effects include numerous deaths, a high proportion of ill-formed pupae, and failure of adults to emerge properly from the pupal case. The significance of these findings is discussed.