Hatching Of Larvae Research Articles

Optimum Salinity for Hatching and Salinity Tolerance of Larvae and Juveniles in the Devil Stinger, Inimicus japonicus

Optimum Salinity for Hatching and Salinity Tolerance of Larvae and Juveniles in the Devil Stinger, Inimicus japonicus

High Hydrostatic Pressure at Low Temperature as a Quarantine Treatment to Improve the Quality of Fruits

Application of high hydrostatic pressure has been proposed as an alternative quarantine process for the Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae), one of the most important insects infesting mangoes, citrus fruits, and other fruits in Mexico and other Latin American countries. The present study was performed to determine the effect of high pressure treatments at 0 degrees C on the survivorship of eggs and larvae of this pest. The effect of time and pressure level at near-freezing temperatures on the egg hatch and survival of larvae is discussed. Eggs and larvae were pressurized at 25, 50, 75, 100, or 150 MPa for 0, 5, 10, or 20 min at 0 degrees C. Hatch was recorded for 1-, 2-, 3-, and 4-day-old pressurized eggs. For pressurized larvae (first, second, and third instars), percentage of survival was registered. Further, third instars were studied for their ability to pupate and develop to adulthood. The results showed that eggs had higher resistance than larvae to pressure. Larvae were not able to resist pressure treatments at 75 MPa for 20 min at 0 degrees C. Treatments at 150 MPa for 20 min at 0 degrees C were needed to destroy all eggs and larvae of A. ludens, indicating that this process might be useful as a quarantine method for infested fruits. However, more studies involving combination of high hydrostatic pressure at low temperature with precooling treatments are needed in order to decrease the pressure level to avoid fruit damage.

Records of horsehair worms (Nematomorpha) in Estonia, with description of three new species from the genusGordiusL.

INTRODUCTION About 300 species of horsehair worms (Nematomorpha) are known, about a third of them from Europe (Schmidt-Rhaesa 1997). The sampling within Europe is nevertheless far from being homogeneous and from some countries no or only a few records are known. This applies to Estonia as well as to the other Baltic states. There is only one brief report of some specimens determined as Gordius aquaticus Linnaeus, 1758 from Lake Vortsjarv (as lake Wirzjerw) by Muhlen & Schneider (1920). We report here several records, including the description of three new species of Nematomorpha from Estonia. It can be expected that the species reported here do not represent the entire diversity of species in the region. As only very fragmentary data are known from neighbouring countries, no estimates on the absolute number can be given here. Adult horsehair worms can be found in fresh water (with the exception of 5 species living in the sea), where they copulate and deposit eggs. From the eggs small larvae (around 100 [micro]m) hatch, which infect hosts. The exact life cycle is still unclear (Hanelt et al. 2005), but there is indication for a host change from aquatic to terrestrial hosts. The major development takes place within hosts such as carabid beetles, crickets, or others. Adult worms have been shown to manipulate their hosts, making them enter water so that the nematomorph can emerge (Thomas et al. 2002). Important for the determination of Nematomorpha species are cuticular characters such as the structure of the body cuticle or cuticular structures in the male posterior end. Representatives of genera such as Gordionus, for example, have spines and bristles in characteristic distribution patterns on the ventral side of the male posterior end (see e.g. Fig. 1C). In contrast, representatives of the genus Gordius are comparably poor in cuticular structures. Characteristic of the genus Gordius is a semicircular cuticular fold, the postcloacal crescent (see e.g. Fig. 2A), but bristles are much finer and fewer compared to Gordionus. Some of such bristles as well as the fine structure of the superficially smooth body cuticle might have been overlooked in earlier investigations that did not use scanning electron microscopy. Both genera, Gordius and Gordionus, are comparably species-rich, with about 60 and 46 described species, respectively. Both are distributed almost worldwide, but Europe appears to host most species, including abundant ones such as Gordius aquaticus Linnaeus, 1758 and Gordionus violaceus (Baird, 1853). MATERIALS AND METHODS Specimens reported here were collected in different locations in Estonia between 1971 and 2009 (in addition one record from Russia). Investigation of the specimens by scanning electron microscopy (SEM) took place in the Zoological Museum of the University Hamburg, Germany. Specimens were preserved in ethanol. Pieces of the cuticle and/or the posterior end were prepared for SEM. Pieces were dehydrated in an increasing ethanol series, critically point dried, and coated with gold in a sputter coater. Observation took place using a LEO SEM 1524 under 10 kV. Digital images were taken. Specimens are deposited in the Zoological Museum Hamburg (ZMH), in the Zoological Museum of the University of Tartu (TUZ), and in the personal collection of Andreas Schmidt-Rhaesa. In total, 39 specimens were investigated, 4 of which could not be determined. Four species could be determined to species level, three of these are new to science. RESULTS AND DISCUSSION A total of 39 specimens were investigated. Four specimens could not be determined because they were damaged and are omitted from this report. The remaining 35 specimens belong to four species, three of which are new to science. Seven specimens belong to the genus Gordius, but could not be determined to species level. Gordionus violaceus (Baird, 1853) Figure 1 Distribution: Himmiste, Saaremaa, found halfway emerging from a Pterostichus niger (Schaller, 1783) (Carabidae) which was caught on a yellow plate (1[female], collected by M. …

In vitro anthelmintic effect of two medicinal plants (Anogeissus leiocarpus and Daniellia oliveri ) on Haemonchus contortus , an abosomal nematode of sheep in Burkina Faso

A study was conducted to evaluate Anogeissus leiocarpus leaf and Daniellia oliveristem barks as effective remedy for gastrointestinal parasites. The anthelmintic activity of these extracts on eggs, first stage larvae and adults of Haemonchus contortus was examined by in vitro tests. The extracts were prepared to obtain six increasing concentrations. This was done with Phosphate Buffered Saline (PBS) for egg hatch, embryonated egg assays (75, 150, 300, 600, 1 200 and 2 400 µg/ml) and adult inhibition of motility assay (0.25, 0.5, 1, 2, 4 and 8 mg/ml). PBS and levamisole (at 0.125 µg/ml in PBS) were used as negative and positive control groups, respectively. Both plant extracts induced anthelmintic effects on the three life-cycle stages of H. contortus and these effects were significantly different when they were compared to the negative control group (PBS) (P<0.05). The effect was dose-dependent on egg hatching and first stage larvae (L1) but not on adult worms. Magnitude of effect was proportional to concentration of plant extracts for egg hatching and L1 but not for adult worms. Besides, the results showed that the D. oliveri stem bark extract was more ovicidal and larvicidal than A. leiocarpus leaves. It is concluded that these two plants do really possess anthelmintic properties. Key words: Anthelmintic, leaf, stem bark, extracts, Anogeissus leiocarpus,Daniellia oliveri, Haemonchus contortus.

Establishment and characterisation of salmon louse (Lepeophtheirus salmonis (Krøyer 1837)) laboratory strains

The salmon louse (Lepeophtheirus salmonis (Krøyer 1837)) is an ectoparasitic copepod which represents a major pathogen of wild and farmed salmonid fishes in the marine environment. In order to facilitate research on this ecologically and economically important parasite, a hatchery and culturing system permitting the closure of the life-cycle of L. salmonis in the laboratory was developed. Here, the hatchery system, breeding practices, and selected louse strains that have been maintained in culture in the period 2002–2009 are presented. The hatchery and culture protocol gave rise to predictable hatching of larvae and infections of host fish, permitting the cultivation of specific strains of L. salmonis for 22 generations. Both in- and out-bred lice and mutant colour strains have been established, and some of these strains were characterised by microsatellite DNA markers confirming their pedigree. No evidence of inbreeding depression, fitness or morphological changes was observed in any of the strains cultured. It is suggested that the culturing system, and the strains produced represent a significant resource for future research on this parasite.

Vitamin contents of eggs that produce larvae showing a high survival rate in the Japanese eelAnguilla japonica

This paper describes the relationship between the egg vitamin concentrations and the egg quality in the Japanese eel Anguilla japonica. No notable relation was found between any vitamin and the fertilization rate. Hatching and survival rates of larvae, however, significantly increased with an elevated level of egg vitamin C (VC). In contrast to VC, the relation between vitamins E (VE) and A (VA) concentrations and survival rate showed a clear peak, with a reduced survival rate at both higher and lower vitamin concentrations. The ratio of VE to lipid or highly unsaturated fatty acid (HUFA) in eggs positively correlated with hatching and survival rates of larvae. High-quality (HQ) eggs were determined as eggs that produced larvae having a survival rate higher than 80% at 8 days post hatch, and low-quality (LQ) eggs were determined as eggs that did not hatch. The level of VC of HQ was significantly higher than LQ. The results of this study suggest that HQ eggs, which produce larvae having a high survival rate, must have high levels of VC and VE/HUFA ratio and contain optimum levels of VA and VE in Japanese eel.

Use of chemical genetics to study zebrafish gut development

The signaling pathway associated with the formation and looping of the early Zebrafish gut is poorly understood. The present study uses a chemical genetics approach to examine aspects of the signaling pathway thought to be involved in the process of gut looping in the Zebrafish. A chemical genetics approach is one that uses small molecules known to modulate the activities of specific proteins in a signaling pathway in order to study their role tissue or organ morphogenseis. Compounds thought to be involved in gut looping used in the present study included rho kinase III inhibitor (rockout), blebbistatin which acts as a reversible inhibitor of non‐muscle myosin II, retinoic acid (RA) and DEAB. Effective maximum working concentrations that allowed for hatching of Zebrafish larvae were determined to be 5 uM DEAB, 0.5 uM RA, 1‐2 uM Blebbistatin and 10 uM Rockout. Gut looping was visualized in 30‐32 hpf embryos utilizing WISH for Fox A3 that recognizes early endoderm tissue of the gut tube and with Zebrafish gut‐GFP mutants (Tg(XlEef1a1:GFP). In addition, IHC staining for laminin, pan‐cadherin, B‐catinin, PKC and smooth muscle actin was utilized for visualization of the polarity, orientation and movement of the endodermal and mesodermal cell layers of the early and later stage Zebrafish gut tube. WISH and gut‐GFP mutant experiments demonstrated that 10 uM rockout but not 2 uM blebbistatin resulted in an inhibition of gut looping in 30‐32 hour old Zebrafish embryos. This work was performed in the lab of Dr. Nannette Nascone‐Yoder and supported by NSF award # 0642012.

Impacts of Suspended Sediments on Fertilization, Embryonic Development, and Early Larval Life Stages of the Pacific Herring,Clupea pallasi

Pacific herring reproduce in the San Francisco Bay estuary during times of the year when suspended sediment loads are highest due to freshwater input, yet little is known about the effects of sediment on herring early life stages. During the first 2 h after eggs contacted water, embryos were adhesive and susceptible to having sediment particles attach permanently to the chorion. Treatment with suspended San Francisco Bay dredged sediments at ecologically relevant concentrations of 250 or 500 mg/l during this time period increased self-aggregation of the eggs and led to sublethal and lethal effects. After the first 2 h in water, sediments that contacted embryos did not attach to chorions and did not have an observable impact. Sediment treatment during the first 2 h was not linked statistically to declines in fertilization or total larval hatch rate, but it did produce significant sublethal effects that included increases in precocious larval hatch and higher percentages of abnormal larvae, as well as an increase in larval mortality.

Parasitism of Entedon costalis (Hymenoptera: Eulophidae) in Glocianus punctiger (Coleoptera: Curculionidae): an example of intentional discovery of the parasitoid-host association

The biology and morphology of early larval instars of Entedon costalis Dalman (Hymenoptera: Eulophidae), are described in detail for the first time. The parasitoid-host association of E. costalis was revealed as a result of selection of candidate host based on combination of assumptions based on biology of related species and field surveys. E. costalis proved to be an egg-larval parasitoid of the weevil Glocianus punctiger (Gyllenhal), which is associated with dandelion (Taraxacum officinale G.H. Weber ex Wiggers). Parasitism rate of G. punctiger by E. costalis was 25% in the model patch which was sampled in May, where infestation of dandelion inflorescence by G. punctiger was 27%. The female of E. costalis lays her egg into the host egg, but the first instar larva hatches within the first instar host. Larvae of G. punctiger start their feeding as internal flower-stalk borers, continue as seed-eaters in flowerheads, and then pupate underground when matured coincident with seed dispersal (generally in the end of May). Parasitized and unparasitized mature larvae of G. punctiger pupate underground, in earthen cells, where the parasitoid larvae finally consume their hosts and pupate 2–3 days thereafter. Adults of E. costalis emerge the following spring (about mid April), as dandelions being flowering. The morphology of immature stages and behaviour of adults is described. Various peculiarities of parasitoidhost relationships superparasitism, siblicide, host immune response are described and discussed. DNA sequences of the nuclear 28S D2 rDNA gene were obtained for E. costalis.

Biology and taxonomic position of an ovoviviparous water mite (Acari: Hydrachnidia) from a hypersaline spring in southern Spain

During field and laboratory studies on the life cycle of the water mite Ignacarus salarius Gerecke, 1999 (Acari: Hydrachnidia: Hydryphantidae) collected from a natural hypersaline stream, the first case of ovoviviparity in water mites was detected and investigated. The particular form of hatching and host preference of larvae are described as well as the characteristics of the extreme environment and its particular biocoenosis. The taxonomic position of the monotypic genus Ignacarus is discussed on the basis of larval and adult morphology. The biogeographical and conservation value of the endemic fauna inhabiting such hypersaline environments is highlighted.

Analysis of Cell Movement in Amphimedon Embryos by Injection of Fluorescent Tracers

INTRODUCTIONAlthough attempts to culture prepigmentation-stage embryos (i.e., blastulas and early gastrulas) outside of brood chambers have so far been unsuccessful in Amphimedon, it is possible to manipulate embryos within the brood chamber and follow their development under laboratory conditions. This protocol describes microinjection of lipophilic tracers such as 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI) into embryos embedded in their native brood chamber. DiI does not appear to perturb embryonic development and is relatively resistant to photobleaching. As long as care is taken not to damage the fragile embryos during observation and photography, the same embryo can be photographed multiple times, permitting its development to be tracked (up to 4 wk) from early cleavage stages to hatching of free-swimming parenchymella larvae. The embryos or larvae also can be fixed without loss of fluorescence. This method also can be used to deliver other types of solutions to embryos or individual cells of early embryos.

Mnemiopsis leidyi Spawning and Embryo Collection

INTRODUCTIONCtenophores, or comb jellies, are a group of marine animals whose unique biological features and phylogenetic placement make them a key taxon for understanding animal evolution. Because of its large size, fecundity, abundance in coastal areas, and recent introduction to European waters, Mnemiopsis leidyi (commonly called "sea walnuts") is the most highly studied ctenophore. Under optimal conditions, these self-fertile hermaphrodites are capable of reproduction at 2 wk of age and can release up to 10,000 eggs per day. Adults can be maintained in large aquaria with gentle aeration as long as they are well fed and can be spawned daily; multiple generations can be raised in the laboratory. This protocol describes how to collect embryos from M. leidyi. Under natural conditions, spawning normally occurs ~8 h after sunset, such that eggs are released under the cover of darkness. Because spawning is triggered by the onset of darkness, keeping animals under an artificial light regimen in the laboratory can alter the time of spawning. This protocol is designed to induce animal spawning at approximately 11:00 a.m.; however, it can be adjusted for other times. The duration from spawning to hatching of larvae is 18-24 h.

Compositions and functions of the hatching froth from ricefield eel (Monopterus albus Zuiew)

The ricefield eel (Monopterus albus) is an economic fish species in China. To improve its artificial reproduction, we studied the compositions and functions of the hatching froth secreted by ricefield eels. The froth showed a viscosity of 2.72 mPaS, composed of glycoproteins with a sugar content of 0.156 mg/ml and a protein content of 0.250 mg/ml at a ratio of 1.60. The froth proteins were identified by SDS-PAGE as four proteins with the molecular weights of 42.5, 58.6, 65.3, and 98.2 kDa respectively. Their total amino acid content was 201.88 mg/100 ml, consisting of 16 kinds of amino acids. Filed observation revealed three beneficial effects of the froth on the hatching of the eel eggs. First, the froth increased the hatching rates of fertilized eggs at a range of water temperatures. Second, the froth decreased the rates of infection of the fertilized eggs by the water mold. Finally, the froth accelerated velum breakage in the fertilized eggs. Of the different hatching methods, froth incubation achieved the highest hatching rate and larvae survival rate. These results demonstrate the indispensable function of the froth of ricefield eels, and offer practical reasons for protecting the froth during the breeding season.

Experimental confirmation of protandric simultaneous hermaphroditism in a Caridean shrimp outside of the genus Lysmata

Caridean shrimps display a variety of sexual systems including gonochorism and various forms of protandry but rarely simultaneous hermaphroditism. Protandric simultaneous hermaphroditism (PSH) has thus far only been demonstrated in the genus Lysmata. The first report of simultaneous hermaphroditism in a caridean shrimp was with Exhippolysmata ensirostris. However, this was not confirmed, since this species was also considered to be strictly protandric. Therefore, inconclusive results about this species' true sexual system led us to examine Exhippolysmata oplophoroides. Mating between female phase individuals resulted in successful spawning, embryonic development and hatching of viable larvae. Furthermore, we have confirmed that this species is not capable of self-fertilization. Juveniles reared in the laboratory matured in a similar manner to that of Lysmata. Data were limited due to the loss of all individuals to a Vibrio infection. However, the results obtained in this study conclusively affirm functionally that PSH occurs outside the genus Lysmata, in E. oplophoroides. Theories examining the evolution of PSH within decapods must be re-examined in light of the present data.

Offspring performance in dynamic habitats: key factors for a riparian carabid beetle

Abstract 1. Knowledge of the ecology of carabid species is largely restricted to adults, although larval mortality is assumed to be the key factor in overall mortality. As low‐mobility larvae are unable to avoid unfavourable conditions, habitat selection of reproducing adults should be clearly affected by the habitat factors which determine offspring performance.2. The present study examines the key habitat factors governing the distribution patterns of Bembidion velox larvae and adults on the river banks of the River Elbe by means of habitat suitability models. The validity of the determined habitat factors for offspring performance and survival was tested in laboratory experiments.3. In the field, B. velox adults as well as larvae show a strong association with semi‐terrestrial, sandy, open soil habitats.4. In the laboratory, overall mortality of larvae reared in different substrates was lowest in sand of medium grain size mixed with fine and coarse sand. The first larval instars in particular reacted sensitively to variations in grain size. Furthermore, flood resistance of eggs was demonstrated, as 90% of larvae hatched under permanently flooded conditions.5. Short development times were recorded, with 4–7 days for hatching of young larvae from eggs after oviposition and approximately 28 days for the development of adults from newly hatched larvae. This probably increases the survival probability for the pre‐imaginal stages in dynamic habitats.6. In conclusion, it can be said that reproductive success is strongly dependent on oviposition site selection by adults as this reflects the ecological demands of the immature stages.

Modulation of digestive enzyme activities during ontogeny of Labeo rohita larvae fed ascorbic acid enriched zooplankton

The effect of supplementation of ascorbic acid through enriched zooplankton [10%, 20% and 30% ascorbyl palmitate (AP) inclusion in diet of zooplankton] on different digestive enzyme activities during ontogeny of Labeo rohita larvae was studied from 4 day to 15 day post hatch. Ascorbic acid (AA) content in different groups of unenriched (8.6 ± 0.71) and enriched zooplankton were, 750 ± 29.3, 1409.1 ± 45.5, 2009.21 ±199.2 μg/g respectively on dry matter basis with differences ( P < 0.05) between the treatments. A difference ( P < 0.05) was found in tissue AA level in different dietary groups. Low amylase, protease, lipase and alkaline phosphatase activities were present in rohu larvae from the mouth opening stage which showed increasing trend with the age of larvae and increasing dietary AA content. A clear dose-dependent modulation of digestive enzyme activities in response to 10%, 20% and 30% AP enriched zooplankton feeding was evidenced from positive correlations between dietary AA content with magnitude of elevation of enzyme activity in different groups. There were 57, 55, 29.2 and 2 fold increases in amylase activity; 7.35, 7.02, 4.43 and 2.73 fold increases in protease activity; 45.636, 41.50, 19.83 and 13.69 fold increases in lipase activity and 6, 5, 3, and 2 fold increases in alkaline phosphatase activity observed in the 15th day post hatch larvae fed 20%, 30%, 10%AP enriched and normal zooplankton respectively, than 4-day post hatch larvae of the respective groups. Enzyme activities were also positively correlated with specific growth rates of wet weight of rohu larvae at the 15th day post hatch. Increased AA might have played an important role in advancing morphological transformation of the digestive tract, protecting gastric mucosa and accelerating growth by the process of tissue formation, which necessitated the requirement of more nutrient thereby, increasing digestive enzyme activity. The regulatory role of AA in the modulation of different digestive enzymes activity and its physiological consequences of nutrient digestibility and utilization during ontogenesis could be extrapolated for better nutrient management of the larvae.

Early Development of the Sacramento Perch

AbstractPopulations of the Sacramento perch Archoplites interruptus, California's only native centrarchid, are declining and early development of this imperiled species is poorly known. Therefore, the main objective of this study was to describe the early development of Sacramento perch from fertilization to initiation of exogenous feeding. Embryos were obtained in the laboratory by spawning induction via photoperiod‐temperature control or gonadotropin‐releasing hormone analog treatment. Gross morphology and histological analyses were integrated to describe the early development. Cleavage was synchronous until the 64‐cell stage, which allowed us to calculate the duration of one mitotic cycle during early synchronous cleavage (τ0) as 10–16 min at 25.4–25.6°C. A description of histological events from time to morulation, gastrulation, hatch, and exogenous feeding larvae is provided. Yolk sac larvae tended to adhere to the spawning substrate or sediment during the critical organogenesis stages. Larvae swam up and began exogenous feeding within 4 d postfertilization. Primordial germ cells were observed in 10‐d‐old larvae, but sex differentiation occurred after 43 d. External sexual dimorphism was not observed in early life stages.

Sensitivity of wild and genetic sexing strain Ceratitis capitata to high‐temperature disinfestation of Valencia oranges

Abstract: The purpose of this research was to investigate post‐harvest heat treatment of Valencia oranges as an effective disinfestation protocol (fast, no fruit damage) for the Mediterranean fruit fly Ceratitis capitata (Wiedemann). Forced high‐temperature air was applied under the following conditions: (a) exposure to air temperature of 56°C, for fast increase of temperature in the interior of the fruit, (b) reduction in air temperature to 47°C when the fruit centre reached 47°C and (c) maintenance of fruits in the chamber for another 30 min. Relative humidity in the treatment chamber was kept between 50% and 65% during treatment. Forced air at 47°C applied for 30 min on eggs before hatch or late third instar larvae (the most heat‐tolerant stages) resulted in complete kill. Egg and larval sensitivity to high temperature differed between a wild strain and a laboratory genetic‐sexing strain based on white pupa mutation. In this strain males emerge from brown pupae and females from white pupae. In particular, mature eggs from the wild strain were significantly more temperature resistant than eggs from the laboratory strain. Exposure of Valencia oranges of a diameter of 7–7.5 cm to 56°C forced air for about 86 and 99 min was required to increase temperature to 47°C at 1.5 cm depth and the fruit centre respectively. Treated oranges showed no substantial peel or interior deterioration, or change in colour and taste when kept at 25°C and 50–60% RH for a period of up to 1 month following treatment. Treatment in 1% O2 atmosphere, produced by flushing of CO2 into the treatment chamber, resulted in about 1°C reduction in killing temperature and faster increase in temperature inside the fruit to a lethal level.

Huffmanela spp. (Nematoda, Trichosomoididae) parasites in coral reef fishes off New Caledonia, with descriptions of H. balista n. sp. and H. longa n. sp.

Two new species of Huffmanela Moravec, 1987 are described from coral reef fishes caught off New Caledonia, South Pacific. H. balista n. sp. is described from the adults and eggs found in the swimbladder wall of a single Abalistes stellatus (Balistidae). The male, 9.9 mm long, has characteristic spermatids and spermatozoa. The female has a characteristic cuticularised anterior oesophagus. The eggs (70 × 34 µm) spontaneously hatch and release larvae, 260 µm long. H. longa n. sp. is described from a single female and from eggs collected in the mesentery, swimbladder and body walls of three Gymnocranius grandoculis (Lethrinidae). The female, although immature, is the longest (20.7 mm) of all species of the genus. The eggs (66 × 27 µm) have superficial filaments, and are differentiated from those of H. filamentosa Justine, 2004 from the same host, by their greater measurements. Eggs of Huffmanela mexicana Moravec et Fajer-Avila, 2000, are redescribed for comparison. The host of Huffmanela sp. of Justine, 2004, is identified as Pentapodus aureofasciatus. New observations on H. ossicola Justine, 2004 are reported, including new hosts (Bodianus busellatus and B. perditio), comparative measurements of eggs in various hosts and organs, description of larvae, 228 µm in length, and X-ray observations of the skeleton of an infected fish.

Development, survival and reproduction of the Brassica leaf beetle, Phaedon brassicae Baly (Coleoptera: Chrysomelidae) under different thermal conditions

Phaedon brassicae is a serious pest of brassicaceous vegetables in Japan and China, but the effects of thermal changes on development, survival and reproduction is not well demonstrated. In this study, effects of constant temperatures and thermoperiods simulated alternating high summer temperatures on the development, survival and reproduction were examined in this beetle at 12L:12D. At constant temperatures, egg hatch and survival of larvae and pupae were highest at 28, 24, and 24°C respectively. Within the range of 12–30°C, the developmental periods of immature stages decreased significantly with increasing temperature, but a delay in development was observed at 30°C. The developmental zeros were estimated at 7.1, 6.9 and 7.1°C and thermal constants of 87.7, 178.6 and 68.0 degree-days were estimated for the development of the eggs, larvae and pupae, respectively. Adult longevity decreased with increasing temperature, but there were no significant differences among temperatures (16–28°C). Fecundity at 24°C (768.68 ± 385.44 eggs per female) was significantly greater than at other temperatures. The optimal temperature is approximately 24°C. Moreover, high alternating temperatures had little effect on egg hatch, but higher thermophase (6 h) temperatures retarded the survival of larvae and pupae. No individual survived to eclosion at thermoperiods with thermophase temperature of 38°C. High temperatures (above 34°C) lasting several hours had detrimental effects on survival, development and reproduction in P. brassicae.