Erfahrungsbericht über die Haltung und deutsche Erstzucht der Borneo-Flussschildkröte (Orlitia borneensis Gray, 1873) im Zoo Dresden

Dresden Zoo bred successfully the Malaysian giant turtle (Orlitia borneensis) in summer 2012. This was the first successful breeding of this species in Germany.Little is known about biology and behaviour of this large river turtle and keeping and especially breeding of this endangered species in captivity is a rarity. In order to create optimal breeding conditions Dresden Zoo rebuilt an enclosure for the turtles in 2010. An area with soil and sand was built for the expected egg deposition. After arranged matings one female dug a nest on this area and buried her eggs. Nine eggs were secured and transferred into an incubator in a box filled with a 1:1 mixture of vermiculite and water. The average temperature was 29 °C. After problems with the temperature regulation the damaged incubator had to be replaced. Because of an estimated incubation period of 3–4 months, one egg was opened on day 127 of incubation. A live hatchling with a big yolk sac was fetched. Because of the non-reabsorbed yolk sac the hatchling was further incubated. On day 154 of incubation all eggs were manually opened and the hatchlings were fetched. All of these hatchlings showed a non-reabsorbed yolk sac and were incubated onwards in a box with wet paper towel until the yolk sac was completely reabsorbed. After that the hatchlings were housed solitarily in a box with water of approximately 4 cm height and a small land area. Two days after housing food was offered for the first time. All hatchlings accepted the offered food consisting of herbal as well as of animal products and later turtle pellets and self-made turtle jelly.Though little is known about breeding this species, the breeding success of Dresden Zoo demonstrates a possible approach to this topic. But there are still things to optimize. For example the manual hatching is something that should be avoided in future. Fertilization and hatching rate of 100% are promising and up to date eight out of nine hatchlings are still alive.     

Factors affecting nest choice by Pekin ducks

To encourage nest use in breeder poultry flocks, it is important that nest boxes are attractive. Few studies have evaluated factors affecting nest attractiveness to ducks. We assessed the effects of nest box experience (Experiments 1 and 2) and features of nests, including degree of enclosure (Experiments 1 and 2) and the presence of an egg (Experiment 3), on nest site selection by sexually mature Pekin ducks. The hens were tested individually in pens containing different nest box choices. Nest preferences were determined based on the locations of 14 successively laid eggs. Ducks in Experiment 1 were provided with nest box access prior to the onset of lay (20 weeks of age, EXP group, N = 12) or at the time of preference testing (35 weeks of age, DELAYED-EXP group, N = 12). Delaying nest box access by 15 weeks did not significantly affect the proportion of eggs laid in nest boxes rather than on the floor (P = 0.40). Regardless of experience ducks laid more than 66% of their eggs in nest boxes offering a higher degree of enclosure. Ducks in Experiment 2 were reared with either open-top (OP, N = 12) or closed-top (CL, N = 12) boxes. Regardless of rearing condition, ducks preferred boxes with the highest level of enclosure offered. Ducks laid twice the expected proportion (25%) of eggs in CL boxes with curtains (P = 0.0004). CL boxes without curtains were used as predicted by chance, 25% (P = 0.746), while OP boxes with (P = 0.009) and without (P = 0.015) curtains each contained only half the expected number of eggs. Ducks in Experiment 3 were provided with two nest boxes, one of which contained the egg laid the previous day. Each day, the newly laid egg was marked and either placed back in the nest box where it was found (HANDLED, N = 12) or moved into the adjacent nest box (MOVED, N = 12). Ducks in HANDLED and MOVED laid 97.6% and 79.8%, respectively, of their eggs in boxes containing the previous day's egg. While ducks in HANDLED were consistent in their choice throughout the test, those in MOVED developed the preference over time (P = 0.039), suggesting that the preference for laying in a nest containing an egg may be influenced by experience. These results indicate that nest box enclosure and the presence of an egg are important in determining the nesting choices of Pekin ducks. Incorporating these features into nest boxes may be useful for increasing consistency of nest use in breeder duck flocks.     

Adaptive difference in daily timing of hatch in two locust species,Schistocerca gregaria and Locusta migratoria: The effects of thermocycles and phase polyphenism

This study examined the effects of temperature and phase polyphenism on egg hatching time in the desert locust, Schistocerca gregaria, and the migratory locust, Locusta migratoria. The two species exhibited differences and similarities in hatching behavior when exposed to different temperature conditions. In 12-h thermocycles of various temperatures, the S. gregaria eggs hatched during the cryoperiod (low temperature period), whereas L. migratoria eggs hatched during the thermoperiod (high temperature period). The eggs of both species hatched during the species-specific period of the thermoperiod in response to a temperature difference as small as 1 °C. Furthermore, the locusts adjusted hatching time to a new thermal environment that occurred shortly before the expected hatching time. In both species, the hatching of the eggs was synchronized to a specific time of the day, and two hatching peaks separated by approximately 1 day were observed at a constant temperature after the eggs were transferred from thermocycles 3 days before hatching. Eggs laid by gregarious females hatched earlier than those laid by solitarious females in S. gregaria but this difference was not observed in L. migratoria.     

Incubation temperature affects hatching success,embryonic expenditure of energy and hatchling phenotypes of a prolonged egg-retaining snake,Deinagkistrodon acutus (Viperidae)

We used eggs of Deinagkistrodon acutus to study the effects of incubation temperature on hatching success, embryonic expenditure of energy and hatchling phenotypes. One egg from each of the 15 fertile clutches was dissected for determination of egg composition, and a total of 164 eggs were incubated at five constant temperatures. Embryonic mortality increased dramatically at 30 °C, and none of eggs incubated at 32 °C hatched. Within the range from 24 to 30 °C, temperature affected incubation length and most hatchling traits examined. The mean incubation length at 24, 26, 28 and 30 °C was 36.4, 28.7, 21.8 and 15.7 days, respectively. Embryos developing at higher temperatures (28 and 30 °C) consumed more energy but produced less developed (and hence smaller) hatchlings, which characteristically had larger residual yolks but smaller carcasses. A principal component analysis resolved two components (with eigenvalues ⩾1) from ten size (initial egg mass)-free hatchling variables, accounting for 79.3% of variation in the original data. The first component (43.8% variance explained) had high positive loading for size-free values of dry mass, lipid mass, energy contents and ash mass of hatchlings, and the second component (35.5% variance explained) had high positive loading for size-free values of SVL, carcass dry mass and fatbody dry mass. Hatchlings from different incubation temperatures did not differ in scores on the first axis of the principal component analysis, whereas hatchlings from higher incubation temperatures (28 and 30 °C) had significantly lower scores on the second axis than did those from lower incubation temperatures (24 and 26 °C). As the second axis mainly represents traits relating to the developmental condition at hatching, the analysis therefore provided further evidence that eggs incubated at higher temperatures produced less developed hatchlings. Taken together, our data show that the optimal temperatures for embryonic development are relatively low in D. acutus largely due to its use of relatively cool habitats.     

Influence of temperature on female,embryonic and hatchling traits in syntopic newts,Ichthyosaura alpestris and Lissotriton vulgaris

Amphibian populations have been declining globally for the last several decades, and climate change is often regarded as one of the most important factors driving these declines. Amphibians are particularly sensitive to climatic changes due to their physiological, ecological and behavioral characteristics. Here we performed a laboratory experiment to investigate how temperature affects ovipositing females, eggs and hatchlings in two syntopic populations of alpine newts, Ichthyosaura alpestris, and smooth newts, Lissotriton vulgaris. Female newts were assigned to two different oviposition temperatures (11 °C and 14 °C) for the duration of their oviposition period. Deposited eggs were equally divided and assigned to three different incubation temperatures (11 °C, 14 °C and 17 °C). We hypothesized that oviposition will be affected by temperature, that the combination of different oviposition and incubation temperatures may have an effect on embryonic and hatchling traits (embryonic mortality, days to hatch and hatchling length), and that these effects might differ between the two newt species. Temperature affected the number of deposited eggs in smooth newts, but not in alpine newts. Larval hatching success was not affected by oviposition or incubation temperature. Temperature effects on hatching time and hatchling length differed between the two species. These results suggest that temperature changes may have disparate effects on amphibian reproduction, even in syntopic taxa.     

Effect of egg storage duration and egg turning during storage on egg quality and hatching of broiler hatching eggs

In commercial hatcheries, it is common to store eggs before incubation. One practice to improve hatchability consists in egg turning during this storage. This work aims to highlight the effects of turning on the physicochemical aspects of eggs and, consequently, how this turning can influence the hatching of chicks. An experiment was conducted to evaluate the effects of storage duration and egg turning during storage on egg quality, hatchability, and residual analysis. A total of 7 500 hatching eggs were collected from a 55-week-old commercial Cobb500 breeder flock and storage according to the treatments. The experiment was completely randomized in a 3 × 2 factorial design with three storage periods (4, 8, and 12 days) and egg turning (180° turn of eggs once a day) or no turning during storage, totaling six treatments. Regardless of turning, eggs stored for 4 days weighed more than turned eggs stored for 8 and 12 days, which were similar (P < 0.05). Non-turned eggs experienced an increase in relative shell weight with increased storage duration, and non-turned eggs stored for 4 and 8 days differed from non-turned eggs stored for 12 days (P < 0.05). Albumen pH of turned eggs stored for 4 and 8 days was lower than that of non-turned eggs stored for the same durations (P < 0.05). Albumen pH of turned eggs increased as storage duration increased (P < 0.05). Egg turning increased hatching by 2.02% over that of non-turning (P < 0.05). Eggs stored for 12 days, irrespective of turning, had higher late embryonic mortality (P < 0.05) compared to the other treatments. It was concluded that turning eggs during pre-incubation storage was adequate to improve hatchability of fertile eggs. Storing fertile eggs for 12 days is harmful to egg quality and increases embryo mortality even if eggs were turned.     

Synthesis and evaluation of novel phosphate ester analogs as neutral sphingomyelinase inhibitors

A novel sphingomyelin inhibitor RY221B-a, which contains a bipyridyl moiety as a metal coordination site was designed based upon the mechanism of phosphate ester hydrolysis. RY221B-a was synthesized from N-Boc-sphingosine in three steps via selective etherification using stannyl acetal. Synthesized RY221B-a exhibited relatively-strong inhibitory activity against Bc-SMase (IC₅₀ = 1.2 μM).     

The cooling time of fertile chicken eggs at different stages of incubation

We asked whether or not the thermal characteristics of fertile avian eggs changed throughout incubation. The cooling and warming times, expressed by the time constant τ of the egg temperature response to a rapid change in ambient temperature, were measured in fertile chicken eggs at early (E7), intermediate (E11) and late (E20) stages of embryonic development. Same measurements were conducted on eggs emptied of their content and refilled with water by various amounts. The results indicated that (1) the τ of a freshly laid egg was ~50 min; (2) τ decreased linearly with the drop in egg water volume; (3) the dry eggshell had almost no thermal resistance but its wet inner membrane contributed about one-third to the stability of egg temperature; (4) the egg constituents (yolk, albumen and embryonic tissues) and the chorioallantoic circulation had no measurable effect on τ; (5) the presence of an air pocket equivalent in volume to the air cell of fertile eggs reduced τ by about 3 min (E7), 5 min (E11) and 11 min (E20). Hence, in response to warming the egg τ at E20 was slightly shorter than at E7. In response to cooling, the egg τ at E20 was similar to, or longer than, E7 because embryonic thermogenesis (evaluated by measurements of oxygen consumption during cold) offset the reduction in τ introduced by the air cell. In conclusion, until the onset of thermogenesis the thermal behavior of a fertile egg is closely approximated by that of a water-filled egg with an air volume equivalent to the air cell. It is possible to estimate the cooling τ of avian eggs of different species from their weight and incubation time.     

Cryoprotective and contraceptive properties of egg yolk as an additive in rooster sperm diluents

The addition of chicken egg yolk to semen extenders is thought to reduce the fertilizing potential of rooster spermatozoa - but not (or at least not as much) that of other avian species. The aim of the present study was to determine whether quail egg yolk, a novel extender additive, provides advantages over chicken egg yolk in the cryopreservation of rooster spermatozoa. Experiments were also performed to determine whether the harmful effect of egg yolk occurs during cryopreservation or during fertilization after artificial insemination. Heterospermic rooster semen samples were divided into aliquots and cooled in a polyvinylpyrrolidone-based medium containing 15% chicken egg yolk, 15% quail egg yolk or no egg yolk at all. The viability of spermatozoa of cooled samples (5 °C) without egg yolk were less viable (P < 0.01) than those of samples containing either type of egg yolk. The same aliquots were then cryopreserved for 15 days. Thawed spermatozoa preserved without egg yolk showed lower motility (P < 0.001) and viability (P < 0.001) than those in samples diluted with either type of egg yolk extender. No eggs were fertilized when hens were inseminated with semen that had been diluted with chicken egg yolk. The fertilization rate was only slightly higher when sperm diluted with quail egg yolk was used (1.5%). The best results were obtained when no egg yolk was used (13.8%). These results show that the addition of egg yolk of either type protects rooster sperm cells against cold shock and during freezing and thawing, but exerts a contraceptive effect in the genital tract of the hen.     

Temperature effects on embryonic development of Paratlanticus ussuriensis (Orthoptera: Tettigoniidae) in relation to its prolonged diapause

Paratlanticus ussuriensis eggs overwinter by entering diapause, which can be prolonged to more than 1 year depending on environmental conditions. To determine temperature effects on diapause duration of P. ussuriensis eggs, the rates of embryonic development and hatching were compared at various temperatures conditions by measuring embryonic stages and egg weights. Most eggs stayed in a very young stage (blastoderm formation, stage 4) when reared at 15 and 20 °C, 10–30% eggs developed into middle or late stages when reared at 25 °C, and most embryos developed fully (stage 23/24) when reared at 30 °C. Egg weight at 30 °C was 1.5 times higher than those reared at 20 °C. Chilling induced hatching in embryos at stage 23/24. Chilling caused stage 4 embryos to develop into stage 24, but they failed to hatch in response to a second warm period. Thus, P. ussuriensis eggs can overwinter either as young embryos (initial diapause) or as fully-developed embryos (final diapause). Eggs that experience an initial diapause overwinter again the second year in a final stage diapause. The post-diapause period was shorter when embryos overwintered in a final stage diapause. The hatching rate was highest in a temperature range of 7.5–15 °C. Our results suggest that temperature is an important environmental factor for the control of prolonged diapause in P. ussuriensis and initial diapause plays an important role in the control of its life cycle.     

Quality assessment of Riptortus pedestris (Hemiptera: Alydidae) eggs cold-stored at different temperature and relative humidity regime

Supplementation of host resource can be more economical method for the biological control of insect pest compared to direct release of adult parasitoids. Periodical release of non-viable cold-stored eggs of Riptortus pedestris (Fabricius) (Hemiptera: Alydidae) has been found to enhance parasitism of this pest in soybean fields. To find the optimum environmental conditions for cold storage of these host eggs, we evaluated nine different combinations of temperature (2, 6, and 10 °C) and relative humidity (high 90–95%, medium 70–75%, and low 30–35%). After 30 d of cold-storage, eggs were weighed and held at 26.6 °C and 75% relative humidity for 8 d before testing. To test the eggs’ suitability as hosts following cold storage, females of Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae) were released individually onto batches of eggs, and parasitization rates and the development, emergence, sex ratio, adult longevity, and size of parasitoid progeny were examined. Eggs stored at high relative humidity showed less weight loss than those stored at low relative humidity. The number of eggs parasitized was highest (5.9/15) on eggs stored at 6 °C and high relative humidity. Developmental times and adult emergence were optimal on host eggs stored at 2 °C and high relative humidity. A significantly lower proportion of eggs produced male parasitoids when eggs were stored at 2 or 6 °C. Adult longevity was not affected by egg storage conditions, but adult size of progeny decreased in eggs stored at 10 °C. In conclusion, eggs of R. pedestris stored below 6 °C and with a high relative humidity maintained the best quality for parasitization by O. nezarae.     

Biological characteristics and thermal requirements of a Brazilian strain of the parasitoid Trichogramma pretiosum reared on eggs of Pseudoplusia includens and Anticarsia gemmatalis

A new strain of the parasitoid Trichogramma pretiosum, was collected in Rio Verde County, State of Goiás, Central Brazil, and designated as T. pretiosum RV. This strain was then found to be the most effective one among several different strains of T. pretiosum tested in a parasitoid selection assay. Therefore, its biological characteristics and thermal requirements were studied, aiming at allowing its multiplication under controlled environmental conditions in the laboratory. The parasitoid was reared on eggs of Pseudoplusia includens and Anticarsia gemmatalis at different constant temperatures within an 18–32 °C temperature range. The number of annual generations of the parasitoid was also estimated at those temperatures. Results have shown that T. pretiosum RV developmental time, from egg to adult, was influenced by all temperatures tested within the range, varying from 6.8 to 20.3 days and 6.0 to 17.0 days on eggs of P. includens and A. gemmatalis, respectively. The emergence of T. pretiosum RV from eggs of A. gemmatalis was higher than 94% at all temperatures tested. When this variable was evaluated on eggs of P. includens, however, the figures were higher than that within the 18–30 °C range (more than 98%), and were also statistically higher than the emergence observed at 32 °C (90.2%). The sex ratio of the parasitoids emerged from eggs of A. gemmatalis decreased from 0.55 to 0.29 at 18–32 °C, respectively. However, for those emerged from eggs of P. includens, the sex ratio was similar (0.73, 0.72 and 0.71) at 20, 28 and 32 °C, respectively. The lower temperature threshold (Tb) and thermal constant (K) were 10.65 °C and 151.25 degree-days when the parasitoid was reared on eggs of P. includens; and 11.64 °C and 127.60 degree-days when reared on eggs of A. gemmatalis. The number of generations per month increased from 1.45 to 4.23 and from 1.49 to 4.79 when the parasitoid was reared on eggs of P. includens and A. gemmatalis, respectively, following the increases in the temperature.     

Effect of electron beam irradiation on developmental stages of Plutella xylostella (Lepidoptera: Plutellidae)

The effect of electron beam irradiation on each developmental stage of diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), was examined. Eggs, larvae, pupae, and adults were irradiated at target doses of 30, 50, or 100 Gy or they were left untreated as controls in replicated experiments. When eggs and pupae were irradiated with 100 Gy, emergence rates greatly decreased and, although some adults laid eggs, they did not hatch. Egg hatching of irradiated larvae and adult decreased with increasing irradiation doses. However, electron beam irradiation did not kill P. xylostella directly. Adult longevity was not affected. Reciprocal crosses between irradiated and unirradiated moths demonstrated that females were more radiosensitive than males in hatchability; however, the difference was not significant. In addition, electron beam-irradiated larvae showed typical DNA fragmentation in a dose-dependent manner compared with cells from unirradiated larvae. Our findings suggest that electron beam irradiation induces abnormal development and reproduction of P. xylostella; therefore, it may contribute to effective disinfestation and quarantine treatments of P. xylostella.     

Parental effects on fertilization and hatching success and development of Atlantic halibut (Hippoglossus hippoglossus L.) embryos and larvae

The parental effects on fertilization and early life history traits were studied in Atlantic halibut, Hippoglossus hippoglossus L. Sperm from 12 different males were used to fertilize eggs of two females in separate crosses. The fertilization success were generally high, above 80% of developing embryos at 16-cell stage in 20 of 24 crosses with an average of 85.9 ± 17.6% and 87.2 ± 16.5% for female A and female B, respectively. Corresponding hatching success was 74.8 ± 17.7% and 41.6 ± 20.1%, respectively. The relationship between fertilization success and hatching success was positive. The parental influence on hatching was dominated by a strong and significant (p < 0.001) maternal effect; however, the paternal effect was also significant (p < 0.001). Furthermore, there was no relationship between fertilization success, hatching success and larvae viability as a high number of larvae developed locked jaws (i.e., were not functional). There was a significant (p < 0.01) difference in yield of functional larvae of female A (43%) and female B (56%), and also between crosses sired by different males. The standard length of offspring of female A (12.4 ± 0.5 mm) and B (12.6 ± 0.6 mm) were significantly (p < 0.001) different, and also significantly influenced by both the female (p < 0.001) and the male (p < 0.001). The present paper provides strong indications that not only the female, but also the male parent influences quantitative features of early development of their offspring.     

Dietary inclusion of raw faba bean instead of soybean meal and enzyme supplementation in laying hens: Effect on performance and egg quality

An experiment was conducted with 160 Hisex Brown laying hens to evaluate the effect of different inclusion levels of faba bean (FB) and enzyme supplementation on productive performance and egg quality parameters. The experimental diets consisted of five levels of FB: 0% (control), 25%, 50%, 75% and 100%, substituting soybean meal (SBM), and two levels of enzyme supplementation (0 or 250 mg/kg). Each dietary treatment was assigned to four replicate groups and the experiment lasted 22 weeks. A positive relationship (P < 0.05) was found between FB inclusion and body weight (BW) change of hens when compared to those of the control treatment. Enzyme supplementation significantly affected the final hens’ BW. Feed consumption (FC) of hens was statistically increased with increasing FB level up to 50%. Supplementing dietary enzyme mixture at 250 mg/kg led to improvement in FC at all studied ages (P < 0.05). Inclusion of 25% or 50% FB in diets had no adverse effects on feed conversion ratio (FCR) compared to the higher FB inclusion levels (75% or 100%). Egg weight (EW), egg number (EN) and egg mass (EM) were significantly (P < 0.05) influenced by FB inclusion in diet during the entire experimental periods, except for EN and EM at 20–24 weeks of age. Egg productive parameters were not influenced by enzyme mixture supplementation (P > 0.05). The main effect of FB levels replacing for SBM affected (P < 0.05) yolk and shell percentages, yolk index, yolk to albumen ratio, shell thickness and egg shape index. It can be concluded that FB and enzyme supplementation could be included in hens diet at less than 50% instead of SBM to support egg productive performance, however higher raw FB levels negatively affected egg production indices and quality.     

Hatching,survival and deformities of piracanjuba (Brycon orbignyanus) embryos subjected to different cooling protocols

Groups of one hundred Brycon orbignyanus embryos at the stage of blastopore closure were subjected to different cooling protocols. Different combinations and concentrations of cryoprotectants were tested: sucrose, methanol, ethylene glycol and dimethyl sulfoxide (Me₂SO); at different temperatures (0.0 ± 2.0 °C and 8.0 ± 2.0 °C) and refrigeration times (6, 10, 24, 72 and 168 h), with the exception of the positive control (incubation without previous cooling). At the end of each refrigeration time, the embryos were acclimatized, rehydrated and incubated to determine hatching, survival and deformity rates. Morphological analysis of embryos was also carried out. The results showed that temperature and refrigeration time are critical factors for embryo survival. No embryos survived after 24, 72 and 168 h of refrigeration. Furthermore, when the refrigeration time increased from 6 to 10 h and the temperature decreased from 8.0 ± 2.0 °C to 0.0 ± 2.0 °C, mortality rates increased significantly. It was also found that in all protocols dead eggs and/or larvae with some degree of deformity were present. The main larval deformities observed were the malformation of the head, tail, yolk sac, vertebral column and eyes.     

Incubation temperature fluctuation does not affect incubation length and hatchling phenotype in the Chinese skink Plestiodon chinensis

Studies examining the effects of incubation temperature fluctuation on the phenotype of hatchling reptiles have shown species variation. To examine whether incubation temperature fluctuation has a key role in influencing the phenotype of hatchling Chinese skinks (Plestiodon chinensis), we incubated eggs produced by 20 females under five thermal regimes (treatments). Eggs in three treatments were incubated in three incubators, one set constant at 27 °C and two ramp-programmed at 27±3 °C and 27±5 °C on a cycle of 12 h (+) and 12 h (−). The remaining eggs were incubated in two chambers: one inside a room where temperatures varied from 23.0 to 31.1 °C, with a mean of 27.0 °C; the other outside the room where temperatures varied from 20.2 to 35.3 °C, with a mean of 26.1 °C. We found that: (1) for eggs at a given embryonic stage at ovipositon, the mean rather than the variance of incubation temperatures determined the length of incubation; (2) most (egg mass, embryonic stage at oviposition, incubation length and all examined hatchling traits except tail length and locomotor performance) of the examined variables were affected by clutch; and (3) body mass was the only hatchling trait that differed among the five treatments, but the differences were tiny. These findings suggest that incubation temperature fluctuation has no direct role in influencing incubation length and hatchling phenotype in P. chinensis.     

Aspects of the reproductive biology of Pseudaphycus maculipennis (Hym: Encyrtidae), a parasitoid of obscure mealybug,Pseudococcus viburni (Hem: Pseudococcidae)

Laboratory experiments to determine aspects of the reproductive biology of Pseudaphycus maculipennis are described. All experiments were carried out at a constant temperature of 21 ± 2 °C, a 16-h photoperiod and ambient RH. Pseudaphycus maculipennis was shown to be an arrhenotokous, synovigenic, gregarious endoparasitoid of Pseudococcus viburni. Females and males lived for 16 and 11 days, respectively, when fed either honey-agar or mealybug honeydew. Relatively, large instars (third instar or adult females) were preferred for oviposition; mated females parasitized more mealybugs than unmated females, and the progeny sex ratio favored females by 3:1. Egg load increased with age from emergence to day 8, averaging 23 mature eggs/female. Mean realised daily fecundity never exceeded 5, with a mean lifetime fecundity of 46 eggs/female. Parasitised mealybugs remained alive for about 5 days and then mummified. Total development period was 20–21 days (larva 4–5 days, prepupa 3 days, pupa 8–9 days). Development periods of eggs and individual larval instars were not measured. A mean of 3.01 ± 0.1 parasitoids/mealybug were reared after individual parasitism events, increasing through super-parasitism (either self or conspecific) to 9 parasitoids/mealybug when hosts were exposed to competing females. Pseudaphycus maculipennis progeny emerged from the mummies in discrete cohorts over periods ranging from 3 min to 18 h (depending on the number of cohorts).     

Bemerkenswerte endogene Farbveränderung der Eischale von Chioninia delalandii (Duméril & Bibron, 1839) (Reptilia: Sauria: Scincidae)

The paper describes an unusual endogenous eggshell colouration observed in an egg of the Cap Verde skink Chioninia delalandii.A female specimen, kept in a terrarium, laid three eggs. Two of them were considered as fertilized (oval germ-disk, weakly pink). They were embedded 1 cm deep in a layer of moistened clay granules (substrate/water 2:1) and kept under different temperatures (egg 1 “cool”, 26–27 °C; egg 2 “warm”, 29–30 °C). There was a normal embryonic development in both eggs from their volume-enlargement and characteristic allometric growth (egg wide > egg length). The young hatch after 51 and 56 days.A change in eggshell colour, however, occurred in the “warm” kept egg during the last third of its incubation period. It started with a small spot (2–3 mm) in the outer area of the animal egg pole and spread into a dark-violet colouration over the whole eggshell within 15 days. After hatching of the young the shells of both eggs were examined. In the non-coloured egg there was no great difference in colour between the inner and outer egg layer, while in the coloured egg there was a distinct difference between the inner part, which was dark violet-gray, and the pale gray calcareous deck-layer. From the macroscopic view along the edge of the eggshell it was not identifiable, if the colour pigment was infiltrated into protein fibrils of the condensed surface layer.A possible explanation for the eggshell colouration could be an unusual embryonic pigmentation. This assumption is based on the first appearance of a restricted, point-like coloured area and its further regular extension. It might be that dark pigments (melanophores?) reached the eggshell (membrana testacea) and infiltrated the border-area to the condensed surface layer.