Porcellio Spinicornis Research Articles

Statistics of insect catch within historic properties

IntroductionCertain species of insect are known to cause damage to historic collections. For more than a decade insects have been identified in traps set out in English Heritage properties, the data from which has been used in this paper. Descriptive statistics have been used to explore the data structure and insect distribution.ResultsAbout 55% of the traps of the more than 30000 traps examined over that period contained insects that were readily categorised. The rate of catch (insects/trap) was highest in London and the Southeast. Booklice (Liposcelis bostrychophila) and silverfish (Lepisma saccharina) were the most frequent catch. Woolly bear (Anthrenus spp.) larvae and crustacean woodlice (Porcellio spinicornis) were also common. A higher frequency of furniture beetles (Anobium punctatum) is notable in the Southeast and West. Despite this overall pattern, catch varied greatly between individual properties. The general view that insects have increased over time was not universal, although the dominant booklouse showed an increased catch over the last decade. The insects did not appear to be randomly distributed, but clustered onto traps in greater numbers than might be expected from a Poisson distribution, which suggested they occurred as infestations. Some insect species appeared in combination with other species at a higher frequency than expected, but the reasons for these associations were not always obvious. Pheromone traps collected more webbing and case bearing clothes moths (Tineola bisselliella, Tinea pellionella) than traps without attractants, much as expected. There are hints that covered traps may collect fewer insects than simple blunder traps.ConclusionsNo obvious drivers of high insect count were identified. Trends over time were not especially clear. The results provide clues to management of insect pests in historic properties. The presence and trapping of insects at a given property is individual in nature, and so mitigation strategies need to be site-specific. Although an insect might occur in low numbers in some periods, the possibility of infestation remains. Future work will examine the trends in catch more carefully and ascertain the importance of various environmental factors.

Terrestrial isopods (Crustacea, Oniscidea) at the Baltic Sea coast in Lithuania

A survey between 2004 and 2010 yielded 2434 individuals of seven terrestrial isopod species – Cylisticus convexus, Oniscus asellus, Trachelipus rathkii, Porcellio scaber, Porcellio spinicornis, Porcellium conspersum, along Ligidium hypnorum – along the Curonian Spit and in various woodlands in Lithuania. The data on the Lithuanian fauna of all terrestrial isopods are presented for the first time. Isopod richness was the highest in woody habitats (dune pine forests and old mixed forests) where common European and Holarctic species (O. asellus, P. scaber, and T. rathkii) formed the majority of isopod assemblages. Additionally, more specialized isopods (L. hypnorum, P. conspersum) were also found in mixed and deciduous forests. Porcellio scaber and T. rathkii, the species tolerating human and natural disturbances, were the only isopods found in sand dunes at the coast. The article includes a detailed list of Isopoda occurrences and the numbers of individuals captured. 2004–2010 metais Kursių nerijoje ir įvai...

Effect of forced fasting on magnesium and manganese regulation in a terrestrial isopod, Porcellio spinicornis Say (Porcellionidae, Isopoda, Crustacea).

Effect of forced fasting on magnesium and manganese regulation in a terrestrial isopod, Porcellio spinicornis Say (Porcellionidae, Isopoda, Crustacea).

Magnesium and manganese regulation during moult-cycle in Porcellio spinicornis Say (Porcellionidae, Isopoda).

One of the most obvious features of the lives of Crustacea is the way in which processes of growth and development are punctuated by the cyclic need to deposit a new cuticle and shed the old one. Much attention has been devoted to the endocrinology of this cyclic phenomenon, but rather less to physiological events accompanying actual events of ecdysis, the act of shedding the old cuticle. In earlier work, the author reports a significant increase in tissue Mg and Mn concentrations in Porcellio spinicornis reared on diets rich in these two metals, and that oxygen consumption and ammonia excretion are significantly affected by these accumulations. The present study provides information on the regulation of Mg and Mn tissue concentrations in adult P. spinicornis Say (Porcellionidae, Isopoda) during proecdysis, ecdysis, and postecdysis.

Magnesium and Manganese Uptake, Accumulation and Regulation by a Terrestrial Isopod,Porcellio SpinicornisSay (Porcellionidae, Isopoda, Crustacea)

Highest Mg concentration in whole intermoult, 7th growth-stage Porcellio spinicornis, exposed for 7 days to various Mg [367.39 ppb (carrot powder-control), 217.6 ppb (apple powder-control), 100, 150, 500, and 1000 ppm Mg, as well as two mixtures containing 500 ppm Mn + 150 ppm Mg and 500 ppm Mg + 500 ppm Mn)], and Mn concentrations [97.9 ppb (carrot powder-control), 2.0 ppb (apple powder-control), 100, 150, 500 and 1000 ppm)], was observed in males feeding on 500 ppm Mn + 150 ppm Mg, and lowest in females on 500 ppm dietary Mg. Highest tissue Mn concentration, on the other hand, was observed in males exposed to 1000 ppm dietary Mn, and lowest in females on 500 ppm Mg. Approximately 42% of the total tissue Mg was present in hepatopancreas and the remaining in other body tissues, including exoskeleton. In contrast, 78.55% Mn was stored in hepatopancreas and 21.4% in remaining body tissues. Differences between hepatopancreatic Mg levels were not significant between the two sexes, but differences in Mn levels between males and females were significant at P less than 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of magnesium and manganese uptake and accumulation on oxygen consumption and ammonia excretion in Porcellio spinicornis Say (Porcellionidae, Isopoda)

Mean concentrations of Mg and Mn in whole intermoult 7th growth-stage Porcellio spinicornis are positively correlated with dietary levels up to and including 1,000 ppm of these two trace metals. Lower tissue concentrations in isopods on 1,500 ppm diets are related to either a low food intake or a higher rate of metal excretion. Mean Mg concentration in whole isopods at the end of 7 days ranged from 27 388.26 +/- 598.56 micrograms/g dry tissue in the control to 69 122.08 +/- 31 682.98 micrograms/g dry tissue in the 1,000 ppm dietary group; in the 1,500 ppm dietary group, it amounted to 25 630.26 +/- 13 102.12 micrograms/g dry tissue. Mean Mn concentration varied from 85.53 +/- 11.23 micrograms/g dry tissue in the control to 229.05 +/- 32.33 micrograms/g dry tissue in 1,000 ppm dietary group; in the 1,500 ppm dietary group, it amounted to 199.57 +/- 18.99 micrograms/g dry tissue. Differences between the two sexes were significant at 5% level. Oxygen consumption was negatively and ammonia excretion was positively related to the dietary metal concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in counts of haemocytes and in their physicochemical properties during the moult cycle in Porcellio spinicornis Say (Porcellionidae, Isopoda)

Total haemocyte counts in seventh and eighth growth-stage intermoult Porcellio spinicornis ranged, on average, from 3663.7 haemocytes/mm3 (61.70% hyalinocytes, 10.97% hemigranulocytes, and 27.31% granulocytes) in the male (mean wet weight = 0.051 g) to 4888.1 haemocytes/mm3 (58.36% hyalinocytes, 13.0% hemigranulocytes, and 28.63% granulocytes) in the female (mean wet weight = 0.054 g). Hyalinocyte count decreased by 59.75% following circumferential ecdysial split but gradually increased during anterior moult to peak at postecdysis. However, redox and surface potentials of hyalinocytes remained elevated during the moult (beginning with circumferential ecdysial split to anterior ecdysis). Granulocyte redox and surface potentials were high during the postmoult and intermoult periods, but were low during the moult. No significant changes in the hemigranulocyte and granulocyte counts were observed during the moult cycle. The significance of these findings is discussed.

Adaptation of enzymes to temperature: Myofibrillar adenosine tri-phosphatase from two terrestrial isopod species

A comparison of the temperature profiles of the myofibrillar ATPase in Porcellio spinicornis and Metoponorthus pruinosus showed that Porcellio enzyme had a maximum activity between pH 6.8-7.2 at 9 degrees C, and that from Metoponorthus between pH 7.0-7.4 at 45 degrees C. The energy of activation for Porcellio enzyme was estimated to be 2.964 kcal/mol and that for Metoponorthus enzyme 9.91 X 10(-1) kcal/mol. The significance of these findings in relation to the natural habitats of these two species is discussed.

Effects of Growth-Stage and Nutritional Status On the Oxygen Consumption and Ammonia Production in Porcellio Spinicornis Say (Isopoda, Porcellionidae)

[La consommation d'oxygene et la production d'ammoniaque etaient reliees, la premiere directement, la seconde inversement, au niveau d'activite et a l'etat nutritionnel chez Porcellio spinicornis. La production d'azote etait plus elevee (P < 0.001), et de facon significative, chez les mâles nourris que chez les mâles a jeun, ou que chez les femelles nourries ou a jeun. La signification de ces observations est discutee., La consommation d'oxygene et la production d'ammoniaque etaient reliees, la premiere directement, la seconde inversement, au niveau d'activite et a l'etat nutritionnel chez Porcellio spinicornis. La production d'azote etait plus elevee (P < 0.001), et de facon significative, chez les mâles nourris que chez les mâles a jeun, ou que chez les femelles nourries ou a jeun. La signification de ces observations est discutee.]

Caloric Value and Ash Content in Relation To Body Length and Dry Weight of Porcellio Spinicornis Say (Isopoda, Porcellionidae)

[Les valeurs caloriques, les teneurs en cendres, les taux de croissance, et les poids frais et sec d'un groupe de Porcellio spinicornis, choisi dans une population elevee en laboratoire, ont ete determinees sur une periode de 132 jours. Les teneurs caloriques moyennes pour le 7eme stade variaient de 4233,66 cal/g poids sec a 5256,57 cal/g poids sec sans cendres, et, pour le 8eme stade, de 4233,66 cal/g poids sec a 5431,33 cal/g poids sec sans cendres. Le poids sec representait environ 32% du poids frais de l'animal, et la teneur en cendres variait de 9,55 a 19,26%. Les valeurs caloriques des exuvies etaient en moyenne de 64,8 cal/g poids sec et leurs teneurs moyennes en cendres representaient 11,88 %' Les valeurs energetiques calculees pour P. sprinicornis appuient l'hypothese de Richman (1958) selon laquelle les animaux a fortes teneurs caloriques ont generalement une fecondite faible et un stockage energetique important, qui peut agir comme amortisseur pendant les periodes defavorables de leur cycle biologique., Les valeurs caloriques, les teneurs en cendres, les taux de croissance, et les poids frais et sec d'un groupe de Porcellio spinicornis, choisi dans une population elevee en laboratoire, ont ete determinees sur une periode de 132 jours. Les teneurs caloriques moyennes pour le 7eme stade variaient de 4233,66 cal/g poids sec a 5256,57 cal/g poids sec sans cendres, et, pour le 8eme stade, de 4233,66 cal/g poids sec a 5431,33 cal/g poids sec sans cendres. Le poids sec representait environ 32% du poids frais de l'animal, et la teneur en cendres variait de 9,55 a 19,26%. Les valeurs caloriques des exuvies etaient en moyenne de 64,8 cal/g poids sec et leurs teneurs moyennes en cendres representaient 11,88 %' Les valeurs energetiques calculees pour P. sprinicornis appuient l'hypothese de Richman (1958) selon laquelle les animaux a fortes teneurs caloriques ont generalement une fecondite faible et un stockage energetique important, qui peut agir comme amortisseur pendant les periodes defavorables de leur cycle biologique.]

The physical characteristics of the haemolymph in Porcellio spinicornis say (Porcellionidae, Isopoda).

Absolute haemolymph volume in Porcellio spinicornis, as determined by the 14C-dilution and the haemolymph sodium estimation techniques, ranged, on the average, from 8.1 microliter in the 6th growth--stage to 15.06 microliter in the 9th growth--stage. The mean haemolymph volume per cent for all growth--stages (6th-9th) amounted to 33.78. The haemolymph pH varied from 6.42 to 6.54, osmotic pressure from 221 to 256 mM NaCl equivalents and the specific gravity from 1.031 to 1.052.

The energy budget of Porcellio spinicornis Say (Porcellionidae, Isopoda) under laboratory conditions.

The rate of energy flow in Porcellio spinicornis was investigated in a select group of a laboratory population. The consumption, assimilation and production were calculated to be 1 233, 1 002 and 304 cal/year, respectively, in the male, and 1 261, 1 198 and 429 cal/year, respectively, in the female. Ignoring loss due to mortality, and applying the population density of 2 295 m2 in the laboratory colony, the isopod population should consume 2 861.8 kcal m-2 year-1, resulting in an assimilation of 2 524.5 kcal m-2 year-1 and a total productivity of 841.1 kcal m-2 year-1.

Porcellio spinicornis Say (Isopoda) demography. III. A comparison between field data and the results of a simulation model

A simulation model for a Porcellio spinicornis Say population was constructed using laboratory data for rates of growth, reproduction, and survival and using winter survival rates observed in the field. The simulated output was compared with field data collected from 1971 to 1973. The expected and observed weight distributions and reproductive periodicities showed good agreement. The expected and observed patterns of numerical change also agreed for all life-history stages, except 18-month-old individuals, which disappeared from the field counts more quickly than expected. Sensitivity analysis showed that the time at which reproduction began each year was not as critical to population growth as were the effects of minor shifts in temperature on individual growth and survival rates. Furthermore, individual growth rate emerged as the factor having the greatest effect on patterns of population growth. Since the laboratory data on growth was reasonably accurate it is probable that the simulation model adequately describes the processes that determine the changes observed in the field population monitored during this study. All of the evidence indicated that during the period of study the population did not increase or decrease and that temperature conditions modifying demographic rates could have accounted for this observation.

Porcellio spinicornis Say (Isopoda) demography. II. A comparison between field and laboratory data

Field data from a demographic study of the terrestrial isopod Porcellio spinicornis Say were analyzed and compared with laboratory data reported by McQueen and Carnio. On the study area, which covered 482.8 m2, it was observed that reproduction began when average temperatures were &gt; 13 °C, and that about 86% of the individuals produced one brood and about 30% produced two broods. During 1972, 25 654 offspring were produced and during 1973, 27 664 offspring resulted from reproduction, which took place during May, June, July, and August. By October of both years, these animals attained sizes ranging from 10 to 30 mg and exhibited 42 to 47% survivorship. During the next summer, females grew to between 30 and 50 mg and males to between 20 and 40 mg, and survivorship ranged from 15% in May to 2% in August. During the third summer, females attained sizes ranging from 80 to 100 mg and males from 40 to 70 mg. Survivorship during this period ranged from 1% in May to 0% in August. All rates of growth, reproduction, and survival, as well as reproductive periodicity, agreed with independent laboratory studies conducted under controlled conditions. During the 3 years studied the field population remained relatively constant and appeared to be limited by temperature conditions.

A laboratory study of the effects of some climatic factors on the demography of the terrestrial isopod Porcellio spinicornis Say.

The demography of Porcellio spinicornis was modelled using growth, survival, and reproduction parameters modified by temperature, humidity, and day length. Growth rates were temperature-dependent (0.0 below 10 °C, increasing to a maximum at 30 °C, and decreasing to 0.0 above 35 °C). Survival rates were both temperature-dependent and size-dependent. Small animals (prejuveniles) survived between 10 °C and 35 °C with maximum survival at 25 °C. Medium-sized animals (juveniles) and adults survived between 0° and 35 °C with maximum survival at 25 °C. Females were able to reproduce between 17.5 °C and 27.5 °C, and the number of young produced increased with female size. P. spinicornis exhibited narrow humidity tolerances (95% RH ± 3% RH) but were able to search out and remain in microhabitats containing the correct humidity conditions. Day length had no detectable demographic effects.Simulations using the laboratory-based demographic model and field temperatures for 1971 and 1972 suggested that a P. spinicornis population should slowly increase in numbers. But when the 1971–1972 temperatures were decreased by art average of 0.77 °C, the simulated population decreased. This suggests that minor temperature fluctuations could regulate the numbers of P. spinicornis; and inspection of field temperature data from 1957–1973 indicates sufficient year to year temperature fluctuation to maintain stable P. spinicornis populations in Southern Ontario.