The Necessity of a New Synthesis Comments on the Book by E. N. Mirzoyan Etyudy po istorii teoreticheskoi biologii (Essays on the History of Theoretical Biology), Kiev, 2001

Russian Journal of Developmental Biology -     

Effect of Temperature on the Life History of Cirrospilus sp. near lyncus (Hymenoptera: Eulophidae), a Parasitoid of Phyllocnistis citrella (Lepidoptera: Gracillariidae)

The effect of four constant temperatures on the life history of Cirrospilus sp. near lyncus was examined in the laboratory. This species is one of the most abundant generalist indigenous parasitoids of the citrus leafminer, Phyllocnistis citrella Stainton, in Spain. Adult lifespan of C. sp. near lyncus decreased from 50.2 to 9.1 days as temperatures increased from 15 to 30°C, respectively. Both gross fecundity and host-feeding were highest at 20°C (170.48 eggs and 32.33 hosts). Oviposition rates were optimal at higher temperatures (5.22 eggs per day at 25°C and 4.79 eggs per day at 30°C) and were dependent on female age. In contrast, host-feeding rates for a given temperature did not depend on age. Generation time decreased with increasing temperatures from 68.05 days at 15°C to 12.19 days at 30°C. Net reproduction peaked at 20°C (68.86 viable females per female). Intrinsic rate of increase doubled from 15°C (0.059 females per female per day) to 20°C (0.127 females per female per day) and almost doubled again from 20 to 30°C (0.210 females per female per day). Given these parameters, C. sp. near lyncus could perform optimally in the area occupied by P. citrella in the Mediterranean region.     

Impact of Ligula intestinalis (L.1758) (Cestode), on the growth of Barbus setivimensis (Cyprinidae) in a lake system in Algeria

The Algerian freshwater fish fauna is mainly represented by the Cyprinidae family, in particular, the genus Barbus. This is represented only by natural populations of the subgenus Barbus. The systematic, based mainly on the methods of biometrics, is quite different from one author to another. However, two nominal species are usually cited: Barbus callensis (Valenciennes, 1842), which is limited to the region of El Kala (eastern Algeria) and Barbus setivimensis (Valenciennes, 1842) in other parts of the North. During the ecological study of this fauna, many individuals were found infested with the tapeworm Ligula intestinalis (Linné, 1758), which led us to study the effect of this parasite on B. setivimensis using the ecological parasites' index (prevalence, abundance and parasite intensity) and to focus on the impact of the parasite on the growth of fish. Tapeworm L. intestinalis presents a wide geographical distribution and a complex lifecycle to multiple hosts: the cycle starts in the body of birds. The life expectancy in the major host is a maximum of 5 days, but in this time, they will lay a multitude of eggs. These eggs are passed into water via the faeces of the bird. Once in the aquatic medium, they hatch and are eaten by a wide range of copepod zooplankton (first intermediate host). The cycle continues when fish (second intermediate host) ingests the copepod. The worm then burrows through the gut wall and continues to develop in the fish's body cavity. The cycle is then complete when the bird (final host) eats the tapeworm-hosting fish. We studied the effects of diet, the hosting period, the habitat on the prevalence, abundance and intensity of the parasitic larvae plerocercoid L. intestinalis and the parasiting effect on the Cyprinids fishs of the genus Barbus in the Keddara dam (Boumerdes, Algeria) during one year. Although L. intestinalis was recorded in several host fish, the available data on the parameters of parasitism are limited and no studies are reported on B. setivimensis. In this study, a total of 613 individuals were sampled and checked on the presence of L. intestinalis plerocercoid stages. Only 64 were infested. The value of the prevalence was 10.44% and the average intensity was 1.89 parasites (average two parasites per infested fish). The infection rate is high during the autumn and low during the spring season. The latter corresponds with the breeding period.     

Hygrohypnum subeugyrium (Renauld & Cardot) Broth. (Hypnales), a neglected British moss,with a note on its occurrence in the Himalayas

Hygrohypnum subeugyrium was first reported for Britain in 1976, but it has been ignored in subsequent British floras and identification guides. Morphologically it is a distinct species. New localities were discovered during a meeting of the British Bryological Society in Scotland in 2017. A subsequent revision of herbarium material has shown that H. subeugyrium is widely distributed in Scotland and occurs southwards to a few localities in England and Wales. Its extra-European distribution is extended to include the Himalayan region (Sikkim and Yunnan). It is described and illustrated, and its diagnostic characters are discussed.     

Studies on the population dynamics and integrated management of Fusarium oxysporum f. sp. psidi (Fop), a cause of guava (Psidium guajava) wilt

To assess the impact of non-host crops intercropping, bioagents and oil cakes, on population dynamics of Fusarium oxysporum f. sp. psidii (Fop) and wilt of guava. Lowest population of Fop was recorded in garlic followed by intercropping with marigold with reduction of 84.9 and 83.9%, respectively. Bioagents viz; Aspergillus niger, Trichoderma viride and Trichoderma harzianum reduced the Fop population significantly, with the lowest in T. harzianum followed by A. niger. Garlic bulb extract exhibited maximum inhibition of Fop growth (2.7 cm) followed by marigold (2.4 cm), respectively, over control. Neem cake significantly reduced population of Fop, closely followed by mahua cake, over control. Integration of neem cake + T. harzianum + garlic reduced the Fop population significantly, over control, followed by neem cake + T. harzianum + marigold but neem cake + T. harzianum + marigold reduced wilt disease significantly in comparison to neem cake + T. harzianum + garlic inter-cropping.     

Allintoshius bioccai n. sp. (Nematoda), a parasite of the bat Eptesicus furinalis from Paraguay,and new data on A. parallintoshius (Araujo, 1940)

A new species of parasitic nematode (Nematoda: Trichostrongylina, Heligmosomoidea) Allintoshius bioccai n. sp., found in the small intestine of the vespertilionid bat Eptesicus furinalis from Paraguay, is described. The new species can be differentiated from A. urumiac (Freitas and Mendon?a, 1960) by the absence of vulvar spines in females, and from A. nudicaudus (Freitas and Mendon?a, 1963) by the shape of the spicules and the dorsal ray of the copulatory bursa. New data on the morphology and distribution of Allintoshius parallintoshius (Araujo, 1940) are also reported. E. furinalis, Myotis albescens and M. riparius are recorded as new hosts for this species. A key for the identification of the species belonging to the genus Allintoshius is also given.     

Effect of cassava exudate and prey densities on the survival and reproduction of Typhlodromalus limonicus (Garman & McGregor) s.l. (Acari: Phytoseiidae), a predator of the cassava green mite,Mononychellus tanajoa (Bondar) (Acari: Tetranychidae)

The effects of cassava exudate and prey densities on reproduction and survival of the predatory mite, Typhlodromalus limonicus (Garman & McGregor) (Acari: Phytoseiidae), were investigated in the laboratory. Females were provided either cassava exudate ad lib. daily, low or high numbers of the cassava green mite prey, Mononychellus tanajoa (Bondar) (Acari: Tetranychidae) daily, or exudate for 5 or 10 days before switching to a low or high prey diet. Females fed only exudate laid no eggs. Females fed exudate before prey experienced a significant decrease (30%) in the number of eggs laid compared to females fed high numbers of prey daily. The reduction in fecundity was the result of prolonged preoviposition periods (2.0 days on prey daily vs 4.0 days on exudate before prey) and reduced number of eggs laid per female per day (1.7 eggs per female per day on prey daily vs 0.4 eggs per female per day on exudate before prey). Females fed only exudate had a greater survival rate and longevity than females fed prey daily or females fed exudate before a diet of prey. These results suggest that T. limonicus can survice for a limited period on cassava exudate during periods of low prey availability, but requires prey to complete oögenesis and propagate the population.     

Bionomic notes on Pachysomoides sp. (Hymenoptera: Ichneumonidae), a parasitoid of the Neotropical social wasp Polistes satan Bequaert (Hymenoptera: Vespidae)

Although most polistine wasp species are found in the Neotropical region, mainly in Brazil, only a very limited number of South American parasitoids or parasites are known to exist. We assessed the frequency of a hymenopterous parasitoid, Pachysomoides sp. (Ichneumonidae, Cryptinae), in the nests of the Brazilian independent‐founding wasp Polistes satan and compared the rates of the parasitization of P. satan by Pachysomoides sp. between the dry (winter) and wet (summer) seasons. Pachysomoides sp. larvae were seen to feed on P. satan pupa and were found in both the upper and lower parts of the host pupal cell (ca. 10 individuals in each host pupal cell). Approximately one‐third of the pupal cells in the P. satan colonies were parasitized in the dry season, whereas there were no parasitized pupal cells in the wet season. Consequently, the rates of parasitization by Pachysomoides sp. were significantly greater during the dry season than during the wet season due to unknown reasons.     

Effects of different temperatures on the life history of Evania appendigaster L. (Hymenoptera: Evaniidae), a solitary oothecal parasitoid of Periplaneta americana L. (Dictyoptera: Blattidae)

The influence of temperatures on the life parameters of the solitary oothecal parasitoid Evania appendigaster, was investigated in the laboratory. Parasitized oothecae of Periplaneta americana were left to develop under seven constant temperatures: 15, 17, 20, 25, 30, 35, and 40 °C. At the end, we found that: (i) E. appendigaster was able to complete development within the temperature range of 17–34 °C; (ii) mean adult longevity decreased as temperature increased, with the temperature of 40 °C being fatal in a matter of hours; (iii) males lived longer than females between 15 and 30 °C; (iv) adult emergence rate was the highest at 25 °C, and (v) no wasps emerged at 15 or 40 °C. Non-emerged oothecae contained either unhatched eggs or dead larvae. We determined the theoretical lower developmental threshold and thermal constant for the complete development as 12.9 °C and 584.8 day-degrees for males, and 13.1 °C and 588.2 day-degrees for females, respectively. A good balance between faster development, maximum adult longevity and good egg viability was obtained between 25–30 °C, and that would be the best temperature range for rearing E. appendigaster.     

Impact of Vairimorpha sp. (Microsporidia: Burnellidae) on Trichogramma chilonis (Hymenoptera, Trichogrammatidae), a hymenopteran parasitoid of the cabbage moth, Plutella xylostella (Lepidoptera, Yponomeutidae).

A multi-generation mass breeding colony of the cabbage moth, Plutella xylostella, was found to be infected with a microsporidium, Vairimorpha sp., which is passed transovarially between generations. The microsporidian infection had little impact on the fitness of this lepidopteran pest. However, when Trichogramma chilonis parasitized such infected host eggs, the offspring of this parasitoid species suffered from severe deficiencies. Microsporidian spores, ingested by parasitoid larvae together with the host egg nutrients, gave rise to stages which developed in various tissues of the parasitoid, such as the flight muscle and the nervous system. This infection resulted in a significantly increased rate of metamorphosis failure (related to host age) and reduced longevity and reproductive performance of the parasitoids. There are two main consequences arising from our findings if T. chilonis is to be used in an integrated control strategy against P. xylostella: (1) T. chilonis must be raised on Vairimorpha-free host eggs to receive viable and efficaceous parasitoids for release and (2) if natural populations of the cabbage moth in cruciferous crops are infected with Vairimorpha to a significant extent, the parasitoid must be released repeatedly within infested crop areas.     

HP(2-9)-magainin 2(1-12), a synthetic hybrid peptide, exerts its antifungal effect on Candida albicans by damaging the plasma membrane.

In our previous study, HP(2-9)-MA(1-12), HP-MA for short, a hybrid peptide incorporating residues 2-9 of Helicobacter pylori ribosomal protein L1 (HP) and residues 1-12 of magainin 2 (MA) was shown to have strong antibacterial activity. In this study the antifungal activity of HP-MA was evaluated using various fungi, and it was shown that the activity was increased when compared with the parent peptides. In order to investigate the fungicidal mechanism(s) of HP-MA its action against fungal cell membranes was examined by the potassium-release test, which showed that HP-MA caused an increase in the amount of K+ released from the cells. Furthermore, HP-MA induced significant morphological changes. These facts suggested that the fungicidal effect of HP-MA involves damaging the fungal cell membranes. CD investigators suggested that the alpha-helical structure of these peptides plays an important role in their antibiotic effect, but that alpha-helicity is less directly correlated with the enhanced antibiotic activity of the hybrid.     

Tss (Tail-short Shionogi), a new short tail mutation found in the BALB/cMs strain, maps quite closely to the Tail-short (Ts) locus on mouse chromosome 11.

A spontaneous morphological mutation characterized by a short and kinky tail (Tail-short Shionogi: Tss) was observed in a BALB/cMs mouse breeding colony. The inheritance mode of the Tss mutation is semi-dominant, and homozygotes (Tss/Tss) are probably embryonic lethal. The viability of the Tss/+ heterozygotes appear to be influenced by the mating partner: 47.1% of the (BALB/cMs-Tss/+ x C57BL/6J)F1 embryos were the mutant phenotype, whereas there were no (BALB/cMs-Tss/+ x A/J)F1 embryos with the mutant phenotype. The Tss locus was mapped by linkage analysis between microsatellite markers D11Mit128 and D11Mit256 on mouse Chromosome 11. These results suggest that the Tss mutation is a new allele on the Tail-short (Ts) locus.