Distribution of Chaetodactylus krombeini (Acari: Chaetodactylidae) within Osmia cornifrons (Hymenoptera: Megachilidae) nests: implications for population management

Chaetodactylus krombeini (Baker) (Acari: Chaetodactylidae) is a cleptoparasitic mite that negatively affects propagation of Osmia spp. (Hymenoptera: Megachilidae) for orchard pollination in the USA. This study was conducted to determine the effect of C. krombeini on mortality of male and female Osmia cornifrons, the Japanese hornfaced bee. A total of 107 O. cornifrons nests were examined to determine within-nest distribution of C. krombeini with regression analyses. A total of 30 mite-free O. cornifrons nests were observed and within-nest distribution of male and female O. cornifrons was determined with non-linear regression analyses. In addition, cocoons from 20 mite-infested O. cornifrons cells were examined to determine whether C. krombeini could be found inside cocoons of O. cornifrons. The results of this study showed that female O. cornifrons and C. krombeini were found more frequently in the inner part of the nest, and male O. cornifrons were found mostly in the center of the nest. No C. krombeini were found inside O. cornifrons cocoons. These results indicate that C. krombeini have a greater negative impact on mortality in the egg and larval stages of female O. cornifrons than in male O. cornifrons. Implications for management of C. krombeini and O. cornifrons populations for orchard pollination are discussed in this article.     

Cytogenetics of the South American DROSOPHILA MULLERI Complex: The MARTENSIS Cluster. More Interspecific Sharing of Inversions

Three Drosophila mulleri complex species have been found to be endemic to the cactus regions of northern South America. The three species are morphologically distinct, and no hybridization between species has been found in either the laboratory or nature. An analysis of their salivary gland chromosomes revealed that they evolved from a single cytological population, subspecies F of the ancestor of the D. mulleri complex, and comprise a cluster of sister species that are homozygous for inversions not found elsewhere. Within the martensis cluster are also found several inversions that are unique for these species, but have segregated out among the three species. Thus 2f² is found in martensis and starmeri, but not in uniseta, while 2t⁶, 3v and 3w are found in starmeri and uniseta, but not in martensis. This is analogous to the situation found within the remainder of the mulleri complex species, all the members of which share homozygosity for six other inversions. An interpretation of the cytological evolution of the martensis cluster is proposed.     

The mountain weasel Mustela kathiah (Carnivora: Mustelidae): Molecular and Karyological data

The karyotype of Mustela kathiah was first described. Its structure is most similar to the karyotype of M. altaica, differing in the morphological peculiarities of five pairs of large chromosomes. A comparative analysis of mitochondrial genes in the species Mustela allowed us to clarify understanding of the place of M. kathiah in the system of the genus. The earlier hypothesized proximity of the species to a group of small weasels (altaica, nivalis) or to a group of South Asian species (strigidorsa, nudipes) was not confirmed. A high level of differences between M. kathiah of Vietnam and specimens from southern China in nucleotide sequences of the cytochrome b (7.7%) and ND2 (6–6.2%) genes was found. It is supposed that difference in the two gene sequences found in geographically distanced populations of M. kathiah may be adaptive.     

Dryinid (Hym.: Dryinidae) parasitoids ofDalbulus leafhopper (Hom.: Cicadellidae) in Mexico

Little is known about the natural enemies of the leafhopperDalbulus spp. (Homoptera: Cicadellidae). Searches for its dryinid (wasps) parasitoids were made in Jalisco, Mexico. Jalisco contains the greatest number ofDalbulus species, and is considered to be near to the center of origin of this leafhopper genus and its host plants: maize, teosintes (Zea spp.) and gamagrasses (Tripsacum spp.). The dryinidGonatopus bartletti was found parasitizingD. maidis on maize and on annual teosinteZea mays spp.parviglumis. G. flavipes was found parasitizingD. elimatus on perennial teosinteZ. perennis; and a new speciesG. moyaraygozai andAnteon ciudadi parasitizingD. quinquenotatus onTripsacum pilosum andT. dactyloides. Parasitism by dryinids was found at altitudes of 680–2,000 m.Dalbulus maidis, the leafhopper species which causes the greatest losses in maize in Latin America, was found to be parasitized from 680–1,760 m. TheDalbulus species associated with annual host plants (maize andZ. mays spp.parviglumis) were parasitized by dryinids during the rainy season, while theDalbulus species associated with perennial host plants (Z. perennis andTripsacum) were parasitized by dryinids during both the rainy and dry season. The greatest diversity of dryinid parasitoids ofDalbulus spp. and the highest levels of parasitism were recorded from perennial plants, indicating that such species are reservoirs of natural enemies ofDalbulus spp.     

Survey for parasites ofSesamia calamistis (Lep.: Noctuidae) andEldana saccharina (Lep.: Pyralidae) in southwestern Nigeria

Field surveys were conducted during 1990–92 to document the relative abundance of different species of parasites of the lepidopterous stem borersSesamia calamistis Hampson andEldana saccharina Walker in maize fields in southwestern Nigeria. Species of parasitoids detected on both stem borers included the larvalpupal parasitoidsSturmiopsis parasitica Curran (Diptera: Tachinidae) andBrachymeria feae Masi (Hymenoptera: Chalcididae), and the larval parasitoidDolichogenidea polaszeki Walker (Hymenoptera: Braconidae). The braconidCotesia sesamiae (Cameron) was found attackingS. calamistis. The hyperparasitoidExoristobia dipterae (Risbec) (Hymenoptera: Encyrtidae) was detected on a pupa ofS. parasitica. Parasitic nematodes belonging toMermis sp. and/orHexamermis sp. were found infesting larvae of both stem borers. Overall, larval/pupal parasitization levels at Ibadan were low and ranged from 4.2 to 22.8% forS. calamistis and 1.2 to 13% forE. saccharina. Of the parasites found,S. parasitica was the most common, followed by nematodes. Four hymenopteran egg parasitoids were found attackingS. calamistis: Telenomus busseolae Gahan,T. isis Polaszek (Scelionidae),Lathromeris ovicida Risbec, andTrichogrammatoidea eldanae Viggiani (Trichogrammatidae). Egg parasitization ranged from 13.4 to 41.5%. The only egg parasitoid detected onE. saccharina wasTelenomus applanatus Bin and Johnson, which inflicted only 5% parasitization.     

Habitat selection by two Mediterranean species of Aplysia: A. fasciata poiret and a. depilans Gmelin (Mollusca : Opisthobranchia)

Factors influencing habitat selection were examined in two species of Mediterranean Aplysia. Animals and egg masses were found in four types of habitats that varied in degree of exposure to wave action. Both species were frequently found in groups. Neither species was common in areas cut off from the surge of the sea. No difference in food preference was observed. A. depilans Gmelin were primarily found in areas subject to greater wave action, while A.fasciata Poiret dominated the calmer habitats. Both species were common in intermediate environments. In late summer, when A. depilans are absent, A. fasciata penetrated some environments previously dominated by the former. Morphological and behavioural features of A. depilans and A.fasciata are consistent with adaptation to rough and calm habitats, respectively.     

Induction of estrus in mice: hypophyseal-adrenal effects

P-Chlorophenylalanine (p-ChPhe) was found to induce estrus in estrogen-primed ovariectomized C57BL/6J and DBA/2J mice but not in adrenalectomized females. α-Methyltyiosine had no such effects. It was concluded that serotonergic pathways are involved in reserpine- or p-ChPhe-induced estrus. Both p-ChPhe and reserpine were found to be ineffective in induction of estrus in hypophysectomized female mice. It appears that pituitary ACTH released by these drugs causes release of an adrenal hormone (probably progesterone) which is of functional significance in estrus.     

Age-specific dose-mortality effects of Beauveria bassiana (Deuteromycotina: Hyphomycetes) on the European corn borer,Ostrinia nubilalis (Lepidoptera: Pyralidae)

Three isolates of Beauveria bassiana were evaluated under laboratory conditions for pathogenicity against the European corn borer, Ostrinia nubilalis. Dose-mortality regressions and nonparametric statistical analyses revealed significant differences in pathogenicity between isolates and across O. nubilalis instars. First instars were found to be the most susceptible of the five larval stages. Little difference was noted for instars 2, 3, and 5 within any of the three B. bassiana isolates. Fourth instar larvae were found to be the most tolerant in all cases.     

Nuclear interactions in a heterokaryon: insight from the model Neurospora tetrasperma

A heterokaryon is a tissue type composed of cells containing genetically different nuclei. Although heterokaryosis is commonly found in nature, an understanding of the evolutionary implications of this phenomenon is largely lacking. Here, we use the filamentous ascomycete Neurospora tetrasperma to study the interplay between nuclei in heterokaryons across vegetative and sexual developmental stages. This fungus harbours nuclei of two opposite mating types (mat A and mat a) in the same cell and is thereby self-fertile. We used pyrosequencing of mat-linked SNPs of three heterokaryons to demonstrate that the nuclear ratio is consistently biased for mat A-nuclei during mycelial growth (mean mat A/mat a ratio 87%), but evens out during sexual development (ratio ranging from 40 to 57%). Furthermore, we investigated the association between nuclear ratio and expression of alleles of mat-linked genes and found that expression is coregulated to obtain a tissue-specific bias in expression ratio: during mycelial extension, we found a strong bias in expression for mat A-linked genes, that was independent of nuclear ratio, whereas at the sexual stage we found an expression bias for genes of the mat a nuclei. Taken together, our data indicate that nuclei cooperate to optimize the fitness of the heterokaryon, via both altering their nuclear ratios and coregulation genes expressed in the different nuclei.     

A new species and record of branchial parasitic isopods (Crustacea: Isopoda: Bopyridae: Pseudioninae) of porcellanid crabs from the Philippines

Branchial bopyrids infesting porcellanid crabs from the Philippines were investigated based on intertidal collections made in 1999-2000. Crabs of the genus Petrolisthes collected from sites in the northern Philippines were examined and two parasite species were found. One new pseudionine species found infesting Petrolisthes sp. [cf. Petrolisthes asiaticus (Leach)] is described as Aporobopyrus galleonus (prevalence 6.1%); this species is distinguished from other members of the genus by a setose palp on the maxilliped of the females, barbula morphology, and male characters including the possession of pleopods. This represents the second described species of Aporobopyrus from the Philippines, and the first from porcellanid crabs. In addition, Pleurocrypta macrocephalaNierstrasz and Brender à Brandis, 1923 (originally described from Indonesia) was found infesting the same unidentified Petrolisthes sp. (prevalence 2.6%); this is the first report of the species from the Philippines.     

Helminths: comparison of their rhodoquinone

A rhodoquinone (RQ) has been isolated from Stephanurus dentatus and has been shown to be identical with RQ-9 from Ascaris lumbricoides var. suis (A. suum). The ratio of RQ/mg N is fairly constant among larval, juvenile, and adult forms of S. dentatus with an average value of 1.63 μg/mg N. A Chromatographie survey found RQ in all eleven species of helminths tested. Ubiquinone (UQ) was found in all larval forms, a free living nematode (Rhabditis strongyloides) and helminths with prepatent periods shorter than 35 days.     

Aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae) in cultivated and non-cultivated areas of Markazi Province, Iran

The fauna of aphid parasitoids (Hymenoptera: Braconidae: Aphidiinae), as well as their diversity and tritrophic (parasitoid-host aphid-host plant) associations in cultivated and non-cultivated areas of Markazi province, was studied during 2004–2009. Thirty species of Aphidiinae belonging to 9 genera were identified. There are presented, in total, 73 associations with 32 host aphids occurring on 42 host plants. Five parasitoid-aphid associations are newly recorded from Iran. Lysiphlebus cardui (Marshall) is newly recorded for the fauna of Iran. Lysiphlebus fabarum (Marshall) and Diaeretiella rapae (M’Intosh) were the most abundant species in non-cultivated (72.96%) and cultivated (41.17%) areas, respectively. In the non-cultivated areas, L. fabarum was found on eight aphid species, while in cultivated areas it was only found on Aphis craccivora Koch. In cultivated areas, Sitobion avenae (F.) has the greatest diversity of parasitoids (Shanon-Weiner H = 0.875) whereas in non-cultivated areas the greatest diversity of parasitoids was recorded upon Acyrthosiphon pisum (Harris) (Shanon-Weiner H = 1.149). Significant differences were found between diversity of two ecosystems based on the overall diversity indices. Both species diversity and evenness were greater in cultivated ecosystems. The results are discussed in relation to the over-all parasitoid-aphid-plant associations in the area.     

(+)-Pinpollitol: A di-O-methyl d-(+)-chiro-inositol from Pinus radiata

(+)-Pinpollitol, a new cyclitol recently isolated from the pollen of Pinus radiata, was found in the needles of this species. (+)-Pinpollitol was found to be a di-O-methyl ether Of d-(+)-chiro-inositol, and tentative isomeric structures have been proposed for the cyclitol. (+)-Pinpollitol is the first di-O-methyl inositol to be found in a gymnosperm and is one of only three di-O-methyl inositols yet found in nature.     

Taxonomy of the genus Aspasia Lindley (Orchidaceae: Oncidieae)

The genusAspasia (Orchidaceae: Oncidieae) consists of five species of epiphytic orchids of Central and South America. The genus is compared with closely related genera of the tribe Oncidieae.Aspasia epidendroides is found in Nicaragua, Costa Rica, and western Panama.Aspasia principissa is found in central and eastern Panama and adjacent Colombia.Aspasia psittacina is endemic to western Ecuador.Aspasia variegata is found in Colombia, Venezuela, Trinidad, Guyana, Surinam, and Brazil.Aspasia lunata is known only from Brazil.     

Ultrastructural Analysis of Spermiogenesis in Segregation Distorter Males of DROSOPHILA MELANOGASTER: The Homozygotes

We have studied spermiogenesis at the ultrastructural level in males of genotype SD(NH)-2/SD-72, which are nearly sterile owing to the dysfunction of virtually all of their sperm. Ultrastructural aspects of spermiogenesis in these homozygous SD males are qualitatively similar to those found among dysfunctional sperm produced by heterozygous SD males. In particular, chromatin condensation and/or compaction has been found to be abnormal. However, major quantitative differences have been noted. Most of the dysfunctional sperm in SD(NH)-2/SD-72 males are individualized and coiled. Then, the sperm evidently undergo degeneration, as few mature sperm can be found in the seminal vesicle. The relevance of these findings to the mechanism leading to near sterility in homozygous SD males is discussed.     

Babesia argentina, Plasmodium vivax and P. falciparum: antigenic cross-reactions

An indirect fluorescent antibody test was used to analyze the antigenic relationships between Babesia argentina, a parasite of cattle, and two human malaria parasites, Plasmodium falciparum and Plasmodium vivax. Elevated antibody titers to P. falciparum were found in cattle infected with B. argentina. Some persons infected with P. falciparum or P. vivax were found to produce antibodies to B. argentina. Explanations for the occurrence of these cross reactions are considered.     

Nesting habitat segregation between closely related terricolous sphecid species (Hymenoptera:Spheciformes): key role of soil physical characteristics

Microhabitat selection based on abiotic factors was examined in five species of digger wasps (Sphex funerarius, Ammophila heydeni, Ammophila pubescens, Ammophila sabulosa, Bembix tarsata), four of which are of high conservation interest. All the study sites were located in areas affected by anthropogenic disturbance (reclaimed brown-coal mining areas, and railway dykes) in Central Europe. The individual species responded differentially to the variability in each of the physical characteristics measured, which resulted in site-specific exclusion of individual sphecid species. The sphecids were found to discriminate between available microhabitats based on ground inclination (slope) and vegetation cover. All but A. heydeni segregated the microhabitats according to the content of gravel and sand particles. S. funerarius and B. tarsata were limited by their preferences of low soil compactness, whereas A. pubescens utilized highly compacted soils, which were predominant in the study area. Soil shear strength (cohesiveness) was driving the level of gregariousness of the sphecids. In B. tarsata, number of cells per burrow was found to be higher in soils with increased penetration resistance. Experimental increase in soil compactness led to the abandonment of nesting microhabitats in the subsequent nesting seasons. Besides the well-known biotic factors, such as specialization at different size or type of prey, variability in abiotic factors between individual microhabitats (e.g. patches of sand) was found to be both necessary and sufficient to allow the parallel presence of viable populations of several sphecid species.     

Longidorus biformis n. sp. and L. glycines n. sp. (Nematoda: Longidoridae): Two Amphimictic Species from Arkansas

Two new amphimictic species of Longidorus were found in Arkansas. Longidorus biformis n. sp., found in the rhizosphere of hardwood trees along streams in sandy soil in 14 Arkansas locations, is characterized by its long body (5.42-9.50 mm), wide expanded flattened head end, head width 20.0 to 26.0 µm, odontostyle 96 to 125 µm, guide ring 29 to 38 µm posterior to the anterior end, elongate conoid tail, and c'' = 0.9-2.1. Females with 2 to 11 vetromedian supplement-like structures were found in 2 of 14 populations of this new species. Longidorus biformis n. sp. is closest to L. seinhorsti Peneva, Loof &Brown, 1998 and L. closelongatus Stoyanov, 1964. Among North American species it is closest to L. glycines n. sp. A distinguishing feature of L. biformis n. sp. is the presence of supplement-like organs in some females. Longidorus glycines n. sp., found in soybean microplots at the Main Research Station, Fayetteville, Arkansas, is characterized by its long body (6.14-8.31 mm), wide offset flattened head end, head width 20.3 to 23.3 µm, odontostyle 87.3 to 99.5 µm, guide ring 22.3 to 26.4 µm posterior to the anterior end, short conoid tail with rounded terminus, and c'' = 0.9-1.4. Longidorus glycines n. sp. is closest to L. lusitanicus Macara, 1985. Among North American species it is close to L. biformis n. sp., L. breviannulatus Norton and Hoffman, 1975, and L. crassus Thorne, 1964. Both new species are believed to have four juvenile stages; the first stage was not found for L. biformis n. sp.