The mutualism of Melissotarsus ants and armoured scale insects in Africa and Magadascar: distribution, host plants and biology

Είδη μυρμηγκιών του γένους Melissotarsus Emery είναι διαδεδομένα στην Αφροτροπική περιοχή (τρία είδη M. beccarii Emery, M. emeryi Forel και M. weissi Santschi) καθώς και ένα είδος στην Μαγαδασκάρη (M. insularis Santschi). Τα μυρμήγκια όλων αυτών των ειδών δημιουργούν τις στοές τους σε ζωντανό ξύλο διαφόρων δικοτυλήδονων δένδρων, κοντά στο φλοιό. Τα μυρμήγκια διατηρούν εντός των στοών πληθυσμούς διαφόρων ειδών κοκκοειδών εντόμων τηςοικογένειας Diaspididae. Στην παρούσα εργασία παρουσιάζεται μια ανασκόπηση πάνω στη γεωγραφική κατανομή της παρατηρούμενης συμβίωσης των ειδών μυρμηγκιών του γένους Melissotarsus και των δέκα ειδών κοκκοειδών εντόμων της οικογένειας Diaspididae, καθώς και των φυτών ξενιστών όπου παρατηρείται η συμβίωση. Η οικολογία της παρατηρούμενης συμβίωσης συζητείται καθώς και τα πιθανά οφέλη που προκύπτουν για τα είδη που συμβιώνουν.Species of the ant genus Melissotarsus Emery are widespread in the Afrotropical region (three species, namely M. beccarii Emery, M. emeryi Forel and M. weissi Santschi) and in the Madagascar region (one species, namely M. insularis Santschi). The ants of all these species tunnel their galleries in live wood of various dicotyledonous trees, close to the bark surface. The ants maintain within these galleries populations of different species of armoured scale insects. A review is presented on the geographical distribution of mutualism, of the Melissotarsus species, the associated 10 species of armoured scale insects, and the host plants on which the mutualism takes place. The ecology of the mutualism is discussed also, together with suggestions on the benefits that the partners gain from the associations

First record of the invasive species Parasaissetia nigra in Greece

Στην παρούσα εργασία γίνεται η πρώτη καταγραφή του είδους Parasaissetia nigra (Nietner) (Hemiptera: Coccidae) επί της ροδιάς στην Ελλάδα. Η παρουσία του είδους αυτού διαπιστώθηκε σε καλλωπιστική ροδιά, τον Ιούνιο του 2014, εντός της Πανεπιστημιούπολης του Γεωπονικού Πανεπιστημίου Αθηνών. Δίδονται πληροφορίες σχετικά με τα μορφολογικά και βιολογικά χαρακτηριστικά, όπως και για την εξάπλωση του εντόμου.In June 2014, the nigra scale Parasaissetia nigra (Nietner) (Hemiptera: Coccidae) was recorded for the first time in Greece on pomegranate, Punica granatum. Its occurrence was observed in an ornamental pomegranate tree in the campus of the Agricultural University of Athens. Information on its morphology, biology and distribution is presented

THE CITRICULUS MEALYBUG, PSEUDOCOCCUS CRYPTUS HEMPEL, AND ITS NATURAL ENEMIES IN ISRAEL: HISTORY AND PRESENT SITUATION

THE CITRICULUS MEALYBUG, PSEUDOCOCCUS CRYPTUS HEMPEL, AND ITS NATURAL ENEMIES IN ISRAEL: HISTORY AND PRESENT SITUATION. The citriculus mealybug, Pseudococcus cryptus Hempel, was first discovered in Israel in 1937 and very rapidly became a key pest of citrus. However, since the early 1940s, the mealybug population has sharply decreased. This occurred in parallel with the establishment of the introduced parasitoid Clausenia purpurea Ishii, which was then believed to be the main cause of the biological control of the mealybug. Since the late 1980s, outbreaks of P. cryptus have been recorded mainly in new citrus varieties, such as red grapefruits, pomelo, “sweety” and several peeling varieties. The current outbreaks are probably related to the susceptibility of these mentioned varieties to P. cryptus, and to the adverse effects of Insect Growth Regulators to coccinellid predators, especially Scymnus spp. The introduced C. purpurea and two other local encyrtid parasitoids, Leptomastix near algirica and Anagyrus diversicornis Mercet, rarely emerged from samples of P. cryptus collected during 1996-1998. Four further parasitoid species were introduced into Israel during 1996-1997 against P. cryptus: from central Asia, the platygasterids Allotropa burrelli Muesebeck and A. convexifrons Muesebeck and the encyrtid, Pseudaphycus malinus Gahan; and from Japan, Anagyrus sawadai Ishii. A. convexifrons and A. sawadai successfully parasitized P. cryptus and, therefore, were released in the field but only A. sawadai has so far been recovered. A considerable reduction in population densities of the pest has been recorded since May, 1998, in the major release site of the latter species. Key words: distribution, host plants, Pseudococcus comstocki, P. citriculus, P. viburni, IGR, Coccinellidae, Planococcus citri, P. ficus, Aonidiella aurantii, Ceroplastes floridensis, Anagyrus pseudococci, Leptomastidia abnormis, Leptomastix flavus, Cryptolaemus montrouzieri, Cecidomyiidae, Sympherobiidae, Chrysopidae

SCALENET: A SEARCHABLE INFORMATION SYSTEM ON SCALE INSECTS

SCALENET: A SEARCHABLE INFORMATION SYSTEM ON SCALE INSECTS. Systematic information on the scale insects of the world is currently being compiled and synthesized in a database system called BASIS. The information is organized by scale insect family and is searchable at a site on the World Wide Web called ScaleNet (http:\\www.sel.barc.usda.gov\scalenet\scalenet.htm). The site provides general information on scale insects, including sections on economic importance, life histories, distribution and ecology, classification and biographies. A query system provides information on valid names and provides a complete systematic catalogue for any valid genus or species. For a particular taxon, queries will give the following information: all hosts of a scale, distribution of a scale, references for a scale, a checklist of all valid species in a family or genus, biological notes and remarks for a scale. It also will give the scales that occur on a particular host, all systematic references on scales that were published between two dates, all references published by an author, all references with any of five selected words in a title or annotations, a list of all scales described by a particular author, all scales from a particular zoogeographic region, country or country subunit, and the scientific name of any common name of a scale. Key words: BASIS, Biological and systematic information service, Coccoidea, Coccinea, Aclerdidae, Asterolecaniidae, Beesoniidae, Cerococcidae, Coccidae, Conchaspididae, Dactylopiidae, Diaspididae, Eriococcidae, Halimococcidae, Kermesidae, Lecanodiaspididae, Margarodidae, Micrococcidae, Ortheziidae, Phoenicococcidae, Phenacoleachidae, Pseudococcidae, Tachardiidae

An autoparasitoid wasp, inferior at resource exploitation, outcompetes primary parasitoids by using competitor females to produce males

1. Autoparasitoids are intraguild consumers that attack and kill heterospecific and conspecific parasitoids as well as immature stages of hemipteran hosts, such as aphids, whiteflies and soft scales. Field experiments assessing the importance of interspecific competition between autoparasitoids and primary parasitoids, as well as its impact on herbivore suppression, are scarcely found in the ecological literature. 2. Using field data from 40 olive orchards, this study examined the mechanisms that regulate: (i) the interspecific competition between primary parasitoids of the genus Metaphycus and the autoparasitoid Coccophagus lycimnia; and (ii) the density of their shared herbivore host, the soft scale Saissetia oleae. 3. Metaphycus parasitoids used smaller hosts than C. lycimnia, yet did not outcompete C. lycimnia. On the other hand, C. lycimnia preferred to use Metaphycus females as secondary hosts for producing males rather than their own females. This preference might explain why the autoparasitoid negatively affected the density of the primary parasitoids. 4. Parasitism by the autoparasitoid C. lycimnia at the beginning of the season was the sole variable positively related to host mortality throughout the season, showing its greater effect on herbivore suppression. 5. In this study, an autoparasitoid, inferior at resource exploitation, was shown to outcompete a primary parasitoid without disrupting herbivore suppression.info:eu-repo/semantics/publishedVersio

Testing systems of identical components

We consider the problem of testing sequentially the components of a multi-component reliability system in order to figure out the state of the system via costly tests. In particular, systems with identical components are considered. The notion of lexicographically large binary decision trees is introduced and a heuristic algorithm based on that notion is proposed. The performance of the heuristic algorithm is demonstrated by computational results, for various classes of functions. In particular, in all 200 random cases where the underlying function is a threshold function, the proposed heuristic produces optimal solutions

Diaspididae (Hemiptera: Coccoidea) of Espírito Santo, Brazil

Twenty-seven species of armored scale insects (Hemiptera: Diaspididae) are newly recorded from Espírito Santo, Brazil, and information on the host plants and geographic distribution of the 31 species of Diaspididae that have been identified in the State is provided. New plant host records are reported for 11 of the diaspidid species studied and results are discussed with respect to development of agriculture in this and similar areas with objectives of modernization and diversification

Apparent wave function collapse caused by scattering

Some experimental implications of the recent progress on wave function collapse are calculated. Exact results are derived for the center-of-mass wave function collapse caused by random scatterings and applied to a range of specific examples. The results show that recently proposed experiments to measure the GRW effect are likely to fail, since the effect of naturally occurring scatterings is of the same form as the GRW effect but generally much stronger. The same goes for attempts to measure the collapse caused by quantum gravity as suggested by Hawking and others. The results also indicate that macroscopic systems tend to be found in states with (Delta-x)(Delta-p) = hbar/sqrt(2), but microscopic systems in highly tiltedly squeezed states with (Delta-x)(Delta-p) >> hbar.Comment: Final published version. 20 pages, Plain TeX, no figures. Online at http://astro.berkeley.edu/~max/collapse.html (faster from the US), from http://www.mpa-garching.mpg.de/~max/collapse.html (faster from Europe) or from [email protected]

Does the universe in fact contain almost no information?

At first sight, an accurate description of the state of the universe appears to require a mind-bogglingly large and perhaps even infinite amount of information, even if we restrict our attention to a small subsystem such as a rabbit. In this paper, it is suggested that most of this information is merely apparent, as seen from our subjective viewpoints, and that the algorithmic information content of the universe as a whole is close to zero. It is argued that if the Schr\"odinger equation is universally valid, then decoherence together with the standard chaotic behavior of certain non-linear systems will make the universe appear extremely complex to any self-aware subsets that happen to inhabit it now, even if it was in a quite simple state shortly after the big bang. For instance, gravitational instability would amplify the microscopic primordial density fluctuations that are required by the Heisenberg uncertainty principle into quite macroscopic inhomogeneities, forcing the current wavefunction of the universe to contain such Byzantine superpositions as our planet being in many macroscopically different places at once. Since decoherence bars us from experiencing more than one macroscopic reality, we would see seemingly complex constellations of stars etc, even if the initial wavefunction of the universe was perfectly homogeneous and isotropic.Comment: 17 pages, LATeX, no figures. Online with refs at http://astro.berkeley.edu/~max/nihilo.html (faster from the US), from http://www.mpa-garching.mpg.de/~max/nihilo.html (faster from Europe) or from [email protected]

The 40Ca(alpha,gamma)44Ti reaction in the energy regime of supernova nucleosynthesis

The 44Ti(t1/2 = 59 y) nuclide, an important signature of supernova nucleosynthesis, has recently been observed as live radioactivity by gamma-ray astronomy from the Cas A remnant. We investigate in the laboratory the major 44Ti production reaction, 40Ca(alpha,gamma)44Ti (E_cm = 0.6-1.2 MeV/u), by direct off- line counting of 44Ti nuclei. The yield, significantly higher than inferred from previous experiments, is analyzed in terms of a statistical model using microscopic nuclear inputs. The associated stellar rate has important astrophysical consequences, increasing the calculated supernova 44Ti yield by a factor ~2 over previous estimates and bringing it closer to Cas A observations.Comment: To be published in Phys. Rev. lett., 4 pages, 1 table, 2 figure