Differential effects of jasmonic acid treatment of Brassica nigra on the attraction of pollinators, parasitoids, and butterflies

Herbivore-induced plant defences influence the behaviour of herbivores as well as that of their natural enemies. Jasmonic acid is one of the key hormones involved in both these direct and indirect induced defences. Jasmonic acid treatment of plants changes the composition of defence chemicals in the plants, induces volatile emission, and increases the production of extrafloral nectar. However, few studies have addressed the potential influence of induced defences on flower nectar chemistry and pollinator behaviour. These have shown that herbivore damage can affect pollination rates and plant fitness. Here, we have investigated the effect of jasmonic acid treatment on floral nectar production and the attraction of pollinators, as well as the effect on the behaviour of an herbivore and its natural enemy. The study system consisted of black mustard plants, Brassica nigra L. (Brassicaceae), pollinators of Brassica nigra (i.e., honeybees and syrphid flies), a specialist herbivore, Pieris rapae L. (Lepidoptera: Pieridae), and a parasitoid wasp that uses Pieris larvae as hosts, Cotesia glomerata L. (Hymenoptera: Braconidae). We show that different trophic levels are differentially affected by jasmonic acid-induced changes. While the herbivore prefers control leaves over jasmonic acid-treated leaves for oviposition, the parasitoid C. glomerata is more attracted to jasmonic acid-treated plants than to control plants. We did not observe differences in pollinator preference, the rates of flower visitation by honeybees and syrphid flies were similar for control and jasmonic acid-treated plants. Plants treated with jasmonic acid secreted less nectar than control plants and the concentrations of glucose and fructose tended to be lower than in nectar from control plants. Jasmonic acid treatment resulted in a lower nectar production than actual feeding damage by P. rapae caterpillars.     

Transmission of visceral leishmaniasis in a previously non‐endemic region of Tunisia: Detection of Leishmania DNA in Phlebotomus perniciosus

Visceral leishmaniasis (VL) has been endemic in northern Tunisia and has occurred sporadically in the center of Tunisia. Recently, there have been several cases from areas known to be free of VL. We report in this work all human and canine cases of VL recorded between 2003 and 2011 and an entomological study of phlebotomine fauna in a previously non‐endemic region. Sixty‐three cases of VL were diagnosed and identified as L. infantum using several different methods. Eight species of 179 sand flies were caught and identified by both morphological and molecular methods. Two genera were present, Phlebotomus and Sergentomya, with an abundance of the subgenus Phlebotomus (Larrousius) spp., a classic vector of VL in Tunisia. Moreover, Leishmania DNA was detected in seven unfed Phlebotomus pernicousus and L. infantum was identified in three of them. This result confirms the establishment of a transmission cycle of VL in the studied region by the coexistence of infected vectors with infected hosts.     

Phylogeny of Heteronychia: the largest lineage of Sarcophaga (Diptera: Sarcophagidae)

Sarcophaga Meigen is one of the megadiverse genera of true flies, with approximately 850 valid species worldwide. The genus is divided into about 160 subgenera, the validity of a vast majority of which has never been verified using cladistic methods. This paper deals with the mainly Palaearctic subgenus Heteronychia Brauer & Bergenstamm, which comprises 89 species and is thus the largest subunit of Sarcophaga. We performed a cladistic analysis of the group based exclusively on male morphological characters. Parsimony analyses were run on a matrix of 84 characters for 88 species. Species of the subgenera Discachaeta Enderlein and Notoecus Stein were also included in the matrix. A further analysis was carried out using a subset of characters from the terminalia alone (70 characters). The results show that the clade formed by Heteronychia, Discachaeta, and Notoecus is monophyletic, with Discachaeta emerging as polyphyletic whereas Sarcophaga (Notoecus) longestylata Strobl is nested within the Sarcophaga filia‐group. Character states supporting Heteronychia and the few well‐supported species‐groups are discussed in detail. The following synonymies are proposed: Discachaeta = Heteronychia ( syn. nov. ) and Notoecus = Heteronychia ( syn. nov. ). The paper also includes a historical background of the taxon in relation to the classification of the genus Sarcophaga over the past two centuries, as well as a terminological review of the male terminalia, particularly of the distiphallus. © 2013 The Linnean Society of London     

Biological control of snail-borne diseases: a review

The need for alternatives to chemical control of snail-borne diseases and the growing interest in biological control methods are noted. Two groups of natural enemies of snails reviewed as especially promising for biological control are competing and predatory snails, and predatory fly larvae. Potentially useful natural enemies of the intramolluscan stages of trematodes include microsporidian infections and antagonistic trematode larvae. More unusual methods of biological control include the use of a toxic plant product (endod) and genetic manipulation of snails to decrease their susceptibility to trematode infection. The disappointing progress in biological control of snail-borne diseases in the past is attributed largely to delay in recognizing the need for alternatives to chemical control and to lack of interdisciplinary communication.     

Seasonal occurrence of black flies (Diptera: Simuliidae) in a desert stream receiving trout farm effluent

The distribution and abundance of black flies (Diptera: Simuliidae) in a small desert stream were influenced by environmental changes caused by recharge of water supply storage basins and an aquaculture operation. Simulium virgatum was the most abundant benthic insect collected in Whitewater Canyon (Riverside County, CA) after April; however, it was never found in trout farm effluent where the ammonium‐nitrogen concentration was > 0.25 mg/liter. S. virgatum densities downstream of the input of water from the Colorado River aqueduct were lower than at other sampling sites in the Whitewater River. Simulium tescorum, an especially anthropophilic black fly, was most abundant during February and March, was not collected from late spring through early autumn, and was found only in the highly enriched, less variable flow of trout farm effluent. The mean concentrations of ammonium nitrogen and nitrate nitrogen in the trout farm effluent nearly 1 km from the fish holding ponds were ten and two times, respectively, the ambient levels in the Whitewater River upstream of the effluent discharge point. A combination of factors probably contributed to the presence of S. tescorum in the trout farm effluent including homogenization of the flow regime, enrichment of larval resources, and the development of riparian vegetation that provided oviposition and attachment sites.     

Additions to the Limoniidae and Pediciidae fauna of Morocco,with an updated checklist (Diptera,Tipuloidea)

Eighteen species of Limoniidae and two species of Pediciidae are recorded for the first time in Morocco, of which 15 species are new to North Africa. An updated checklist of Moroccan short-palped craneflies (Limoniidae and Pediciidae) is appended, containing 73 species in 25 genera.     

Effect of dimethoate on the developmental rate of forensic importance Calliphoridae flies

Forensic entomotoxicology has grown to impact judicial systems in developed countries. Where the use of insects and maggots as samples in death investigations as an alternative technique, especially following degradation or loss of the conventionally used samples. Carrion flies feed on dead bodies and may ingest toxic substances found in the dead body, especially when the body was poisoned before death. The knowledge of how the chemicals interact with the insect following ingestion is crucial to forensic entomotoxicologists. The study investigated the impact of dimethoate on the life cycle of four species of Calliphoridae flies, namely Chrysomya megacephala, Chrysomya saffranea, Chrysomya rufifacies and Chrysomya indiana. Various concentrations of dimethoate (1 ppm, 2 ppm, 3 ppm and 4 ppm) were utilized in the study. The rate of development of the carrion flies showed a negative correlation with the concentration of the chemical. This paper glares at the impact of the chemicals may pose to the insects, and how analysis of such impacts can guide forensic investigations of poisoning and help the investigators to solve the crime puzzle.     

Variation in density of cattle-visiting muscid flies between Danish inland pastures

Abstract. The density of cattle-visiting flies (Muscidae) and the load of black-flies (Simulium spp.) were estimated in twelve and eighteen inland pastures in Denmark in 1984 and 1985 respectively. No differences in the geographical distribution pattern of the predominant cattle-visiting Muscidae were recorded, whilst the relative abundance and density of the species and the total fly-load varied considerably between pastures. In most cases the mean loads of Haema-tobia irritans (L.) and Hydrotaea irritans (Fall.) on heifers varied significantly in relation to site topography and shelter. These crude site variables explained 65–98% of the variation in densities of horn flies and sheep head flies observed between pastures. Highest densities of Hydrotaea irritans were primarily associated with permanent, low-lying, fairly sheltered grassland sites, whereas the density was low in temporary, dry, wind-exposed pastures. A comparable relationship was found for Haematobia irritans. With Haematobosca stimulans (Mg.) and Morellia spp. no relation between grassland environment and fly density was detected.     

Test for the effects of 60-Hz magnetic fields on fecundity and development in Drosophila

Ramirez et al (1983) reported reduced egg laying by Drosophila melanogaster and reduced survival of those eggs to adulthood when adult flies were exposed to magnetic fields. In a similar study, no effects from exposures of Drosophila to 1-mT, 60-Hz magnetic fields were found.     

Global distribution patterns provide evidence of niche shift by the introduced African dung beetle Digitonthophagus gazella

The establishment of cattle ranches throughout the world has prompted the release of dung beetles as biological control agents that reduce pasture fouling and control dung-breeding flies. One of these beetles, Digitonthophagus gazella (Fabricius) (Coleoptera: Scarabaeidae), that is native to southeast Africa, has been introduced into the Americas, Australia, and New Zealand. Distribution records for this species have been used to develop climate models of potential future establishment. Recent studies, however, identify D. gazella as a complex of seven species. Taking into account this revision, and the clear identification of the records belonging to the actual D. gazella, we developed environmental models to identify factors that have contributed to the establishment of this species across regions and habitats. We compared the environmental conditions of D. gazella in its native range against those in the regions where the species has or has not established. Our results indicate that D. gazella is still absent in certain parts of Central and South America and parts of Africa where it could potentially establish. We speculate that its distribution in Africa is limited by competitive exclusion. The introduction of D. gazella in America is relatively recent, such that the full extent of its distribution has probably yet to be realized. In Australia and North America, D. gazella is present in regions not predicted according to its native environmental conditions. This discrepancy may reflect a lack of competitive exclusion, phenotypic plasticity, and/or genetic adaptation. Our analyses suggest that the species has the ability to adapt to a wide range of environmental conditions that are extremely different from those in their native region. The species represents a useful case study to indicate that an introduced species may expand its realized niche beyond what is expected based on apparent environmental limits in the species native range.