Reproductive aspects of Meloetyphlus fuscatus a meloid beetle cleptoparasite of the bee Eulaema nigrita (Hymenoptera, Apidae, Euglossini)

This study investigated the reproductive biology of the meloid beetle Meloetyphlus fuscatus Waterhouse, a cleptoparasite of Eulaema nigrita nests. New E. nigrita nests had rates of cell parasitism by meloids ranging from 3.7% to 15.8%, while in re-used nests the rate of cell parasitism ranged from 1.4% to 18.7%. The adult parasites were never observed trying to leave the host nests. Both sexes mated more than once. Females had a high fecundity (more than 8,000 eggs), and in most cases, deposited their eggs into the empty, old cells of the host. The triungulins (the first larval instars) hatched from eggs 18-20 days after oviposition and dispersed from the host nest by attaching themselves to males as they emerged. The triungulins most likely transfer to female bees during mating and are transported to the nests of their hosts. Within an attacked cell, the triungulin consumes the bee egg and completes its development by consuming the larval food stored in the cell.

Vectorial Competence of Larvae and Adults of Alphitobius diaperinus in the Transmission of Salmonella Enteritidis in Poultry

Introduction: The ingestion of food products originating from poultry infected with Salmonella spp. is one of the major causes of food poisoning in humans. The control of poultry salmonellosis is particularly difficult since birds are asymptomatic and numerous factors may expedite the maintenance of bacteria in poultry production facilities. Objective: The aim of the study was to determine the vectorial capacity of adults and larvae of Alphitobius diaperinus (Coleoptera: Tenebrionidae) in the experimental transmission of Salmonella Enteritidis phage type 4 to 1-day-old specific pathogen-free White Leghorn chicks. Methods: Adult insects and larvae were starved for 1 day, fed for 24 h or 7 days on sterile ration that had been treated with Salmonella Enteritidis phage type 4, and the levels of bacterial infection were determined. Infected adult insects and larvae were fed to groups of day-old chicks, after which bacteria were recovered from cecum, liver, and spleen samples over a 7-day period. Results: Infected larvae were more efficient than adult insects in transmitting Salmonella Enteritidis to chicks. Higher concentrations of bacteria could be reisolated from the cecum, liver, and spleen of chicks that had ingested infected larvae compared with those that had ingested infected adults. Conclusions: The control of A. diaperinus, and particularly of the larvae, represents a critical factor in the reduction of Salmonella spp. in poultry farms.

Regulatory effects of an inhibitor from Plathymenia foliolosa seeds on the larval development of Anagasta kuehniella (Lepidoptera)

The Mediterranean flour moth, Anagasta kuehniella, is one of the most important insect pests of grains, reported worldwide, feeding on stored grains and products of rice, rye, corn and wheat. Plants synthesize a variety of molecules, including trypsin inhibitors, to defend themselves against attack by insects. In this study, a trypsin inhibitor (PFTI) was purified from Plathymenia foliolosa (Benth.) seeds and was tested for insect growth regulatory effect. The survival and mass of A. kuehniella larvae feeding on control seeds were about 82.7% and 5 ring, respectively, whereas survival on seeds containing 0.7% PFTI was about 56%, while a 66.1% reduction in the average mass of the larvae was observed. The results from dietary utilization experiments with A. kuehniella larvae showed a reduction in efficiency of conversion of ingested food and digested food, and an increase in approximate digestibility and metabolic cost. The level of trypsin was significantly decreased in larval midgut and increased in the feces of larvae reared on a diet containing 0.7% PFTI. Results indicate that PFTI possesses a toxic effect against A. kuehniella larvae. (C) 2008 Elsevier Inc. All rights reserved.

Aldermaston Peace March April 5 1964 Brisbane Australia

Three men and a woman during Aldermaston Peace March, April 5 1964 in Brisbane Australia. The march covered the distance between Ipswich and Brisbane, Australia. Marchers walked in relays covering approximately two miles each. Most relay sections were sponsored by one or more individual organisations. Convoy of Volkswagon Beetles and FB Holdens can be seen following them. Facades of Elphinstones store, Masonic Centre and St Andrews can be seen on the left with the People's Palace in the distance and the Central Railway Station on the right.

Host age effect and expression of cytoplasmic incompatibility in field populations of Wolbachia-superinfected Aedes albopictus

The Asian tiger mosquito, Aedes albopictus (Skuse), is a known vector of dengue in South America and Southeast Asia. It is naturally superinfected with two strains of Wolbachia endosymbiont that are able to induce cytoplasmic incompatibility (CI). In this paper, we report the strength of CI expression in crosses involving field-caught males. CI expression was found to be very strong in all crosses between field males and laboratory-reared uninfected or wAlbA infected young females. In addition, crossing experiments with laboratory colonies showed that aged super- infected males could express strong CI when mated with young uninfected or wAlbA infected females. These results provide additional evidence that the CI properties of Wolbachia infecting Aedes albopictus are well suited for applied strategies that seek to utilise Wolbachia for host population modification.

In vitro cultivation of Wolbachia pipientis in an Aedes albopictus cell line

A continuous cell line, Aa23, was established from eggs of a strain of the Asian tiger mosquito, Aedes albopictus, naturally infected with the intracellular symbiont Wolbachia pipientis. The resulting cell line was shown to be persistently infected with the bacterial endosymbiont. Treatment with antibiotics cured the cells of the infection. In the course of establishing this cell line it was noticed that RFLPs in the PCR products of two Wolbachia genes from the parental mosquitoes were fixed in the infected cell line. This indicates that the mosquito host was naturally superinfected with different Wolbachia strains, whereas the infected cell line derived from these mosquitoes only contained one of the original Wolbachia strains. The development of anin vitroculture system for this fastidious microorganism should facilitate molecular analysis of the reproduction distorting phenotypes it induces in natural arthropod hosts.

Replacement of the natural Wolbachia symbiont of Drosophila simulans with a mosquito counterpart

Inherited rickettsial symbionts of the genus Wolbachia occur commonly in arthropods and have been implicated in the expression of parthenogenesis, feminization and cytoplasmic incompatibility phenomena in their respective hosts. Here we use purified Wolbachia from the Asian tiger mosquito, Aedes albopictus, to replace the natural infection of Drosophila simulans by means of embryonic microinjection techniques. The transferred Wolbachia infection behaves like a natural Drosophila infection with regard to its inheritance, cytoskeleton interactions and ability to induce incompatibility when crossed with uninfected flies. The transinfected flies are bidirectionally incompatible with all other naturally infected strains of Drosophila simulans, however, and as such represent a unique crossing type. The successful transfer of this symbiont between distantly related hosts suggests that it may be possible to introduce this agent experimentally into arthropod species of medical and agricultural importance in order to manipulate natural populations genetically.

Glow worms as a tourist attraction in Springbrook National Park: Visitor attitudes and economic issues

nsect-based tourism mainly caters to a niche market, but its popularity has been growing in recent years. Despite its popularity this form of tourism has remained under-researched and in a sense its contribution to the tourism industry has gone mostly unnoticed. This paper reports the results of a study undertaken on one form of popular insect-based tourism, namely glow worms. The study was undertaken in Springbrook National Park (Natural Bridge section) southeast Queensland, which has one of the largest glow worm colonies in Australia that attracts thousands of visitors each year. A study of this form of tourism is important and useful for several reasons. It is important to understand this hitherto under-studied tourism activity to determine the type of visitors, their socio-economic attributes, economic benefits to the local economy, visitors’ knowledge of glow worms, education imparted, visitor satisfaction of glow worm viewing and visitor attitudes for the introduction of a user fee system to view glow worms. An understanding of these issues could not only help to better manage this valuable biological resource, but can be used to develop the industry to cater to a growing number of visitors. Tourism in glow worms can potentially be used not only to educate the public on the threats affecting glow worms and their colonies, but could also be used to conserve them. Lessons learnt from glow worms as an attraction to Springbrook National Park can be used to better manage and further develop other existing and new glow worm sites in Australia and elsewhere for tourism. Furthermore, it could provide some guidance for the management and development of other forms of current insect-based tourism activities (eg. butterflies) and develop new tourism ventures based on species such as stick insects and jewel beetles for which Australia is well known (Reader’s Digest, 1997)

Life tables of the processionary caterpillar Ochrogaster lunifer Herrich-Schaffer (Lepidoptera : Thaumetopoeidae) at local and regional scales

A major ongoing debate in population ecology has surrounded the causative factors underlying the abundance of phytophagous insects and whether or not these factors limit or regulate herbivore populations. However, it is often difficult to identify mortality agents in census data, and their distribution and relative importance across large spatial scales are rarely understood. Were, we present life tables for egg batches and larval cohorts of the processionary caterpillar Ochrogaster lunifer Herrich-Schaffer, using intensive local sampling combined with extensive regional monitoring to ascertain the relative importance of different mortality factors at different localities. Extinction of entire cohorts (representing the entire reproductive output of one female) at natural localities was high, with 82% of the initial 492 cohorts going extinct. Mortality was highest in the egg and early instar stages due to predation from dermestid beetles, and while different mortality factors (e.g. hatching failure, egg parasitism and failure to establish on the host) were present at many localities, dermestid predation, either directly observed or inferred from indirect evidence, was the dominant mortality factor at 89% of localities surveyed. Predation was significantly higher in plantations than in natural habitats. The second most important mortality factor was resource depletion, with 14 cohorts defoliating their hosts. Egg and larval parasitism were not major mortality agents. A combination of predation and resource depletion consistently accounted for the majority of mortality across localities, suggesting that both factors are important in limiting population abundance. This evidence shows that O. lunifer is not regulated by natural enemies alone, but that resource patches (Acacia trees) ultimately, and frequently, act together to limit population growth.

Toxicity of biorational insecticides to Helicoverpa spp. (Lepidoptera : Noctuidae) and predators in cotton field

Field trials on upland cotton (Gossypium hirstum L.) during its reproductive phase were used to assess the toxicity of several biorational pesticides and chemicals to Helicoverpa armigera (Hubner) and H. puntigera Wallengren, as well as major predators at Dalby, Queensland, Australia. Moderate rate-dependent control was obtained in plots treated with neem (Azadirachta indica A. Juss) seed extract-azadirachtin (Aza) at rates of 30, 60 and 90 g/ha. Plots treated with Talstar EC (bifenthrin) applications achieved the best results, followed by treatment with alternation of chemicals (methomyl, bifenthrin, thiodicarb and endosulfan) and biorational insecticides (neem oil, azadirachtin and Bacillus thuringiensis kurstaki var. Berliner). Predators, including lady beetles, lacewings, spiders and predatory bugs, were insensitive to Aza, tooseendanin (Tsdn) and BT applications. In contrast, chemicals were very destructive of predators. All treatments provided some protection from infestation of H. armigera and H. puntigera. The effect of Aza on Helicoverpa spp. was reflected in a relatively higher yield of seed cotton harvested from Aza-treated plots compared with the control, but chemical control achieved significantly higher yields than any other treatment.

Extensive chromosomal variation associated with taxon divergence and host specificity in the gall-inducing scale insect Apiomorpha munita (Schrader) (Hemiptera : Sternorrhyncha : Coccoidea : Eriococcidae)

Apiomorpha Rubsaamen (Hemiptera: Coccoidea: Eriococcidae) is one of the most chromosomally diverse of all animal genera. There is extensive karyotypic variation within many of the morphologically defined species, including A. munita (Schrader) which is here reported to have diploid chromosome counts ranging from 6 to more than 100. Each of the three morphologically defined subspecies of A. munita also displays considerable chromosomal variation: A. m. tereticornuta Gullan (2n =6, 8, 20, 22 or 24), A. m. malleensis Gullan (2n =6, 20, 22, 24 or 26), and A. m. munita (Schrader) (2n=54 or >100). Apiomorpha munita appears to occur only on eucalypts of the informal subgenus Symphyomyrtus, with each of the subspecies of A. munita restricted to discrete symphyomyrt sections. Several different karyotypic forms within each subspecies of A. munita appear to be restricted to only one or a few eucalypt species or series. The association between apparent host specificity and chromosomal rearrangements in A. munita suggests that both may be playing an active role in taxon divergence in Apiomorpha. (C) 2001 The Linnean Society of London.

Females of the weevil Zabrotes subfasciatus manipulate the size and number of eggs according to the host seed availability

In some insects, the finding of oviposition substrate triggers the uptake into oocytes of yolk proteins that are stored in the fat body during post-embryonic development. The main host of the bean weevil Zabrotes subfasciatus (Coleoptera; Chrysomelidae; Bruchinae; Amblycerini), in which larval resources are the sole source for future egg maturation, is Phaseolus vulgaris. Despite not feeding as adults, females of this species are able to lay eggs after encountering host seeds but it is not known how females react to changes in the availability of bean seeds. In the present study, the behaviour of Z. subfasciatus facing two very different environments for oviposition is investigated, as well as how this influences offspring fitness. The results obtained show that females of Z. subfasciatus react to variations in the availability of seeds belonging to the same host species by adjusting egg size and number. Females on low bean seed density lay larger and fewer eggs than those on high bean seed density, demonstrating a trade-off between these reproductive traits. Moreover, females can adjust egg size to changing levels of host availability during the first 4 days of their oviposition period. Although no difference in offspring weight is found, those from small eggs (low competition environment) result in larger adults. No response to selection on these traits after rearing beetles on the same host for 40 generations is observed. This unresponsiveness may indicate that beetle populations behave according to their reaction norm that already allows rapid adaptation to a varying amount of host-seed availability and better exploitation of the environments of this widespread stored-seed pest.

Host preference of the bean weevil Zabrotes subfasciatus

It is largely known that the range of an insect diet is mostly determined by oviposition behavior, mainly in species with endophytic larvae such as Zabrotes subfasciatus. However, the proximate factors determining host choice and the subsequent steps leading to the expansion or reduction of the host number and occasional host shifts are largely unknown. We analyzed various factors determining host preference of Z. subfasciatus through the evaluation of: (i) oviposition preference of a wild population of Z subfasciatus on the usual host (bean) and unusual hosts (lentil, chickpea and soy), and the performance of the offspring; (ii) artificial selection for increasing preference for hosts initially less frequently chosen; (iii) comparison of oviposition behavior between two different populations (reared for similar to 30 generations in beans or chickpeas, respectively); (iv) oviposition timing on usual and unusual hosts; and (v) identification of preference hierarchies. We found that when using unusual hosts, there is no correlation between performance and preference and that the preference hierarchy changes only slightly when the population passes through several generations on the less frequently accepted host. We also found a positive response to artificial selection for increasing oviposition on the less preferred host; however, when the host-choice experiment involved two varieties of the usual host, the response was faster than when the choice involved usual and unusual hosts. Finally, beetles reared on an unusual host (chickpea) for 26 generations showed similar good fitness on both usual and unusual hosts, indicating that the use of a new host does not necessarily result in the loss of performance on the original host. Nevertheless, this population showed lower fitness on the usual host than that of the original population, suggesting an underlying partial trade-off phenomenon which may contribute to a broadening of diet of this insect species.

Local dispersion of the Eucalyptus leaf beetle Chrysophtharta bimaculata (Coleoptera: Chrysomelidae), and implications for forest protection

1. Chrysophtharta bimaculata is a native chrysomelid species that can cause chronic defoliation of plantation and regrowth Eucalyptus forests in Tasmania, Australia. Knowledge of the dispersion pattern of C. bimaculata was needed in order to assess the efficiency of an integrated pest management (IPM) programme currently used for its control. 2. Using data from yellow flight traps, local populations of C. bimaculata adults were monitored over a season at spatial scales relevant to commercial forestry: within a 50-ha operational management unit (a forestry 'coupe') and between coupes. In addition, oviposition was monitored over a season at a subset of the between-coupe sites. 3. Dispersion indices (Taylor's Power Law and Iwao's Mean Crowding regression method) demonstrated that C. bimaculata adults were spatially aggregated within and between coupes, although the number of egg-batches laid at the between-coupe scale was uniform. Spatial autocorrelation analysis showed that trap-catches at the within-coupe level were similar (positively autocorrelated) to a radius distance of approximately 110 m, and then dissimilar (negatively autocorrelated) at approximately 250 m. At the between-coupe scale, no repeatable spatial autocorrelation patterns were observed. 4. For any individual site, rapid changes in beetle density were observed to be associated with loosely aggregated flights of beetles into and out of that site. Peak adult catches (> the weekly mean plus standard deviation trap-catch) for a site occurred for a period of 2.0 +/- 0.22 weeks at a time (n = 37), with normally only one or two peaks per site per season. Peak oviposition events for a site occurred on average 1.4 +/- 0.11 times per season and lasted 1.5 +/- 0.12 weeks. 5. Analysis of an extensive data set (n = 417) demonstrated that adult abundance at a site was positively correlated with egg density, but negatively correlated with tree damage (caused by conspecifics) and the presence of conspecific larvae. There was no relationship between adult abundance and a visual estimate of the amount of young foliage on trees. 6. Adults of C. bimaculata are show n to occur in relatively small, mobile aggregations. This means that pest surveys must be both regular (less than 2 weeks apart) and intensive (with sampling points no more than 150 m apart) if beetle populations are to be monitored with confidence. Further refinement of the current IPM strategy must recognize the problems posed by this temporal and spatial patchiness, particularly with regard to the use of biological insecticides, such as Bacillus thuringiensis, for which only a very short operational window exists.

Amino acids and their transporters in the retina

This review provides an overview of the distributions, properties and roles of amino acid transport systems in normal and pathological retinal tissues and discusses the roles of specific identified transporters in the mammalian retina. The retina is used in this context as a vehicle for describing neuronal and glial properties. which are in semi, but not all cases comparable to those found elsewhere an the brain. Where significant departures are noted, these are discussed in the context of functional specialisations of the retina and its relationship to adjacent supporting tissues such as the retinal pigment epithelium. Specific examples are given where immunocytochemical labelling for amino acid transporters may yield inaccurate results, possibly because of activity-dependent conformation changes of epitopes in these proteins which render the epitopes more or less accessible to antibodies. (C) 2001 Elsevier Science Ltd. All rights reserved.