Colony Health Research Articles

Lethal and sub‐lethal effects of spinosad on bumble bees (Bombus impatiens Cresson)

Recent developments of new families of pesticides and growing awareness of the importance of wild pollinators for crop pollination have stimulated interest in potential effects of novel pesticides on wild bees. Yet pesticide toxicity studies on wild bees remain rare, and few studies have included long-term monitoring of bumble bee colonies or testing of foraging ability after pesticide exposure. Larval bees feeding on exogenous pollen and exposed to pesticides during development may result in lethal or sub-lethal effects during the adult stage. We tested the effects of a naturally derived biopesticide, spinosad, on bumble bee (Bombus impatiens Cresson) colony health, including adult mortality, brood development, weights of emerging bees and foraging efficiency of adults that underwent larval development during exposure to spinosad. We monitored colonies from an early stage, over a 10-week period, and fed spinosad to colonies in pollen at four levels: control, 0.2, 0.8 and 8.0 mg kg(-1), during weeks 2 through 5 of the experiment. At concentrations that bees would likely encounter in pollen in the wild (0.2-0.8 mg kg(-1)) we detected minimal negative effects to bumble bee colonies. Brood and adult mortality was high at 8.0 mg kg(-1) spinosad, about twice the level that bees would be exposed to in a 'worst case' field scenario, resulting in colony death two to four weeks after initial pesticide exposure. At more realistic concentrations there were potentially important sub-lethal effects. Adult worker bees exposed to spinosad during larval development at 0.8 mg kg(-1) were slower foragers on artificial complex flower arrays than bees from low or no spinosad treated colonies. Inclusion of similar sub-lethal assays to detect effects of pesticides on pollinators would aid in development of environmentally responsible pest management strategies.

Xylophagous insects: developments in feeding assays

Xylophagous insects: developments in feeding assays

A new technique for monitoring Trigona carbonaria nest contents, brood and activity using X-ray computerized tomography

SUMMARYBrood status in the Australian stingless bee Trigona carbonaria is difficult to monitor non-invasively as splitting the hive damages the nest, and the involucrum prevents observations of internal structures and evidence of queen activity. In addition, increases in hive weight, also used as a measure of colony health, can be attributed to increased pollen and nectar collection by foragers in times of colony stress rather than improved brood status. To assess brood status and queen activity, we performed helical two-dimensional and three-dimensional X-ray computerized tomography (CT) to measure brood chamber volume in a T. carbonaria hive. All previously reported nest structures including larval cells, pupal cocoons, involucrum, cerumen and batumen layers were clearly identifiable. In addition, the on-screen linear callipers enabled accurate estimates of brood chamber volume to be made. A batumen bridge was found that may secure the brood chamber to the base of the hive box; this structure has not been reported before. CT could be used to follow the life cycle of stingless bees, track the development of natural nests and observe nest morphology to distinguish between species of Trigona. In addition, sequential scans will be useful in non-invasively assessing changes in brood status.

Effects of clothianidin on Bombus impatiens (Hymenoptera: Apidae) colony health and foraging ability.

We conducted laboratory experiments to investigate the lethal and sublethal effects of clothianidin on bumble bee, Bombus impatiens Cresson, colony health and foraging ability. Bumble bee colonies were exposed to 6 ppb clothianidin, representing the highest residue levels found in field studies on pollen, and a higher dose of 36 ppb clothianidin in pollen. Clothianidin did not effect pollen consumption, newly emerged worker weights, amount of brood or the number of workers, males, and queens at either dose. The foraging ability of worker bees tested on an artificial array of complex flowers also did not differ among treatments. These results suggest that clothianidin residues found in seed-treated canola and possibly other crops will not adversely affect the health of bumble bee colonies or the foraging ability of workers.

Critères d’évaluation de la dégradation des communautés coralliennes dans la région caraïbe

Almost all the coral reefs of the Caribbean region present important signs of alteration. In the French Antilles, about 80 % of the coral communities are more or less damaged. A study has been undertaken in order to describe and understand the dynamics of this recent evolution. The aim of this study was also to detect the ecological descriptors able to characterize the state of health of coral communities by remote sensing. The species richness of coral communities, the most simple indicator of the biodiversity of the studied area, as well as diversity indices, revealed to be descriptors particularly stable and very little reactive to the degradation of the reef community. The coverage rate of the bottom by corals may be very different from one reef to another one or from one area to another one on the same reef. This does not necessarily imply the existence of a difference in the state of health between the communities. The most relevant criteria revealed to be associated with the state of health of coral colonies and the abundance of juvenile recruits. For the other components of the reef benthic community, the most pertinent descriptor was the ratio of the bottom covered with algal turf (healthy reefs) to that occupied by macro-algae (damaged reefs). These ecological descriptors revealed to be easy to estimate in a reproducible manner by observers who are not specialists of reef ecology. This extends the possibilities of monitoring the health of coral reefs through the assistance of non-scientific personnel (staff of the marine reserves, volunteers, etc.).

Effects of Novel Pesticides on Bumble Bee (Hymenoptera: Apidae) Colony Health and Foraging Ability

Abstract Two experiments were conducted testing for lethal and sublethal effects of the transgenic proteins Cry1Ac and chitinase, and the chemical seed and soil treatment imidacloprid on bumble bees (Bombus occidentalis Greene and B. impatiens Cresson, Hymenoptera: Apidae). In the first experiment, B. occidentalis colonies were exposed to realistic residue levels of Cry1Ac, chitinase, and imidacloprid found in pollen. There were no effects on pollen consumption, bumble bee worker weights, colony size, amount of brood, or the number of queens and males produced. In the second experiment, using B. impatiens, we tested the effects of Cry1Ac and two levels of imidacloprid. Similar colony health measures were collected as in the first experiment, but in addition foraging ability of individual bees was tested on complex artificial flowers. There were no differences in colony characteristics among treatments. However, bees in the high-imidacloprid treatment had longer handling times on the complex flowers than b...

RNA/DNA ratios of scleractinian corals suggest acclimatisation/adaptation in relation to light gradients and turbidity regimes

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 227:233-239 (2002) - doi:10.3354/meps227233 RNA/DNA ratios of scleractinian corals suggest acclimatisation/adaptation in relation to light gradients and turbidity regimes E. H. Meesters1, G. Nieuwland1, G. C. A. Duineveld1, A. Kok1, R. P. M. Bak1,2,* 1Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1970 AB Den Burg, Texel, The Netherlands 2Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, The Netherlands *Corresponding author. E-mail: rbak@nioz.nl ABSTRACT: RNA/DNA ratios are used in many organisms as an indicator of growth, biomass or metabolic functioning. We hypothesised that hermatypic corals, as they depend for growth largely on energy transferred from their algal symbionts, may show an effect in the RNA/DNA ratio with factors influencing irradiance. This was tested along 2 environmental gradients: in relation to depth (decreasing irradiance) and in relation to environmental degradation (increased turbidity). RNA/DNA ratios were determined by HPLC in coral samples collected over depth gradients in 3 islands off the coast of north-west Java, Indonesia. The reefs range from shallow reefs (depth <3 m) in very turbid water, which are close to eroded shores, to intermediate reefs (depth <6 m) further from the shore with less turbid water, to offshore clear water control reefs (depth <20 m). RNA/DNA ratio was shown to be negatively correlated with depth in all but the most turbid conditions, suggesting it is an expression of metabolic acclimatisation of the coral host-symbiont community with decreasing irradiance (i.e. photoadaptation). Comparing the RNA/DNA ratio in clear and turbid waters, the decrease with depth tended to be steeper over a shorter depth range under turbid conditions, analogous with the more rapid extinction of light in these conditions. The relationship between the RNA/DNA ratio and light was consistently higher under turbid conditions (p = 0.0037), indicating that RNA/DNA ratio had shifted to a higher level, possibly indicating a genetic adaptation in the metabolic functioning of corals in the turbid environment. The positive relation between light and RNA/DNA ratio would suggest the opposite, i.e. lower ratio under turbid conditions. The RNA/DNA ratio may provide a relatively reliable method to determine the metabolic functioning (health) of individual coral colonies. KEY WORDS: RNA/DNA ratios · Coral health · Environmental stress · Sediment · Turbidity · Photoadaptation · Growth · Bio-indicator Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 227. Online publication date: February 13, 2002 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2002 Inter-Research.

Evaluation of honey bee miticides, including temporal and thermal effects on formic acid gel vapours, in the central south-eastern USA

SUMMARYTwo field studies were conducted in the central south-eastern USA (Tennessee) to evaluate the efficacy of miticides for Varroa destructor and Acarapis woodi and treatments' effects on honey bee (Apis mellifera) colony health. We also determined the concentration of formic acid throughout the period that colonies were treated with formic acid applied to pressed fibre-board and in gel packs. In a late spring application, formic acid vapours dissipated more rapidly in gel-pack-treated colonies, dropping to an average of < 5 ppm at 13 d post-application. Average concentrations were 15 ppm at 13 d post-application in board-treated colonies. No deleterious effects on adult bee or brood populations were detected. However, formic acid fibreboard-treated colonies stored less honey during the treatment period. In a trial begun in late summer, gel packs, Apilife VAR (containing thymol, eucalyptus oil, menthol and camphor), Apistan (tau-fluvalinate) and oil strips (containing origanum and bay in olive oil) were evaluated. Comparisons of mite drop after a 42-d treatment period indicated Apilife VAR and formic acid gel packs provided control similar to that of Apistan. Oil strips were usually shredded and removed by bees and provided little control. Tracheal mite incidence was reduced 100%, 97% and 92% by formic acid gel packs, oil strips and Apilife VAR, respectively, whereas incidence increased by 75% in untreated colonies. Amounts of bees and brood were less in all treatment groups and in untreated controls. We believe this was a result of natural colony size reduction. Amounts of food stores were unchanged for all treatment groups except there was less honey found in oil-strip treated colonies after treatment. Formic acid vapours from gel packs dissipated less rapidly as ambient temperatures decreased. A regression equation predicted that, under early autumn climatic conditions, vapour concentrations would reach 10 ppm at 21 days after application.

Practical science—research helping beekeepers 2. Colony manipulations for honey production

Because they are good pollinators, honey bees contribute profoundly to world food production. Because they flourish in hives, they provide hours of fun and relaxation to hobby beekeepers. Because they are social and manageable, honey bees are a favoured laboratory animal for scientists and educators. But for most people, honey bees are what their name says—bees that make a lot of honey. Optimizing honey production has been the focus of much research over several decades, and there are many success stories in which scientists and beekeepers identified a principle of bee biology and developed it into a profitable practice. I describe some of these success stories here. Honey production is a function of local weather, flora, bee densities, bee genetics, colony health, and colony manipulations by the beekeeper. I limit this discussion to colony manipulations.

Feeding Preference and Survival of Young Worker Honey Bees (Hymenoptera: Apidae) Fed Rape, Sesame, and Sunflower Pollen

Young worker honey bees, Apis mellifera L., exhibited differences in feeding preferences and survival when fed pollen of rape, Brassica napus L., sesame, Sesamum indicum L., and sunflower, Helianthus annuus. Rape pollen was readily consumed and increased Longevity 2.5 times relative to the controls fed only sucrose water. Sunflower pollen was readily consumed with bees on average surviving 1.6 times longer than the controls. Sesame pollen was not readily consumed and bees survived 1.7 times longer than the controls. The results suggest that honey bees used to pollinate monoculture crops of either sunflowers or sesame, but not rape, will need to be provided alternate floral or nutritional supplements source to enrich their diets and maintain colony health.

Study of spontaneous infectious diseases of primates: Contributions of the regional primate research centers program to conservation and new scientific opportunities.

Careful investigation of spontaneous diseases of nonhuman primates is critical to maintaining the health of captive breeding colonies and, therefore, conservation. Without an understanding of those infectious agents to which nonhuman primates are susceptible and their sources, all colonies are at risk of catastrophic illness. Such studies also regularly generate new opportunities for improved studies of the causes and nature of diseases of human beings. Inquiries into an epizootic in owl monkeys (Aotus trivirgatus) led to the identification of fatal herpes virus infections transmitted by squirrel monkeys (Herpesvirus T) and human beings (H. simplex), and to mechanisms for their prevention. This also paved the way for the discovery of a new virus, H. saimiri, which has provided a unique opportunity to study mechanisms of viral oncogenesis. Research on spontaneous immunodeficiency disease of macaques led to uncovering a new group of viral diseases (type D retrovirus) of major importance to colony health, and subsequently to the identification of another new virus (simian immunodeficiency virus) which has provided an exquisite system in which to investigate AIDS of human beings. © 1994 Wiley-Liss, Inc.

Hong Kong.

Good news for the colony's health service came in the recently announced budget. Significant increases in spending have been granted to allow expansion of various welfare services.

Honey Bees (Hymenoptera: Apidae) Contaminated with Pesticides and Polychlorinated Biphenyls

Multiple pesticides were simultaneously present in dead honey bees, Apis mellifera L., or in brood comb in 28 of 55 poisoned apiaries in Connecticut in 1983–85. Methyl parathion (Penncap-M), carbaryl, and endosulfan were each detected in 34, 33, and 13 of the apiaries, respectively. Less frequently detected pesticides were methomyl, chlordane, diazinon, captan, and malathion. Health of colonies poisoned with methyl parathion only or methyl parathion in combination with other insecticides was often severely affected (141 of 168 poisoned colonies were either killed or weakened), whereas colonies affected by carbaryl only or carbaryl plus insecticides other than methyl parathion often recovered (16 of 79 poisoned colonies were either killed or weakened). One-half of the poisonings occurred in July. Aroclor 1248 and 1260 (polychlorinated biphenyls) were detected in dead bees, brood comb, honey comb, or honey. Environmental sources of these chlorinated hydrocarbons are unknown. Detectable quantities of polychlorinated biphenyls ≥0.80 ppm were in 4 of 71 honey samples.

Persistent Adrenocortical Activation in Female Rhesus Monkeys after New Breeding Group Formation

Persistent elevated adrenocortical responsiveness to ACTH has been demonstrated in female rhesus monkeys as long as 13 weeks after relocation into new single male breeding groups. Measures of immediate responses to psychosocial stress of grouping such as aggressive interaction and circulating plasma cortisol levels were highest immediately after grouping, but tended to decline to lower levels after the first month. In a retrospective comparison of such 'new' breeding groups (less than one year) versus established breeding groups (more than two years), stress-related morbidities such as trauma (wounding) and loose stools were higher for as long as six months after new group formation. The actual and potential adverse effects of regrouping stress on colony health and reproduction are relevant to cost-benefit assessment of such colony management procedures.

The passamaquoddy tidal-power project

The colonial ascidian Didemnum sp. has colonized northwestern Atlantic coastal habitats from southern Long Island, New York, to Eastport, Maine. It is also present in offshore habitats of the Georges Bank fishing grounds. It threatens to alter fisheries habitats and shellfish aquacultures.Observations in a tide pool at Sandwich, MA from December 2003 to February 2006 show that Didemnum sp. tolerates water temperatures ranging from ≤ 1 to > 24°C, with daily changes of up to 11 °C. It attaches to pebbles, cobbles, and boulders, and it overgrows other tunicates, seaweeds, sponges, and bivalves. From May to mid July, colonies appear as small patches on the bottoms of rocks. Colonies grow rapidly from July to September, with some growth into December, and they range in color from pink to pale yellow to pale orange. Colony health declines from October through April, presumably in response to changes in water temperatures, and this degenerative process is manifested by color changes, by the appearance of small dark brown spots that represent clumps of fecal pellets in the colony, by scavenging by periwinkles, and by a peeling-away of colonies from the sides of cobbles and boulders. At Sandwich, colonies died that were exposed to air at low tide. The species does not exhibit this seasonal cycle of growth and decline in subtidal habitats (40–65 m) on the Georges Bank fishing grounds where the daily climate is relatively stable and annual water temperatures range from 4 to 15 °C. Experiments in the tide pool with small colony fragments (5 to 9 cm2) show they re-attach and grow rapidly by asexual budding, increasing in size 6- to 11-fold in the first 15 days. Didemnum sp. at Sandwich has no known predators except for common periwinkles (Littorina littorea) that graze on degenerating colonies in the October to April time period and whenever colonies are stressed by desiccation.The tendencies of the ascidian (1) to attach to firm substrates, (2) to rapidly overgrow other species, (3) to tolerate a wide temperature range, (4) to be free from predation, and (5) to spread by colony fragmentation combine to make it a potential threat to benthic marine habitats and aquacultures. Didemnum sp. is known to overgrow mussels, oysters, and sea scallops, and it likely envelops other bivalves too.