Ponašanje pri gniježđenju i parenju pčele Andrena patella (Hymenoptera: Andrenidae)

This study of nesting and associated behavior patterns of Andrena patella was carried out at 27 locations with different landscape categories, from 2013 to 2016. The research areas chosen were generally flat or marshy areas. A total of 15 major nest aggregations were spotted and 120 nests were excavated. This species nests in soil, males emerge earlier than females, and mating occurred on flowers during the foraging season, in the 3rd week of May. The various nest and cell parameters showed low variability in the different years and different sites, but nest cell length, diameter and number varied significantly, as well as depth even at the same site. The nests were multi-cellular, oblique to horizontal, and cell shape was oval. The mating attempts of the pairs and copulatory behavior involved various steps which were completed in a very few seconds. The males appeared first on the flowers, near to the nesting site, and lived shorter than the females. The females started foraging in the 2nd to 3rd weeks of May and laid eggs in the 1st week of June. The adult phenology, egg placement, cell provision and larval feeding are described.Istraživanje gniježđenja i povezanih obrazaca ponašanja pčele Andrena patella provedeno je na 27 lokacija različitih krajobraznih kategorija, od 2013. do 2016. godine. Odabrana područja istraživanja općenito su bila ravna i vlažna. Uočeno je 15 velikih agregacija gnijezda, a iskopano je 120 gnijezda. U vrsta koje su bile ugniježđene na glinenom zemljištu mužjaci su se razvili prije ženki, a parenje se zbilo na cvijeću za vrijeme sezone paše, treći tjedan u svibnju. Različiti pokazatelji gnijezda i stanica pokazali su nisku varijabilnost u različitim godinama i na različitim lokacijama, no dužina stanica saća, njihov promjer i broj statistički su se znakovito razlikovali čak i na istom mjestu. Gnijezda su bila multistanična, kosa do vodoravna, a oblik stanica ovalan. Pokušaj parenja i kopulacijsko ponašanje uključili su različite faze koje su završene u nekoliko sekunda. Mužjaci su se prvi pojavili na cvijeću, blizu mjesta za gniježđenje, i živjeli su kraće od ženki. Ženke su počele s pašom drugi i treći tjedan svibnja, a jajašca su položile prvi tjedan u lipnju. Opisani su oblici odraslih jedinki, polaganje jaja, opskrba stanica i hranjenje ličinki

Relationship between incidence of Leucinodes orbonalis (Guenee) and Chlorophyll content in leaves of Brinjal (Solanum melongena L.)

The present study on biochemical basis of resistance against Leucinodes orbonalis infestation was conducted during the year 2011-2012. The results revealed that highest chlorophyll-‘a’- content of 0.497 mg/gfw was recorded in the susceptible genotype SHB-1.The lowest amount of 0.319 and 0.381 mg/gfw was observed in the resistant genotypes Brinjal-85 and Local long respectively, which were significantly different from other evaluated genotypes. The chlorophyll ‘a’content was positively correlated with the brinjal shoot and fruit borer infestation. Thehighest chlorophyll -‘b’- content of 0.442 mg/gfw was recorded at 70 DAT (days after transplanting). The amount of chlorophyll -‘b’- varied significantly among the genotypes at different ages and decreased with the age of crop. The average highest amount of chlorophyll -‘b’- was estimated in the genotype SBH-1 which was significantly at par with hybrid SBH-2. The lowest chlorophyll -‘b’- content was recorded at 40 DAT in the genotype Brinjal-85 followed by Local Long. The lowest amount of total chlorophyll was estimated in the resistant variety as compared to susceptible therefore exhibiting lowest level of infestation

Causes and Reasons of Insect Decline and the Way Forward

There are lot of reasons and causes of insect decline. The main causes of insect decline is attributed to habitat destruction, land use changes, deforestation, intensive agriculture, urbanization, pollution, climate change, introduction of invasive insect species, application of pesticides, mass trapping of insects using pheromones and light traps, pathological problems on various insects, and introduction of exotic honey bees in new areas that compete with the native bees for resource portioning and other management techniques for pest management, and even not leaving any pest residue for predators and parasitoids for their survival. The use of chemical insecticides against target or non-target organisms is major cause for insect decline. The diseases and decline of the important pollinators is still a mistry for colony collapse disorder. To overcome the cause of insect decline, various conservation techniques to be adopted and augmentation of artificial nesting and feeding structures, use of green pesticides, maintaining the proper pest defender ratio (P:D), policies and reaching to political audience at global level and other factors already discussed in the chapter may be helpful for mitigating the insect decline and especially for the pollinators, a key insect for life

Quantitative response of wheat to sowing dates and irrigation regimes using ceres-wheat model

An experiment was conducted at Punjab Agricultural University, Ludhiana during 2014–15 and 2015–16, keeping four sowing dates {25th Oct (D1), 10th Nov (D2), 25th Nov (D3) and 10th Dec (D4)} in main plots and five irrigation schedules {irrigation at 15 (FC15), 25 (FC25), 35 (FC35) and 45 (FC45) % depletion of soil moisture from field capacity (FC) and a conventional practice} in sub plots. The objective of the study was to evaluate the performance of CERES-Wheat model for simulating yield and water use under varying planting and soil moisture regimes. The simulated and observed grain yield was higher in D1, with irrigation applied at FC15 as compared to all other sowing date and irrigation regime combinations. Simulated grain yield decreased by 19% with delay in sowing from 25th October to 10th December because of 8% reduction in simulated crop evapotranspiration. Simulated evapotranspiration decreased by 16%, wheat grain yield by 23% and water productivity by 15% in drip irrigation at 45% depletion from field capacity as compared to drip irrigation at 15% of field capacity. It was further revealed that the model performed well in simulating the phenology, water use and yield of wheat

Are Honey Bees at Risk from Microplastics?

Microplastics (MPs) are ubiquitous and persistent pollutants, and have been detected in a wide variety of media, from soils to aquatic systems. MPs, consisting primarily of polyethylene, polypropylene, and polyacrylamide polymers, have recently been found in 12% of samples of honey collected in Ecuador. Recently, MPs have also been identified in honey bees collected from apiaries in Copenhagen, Denmark, as well as nearby semiurban and rural areas. Given these documented exposures, assessment of their effects is critical for understanding the risks of MP exposure to honey bees. Exposure to polystyrene (PS)-MPs decreased diversity of the honey bee gut microbiota, followed by changes in gene expression related to oxidative damage, detoxification, and immunity. As a result, the aim of this perspective was to investigate whether wide-spread prevalence of MPs might have unintended negative effects on health and fitness of honey bees, as well as to draw the scientific community's attention to the possible risks of MPs to the fitness of honey bees. Several research questions must be answered before MPs can be considered a potential threat to bees

Are honey bees at risk from microplastics?

Microplastics (MPs) are ubiquitous and persistent pollutants, and have been detected in a wide variety of media, from soils to aquatic systems. MPs, consisting primarily of polyethylene, polypropylene, and polyacrylamide polymers, have recently been found in 12% of samples of honey collected in Ecuador. Recently, MPs have also been identified in honey bees collected from apiaries in Copenhagen, Denmark, as well as nearby semiurban and rural areas. Given these documented exposures, assessment of their effects is critical for understanding the risks of MP exposure to honey bees. Exposure to polystyrene (PS)-MPs decreased diversity of the honey bee gut microbiota, followed by changes in gene expression related to oxidative damage, detoxification, and immunity. As a result, the aim of this perspective was to investigate whether wide-spread prevalence of MPs might have unintended negative effects on health and fitness of honey bees, as well as to draw the scientific community’s attention to the possible risks of MPs to the fitness of honey bees. Several research questions must be answered before MPs can be considered a potential threat to bees