Amount Of Brood Research Articles

Pharaoh ant (Hymenoptera: Formicidae) colony development after consumption of pyriproxyfen baits.

Pharaoh ant, Monomorium pharaonis (L.), colonies were effectively controlled following ingestion of pyriproxyfen formulated in peanut butter oil. Pyriproxyfen, a juvenile hormone analog, reduced egg production in the queens, decreased the amount of brood due to delayed death in the eggs and larvae, caused death of pupae about 3 wk after treatment, and decreased the number of workers due to attrition and toxic effects. Queens, which continued to produce a small amount of eggs, eventually died. Queen death may have been caused by lack of workers required to tend them, old age or toxic effects. At concentrations of 0.25, 0.5 and 1%, pyriproxyfen was more effective than the once commercially available bait, Pharorid (methoprene) for the control of the Pharaoh ant.

The relationship between population size, amount of brood, and individual foraging behaviour in the honey bee, Apis mellifera L.

This study experimentally examines the relationship between colony state and the behaviour of individual pollen and nectar foragers in the honey bee, Apis mellifera L. In the first experiment we test the prediction that individual pollen foragers from colonies with higher brood quantities should exhibit a greater work effort for pollen resources than individual pollen foragers from colonies with low brood quantities. Eight colonies were assigned into two treatment groups; HIGH brood colonies were manipulated to contain 9600±480 cm2 brood area; LOW brood colonies were manipulated to contain 1600±80 cm2 brood area. We measured colony brood levels over the course of the experiment and collected individual pollen loads from returning pollen foragers. We found that, while colonies remained significantly different in brood levels, individual pollen foragers from HIGH brood colonies collected larger loads than individuals from LOW brood colonies. In the second experiment we investigated the influence of colony size on the behaviour of individual nectar foragers. We assigned eight colonies to two treatment groups; LARGE colonies were manipulated to contain 35000±1700 adult workers with 3500±175 cm2 brood area, and SMALL colonies were manipulated to contain 10000±500 adult workers with 1000±50 cm2 brood area. We observed foraging trips of individually marked workers and found that individuals from LARGE colonies made longer foraging trips than those from SMALL colonies (LARGE: 1666.7±126.4 seconds, SMALL: 1210.8±157.6 seconds), and collected larter nectar loads (LARGE: 19.2±1.0 μl, SMALL: 14.6±0.8 μl). These results indicate that individual nectar foragers from LARGE colonies tend to work harder than individuals from SMALL colonies. Both experiments indicate that the values of nectar and pollen resources to a colony change depend on colony state, and that individual foragers modify their behaviour accordingly.

A preliminary study on the development of colonies ofMelipona beecheiiin traditional and rational hives

SUMMARYSeventeen colonies of Melipona beecheii were collected from different parts of Yucatán, Mexico, and housed in rational (box) hives or in traditional log hives. Two designs of rational hive were used: the Nogueira-Neto hive (P) and the Instituto Nacional de Pesquisas de Amazonia hive (I). The internal volumes of the P, I and log hives were 14.30, 14.52 and 10.06 litres, respectively. Food stores in the original nests were not transferred to the hives and the colonies were fed on sugar syrup and supplied with cerumen. Brood volumes and numbers of food pots were determined every 15 days for 3 months following the colony transfers. The amount of brood which developed in the log hives (mean 848.21 cm3) was significantly greater than in P (mean 543.64 cm3) and I (mean 413.84 cm3) hives, but there were no significant differences between domiciles in the number of food pots built, indicating that colonies need to build up food stores before producing brood. It is suggested that the volumes of the P and I hives should be reduced by at least one-third, to allow better control of temperature and environment by the bees.

Genotypic variation in foraging responses to environmental stimuli by honey bees,Apis mellifera

We experimentally tested a model predicting that colony-level genotypic diversity contributes to colonylevel foraging flexibility in honey bees. We established a colony into which we placed individually marked workers from three genetically distinct groups. The colony was placed in an enclosure that contained feeding stations with pollen and sugar syrup. Foraging resources, stores of pollen and the quantity of brood within the colony were varied temporally. Individual foragers switched between resource types in response to changes in relative resource quality and colony need, demonstrating flexibility in resource choice at the individual level. However, genetic groups within the colony varied in their tendency to collect pollen versus nectar, and in lability of response to changes in foraging stimuli. Our data suggest that within-colony genotypic diversity contributes to a resilient foraging response to environmental variation.

Pharaoh Ant (Hymenoptera: Formicidae): Fenoxycarb Baits Affect Colony Development

Fenoxycarb, an insect growth regulator, was highly effective against the Pharaoh ant, Monomorium pharaonis (L.). Fenoxycarb acts by reducing egg production in the queens; the colonies eventually die because of worker attrition. The best laboratory results were obtained using concentrations of 0.25, 0.5, and 1% in peanut oil. These concentrations significantly reduced worker numbers by 12 wk and quantity of brood by 5 wk, if not sooner; however, more than one baiting was necessary to eliminate the colonies completely. Also, in some tests, colonies fed fenoxycarb baits at concentrations of 0.1, 0.25, and 0.5% significantly delayed the production of winged reproductives. Intermediate castes (individuals that were larger than workers yet smaller than queens) were produced at lower concentrations (0.05, 0.1, and 0.25%). Higher concentrations of 2.5 and 5% were not effective, probably because of repellency of the chemical. These results demonstrate that fenoxycarb is as effective as the commercially available bait, Pharorid (methoprene), for the control of the Pharaoh ant.

Analysis of the Brooding Cycle of Broody Jungle Fowl Hens With Chicks

Abstract Broody hens with chicks show a sequence of behaviors that is cyclical in nature: brooding, preening, feeding with drinking, exploring, dustbathing, and then brooding once again. In inexperienced hens, the average cycle length was about half an hour, with brooding and feeding taking up about 90% of the time. The amount of brooding, preening, and feeding correlated positively with the length of the cycle, whereas exploring and dustbathing had no significant effect on cycle length. Hens with previous experience brooding chicks showed a significantly shorter cycle length, but the sequence of behaviors was unaltered. The results were discussed in the context of ultradian rhythms in behavior. A clock mechanism was not able to account for the results. A model that included the interaction of causal factors provided by the chicks and by the hen's dustbathing system was more successful.

Behaviour and ecology of the subtropical carpenter bee,Xylocopa fenestrataF. 8. Life cycle, seasonal mortality, parasites and sex ratio

SUMMARYXylocopa fenestrata in a semi-arid subtropical climate at Hisar, India, exhibited a multivoltine life cycle, producing seven seasonal broods which could be characterized by the range of ambient temperatures experienced. Amounts of parasitization and mortality due to other causes varied with the seasons. Late summer was the most unfavourable season, with high parasitization and mortality, and minimal brood production. Early summer and early autumn were favourable periods for this bee, when large amounts of brood were produced. Adult emergence, parasitization and seasonal mortality in the various seasons were cyclic. The sex ratio in different seasonal broods was generally female-biased, especially during early summer and early autumn. There was no diapause during the developmental stages.

Steinernematid Nematode Drenches for Control of Fire Ants, Solenopsis invicta, in Florida

Recent developments in low-cost, large-scale production of entomogenous nematodes of the genera Steinernema and Heterorhabditis (Bedding 1984) have facilitated largescale field testing against various soil-infesting insect pests (Kaya 1985, Poinar 1986), with good potential for commercial control in some applications. Early research by Poole (1976) and Quattlebaum (1980) showed promise that entomogenous nematodes have potential for controlling fire ants, Solenopsis spp. Furthemore, these nematodes have the ability to invade adult insects, and thus potential to kill fire ant queens. Agents which only kill worker ants do not effectively eliminate colonies, although they may temporarily reduce their size. A variety of entomopathogens, including viruses, bacteria, fungi, protozoa, and other species of nematodes have been evaluated for fire ant control. These organisms, with the possible exception of a fungus (Beauveria sp.) isolated from fire ants in Brazil (Stimac et al. 1987), produced little or no mortality in laboratory and/or field tests. Jouvenaz (in press) recently reviewed these evaluations and discussed the special problems attending the development of biological formicides. We selected a strain of Steinernemafeltiae produced by Biosys Inc. (Palo Alto, CA) for field evaluation after screening several strains of Steinernema and Heterorhabditis spp. in the laboratory. In the laboratory tests, groups of ants composed of queens (from a polygynous colony), about 25-30 workers, and a small quantity of brood were placed in 16 x 125 mm glass culture tubes containing 25 mm of slightly moistened sandy soil. The tubes were capped with plastic tops which allowed gas exchange and were maintained at 290 C. After two or three days of acclimation, one ml of deionized water without nematodes or containing 5,000 or 50,000 nematodes was added to each tube, and survival of queens was scored daily for four days. Ten replicates (a total of 50 queens) were used for each nematode concentration and for the control. After 96 h, the strain we selected had produced queen mortalities of 40% and 58% in 5,000 and 50,000 nematode dosaged, respectively. Mortality of workers and brood, although not quantitatively determined, was estimated to be at least 80%. Mortality of queens, workers or brood was not observed in the control group. In separate tests we observed that colonies of ants vacated soil treated with high concentrations of nematodes. The first of the two field evaluations reported here was conducted in October and November, 1987, at Site No. 1 in southeast Gainesville, Alachua Co., Florida. This site was a utiities right-of-way measuring about 365 x 23-30 m, with sandy soil and surrounded by trees. The site had been mowed regularly prior to the test, but was not mowed during the test period. The second test was conducted during June and July, 1988, at Site No. 2, 4 mi north of LaCrosse, Alachua Co., Florida. This site was an approximately rectangular plot 1.4 ha in size on a sod farm and was also bordered by trees. On both plots, the grass varied from 10-30 cm high, and was not mowed during the test period.

Differential viability of eggs laid by queens in polygyne colonies of the fire ant, Solenopsis invicta

The viability of eggs laid by individual functional queens from polygyne colonies of the fire ant, Solenopsis invicta Buren, was examined by staining for chromatin. In isolation units held in the laboratory inseminated queens laid nearly 100% viable eggs, compared to <10% for uninseminated queens. Experiments in which the quantity of brood was manipulated demonstrated that the number of brood and workers present has little, if any, effect on the ability of a queen's eggs to form embryos, in contrast to the stimulatory effect of larvae on oviposition rate. In field colonies, although there was considerable variability among queens, inseminated queens laid a significantly greater proportion of viable eggs than did uninseminated queens. Inseminated queens taken directly from polygyne colonies in the field laid a smaller proportion of viable eggs than those maintained individually for several weeks in the laboratory, suggesting that there is mutual inhibition among cohabiting inseminated queens which affects viable egg production. Among queens taken from the field, there was no significant correlation between the proportion of viable eggs laid and queen weight, a reliable indicator of oviposition rate. Thus caution should be exercised in equating relative rates of egg production with reproductive success in studies of reproductive roles in social insect colonies.

Field Experiments to Determine the Effect of Perizin onVarroaMite in Honeybee Colonies in Iran

SummaryPerizin was used against the Varroa mite in honeybee colonies in cold climate conditions when no brood was present. In 10 colonies with the recommended dose rate, a mean efficacy of 97·6% was achieved.In another experiment in mild climate conditions, when the least amount of brood was present in 10 colonies, four applications of Perizin emulsion at 4-day intervals and at half the recommended dose rate achieved a mean efficacy of 95·31%. The result for full dose treatment in the same experiment showed an efficacy of 96·02%.

Effect of Comb Size on Population Growth of Honey Bee (Hymenoptera: Apidae) Colonies

Population growth was compared in 21 colonies of honey bees, Apis mellifera L., during the period of maximal population growth in Louisiana. Each colony began with 1.25 kg of bees, no brood, and 40 liters of hive space (measured empty). Colonies differed in comb size (13 by 19, 13 by 43, 20 by 43, or 26 by 43 cm), but each hive had the same comb surface area (1.1 m2). Bees were put into hives on 12 March, queens were released 15 March, and hives were expanded to 1.4 m2 of comb surface area and 48 liters on 10 April. Colonies with the largest combs produced more brood and had more adult workers on 13 May than colonies with the two smallest combs. At the end of the experiment, mean adult populations were 19,300, 22,900, 23,600, and 28,400 in colonies with the smallest to largest combs, respectively. A second experiment compared comb effects versus queen effects by measuring the amount of brood produced in 10 d by colonies with instrumentally inseminated or naturally mated queens on either the largest or smallest comb sizes. Comb effects were significant, queen effects were not. Small combs reduced brood production and diminished differences among queens; therefore, one must use large combs when evaluating queen fecundity.

Response of foster Asian honeybee ( Apis cerana Fabr.) colonies to the brood of European honeybee ( Apis mellifera L.) infested with parasitic mite, Varroa jacobsoni oudemans

The response of Asian honeybee ( Apis cerana Fabr.) colonies toward the introduced worker brood of the European honeybee ( Apis mellifera L.) infested with the parasitic mite Varroa jacobsoni Oudemans was investigated. When no mites were present, 40% of the healthy open brood and 3% of the healthy capped brood of the European honeybees were rejected by the Asian honeybee colonies. When the brood was infested, brood rejection was significantly higher for open ( P < 0.05) and capped broods ( P < 0.01). The brood removal activity decreased with time. The quantity of brood removed was also correlated with mite infestation level for open ( r 2 = 0.933) and sealed broods ( r 2 = 0.918). The feasibility of using heterospecific colonies to control Varroa mite is unclear and is discussed from behavioral and ecological points of view.

Influence Upon Honeybees of Chronic Exposure to Very Low Levels of Selected Insecticides in Their Diet

SummarySeveral sizes of hive were treated for colony viability and ease of manipulation when colonies of honeybees were confined within screened cages. Hives containing either a single standard frame (1742 cm2) or a single miniature frame (431 cm2) were acceptable, but hives containing a single standard frame were used in our experiments because they were easier to manipulate and produced more brood that could be used for other experimental purposes.A small colony was established in each of several 1·8 × 1·8 × 2·0-m screened cages. Pollen cakes containing 0·017 ppm permethrin, 0·16 ppm malathion, 5·12 ppm methoxychlor, 10 ppm difiubenzuron, 0·17 ppm carbaryl or no pesticide were fed to the colonies to determine the effects on the bees of chronic exposure. During a test period of 10 weeks only methoxychlor caused a significant reduction (P<0'05) in quantity of brood reared, amount of pollen cake consumed, and amount of sucrose syrup stored in the colonies. Diflubenzuron at 10 ppm caused greater than 50% reduction in the amount of syrup stored compared to control colonies, but it did not cause reduction in consumption of pollen or in the quantity of brood reared.In general, colonies fed insecticides accumulated debris and dead bees on the hive bottom because of reduced house-cleaning. Colonies fed methoxychlor or malathion were particularly susceptible to invasion by wax moth.

Pollen Hoarding and Use by High and Low Pollen-Hoarding Honeybees During the Course of Brood Rearing

SummaryHoneybees (Apis mellifera) from a line which had been selected for high pollen-hoarding behaviour (HPH) hoarded more pollen than bees from a low pollen-hoarding line (LPH) when they were kept in observation colonies with known amounts of brood. These differences were not found when brood was in the egg stage and pollen stores were small, but were large and significant when brood was in the larval stage and pollen stores were more abundant. Differences in amounts of stored pollen that were established between the lines during the larval stage were maintained after brood cells were capped, but amounts of pollen stored did not change significantly. HPH bees also hoarded more pollen in the absence of brood. The two lines used similar amounts of pollen and reared similar amounts of brood. Mortality of the LPH bees was higher and varied significantly more than that of the HPH bees. It is suggested that bees which hoard a large amount of pollen are either less inhibited from collecting pollen by the presence of stored pollen or more stimulated to collect pollen by its absence.

Increase in Life-Span, Unit Honey Productivity and Honey Surplus With Fumagillin Treatment of Honeybees

SummaryAn apiary of 24 overwintered colonies of honeybees (Apis mellifera) was divided in the spring into 2 groups so that each group contained weak, medium and strong colonies with similar amounts of brood. All colonies were fed with sugar syrup and each colony of one group received in addition 70 mg fumagillin. Treatment with fumagillin increased both brood production and length of worker life by 20%, resulting in a 40% increase in colony population. Fumagillin treatment also increased unit honey production by 19%, so that the total increase in honey surplus amounted to 58%. Unit productivity was not correlated with any of the 7 parameters of colony strength that were measured and so should be treated as an independent genetic character.

Effect of Feeding Pollen Substitutes to Colonies of Honey Bees (Hymenoptera: Apidae) Exposed to Carbaryl1

Twenty-four colonies, established from 3-lb (ca. 1.4-kg) packages of Italian bees, were divided into two groups of 12 colonies each. Twelve colonies were exposed to Sevin (50w) at a rate of 2.5 lb (AI) per acre (2.5 kg/ha) on 8 July 1981. Twelve colonies were moved to a second apiary the day before spraying. In each group, six colonies were fed a lactalbumin-yeast pollen substitute and six were not fed. Colony weights, dead bee trap counts, and brood measurements were recorded from April to October 1981. The 12 colonies exposed to carbaryl survived the spray, but a significant number of dead bees were counted daily for 7 days after the spray treatment. After 7 days the mortality was normal. Overall, the total amount of brood reared to the sealed stage was not significantly different, as determined by a three-way analysis of variance. However, immediately after the spray, the pollen substitute-fed colonies reared significantly more brood than unfed colonies. The carbaryl-treated and untreated colonies yielded similar amounts of honey, indicating that the loss of several thousand foraging bees did not have a long-range affect on the colonies.

3.5 Statistical Approaches to Model Building

There is a belief among research workers that their experiments have two possible outcomes, either they are successful or else the results will have to be taken to a statistician. Although the belief is not universal, it does account for a certain amount of brooding by statisticians on their place in scientific research. This may be why I have made the title I was given, the excuse for examining some of my own activities and attitudes in bringing agricultural research data into juxtaposition with mathematical models. I apologize in advance for the egocentricity.Statisticians in agricultural research find considerable employment in enabling their customers to adorn papers with a sufficiency of standard errors and significance tests for the satisfaction of editorial boards. Underlying this apparently cosmetic activity is the important function of testing the logic of experimental conclusions and preventing their too easy or too general acceptance. The statistical approach to model building is therefore that of a strength tester. Theoretical assumptions may be vital for the construction of the model but statistical appraisal must be empirical, testing the correspondence between the model and these aspects of experience which it is intended to describe. On the basis of these tests, some parts or some uses of the model may be rejected as unsound and other parts or uses may be accepted, with varying degrees of confidence, as being reliable. Warning notices against undue dependence may be posted on these parts which cannot be tested for lack of data.

EFFECT OF DIET ON THE RATE OF BROOD REARING BY NATURALLY AND INSTRUMENTALLY INSEMINATED QUEENS

SUMMARY Small colonies of honey bees were established with ca. 4,000 newly emerged Italian bees and placed in 2 x 2 x 2 m flight cages. The colonies (total of 24) were divided into two groups; twelve were headed by instrumentally inseminated queens purchased from a commercial queen breeder and twelve headed by free flight mated queens reared at Beltsville, Maryland. Each group of l2 colonies was further divided into three treatments of four colonies each. Each group was offered diets containing either Yeaco (43 ‘% protein), Wheast (58 % protein), or soybean protein (90 % protein) as the sole protein source. The amount of sealed brood reared by each colony was measured for 12 weeks. Colonies of bees fed Wheast diets and headed by either instrumentally inseminated queens or free flight mated queens reared significantly more brood than similar units of bees fed either Yeaco or soybean diets. The second greatest amount of brood was reared by bees fed Yeaco diets followed by soybean fed bees. The results of this experiment demonstrated that, overall, instrumentally inseminated queens did as well as free mated queens under controlled conditions. This study also demonstrated that bees fed poor diets regardless of the genetic background of the queens will do poorly.

Observations on the Annual Cycle of Foraging and Brood Rearing byApis Cerana IndicaColonies

SummaryTwo years' field study of foraging and brood rearing in the Indian honeybee Apis cerana indica showed that the proportion of bees in a colony that foraged for pollen, the pollen stores in the hive, and the amount of brood reared, followed a similar seasonal pattern. The proportion of flying bees collecting pollen showed greater seasonal variations than the proportion collecting nectar, and than the proportion that collected water (or nothing).

A Washing Technique for Collection of Honeybee Semen

SummaryA simple and fast method for collecting honeybee semen in large quantity is described. Semen and mucus of many drones, everted and ejaculated by hand, were scraped into Kiev diluent in a semen-washing funnel and a collecting tube. The semen-mucus-diluent mixture was centrifuged at 2500 rpm for 10 min to separate semen from mucus and the diluent. The collecting tube containing semen was incorporated into a special large-capacity syringe, and the semen was used to inseminate queen honeybees.No significant differences were found in the amount of brood produced between 31 queens instrumentally inseminated with semen collected by this method, queens inseminated with semen collected by the conventional Mackensen technique, and open-mated queens (P > 0·05 in all cases). However, significant differences were observed in the onset of oviposition (P < 0·05 in all cases). There was a delay before oviposition by all the instrumentally inseminated queens, which was greatest for queens inseminated with semen col...