An account is given of the development of a reliable method for the isolation of Streptococcus pluton (Bacillus pluton White), an organism associated with European foul-brood disease of the larval honeybee. S. pluton, isolated as an anaerobe, may be trained to grow as an aerobe in rod form. Its principal anaerobic growth requirements are a low molar ratio of Na: K, high inorganic phosphate concentration, glucose or fructose, and undetermined factors provided by yeast extract. Peptones are harmful to growth. Aerobic growth has no very critical requirements other than glucose, fructose or sucrose. Bacterium eurydice White which, together with S. pluton, causes European foul-brood disease grows well anaerobically on a yeast extract + glucose + fructose medium; either sugar alone supports only feeble anaerobic growth. Anaerobic growth of B.eurydice is also accelerated by a low molar ratio of Na: K and is inhibited by peptones. S. pluton and B.eurydice appear to be separate organisms; no evidence has been obtained to support claims by previous workers that S. pluton is a variant of B. eurydice.
The proportion of honey-bees infected with Nosema apis (Zander) declines in summer as the old infected bees die, for they cease to transmit their infection to the newly emerged individuals during the flying season. N. apis spores survive the summer on combs contaminated with infected faeces during the preceding winter. Although bees clean the combs during the summer, all infected material is not removed, and even well-used brood comb, which has been repeatedly cleaned by bees, can carry infection. Only a few bees may contract infection in the autumn from these faeces, but they join the winter cluster and initiate the next outbreak of the disease. Transferring a colony on to clean comb early in the spring or summer removes the source of the disease, and it then disappears when all the old infected bees die.
Old broodless comb can be sterilized quite simply by fumigation for a few days with the vapours of formalin or glacial acetic acid. Acetic acid is preferable, because it does not poison any honey or pollen in the combs. Formaldehyde can safely be used only with empty combs.
The autumn is the best time for treating colonies chemotherapeutically, because the combs are then cleanest and the few bees which are infected can be cured during the winter. The drug can be incorporated in the syrup normally fed to colonies in autumn...
IN connexion with an attempt to isolate pheromone from the queens of the honey bee, Apis mellifica L., an examination was carried out on the neutal portion of the extract obtained by perfusion of the powdered whole-bodies of the queens with ethanol and tert-butanol. By chromatographing the neutral portion on alumina, or silica gel, a crystalline substance, m.p. 138–145° C. [α]D = −31.6 ± 6° (c = 0.39 in chloroform), was obtained, which resembled cholesterol in behaviour and chemical properties. The Liebermann-Burchard reaction gave the same coloration as that obtained with cholesterol and the mixed melting point was the same. However, there were two bands (6.08µ and 11.33µ) in the infra-red spectrum of the substance which are not found in the spectrum of cholesterol and its derivatives. The same substance was isolated by similar means from worker bees. The constitution 1 for the sterol was elucidated from the following: An Oppenauer oxidation using cyclohexanone and aluminium isopropylate in toluene produced a conjugated unsaturated ketone; m.p. 77–84° C., λmax = 242 mµ, log ε = 4.0 calculated for C28H44O, 396.6. Besides, the double bond of the αβ-unsaturated ketone function, a second double bond was present as shown by titration with bromine (1.155 mgm. of substance used...
Spores of Bacillus larvae White germinate and make initial vegetative growth best in a limited range of low redox potentials, but later growth and sporulation occur best aerobically. Different media needed for best results with each phase of development of the bacillus are described. Spores of B. larvae germinate in the mid-gut contents of honey-bee larvae up to 2 days old. The vegetative forms then migrate and become closely applied to, but do not penetrate, the mid-gut epithelium. Most organisms seem to be voided with the contents of the intestine when an infected larva defaecates shortly before it pupates. A few organisms are presumably left in the intestine and probably invade the tissues of the larva as it pupates.
Studies were made to determine the incidence of hatching of honey bee, Apis mellifera L., eggs incubated in various positions. Petri dishes with basal layers of wax, paraffin, or drone foundation were used as supporting surfaces for eggs. The lowest successful hatching incidence was 58% for eggs kept in the inverted position; the highest incidence was 67% in an ordinary prone position. The averagc hatching incidence of 62% shows that hatching is not influenced strongly by the position of the egg. Eggs placed into petri dishes but without regard to their position showed an average of 78% hatchability.
The resulting larvae, reared artificially on larval food, showed normal growth and development. Excessivc shaking or bumping does not appear to affect satisfactory hatching. A convenient and rapid method for transfer of honey bee eggs using an ordinary grafting tool was described. The different incubation positions are illustrated by photographs.
Nurse bees were forced to rear brood continuously, under field and laboratory conditions. The weight and the length of life of the bees they reared decreased when the nurse bees were much older than is normal (40-98 days instead of 5-16 days). Intestines of emerged bees reared by nurse bees 50 days old and more were very fragile. In the control colonies these phenomena were not observed.
Small colonies of emerged bees were kept in confinement, and fed fresh pollen, or pollen two years old supplemented with: nothing, pantothenic acid, 20% dried brewers yeast, 20% vitamin-free casein, casein plus pantothenic acid. The number of sealed brood cells in these colonies (in the above order) was 8-9,l-0,2-8,4-4,5-6, and 5-8 times the number in the colonies fed old pollen alone. Deterioration of proteins and of pantothenic acid is thus partially responsible for the inferior value of stored pollen for brood rearing.
1. The proventriculus of the worker honeybee is an organ which effects a highly efficient separation of pollen grains from the medium in which they are suspended.
2. The pollen grains are packed tightly together by the proventriculus and are passed as a bolus down to the ventriculus.
3. The boluses pass quite quickly towards the posterior end of the ventriculus (5-20 min.), depending on the concentration and amount of pollen suspension which is fed.
4. The peritrophic membranes do not move down the ventriculus with these packages but pass down at a slower rate.
5. At the posterior end of the ventriculus the pollen may be held up for a considerable time. In the brood-rearing bee it stays there for many hours (up to 12 or more). In the forager it begins to pass down the hindgut to the rectum after 3 hr. or less.
6. The volume of fluid within the honey stomach, the size of particles in suspension and their concentration have significant effects on the rate and efficiency of filtration by the proventriculus.
7. Some reflexions are made on the possible physiological significance of the mechanism of the proventriculus to the worker honeybee.
In certain brain parts of queen bees, 2 and 3 years old, a defective tissue is found that, in bilateral structures also occurs symmetrically. The cavities can reach 0.0015 mm3 of volume, this size being found almost exclusively in the nuclear parts. Very seldom there are comparatively small lacunas in the fibrillar tissue. In these investigations the corpora pedunculata (mushroom bodies) - the place of associative functions - showed no signs of degeneration in the cup sphere. This divergent behaviour of the superior centres is in accordance with already know statements.
Under honeydew flow conditions, honeybee colonies with queens of defined origin proved to be especially liable to paralysis.
The tendency was irrespective to the mating drone. The observation suggest a matrocline heredity of the honeybee. The liability for the disease is considered to be a symptom of inbreeding.
The worker bees' behaviour towards those bees that had died of paralysis on the combs in the hive is described.
The cocoon of the queen cell extends on the top also over the royal jelly. The upper part of the cocoon consists sometimes only of a few threads and sometimes of a ring or a net made of threads and plates. This statement is in contradiction with the general view, though it confirms the observation of Prell.
Worker bees dissolve dry sugar, clean their queen's body, and possibly also soften or lubricate materials being chewed, with the watery secretion of their labial glands. The small amount of oil produced by these glands accumulates in them and what little is discharged adheres to the tongue hairs and is not mixed with the food ; its function is obscure. The secretion of the mandibular glands is discharged by a movement of the hypopharyngeal plate. It is an aqueous emulsion with a non-aqueous phase insoluble in lipoid solvents but soluble in alcohol, glycol, etc. The function of the secretion of worker' mandibular glands is discussed ; it is not used in chewing. Salivary invertase comes only from the hypopharyngeals glands.
The sting of the honey bee (Apis mellifera L.) carries volatile substances which incite bees to aggression. This was first demonstrated by Huber, who elicited attacks by the guard bees when he placed freshly excised stings or the odour of stings near the hive entrance. Free found that cotton balls containing stings were more frequently stung than control balls.
The valve-fold of the queen honeybee is an epithe1ian fold of the ventral vaginal wall which is interlaced with ascending muscle fibres. The valve-fold projects into the lumen of the vagina like a tongue-shaped roll just behind the caudal end of the median oviduct and directly above the sternal antecosta of the VII. segment. Opinions about the function of this fold are dlsagreeing.
A short description of the histological structure of the valve-fold is given. Furthermore, reference is made to a premature, progressive degeneration and calcification of the valve-fold's musculature in most of the queen honeybees, dependent on age. In discussions concerning the function of the valve-fold, these causally not clarified degeneration processes must be considered.
According to the previous studies, the pollen income to the honeybee colony varies seasonally and increases parallel to the upswing of brood rearing. This fact suggests that some regulative functions act to increase the number of pollen-foragers. As the first step to analyse such probable regulation, the diurnal and seasonal variations of the number of pollen-foragers were observed correspondent to the population growth of a single honeybee colony. The counts were made about weekly from late April to mid September on the days of favorable weather conditions in 1959. The number of homing bees and pollen-foragers among them were counted at the hive entrance from 8 : 00 to 17 : 00 for 10 minutes at intervals of an hour. The population growth was estimated by BODENHEIMER' smethod and corrected by NICKEL-ARMBRUSTER's death rate. The results are summarized as follows : 1) Except under unfavorable weather condition, the pollen-foragers were always more abundant in the forenoon than in the afternoon, while other homing bees were often more abundant in the afternoon than in the afternoon. 2) From the records taken during 10 : 00 to 10 : 10 a.m., the fluctuation of the number of homing bees was more conspicuous than that of the pollen-foragers. The number of homing bees corresponded in general to that of more than 10 days old bees (potential foragers) but the number of pollen-foragers showed no such correlation. 3) The ratio of the pollen-foragers to the homing bees was high during early spring...