Insectes Sociaux

Maschwitz, U.;Tho, Y. Pong;

doi: 10.1007/BF02226915pmid: N/A

Zusammenfassung Sechs Macrotermitinenarten aus der GattungenMicrotermes, Macrotermes, Odontotermes undHypotermes werden auf das Vorhandensein von Wehrsekreten untersucht. Die Soldaten von fünf Arten geben beim Kampf aus ihren großen Labialdrüsen Wehrflüssigkeit ab. BeiMacrotermes gilvus-Soldaten, die sehr kleine Labialdrüsen besitzen, läßt sich keine Sekretabgabe beobachten. Bei allen vier Gattungen finden sich Arten, deren Sekret Chinone enthält. Diese Verbindungen fehlen beiMacrotermes gilvus undOdontotermes horni. Im Sekret vonOdontotermes, Microtermes undHypotermes sind zuzätzlich Klebstoffe enthalten.

Cammaerts-Tricot, M. -C.;

doi: 10.1007/BF02226916pmid: N/A

Summary The workers of four colonies ofMyrmica rubra were separated into 5 different age categories on the basis of their degree of pigmentation (fig. 1). The production of mandibular and Dufour's glands secretions by ants of each pigmentary group was investigated. Both the quantity of 3-octanol and 3-octanone (the 2 major constituents of the mandibular gland secretion) and the proportion of 3-octanol contained in the mixture increase with the age of the ants (fig. 3 and 4). The Dufour's reservoirs enlarge until the ants reach the pigmentary group 3 (fig. 6). The attractive power of the mandibular and Dufour's glands secretions increases during the adult life of the workers (fig. 5 and 6). The reactions of differently pigmented ants to the mandibular and Dufour's glands of foragers were analysed. The callows respond only to Dufour's gland secretion, whereas older ants are attracted both by the mandibular and Dufour's glands pheromones (fig. 7 and 8). The first foragers to leave their nest emit the largest amounts of attractive pheromones and also give the best responses to these secretions. this is of functional significance for the society, since it is these foragers which recruit or else are recruited most frequently outside the nest during the defence of the colony and the collection of food.

Röseler, Peter-Frank;

doi: 10.1007/BF02226917pmid: N/A

Zusammenfassung Bei 1 bis 5 Tage alten Arbeiterinnen der HummelartB. terrestris wurde die Oogenese untersucht, um zu klären, welche Vorgänge bei der Eibildung im weiselrichtigen Zustand des Volkes gedrosselt sind und im weisellosen Zustand gefördert werden. Weisellose Gruppen wurden aus je 4 frischgeschlüpften Arbeiterinnen gebildet. Am 2. Lebenstag besitzen weisellose Arbeiterinnen größere Nährzellkerne als gleichaltrige weiselrichtige Arbeiterinnen, am. 3. Tag treten bei ihnen in den Oocyten akzessorische Kerne auf und es setzt starkes Längenwachstum ein. Der RNS-Stoffwechsel in den Nährzellen wurde autoradiographisch untersucht. Weisellose Arbeiterinnen besitzen vom 2. Tag an einen erhöhten RNS-Umsatz. Die RNS-Synthese ist ca. 5mal höher als bei weiselrichtigen Arbeiterinnen, bei denen die RNS-Synthese vom 1. Tage an abnimmt. Erst am 3. Tag ließ sich in den endständigen Oocyten weiselloser Arbeiterinnen autoradiographisch eine verstärkte Eiweißsynthese nachweisen. Dagegen zeigte die diskelektrophoretische Auftrennung der löslichen Ovarproteine, daß weisellose Arbeiterinnen bereits am 1. Lebenstag einen höheren Proteingehalt im Ovar besitzen als weiselrichtige Arbeiterinnen. In der Haemolymphe weiselloser Arbeiterinnen sind die dotterpflichtigen Protein-fraktionen bereits am 1. Lebenstag in höherer Konzentration vorhanden. Diese Ergebnisse zeigen, daß die Synthesen für die Eibildung im weiselrichtigen Zustand nicht völlig unterdrückt sind, sondern auf einem niedrigen Niveau ablaufen, wobei es aber in den ersten 5 Lebenstagen nicht zur Dotterbildung kommt. Gleich nach dem Schlüpfen registrieren die Arbeiterinnen den weiselrichtigen oder weisellosen Zustand des Volkes und regulieren dementsprechend die Synthesen für die Eibildung im Fettkörper und im Ovar bereits am 1. Tag. Diese Befunde werden im Hinblick auf die hormonelle Steuerung der Eireifung diskutiert.

Cammaerts-Tricot, M. -C.;Verhaeghe, J. -C.;

doi: 10.1007/BF02226918pmid: N/A

Summary Trail pheromone production and trail following behaviour of workers ofMyrmica rubra of different age groups, categorized by their cuticular pigmentation, were analysed. The dimensions of the poison gland reservoir increase as workers grow older. No trail pheromone could be detected in callows. Its activity, as measured by the reactions of ants to it, appears and increases as ants grow older, the workers responding to their trail pheromone throughout adult life, although their response becomes increasingly obvious as the ants become older. The oldest ants, the foragers, are thus able to emit the largest amount of trail pheromone and follow more readily their own and congeners' trails. These capabilities help the colony when recruitment to repel an enemy or to exploit a source of food occurs in its foraging area.

Simpson, J.;Greenwood, Susan P.;

doi: 10.1007/BF02226919pmid: N/A

Summary Sinusoidal 650 Hz vibrations, pulsed in a manner similar to that of the piping sound made by queen honeybees, were applied to hives containing colonies of bees. When the vibrations were applied to four hives containing very small colonies with unmated queens less than one week old, all four colonies swarmed, leaving no bees in their hives. Sixteen slightly larger colonies, also containing queens a few days old, were divided into two groups of eight. One group received vibrations and five of the colonies in it swarmed, each leaving a proportion of its bees in its hive. The other eight colonies did not receive vibrations and none of them swarmed.

Gray, B.;

doi: 10.1007/BF02226920pmid: N/A

Summary A large number of associated organisms have been found in nest ofMyrmecia; the following orders and numbers of species, in brackets, are represented:Anura (1); Araneae (9); Acarina (1); Blattodea (3); Coleoptera (20+); Collembola (3); Diptera (1); Hemiptera (2); Hymenoptera (14); Isoptera (2); Lepidoptera (4); Neuroptera (1); Orthoptera (2); Thysanura (4+); Isopoda (13) and Nematoda (1). Most abundant were specimens of Collembola and Isopoda which were found in the majority of nests; these occurred principally as scavengers. The termite species and two ant species were found in colonies co-inhabiting the large earthen mounds ofMyrmecia. Some of the Coleoptera and Diptera species occurred as larvae in the debris left in chambers, whereas many of the adult beetles were present as prey. Noteworthy were the several occurrences of large Carabidae larvae in the nests of fourMyrmecia species.

Marikovsky, P. I.;

doi: 10.1007/BF02226921pmid: N/A

Summary A description is given of the biology ofR. proformicarum from south-east Kasachstan, which keepsProformica slaves. Rossomyrmex is a desert ant; its nest corresponds to that ofProformica, with vertical passage-ways and horizontal chambers. A colony contains 23–200 individuals ofRossomyrmex and 65–650 slaves. The activity begins early in the year; the nest is closed in July to August, and the following rest period extends into winter dormancy. The nests are established very close to one another at the borders ofProformica colonies. Each nest contains a queen. The slaves bring in nutrients, chiefly honey, with which they fill repletes that hang from the roof of the lowest chamber. TheProformica workers are polymorphic. Only the small insects are active outside during the day; large ones, which later become repletes come to the surface at night. TheRossomyrmex workers make raids and protect the nest. A raid is preceded by a reconnaissance. A sout takes a nest-mate to the colony that is to be attacked, these two then bring along others until finally a sufficient number of insects begins the attack. After destruction of the largeProformica workers, which do not defend themselves, larvae, pupae and eggs are carried away. The maintenance of colonies in observation nests is described.

Spragg, W. T.;Fox, R. E.;

doi: 10.1007/BF02226922pmid: N/A

Summary A new method for the tracing of termite nesting systems is proposed and proved in field trials withMastotermes darwiniensis nesting systems. An attractive bait containing γ-ray emitting scandium-46 oxide is inserted into an infested site. The bait is eaten rapidly and taken to the nests where trophallactic transfer spreads the scandium through the colony members. The scandium is finally excreted and the excreta fixed in the gallery walls and carton of all subcentres which can then be found using a γ-ray detector. The use of other radionuclides as colloids in similar bait is described. This new method appears to introduce a new concept into the tracing of social insects.

Schumacher, Aileen;Whitford, Walter G.;

doi: 10.1007/BF02226923pmid: N/A

Summary The foraging ecology of two ant species inhabiting the same area in the Chihuahuan desert was investigated by study of conditions and magnitude of forager activity, estimation of forager population numbers, determination of critical maximum and minimum temperatures, and observation of foraging behavior. The foraging activity ofFormica perpilosa was relatively independent of soil temperature and saturation deficits probably because of their ability to lose water without detriment and the fact that they forage in plants. Foraging activity inTrachymyrmex smithi neomexicanus ceased at saturation deficits greater than 35 gms/m3 and soil surface temperatures greater than 50 °C. The mean critical thermal maxima and minima inF. perpilosa were 45.2 °C and 5.2 °C and inT. s. neomexicanus were 36.7 °C and 9.7 °C. The estimated forager population size inF. perpilosa ranged from 2,000 to 3,500 per colony. We estimated that the average forager population size inT. s. neomexicanus was about one half that ofF. perpilosa. F. perpilosa forage on both honey dew and insects.T. s. neomexicanus forage on leaf litter, and appear to exhibit a seasonal change in forage preference.