The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Francis L. W. Ratnieks - One of the best experts on this subject based on the ideXlab platform.
-
Insect communication: 'no entry' signal in ant foraging.
Nature, 2005Co-Authors: Elva J. H. Robinson, Mike Holcombe, Duncan E. Jackson, Francis L. W. RatnieksAbstract:Forager ants lay attractive trail pheromones to guide nestmates to food1, 2, but the effectiveness of foraging networks might be improved if pheromones could also be used to repel foragers from unrewarding routes3, 4. Here we present empirical evidence for such a negative trail pheromone, deployed by Pharaoh's ants (Monomorium pharaonis) as a 'no entry' signal to mark an unrewarding foraging path. This finding constitutes another example of the sophisticated control mechanisms used in self-organized ant colonies
-
Pheromone trail decay rates on different substrates in the Pharaoh's ant, Monomorium pharaonis
Physiological Entomology, 2003Co-Authors: Raphaël Jeanson, Francis L. W. Ratnieks, Jean-louis DeneubourgAbstract:Many ants use pheromone trails to organize collective foraging. This study investigated the rate at which a well-established Pharaoh's ant, Monomorium pharaonis (L.), trail breaks down on two substrates (polycarbonate plastic, newspaper). Workers were allowed to feed on sucrose solution from a feeder 30 cm from the nest. Between the nest and the feeder, the trail had a Y-shaped bifurcation. Initially, while recruiting to and exploiting the feeder, workers could only deposit pheromone on the branch leading to the feeder. Once the trail was established (by approximately 60 ants per min for 20 min), the ants were not allowed to reinforce the trail and were given a choice between the marked and unmarked branches. The numbers of ants choosing each branch were counted for 30 min. Initially, most went to the side on which pheromone had been deposited (80% and 70% on the plastic and paper substrates, respectively). However, this decayed to 50% within 25 min for plastic and 8 min for paper. From these data, the half-life times of the pheromone are estimated as approximately 9 min and 3 min on plastic and paper, respectively. The results show that, for M. pharaonis, trail decay is rapid and is affected strongly by trail substrate.
O. C. Bueno - One of the best experts on this subject based on the ideXlab platform.
-
ocorrencia de megaselia scalaris loew 1866 diptera phoridae em ninhos de laboratorio de Monomorium pharaonis linnaeus 1758 e paratrechina longicornis latreille 1802 hymenoptera formicidae
Revista Brasileira de Zoociências, 2005Co-Authors: Daniel Russ Solis, O. C. Bueno, Itamar Cristina Reiss, Leonardo GomesAbstract:Megaselia scalaris (Loew, 1866) is a cosmopolite specie and a detriturer insect, commanding to act as a facultative predator. There are little reports about the invasion of nests in social Hymenoptera by this phorid. Nests of Monomorium pharaonis (Linnaeus, 1758) and of Paratrechina longicornis (Latreille, 1802), kept in the Centro de Estudos de Insetos Sociais (UNESP, Rio Claro), were invaded by M. scalaris. Immature from this Diptera were found in a deposit of food of M. pharaonis, commanding, with this, to compete by food and to prejudice the development of the colony. In the case of P. longicornis, apparently there was not damages, because the immature and adults of the phorid sheltered in the deposit of trash. M. scalaris did not caused any prejudice for the immature and adults of both species of ants. This fact can by related with the internal dynamic of the colonies, what hinder any harmful action of the Diptera. This is the first report of this phorid specie in nests of home ants in the Brazil.
-
Larval instars and immature development of a Brazilian population of pharaoh's ant, Monomorium pharaonis (L.) (Hym., Formicidae)
Journal of Applied Entomology, 1993Co-Authors: Lucia E. Alvares, O. C. Bueno, H. G. FowlerAbstract:The immature development of pharaoh's ant, Monomorium pharaonis, workers was studied in a naturally collected Brazilian population. Three larval instars were confirmed by measuring maximal cephalic widths in cohorts of known age. Minimum egg to adult duration was 25 days, while the maximum duration was 54 days, both of which are larger than those reported for European populations. Larval instar development is cyclical at the colony level, suggesting reproductive bursts followed by lower reproductive activity of the queens. Zusammenfassung Larvenstadien und Entwicklung einer brasilianischen Population der Pharao-Ameise, Monomorium pharaonis (L.) (Hym., Formicidae) Die Entwicklung der Pharao-Ameise, Monomorium pharaonis, wurde anhand einer in Brasilien gesammelten Population untersucht. Mittels Messung der maximalen Kopfkapselbreiten wurden 3 Larvalstadien festgestellt. Die minimale Ei-Adulten-Entwicklungszeit wurde mit 25 Tagen ermittelt, wahrend die Maximaldauer 54 Tage betrug. Beide Werte sind groser als die von europaischen Populationen bekannten. Die Larvalentwicklung verlauft im Kolonie-Bereich zyklisch, woraus hervorgeht, das Phasen starkerer Produktionskraft der Koniginnen mit solchen geringerer Produktion abwechseln.
-
DYNAMICS OF COLONIZATION AND GYNE PRODUCTION BY Monomorium-pharaonis (L) (HYM, FORMICIDAE) IN BRAZIL
Journal of Applied Entomology, 1993Co-Authors: H. G. Fowler, M. Aparecida De Freitas, O. C. BuenoAbstract:The colonization characteristics of two neighboring populations of Monomorium pharaonis in human structures in Brazil were compared. No differences in the seasonality of colonizations into fixed trap nests between the two populations were found. However, one population had higher frequencies of colonizations with accompanying queens than the other. This resulted in the other population producing new queens at a higher frequency than the other. There was a clumping of colonization attempts at specific points, which shows that colonization may be predictable. These findings may be of importance in control programs for M. pharaonis in structures. Zusammenfassung Zur Dynamik der Ansiedlung und Weibchen-Produktion bei Monomorium pharaonis (L.) (Hym., Formicidae) in Brasilien Es wurden die Ansiedlungsmerkmale von zwei benachbarten Populationen von Monomorium pharaonis im menschlichen Siedlungsbereich in Brasilien vergleichend untersucht. In der Saisonalitat der Ansiedlung wurde zwischen den beiden Populationen kein Unterschied festgestellt. Jedoch hatte eine Population eine hohere Frequenz der Koloniebildung mit den zugehorigen Koniginnen als die andere. Daraus resultierte bei der anderen Population eine Produktion neuer Koniginnen in hoherer Frequenz als in der ersten. Es gab eine Konzentration der Ansiedlungsversuche an spezifischen Stellen, woraus sich eine Vorhersehbarkeit der Ansiedlung ergibt. Diese Ergebnisse konnen fur die Bekampfung der Pharao-Ameise von Bedeutung sein.
-
Dynamics of colonization and gyne production by Monomorium pharaonis (L.) (Hym., Formicidae) in Brazil
Journal of Applied Entomology, 1993Co-Authors: H. G. Fowler, M. Aparecida De Freitas, O. C. BuenoAbstract:The colonization characteristics of two neighboring populations of Monomorium pharaonis in human structures in Brazil were compared. No differences in the seasonality of colonizations into fixed trap nests between the two populations were found. However, one population had higher frequencies of colonizations with accompanying queens than the other. This resulted in the other population producing new queens at a higher frequency than the other. There was a clumping of colonization attempts at specific points, which shows that colonization may be predictable. These findings may be of importance in control programs for M. pharaonis in structures
-
Larval instars and immature development of a Brazilian population of pharaoh's ant,Monomorium pharaonis(L.) (Hym., Formicidae)
Journal of Applied Entomology, 1993Co-Authors: Lucia E. Alvares, O. C. Bueno, H. G. FowlerAbstract:The immature development of pharaoh's ant, Monomorium pharaonis, workers was s died in a naturally collected Brazilian population. Three larval instars were confirmed by measuring maximal cephalic widths in cohorts of known age. Minimum egg to adult duration was 25 days, while the maximum duration was 54 days, both of which are larger than those reported for European populations. Larval instar development is cyclical at the colony level, suggesting reproductive bursts followed by lower reproductive activity of the queens
B. Gobin - One of the best experts on this subject based on the ideXlab platform.
-
sperm transfer during mating in the pharaoh s ant Monomorium pharaonis
Physiological Entomology, 2006Co-Authors: D. Allard, L. W. Børgesen, Johan Billen, M.m. Van Hulle, A. Bobbaers, B. GobinAbstract:Sperm transfer in the pharaoh’s ant Monomorium pharaonis (L.) is studied by making longitudinal sections through the gasters of mating pairs fixed in copula. Sperm is transferred inside a spermatophore similar to those found in two other ants, Diacamma sp. from Japan and Carebara vidua. Sharp teeth-ridges are present on the penis valves and, during copulation, these teeth make contact with a thick and soft cuticular layer covering the bursa copulatrix. This ensures an attachment long enough for the successful transfer of the spermatophore to the right position inside the female oviduct. The thick cuticle also protects the queen from serious damage by the male’s sharp claspers. After a first successful copulation, sperm is still present inside the male’s seminal vesicles, suggesting that males can mate multiply. Additional experiments, where single, initially virgin males are presented to several virgin females, confirm this.
-
Sperm transfer during mating in the pharaoh’s ant, Monomorium pharaonis
Physiological Entomology, 2006Co-Authors: D. Allard, L. W. Børgesen, Johan Billen, M.m. Van Hulle, A. Bobbaers, B. GobinAbstract:Sperm transfer in the pharaoh's ant Monomorium pharaonis (L.) is studied by making longitudinal sections through the gasters of mating pairs fixed in copula. Sperm is transferred inside a spermatophore similar to those found in two other ants, Diacamma sp. from Japan and Carebara vidua. Sharp teeth-ridges are present on the penis valves and, during copulation, these teeth make contact with a thick and soft cuticular layer covering the bursa copulatrix. This ensures an attachment long enough for the successful transfer of the sper- matophore to the right position inside the female oviduct. The thick cuticle also protects the queen from serious damage by the male's sharp claspers. After a first successful copulation, sperm is still present inside the male's seminal vesicles, suggesting that males can mate multiply. Additional experiments, where single, initially virgin males are presented to several virgin females, confirm this.
-
Sperm transfer during mating in the pharaoh’s ant Monomorium pharaonis. Physiol Entomol 31:294–298
Princeton University Press Princeton, 2006Co-Authors: D. Allard, M.m. Van Hulle, A. Bobbaers, L. Børgesen, J. Billen, B. GobinAbstract:Abstract. Sperm transfer in the pharaoh’s ant Monomorium pharaonis (L.) is studied by making longitudinal sections through the gasters of mating pairs fixed in copula. Sperm is transferred inside a spermatophore similar to those found in two other ants, Diacamma sp. from Japan and Carebara vidua. Sharp teeth-ridges are present on the penis valves and, during copulation, these teeth make contact with a thick and soft cuticular layer covering the bursa copulatrix. This ensures an attachment long enough for the successful transfer of the spermatophore to the right position inside the female oviduct. The thick cuticle also protects the queen from serious damage by the male’s sharp claspers. After a first successful copulation, sperm is still present inside the male’s seminal vesicles, suggesting that males can mate multiply. Additional experiments, where single, initially virgin males are presented to several virgin females, confirm this. Key words. Formicidae, genital spines, mating, spermatophore
Chow-yang Lee - One of the best experts on this subject based on the ideXlab platform.
-
effects of a juvenile hormone analogue pyriproxyfen on monogynous and polygynous colonies of the pharaoh ant Monomorium pharaonis hymenoptera formicidae
Tropical Biomedicine, 2015Co-Authors: Jia-wei Tay, Chow-yang LeeAbstract:To evaluate the effects of the juvenile hormone analogue pyriproxyfen on colonies of the Pharaoh ant Monomorium pharaonis (L.), peanut oil containing different concentrations (0.3, 0.6, or 0.9%) of pyriproxyfen was fed to monogynous (1 queen, 500 workers, and 0.1 g of brood) and polygynous (8 queens, 50 workers, and 0.1 g of brood) laboratory colonies of M. pharaonis. Due to its delayed activity, pyriproxyfen at all concentrations resulted in colony elimination. Significant reductions in brood volume were recorded at weeks 3 - 6, and complete brood mortality was observed at week 8 in all treated colonies. Brood mortality was attributed to the disruption of brood development and cessation of egg production by queens. All polygynous colonies exhibited significant reduction in the number of queens present at week 10 compared to week 1. Number of workers was significantly lower in all treated colonies compared to control colonies at week 8 due to old-age attrition of the workers without replacement. At least 98.67 ± 1.33% of workers were dead at week 10 in all treated colonies. Thus, treatment with slow acting pyriproxyfen at concentrations of 0.3 - 0.9% is an effective strategy for eliminating Pharaoh ant colonies.
-
induced disturbances cause Monomorium pharaonis hymenoptera formicidae nest relocation
Journal of Economic Entomology, 2015Co-Authors: Jia-wei Tay, Chow-yang LeeAbstract:Budding and relocation of nests are important characteristics of the Pharaoh ant, Monomorium pharaonis (L.), an important pest of artificial structures. Pharaoh ant colony movements induced by several types of disturbances were evaluated in the laboratory. The percentages of workers and brood in the source and new nest sites were determined at Days 0, 1, 3, and 5 following physical disturbance (temporal removal of nestmates), chemical disturbance (application of pyrethroid insecticide), invasion by heterospecific ants, food depletion, and moisture depletion in the laboratory. All disturbances were performed in the source nest, which was connected to an empty new nest site. Almost all workers moved and carried the entire brood to the new nest site when subjected to physical disturbance, chemical disturbance, and ant invasion on Day 1, whereas only <5% of workers were present in the new nest site in the undisturbed control. After these disturbances, the brood was never relocated back to the original nest site in this 5-d study. When subjected to food depletion, ∼60% of the brood were found in the new nest site and ∼40% of the brood remained in the original nest on Day 5, resulting in a polydomous population. In contrast, moisture depletion did not show any significant effect on colony movement. These results provide useful information about the causes of Pharaoh ant colony budding and guidance about how to develop effective control and prevention strategies.
-
Induced Disturbances Cause Monomorium pharaonis (Hymenoptera: Formicidae) Nest Relocation.
Journal of economic entomology, 2015Co-Authors: Jia-wei Tay, Chow-yang LeeAbstract:Budding and relocation of nests are important characteristics of the Pharaoh ant, Monomorium pharaonis (L.), an important pest of artificial structures. Pharaoh ant colony movements induced by several types of disturbances were evaluated in the laboratory. The percentages of workers and brood in the source and new nest sites were determined at Days 0, 1, 3, and 5 following physical disturbance (temporal removal of nestmates), chemical disturbance (application of pyrethroid insecticide), invasion by heterospecific ants, food depletion, and moisture depletion in the laboratory. All disturbances were performed in the source nest, which was connected to an empty new nest site. Almost all workers moved and carried the entire brood to the new nest site when subjected to physical disturbance, chemical disturbance, and ant invasion on Day 1, whereas only
-
2002: Effects of starvation on nutrient distribution in the pharoah ant, Monomorium pharaonis (Hymenoptera: Formicidae
2015Co-Authors: Er Chong, Ngo-long Chong, Han-heng Yap, Chow-yang LeeAbstract:Abstract The Pharaoh ant, Monomorium pharaonis (L.) is an important pest ant species in many parts of the world. Knowledge and understanding of feeding behavior of this species are essential to the success of baiting. Transfer of a toxicant in a bait to kill a targeted colony depends on the ability of the nutrient to move within various castes and stages of a colony. Here we report the effects of nutrient distribution in workers and larvae of laboratory colonies of the Pharaoh ant. Three types of baits: 10 % sucrose solution (represent-ing carbohydrate), corn oil (representing lipid), and boiled egg yolk (representing protein) were stained with an artificial food-coloring agent and offered to colonies undergoing 1, 3, and 6 days of starvation. Larvae were divided into three stages: stage I (1 – 5 days after hatching), stage II (5 – 10 days after hatching), and stage III (10 – 15 days after hatching). The number of larvae fed by their workers at 1, 8, and 24 hours after introduction of baits were counted. Results indicated that workers actively donate carbohydrate and protein-based food to all larval stages, irrespective of their starvation period; however, oil was transferred only upon a lengthened period of starvation. Larval stage III also showed the highest percentage of individuals oil-fed by the workers. We also observed that starved colonies showed a higher number of larvae receiving food from their workers. Food was more actively transferred to the latter two stages when compared to the youngest one. The function of each nutrient for colony development, role of larval stages as storage and digestion component of an ant colony, and the implication of our findings towards baiting strategies for Pharaoh ant control are discussed. Key Words Monomorium pharaonis trophallaxis starvation feeding behavior nutrient distributio
-
the roles of the queen brood and worker castes in the colony growth dynamics of the pharaoh ant Monomorium pharaonis hymenoptera formicidae
2014Co-Authors: Chow-yang Lee, Jia-wei Tay, Timothy A Linksvayer, Kokboon NeohAbstract:Known for its high reproductive rate, sociotomy, and unique nesting habits, the Pharaoh ant Monomorium pharaonis (LINNAEUS, 1758) is one of the most successful tramp ant species. In this study, combinations of different caste groups were used to examine the effects of each caste on queen and worker population growth dynamics over time. The initial number of queens in an incipient colony significantly affected queen population growth and accounted for 42.2% of the overall variability over a six-month period. Queen population growth significantly decreased as the initial number of queens increased in the incipient colonies, and in most cases, each colony retained its original number of queens (eight). The brood quantity had little effect on queen population growth and was responsible for an increase of only 2.5% in the overall variability, and the worker number had no effect on queen population growth. Worker population growth was primarily affected by the initial queen number of the incipient colony, although the effects of queen, brood, and worker number on worker population growth were all significant. Overall, our results showed that the number of caste components required for colony success was much lower than expected: A mere 50 workers and one queen were sufficient for colony survival and productivity irrespective of the presence of brood.
L. W. Børgesen - One of the best experts on this subject based on the ideXlab platform.
-
Functional morphology of the mandibular gland of queens of the ant Monomorium pharaonis (L.)
Acta Zoologica, 2012Co-Authors: Sofie Boonen, Dieter Eelen, L. W. Børgesen, Johan BillenAbstract:Boonen, S., Eelen, D., Borgesen, L. and Billen, J. 2012. Functional morphology of the mandibular gland of queens of the ant Monomorium pharaonis (L.). — Acta Zoologica (Stockholm) 00: 1–9. In this study, the functional morphology of the mandibular glands of pharaoh ant queens is investigated through histological and behavioural observations. The mandibular glands of queens of different age stages and mating status were examined at the light microscopical as well as the ultrastructural level. The results clearly show a high activity of the gland at the time of hatching, followed by a rapid degeneration independent of the queens’ mating status. We therefore hypothesize the glandular secretion serves to stimulate workers to remove the queens’ pupal skin. Experiments to compare hatching ability of isolated pupae and pupae assisted by workers confirmed the necessity of worker assistance, which is even more crucial to allow proper wing formation in queens and males. Together with the histological data, this suggests that the mandibular gland may indeed play a role in the social facilitation of hatching, although bioassays are required to give decisive answers about the mandibular gland’s function.
-
sperm transfer during mating in the pharaoh s ant Monomorium pharaonis
Physiological Entomology, 2006Co-Authors: D. Allard, L. W. Børgesen, Johan Billen, M.m. Van Hulle, A. Bobbaers, B. GobinAbstract:Sperm transfer in the pharaoh’s ant Monomorium pharaonis (L.) is studied by making longitudinal sections through the gasters of mating pairs fixed in copula. Sperm is transferred inside a spermatophore similar to those found in two other ants, Diacamma sp. from Japan and Carebara vidua. Sharp teeth-ridges are present on the penis valves and, during copulation, these teeth make contact with a thick and soft cuticular layer covering the bursa copulatrix. This ensures an attachment long enough for the successful transfer of the spermatophore to the right position inside the female oviduct. The thick cuticle also protects the queen from serious damage by the male’s sharp claspers. After a first successful copulation, sperm is still present inside the male’s seminal vesicles, suggesting that males can mate multiply. Additional experiments, where single, initially virgin males are presented to several virgin females, confirm this.
-
Functional morphology of the postpharyngeal gland of queens and workers of the ant Monomorium pharaonis (L.)
Acta Zoologica, 2006Co-Authors: Dieter Eelen, L. W. Børgesen, Johan BillenAbstract:Eelen D., Borgesen L.W. and Billen J. 2006. Functional morphology of the postpharyngeal gland of queens and workers of the ant Monomorium pharaonis (L.). — Acta Zoologica (Stockholm) 87 : 101-111 The postpharyngeal gland (PPG) is unique to ants and is the largest exocrine gland in their head. In queens of the pharaoh's ant, Monomorium pharaonis , the gland contains approximately 15 finger-like epithelial extensions on each side and opens dorsolaterally in the posterior pharynx. In these ants the PPG morphology varies considerably according to age and mating status. The epithelial thickness increases with age and reaches a maximum at 3 weeks in both virgin and mated queens. A considerable expansion of the lumen diameter occurs in both groups between 4 and 7 days. Virgin queens release their secretion into the gland lumen from an age of 7 days, whereas mated queens accumulate large amounts of secretion in their epithelium. The increasing epithelial thickness, together with the increasing lumen diameter, the presence of numerous inclusions in the epithelium and the release of secretion, are indicative for increasing gland activity. The gland ultrastructure indicates involvement in lipid metabolism and de novo synthesis of lipids. The PPG of workers consists of 12 finger-like tubes at each side. There is a significant difference in epithelial thickness between nurses and repletes and between nurses and foragers. We suggest the PPG serves different purposes in pharaoh's ants: it is likely that the PPG of workers and virgin queens is used to feed larvae. In mated queens the gland probably plays a role in providing the queen with nutritious oils for egg production. The PPG may also function in signalling species nestmate and caste identity, as well as in the reproductive capacity of the queens.
-
Sperm transfer during mating in the pharaoh’s ant, Monomorium pharaonis
Physiological Entomology, 2006Co-Authors: D. Allard, L. W. Børgesen, Johan Billen, M.m. Van Hulle, A. Bobbaers, B. GobinAbstract:Sperm transfer in the pharaoh's ant Monomorium pharaonis (L.) is studied by making longitudinal sections through the gasters of mating pairs fixed in copula. Sperm is transferred inside a spermatophore similar to those found in two other ants, Diacamma sp. from Japan and Carebara vidua. Sharp teeth-ridges are present on the penis valves and, during copulation, these teeth make contact with a thick and soft cuticular layer covering the bursa copulatrix. This ensures an attachment long enough for the successful transfer of the sper- matophore to the right position inside the female oviduct. The thick cuticle also protects the queen from serious damage by the male's sharp claspers. After a first successful copulation, sperm is still present inside the male's seminal vesicles, suggesting that males can mate multiply. Additional experiments, where single, initially virgin males are presented to several virgin females, confirm this.
-
Morphology of a novel glandular epithelium lining the infrabuccal cavity in the ant Monomorium pharaonis (Hymenoptera, Formicidae).
Arthropod structure & development, 2004Co-Authors: Dieter Eelen, L. W. Børgesen, Johan BillenAbstract:Abstract A novel glandular epithelium lining the infrabuccal cavity and anterior pharynx is described in both workers and queens of the pharaoh's ant Monomorium pharaonis. The infrabuccal cavity, connected with the buccal tube, forms a ventral outgrowth of the anterior pharynx, and as such displays the tegumental lining with a cuticle and an epithelial layer. In its dorsal region, the cavity's epithelium reaches a thickness of approx. 11–12 μm in both workers and queens, which is considerably thicker than the epithelium lining the rest of the infrabuccal cavity. Also the possible role of the infrabuccal gland is discussed.