Nesting biology and social organization of Halictus sexcinctus (Fabricius) in southern Greece

2001 ◽  
Vol 79 (12) ◽  
pp. 2210-2220 ◽  
Author(s):  
M H Richards
Keyword(s):  
Central Europe ◽  
Ovarian Development ◽  
Mediterranean Population ◽  
Nesting Biology ◽  
Colony Cycle ◽  
Nest Founding ◽  
Males And Females ◽  
Worker Mating ◽  
High Degree ◽  
Southern Greece

Halictus sexcinctus is a large halictine bee species widely distributed across central Europe and into the Middle East. Although its behaviour had not previously been studied in detail, it is known to exhibit solitary behaviour in central Europe. An aggregation nesting beside the seashore at Pyla-Daimonia, Demos Molai, in the southeastern Peloponnesos, Greece, was studied during the summers of 1997 and 1998. In southern Greece, H. sexcinctus exhibits weakly eusocial colonies, based on a partially bivoltine colony cycle, so across its range it is socially polymorphic. Weak eusociality in this Mediterranean population is characterized by haplometrotic nest-founding, a relatively high degree of queen–worker size dimorphism, high rates of worker mating and ovarian development, relatively short queen life-spans, and relatively low second-brood productivity. Overall, the sex ratio of the first brood is highly female-biased, while that of the second brood is variable, the proportions of males and females varying significantly in the 2 years. An unusual characteristic of nest foundresses in this population is that some are un-inseminated and produce all-male first broods rather than workers.

Evidence for geographic variation in colony social organization in an obligately social sweat bee, Lasioglossum malachurum Kirby (Hymenoptera; Halictidae)

2000 ◽  
Vol 78 (7) ◽  
pp. 1259-1266 ◽  
Author(s):  
Miriam H Richards
Keyword(s):  
Social Organization ◽  
Western Europe ◽  
Late Summer ◽  
Species Variation ◽  
Sweat Bee ◽  
Colony Cycle ◽  
Social Species ◽  
Lasioglossum Malachurum ◽  
Reproductive Brood ◽  
Southern Greece

The expression of altruism and colony eusociality are both a matter of degree in social sweat bees. Even in obligately social species, variation in these traits may be observed across a species' range. Lasioglossum (Evylaeus) malachurum (Kirby) is an obligately eusocial sweat bee found across Europe. In western Europe, L. malachurum exhibits north-south clines of increasing colony size associated with the production of more worker broods, and worker production of males, but societies conform to the model of a classically eusocial hymenopteran insect. A population of L. malachurum studied from 1994 to 1998 at Agios Nikolaos Monemvasias in southern Greece exhibits a startlingly different type of social structure. Dissections of female bees collected while foraging on flowers or from excavations of nests showed that the majority of mid- to late-summer workers are mated and (or) have developing ovaries, indicating that some workers are highly reproductive. Nest excavations indicated that in many or most colonies, the queen has disappeared by midsummer, before ovipositing the final, reproductive brood. In orphan nests, workers become the major reproductives, which suggests that males and gynes in the final brood are the offspring of workers. The very long breeding season in southern Greece may explain why colonies often outlive their queen. The result is the expression of a multivoltine colony cycle and a behavioural switch from eusocial to semisocial colony organization.

Photobehavioral differentiation within and between the sexes of Drosophila pseudoobscura

1975 ◽  
Vol 53 (10) ◽  
pp. 1395-1402 ◽  
Author(s):  
Robert F. Rockwell ◽  
Rudolf Harmsen ◽  
Fred Cooke ◽  
Joseph Grossfield
Keyword(s):  
Sexual Dimorphism ◽  
Drosophila Pseudoobscura ◽  
Isofemale Line ◽  
Isofemale Lines ◽  
Biochemical Traits ◽  
Behavioral Traits ◽  
Ecological Selection ◽  
Males And Females ◽  
Per Se ◽  
High Degree

Photoresponse and changeability of photoresponse were measured separately with males and females of Drosophila pseudoobscura. The measurements indicate no sexual dimorphism in photobehavior, but do show a distinct sexual dimorphism in changeability of photobehavior. Differentiation between isofemale lines of the population was observed from photobehavior and shown to be of equal magnitude in both sexes. However, such isofemale line differentiation in changeability of photobehavior was very low and restricted to females. Previously published work indicating sexual dimorphism in photobehavior may be the result of experimental designs confounding two effects: (1) photobehavior per se, and (2) changeability of photobehavior.This study of photobehavior suggests that two distinct, but not necessarily mutually exclusive, strategies are involved in the development of intrapopulation differentiation: one leading to a high degree of sexual dimorphism, the other leading to intrasexual differentiation. Concerning the former, it is methodologically and conceptually important to separate sexual dimorphism related to sexual selection from that related to ecological selection. This separation may be easier with behavioral traits than with morphological or biochemical traits.

scholarly journals First Case of Dual Size Asymmetry in an Identical Arthropod Organ: Different Asymmetries of the Combative (Sexual) and Cutting (Non-Sexual) Parts of Mandibles in the Horned Stored-Product Beetle Gnatocerus cornutus (Fabricius, 1798)

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 151 ◽  
Author(s):  
Tomas Vendl ◽  
Vaclav Stejskal ◽  
Radek Aulicky
Keyword(s):  
Sexual Dimorphism ◽  
Regulatory Mechanisms ◽  
Directional Asymmetry ◽  
Sexually Dimorphic ◽  
First Case ◽  
Males And Females ◽  
Long Life ◽  
High Degree ◽  
Size Asymmetry ◽  
Single Organ

Although it is known that separate insect body structures may be asymmetrical within one species, the different functional asymmetries within a single organ as a result of differential selective regimes have not been described. Based on microscopic measurements and SEM photography, we examined the size, shape and asymmetry of the mandibular structures of males and females of the sexually dimorphic broad-horned flour beetle, Gnatocerus cornutus (Tenebrionidae, Coleoptera). It was found that sexual dimorphism only manifests in certain outgrowth parts (horns) of male mandibles, while the remaining cutting parts of the mandibles hold identical morphologies for both sexes. A more interesting finding—since this is the first published case of dual functionally selected asymmetry in an identical arthropod organ—was that the cutting part of the male mandible exhibited directional asymmetry, whereas the outgrowth horn part of the mandible showed a high degree of symmetry. Moreover, there was no relationship between the size and asymmetry of horns. The results indicate different regulatory mechanisms of sexually selected combative horns and the food-functional, more conservative (constrained by hard food and adult long life) cutting parts of mandibles.

A revision of the subgenus Osmia (Diceratosmia), with descriptions of four new species (Hymenoptera, Megachilidae)

Zootaxa ◽  
2017 ◽  
Vol 4337 (1) ◽  
pp. 1 ◽  
Author(s):  
TERRY GRISWOLD ◽  
MOLLY G. RIGHTMYER
Keyword(s):  
New Species ◽  
North American ◽  
Geographic Range ◽  
Junior Synonym ◽  
Nesting Biology ◽  
The Bahamas ◽  
The North ◽  
Males And Females ◽  
Eleven Species

The eleven species of the North American subgenus Osmia (Diceratomsia) are revised, four of which are new: Osmia (Diceratosmia) exquisita, n. sp., from Honduras; Osmia (Diceratomia) gonzalezi, n. sp., and Osmia (Diceratomia) spinulifera, n. sp., from Mexico; and Osmia (Diceratomsia) lacunosa, n. sp., from the Bahamas. Diagnoses for the remaining seven species and a key to the males and females of all species are provided. We newly designate a neotype for Osmia botitena Cockerell, junior synonym of Osmia subfasciata Cresson, and remove from synonymy Osmia marilaunidii Cockerell, new status. In addition, we review the known nesting biology, floral hosts, and geographic range of each species. 

Nesting biology and subsociality in Ceratina calcarata (Hymenoptera: Apidae)

2010 ◽  
Vol 142 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Sandra M. Rehan ◽  
Miriam H. Richards
Keyword(s):  
Life History ◽  
Adult Development ◽  
Social Life ◽  
North American Species ◽  
Nesting Biology ◽  
Southern Ontario ◽  
Active Season ◽  
Carpenter Bees ◽  
Nest Founding ◽  
Ceratina Calcarata

AbstractTo evaluate sociality in small carpenter bees (Ceratina Latreille), we studied the life history and nesting biology of a common eastern North American species, Ceratina (Zadontomerus) calcarata Robertson. Pan-trap and nest collections throughout the active season (May to September 2006) were used to assess C. calcarata’s seasonal phenology and nesting biology in southern Ontario. Adults overwintered in their natal nests. Males emerged in early May and occupied preexisting hollows in twigs and stems. Females emerged from hibernacula 2 weeks later, founding new nests. Nest founding and provisioning occurred throughout the spring; females remained with developing brood through the summer. Complete nests contained, on average, 6.9 offspring, with egg-to-adult development averaging 46 days. Ceratina calcarata is subsocial rather than solitary: mothers are long-lived and nest-loyal, and care for offspring from egg to adulthood. Subsociality is found in all behaviourally classified small carpenter bees, while some species cross the boundary into social life, making Ceratina an important genus for the study of the transition between solitary and social life.

Nesting Biology and Taxonomy of Arpactophilus-Mimi, a New Species of Social Sphecid (Hymenoptera, Sphecidae) From Northern Australia

1988 ◽  
Vol 36 (5) ◽  
pp. 585 ◽  
Author(s):  
RW Matthews ◽  
ID Naumann
Keyword(s):  
National Park ◽  
Ovarian Development ◽  
Brood Care ◽  
Northern Australia ◽  
Nesting Biology ◽  
Selective Pressures ◽  
Nest Sites ◽  
Adult Females ◽  
Single Nest ◽  
A New Species

Arpactophilus mimi, Naumann, sp. nov., is described from Kakadu National Park, N.T. and its biology is outlined. A. mimi nests in abandoned cells of mud-dauber wasps in sandstone overhangs. Its nests are lined heavily with silk and contain 1-15 cells and 1-10 adult wasps (1-7 females, 0-3 males). On average nests contain 5.2 cells and 2.75 adult females. Prey (immature Psyllidae and Tingidae) are supplied progressively. Nests are parasitised by a species of megalyrid wasp, but incidence of parasitism is low. Nest defense is both physical (entrance guard always present) and chemical (citrus odour from heads of both sexes). Females from a single nest could be ranked on the basis of relative ovarian development, suggesting that more than one female oviposits. Females apparently cooperate in brood care and offspring in a nest develop asynchronously. The biology of A. mimi is compared to that of Microstigmus comes Krombein, the most socially advanced sphecid known, and selective pressures that may have acted to promote female cooperation in the two genera are discussed. For A. mimi the lack of available nest sites could be an important factor restricting the ability of offspring to disperse and establish nests.

scholarly journals Leptin pharmacokinetics in male mice

2017 ◽  
Vol 6 (1) ◽  
pp. 20-26 ◽  
Author(s):  
Robert A Hart ◽  
Robin C Dobos ◽  
Linda L Agnew ◽  
Neil A Smart ◽  
James R McFarlane
Keyword(s):  
Digestive Tract ◽  
Time Course ◽  
Normal Male ◽  
Male Mice ◽  
Male And Female ◽  
Female Mice ◽  
Males And Females ◽  
High Degree ◽  
The Brain ◽  
Major Target

Pharmacokinetics of leptin in mammals has not been studied in detail and only one study has examined more than one time point in non-mutant mice and this was in a female mice. This is the first study to describe leptin distribution over a detailed time course in normal male mice. A physiologic dose (12 ng) of radiolabelled leptin was injected into adult male mice via the lateral tail vein and tissues were dissected out and measured for radioactivity over a time course of up to two hours. Major targets were the digestive tract, kidneys, skin and lungs. The brain was not a major target, and 0.15% of the total dose was recovered from the brain 5 min after administration. Major differences appear to exist in the distribution of leptin between the male and female mice, indicating a high degree of sexual dimorphism. Although the half-lives were similar between male and female mice, almost twice the proportion of leptin was recovered from the digestive tract of male mice in comparison to that reported previously for females. This would seem to indicate a major difference in leptin distribution and possibly function between males and females.

THE EFFECT OF CERTAIN PLANT PREPARATIONS ON THE FERTILITY OF LABORATORY MAMMALS

1955 ◽  
Vol 12 (4) ◽  
pp. 267-272 ◽  
Author(s):  
JUNE EAST
Keyword(s):  
Female Fertility ◽  
Equivalent Amount ◽  
Stock Diet ◽  
Immature Female ◽  
Male And Female ◽  
Female Mice ◽  
Males And Females ◽  
High Degree

SUMMARY Capsella bursa pastoris ('Shepherd's Purse'), dried and ground, was added at rates of 20 and 40% to the stock diet of male and female mice. Diets similarly diluted with grass meal were used for comparison. At the 40% level, both materials impeded ovulation and produced temporary infertility in males and females. 20% Capsella did not affect female fertility, and previous experiments had shown that an equivalent amount of grass meal was harmless. Neither substance affected the establishment of vaginal patency in immature female mice or produced signs of oestrogenization in spayed animals. The infertility produced was probably due to the high degree of dilution of the diet rather than to specific anti-fertility activity, but the latter possibility has not been excluded entirely.

scholarly journals Reproductive biology of Poecilia sphenops Valenciennes, 1846 (Cyprinidontiformes: Poeciliidae) at the Emiliano Zapata Reservoir in Morelos, Mexico

2016 ◽  
Vol 14 (2) ◽  
Author(s):  
José L. Gómez-Márquez ◽  
Bertha Peña-Mendoza ◽  
José L. Guzmán-Santiago
Keyword(s):  
Reproductive Biology ◽  
Native Species ◽  
Ovarian Development ◽  
Mesh Size ◽  
Central Mexico ◽  
Development Stages ◽  
Males And Females ◽  
Male Sex ◽  
Poecilia Sphenops ◽  
Monthly Variations

ABSTRACT Poecilia sphenops is a native species recently recorded in the Balsas basin and the Amacuzac River in Morelos (Mexico), in which it is abundant and widely distributed. This study analyzed some aspects of the reproductive biology of Poecilia sphenops from the Emiliano Zapata Reservoir, in Central Mexico. Specimens were collected using a 20 m-long seine with a 5 mm mesh size, from January to December 2006. A total of 581 specimens were collected: 407 females (70.0%), 83 males (14.3%) and 91 individuals with no differentiated sex (15.7%). Fish ranged from 20 to 96 mm in total length and 0.01 to 13.07 g in body weight. The female to male sex ratio (4.9:1) deviated significantly from the unity (χ2= 214.2, p<0.05). Monthly variations in gonadosomatic (GSI) and hepatosomatic (HSI) indexes and ovarian development stages showed that P. sphenops spawning season occurred between July and October, concurring with the rainy season. Another reproduction peak was registered in February. The largest length registered for males and females was 96 mm and 83 mm, respectively.

scholarly journals Área de actividad de Heteromys gaumeri en una selva mediana subcaducifolia de Yucatán

2004 ◽  
Vol 6 (1) ◽  
pp. 5 ◽  
Author(s):  
José Adrián Cimé Pool ◽  
Silvia F. Hernández Betancourt ◽  
Salvador Medina Peralta
Keyword(s):  
Home Range ◽  
Tropical Rainforest ◽  
Total Population ◽  
Deciduous Forest ◽  
Reproductive Condition ◽  
Total N ◽  
Male And Female ◽  
Males And Females ◽  
The Mean ◽  
High Degree

Resumen. Se estudió el área de actividad (AA) de Heteromys gaumeri en una selva mediana subcaducifolia en el Rancho Hobonil, Tzucacab al sur del estado de Yucatán, México. Se trabajó con el 30 % (n = 78) de la población total (n = 270); 53 % fueron hembras y 47 %, machos. Las hembras permanecieron en el área de estudio en promedio 7.6 meses y los machos 6.6 meses. La permanencia entre sexos no mostró diferencias significativas (p > 0.05). Los machos presentaron mayor AA promedio (555 m2) que las hembras (465 m2). El AA de individuos reproductivos (540 m2) y no reproductivos (439 m2) fue similar para ambos sexos (p > 0.05). No se observó una correlación entre el AA y el peso corporal en ninguno de los sexos (p > 0.05 para ambos sexos). La distancia máxima recorrida (DMR) no fue influenciada por la interacción de los factores sexo y época (p > 0.05). El AA de los machos mostró un promedio de 86 % de sobreposición y las hembras de 75 %; sin embargo, no fue significativa (p > 0.05). El tamaño y la alta sobreposición del AA y la distribución de las hembras, sugiere que esta especie es polígama y su sistema de pareja promiscuo, con un alto grado de tolerancia social intra e intersexual.Palabras clave: Área de actividad, Heteromys gaumeri, Rodentia, selva mediana subcaducifolia, Yucatán.Abstract. The home range (HR) of Heteromys gaumeri was studied in a subdeciduous tropical rainforest located at Rancho Hobonil, Tzucacab, Yucatan, Mexico. Thirty percent (n = 78) of the total population (n = 270) were residents, being 53 % females and 47 % males. The mean was 7.6 months for females, and 6.6 months for males. Average HR was 555 m2 for males and 465 m2 for females. Nevertheless, males and females did not differ significantly in the size of their HR (p > 0.05). The reproductive condition of individuals did not influence their HR and movement patterns. For both sexes, reproductive individuals showed the same HR than non-reproductive individuals (p > 0.05). HR was not correlated with individual weight of males and females in this population (p > 0.05). Neither season (dry and wet) nor sex (male and female) influenced maximum distance moved (MDM) (p > 0.05). Males and females had HR that overlapped the HR of multiple females and males intrasexually (p > 0.05). Based on HR size, high degree of HR overlap and female distribution, we concluded that mating system of H. gaumeri in rainforest of Yucatan is probably promiscous with a high degree of intra and intersexual tolerance.Key words: Activity area, Heteromys gumeri, Rodentia, medium deciduous forest, Yucatán.

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