Hole repair and the influence of learning on nest repair in the paper wasp,Polistes fuscatus (Hymenoptera: Vespidae)

Two methods of hole repair used by the paper wasp, Polistes fuscatus,were examined and compared, and the hypothesis that nest repair behavior may improve with experience was tested. Similarly sized holes were repeatedly made in the sides of nests and the repair behavior of the nest residents was recorded. The distance of the hole from the cell mouth determined which repair method was used. In addition, both the amount of time for hole repair completion and the number of pulp loads used in making the repair decreased significantly with experience.     

Information analysis by the paper wasp,Polistes fuscatus,during nest construction (Hymenoptera,Vespidae)

Summary The building decision process of the paper wasp,Polistes fuscatus, was studied by 1) analyzing the search pattern of the wasps prior to the addition of pulp to different areas of the nest, 2) comparing the pulp addition needs of the cell chosen for lengthening to those of other cells in the nest, and 3) presenting the wasps with eight types of dichotomous building choices, which provided information about the relative influence of different building cues. Wasps conduct a hierarchical search prior to pulp addition, which means that they search the comb face and petiole disproportionately more often and more thoroughly than the comb back and sides. Once a particular nest area triggers closer scrutiny, comparisons are made with adjoining areas. The most needy location is then chosen based on nest cues. When lengthening a cell, the development of the brood and relative cell length have a strong influence on which cell is chosen at all times, while distance of the brood from the cell mouth becomes important during the later stages of brood development. The results indicate that there is no simple hierarchical weighting of cues. The decision process involves comparisons among multiple cues, which for the most part have an additive influence when variation in relative cue strength is considered.     

Nest surface hydrocarbons facilitate nestmate recognition for the social wasp,Polistes metricus Say (Hymenoptera: Vespidae)

Nestmate recognition was observed inPolistes metricus Say workers only if the workers were exposed to their nest surface hydrocarbons after eclosion. If the newly emerged workers were never exposed to the nest hydrocarbons as adults, they showed no discrimination between nestmates and nonnestmates. Furthermore, the newly emerged workers were accepted more readily by their experienced nestmates than by experienced nonnestmates only if the newly emerged wasps had been exposed to the nest surface hydrocarbons. This reciprocal recognition implies that the nest recognition cues are nest surface hydrocarbons that are learned and that may be acquired byP. metricus workers as adults on the natal nest.     

Post-eclosion sensitivity to social context inPolistes dominulus Christ females (Hymenoptera,Vespidae)

Summary Polistes dominulus females were subjected to the following changes of social environment as soon as they emerged: females which emerged in young colonies (presumably most workers) were transferred to more mature colonies, and conversely, females which emerged in mature colonies (presumably mostly gynes) were transferred to younger colonies. The behavioural and biological data obtained here show that when exposed to the new social environment, females from young colonies were able to lengthen their life span and become gynes. Only the very first females to emerge from colonies were less able to survive hibernation. Conversely, females from mature colonies were able to become workers and, as a result of their participation in social tasks, had a shorter life span. This great plasticity in the roles which young adult females can adopt constitutes an important characteristic of primitively eusocial species.     

Male swarms at landmarks and scramble competition polygyny inPolistes gallicus (Hymenoptera: Vespidae)

At the end of summer, males of Polistes gallicusfly in swarms around vertical landmarks and land in clusters on their favorite perches, where they drag their legs and abdomen. Here males occasionally crowd around a perched female; they make no effort to defend an exclusive mating territory but instead attempt to copulate by displacing rivals from the female. In this work we describe this spatial-nuptial system, which entails site fidelity without territoriality, unisexual swarms, common patrol routes, collective sexual approaches, and scramble competition polygyny. Mating success is evaluated in relation to the familiarity with flight paths (routine patrollers versus newcomers), to the type of sexual approach (single males versus in- group males), and, in the laboratory, to the individual activity level.     

Leg tegumental glands and male rubbing behavior at leks inPolistes Dominulus (Hymenoptera: Vespidae)

In summer, males of Polistes dominulus defend adjacent territories at landmarks. Patrol flights are interrupted by stops at selected perches and conspicuous dragging movements of the last sternites and all the legs over the substrate, especially at a high intruder density. Leg rubbing is regularly associated with prolonged grooming sessions. Single secretory cells, resembling the sternal glands formerly described in this species (class 3 ducted glands), were found in all the legs (in the femur, the tibia, and especially the tarsus) and in both sexes. Leg tegumental gland cells, like sternal glands, are probably a source of pheromones. They have not previously been described in polistine wasps.     

Usurpations and late associations in the solitary founding social wasp,Polistes biglumis bimaculatus (Hymenoptera: Vespidae)

One hundred twenty-five colonies of a population of the montane, haplometrotic, paper waspPolistes biglumis bimaculatus were marked for identification and then periodically surveyed during an entire summer period. This made it possible to record intraspecific nest usurpations (both single and multiple) and to observe associations between two females, defined here as late associations. Both usurpation and late association occurred primarily in the latter half of the preemergence period. Some evidence suggests that a foundress usurps a conspecific nest as a consequence of her own nest failure. After nest failure, usurpation and late association are the only available options for achieving reproductive success because, in the mountain habitat, the short summer does not allow for successful renesting. Late associations generally occurred earlier than usurpation. However, our evidence suggests that nest usurpation and late association may be the same phenomenon.     

Behaviour in usurpers and late joiners ofPolistes biglumis bimaculatus (Hymenoptera,Vespidae)

Summary During the late pre-emergence phase, a foundress of the paper waspPolistes biglumis bimaculatus may be expelled by a conspecific female from her own nest (usurpation) or, less frequently, joined by another female of the same species (late association). The behaviour of femalePolistes biglumis bimaculatus, when usurping a conspecific colony or joining another foundress, is compared with that of foundresses on non-usurped colonies. The most conspicous difference is the intense abdomen stroking behaviour the usurper performs over the comb surface on the first days after usurpation. As observed in otherPolistes species, once usurpers and joiners arrive on a strange nest they will destroy most of the immature brood of the previous nest owner. Although host workers are not aggressive towards the intruder females, reproductive success of usurpers and joiners is low compared with that of legitimate foundresses. The same behaviours observed on usurped colonies are found in the obligate social parasites ofPolistes. These behaviours are therefore discussed in the context of the evolution of intra- and inter-specific parasitism.     

A new role for antennation in paper wasps (Hymenoptera,Vespidae): antennal courtship and sex dimorphic glands in antennomeres

Summary. Males of Polistes dominulus perform antennal vibrations and grasping of female antennae during pre-copulatory and copulatory phases. Male antennation plays a relevant role in mating success. In several antennomeres of males of P. dominulus and Vespa crabro, a further species in which we observed male antennation, we found secretory cells of class 1 and 3 associated to the same release site. In P. dominulus, class 3 cells with ampulla-like reservoirs and class 1 cells release their secretion through hairless multiporous areas. In V. crabro, tyloid-like structures are associated with large apodemes. The as yet unidentified secretion of these glands may act as a contact or low-volatile sex pheromone during courtship behaviour.Received 4 December 2003; revised 16 August 2004; accepted 7 September 2004.     

Lateral Vibrations by Social Wasps Signal Larvae to Withhold Salivary Secretions (Polistes fuscatus, Hymenoptera: Vespidae)

The communicative meaning of an oscillation (lateral vibration) performed by foundresses of social wasps (Polistes fuscatus) was investigated by sampling larval saliva from 12 postworker, single-foundress colonies and by viewing videotapes of 17 multiple-foundress (139.3 h) and 16 single-foundress (32 h) preworker colonies. Foundresses spent significantly more time inspecting cells before performing a lateral vibration (LV) than after and commonly became inactive after performing an LV. The proportion of departures temporally proximate to LVs was significantly greater in single- than in multiple-foundress colonies. Departures and LVs were significantly temporally associated in single-foundress colonies. Single foundresses were significantly more likely to perform an LV prior to departing on longer than shorter trips. In multiple-foundress colonies there was a significant temporal relationship between LVs and departures that left the nest unattended. Larvae secreted significantly less saliva, a nutritious substance provided to adults, immediately after an LV than in the absence of an LV. Contextual evidence and results of sampling larval saliva indicate that LVs by foundresses signal larvae to withhold or reduce their secretion of saliva.     

Development of the embryo nest ofVespa affinis (Hymenoptera: Vespidae) in Southern Japan

Summary The aerial nests ofVespa affinis on Ishigaki Island, Japan, were found mainly within 1 m of the ground, attached to a twig roughly 4 mm in diameter. These are probably adaptations to survive adverse weather conditions. The favoured nesting habitat was in open farmland areas rather than in the natural forest. The entire envelope and more than half of the comb of the embryo nest is constructed during the first 10–12 days. The first workers emerge around 34 days after nest initiation. The duration of larval development was found to be linked to the number of larvae present in the nest, with the earlier progeny developing faster. The changes in the ovarian index of the mother queen during the early stages of nesting are described.     

Ground nesting in the paper wasp <Emphasis Type="Italic">Polistes aurifer</Emphasis> (Hymenoptera,Vespidae)

Summary Polistes paper wasp species vary in their nest site selection, with some nesting in relatively exposed areas and others in protected cavities. Locating the nest sites of cavity dwelling species in natural habitat can prove difficult, and most behavioral studies on these species are therefore conducted using human-built structures. Since Hungerford and Williams (1912) and Rau (1929) noted the location of several P. fuscatus (Fabricius) nests in rodent burrows, there have been no published accounts of ground nesting Polistes species. I report the occurrence of a large, dense cluster of P. aurifer (Saussure) nests located within cracks in the dried soil of the Santa Monica Mountains of southern California, USA.Received 8 April 2003; revised 10 October 2003; accepted 31 October 2003.     

A role of the Dufour's gland in the dominance interactions of the paper wasp,Polistes fuscatus (Hymenoptera: Vespidae)

The Dufour's gland of the paper wasp, Polistes fuscatus,is a source of the cues used by dominant females to recognize the eggs laid by subordinates or nonnestmates on pre (worker)-emergence nests. When dominant wasps were presented with an egg covered with either (1) the Dufour's gland extract of a subordinate cofoundress, (2) the extract of an egg from the same subordinate, or (3) the solvent alone, the dominant female destroyed and replaced the eggs covered with the Dufour's extract significantly more frequently than the other eggs. Eggs with the extract of a nonnestmate's Dufour's gland were also eaten significantly more frequently than those with the solvent. Given similar choices, subordinates did not destroy any eggs. The Dufour's gland appears to have little or no role in communicating dominance directly among aggressively interacting cofoundresses.     

Nest-founding behavior induced in the first descendants ofPolistes dominulus Christ (Hymenoptera: Vespidae) colonies

Summary First descendants' founding ability was tested inP. dominulus colonies by experimentally removing the original nests and queens 21–24 days after the first emergence. Foundation tests were carried out after three different periods had elapsed after the removal and the results were analyzed with regards to the effects of participation in social tasks, duration of stay within the colony and seasonal factors. 1.Immediately after the removal, the foundations that occurred were performed almost entirely by workers, regardless of the duration of their stay within the colony. The number of foundations depended on the season in which the females had emerged. 2.Two months and four months after the removal, foundations were made by only a small number of females (workers and non-workers). These females, which were therefore able to found a nest the year they were born, were mostly among the very first-born individuals in the colonies. 3.The following year after hibernation: females (workers and non-workers) which had stayed for only a short time within the colony (1–15 days) had the highest survival rates. The foundation rates among the surviving females depended only on seasonal factors, since the foundation rates were higher among the non-workers which had emerged later in the season. The results throw some light on the first descendants' nest-founding potential in colonies developing under natural conditions, where many workers in fact stay for only a short time at the nest.     

Timing of insemination in terms of age of new reproductive females of a temperate-zone polistine wasp,Polistes snelleni (Hymenoptera: Vespidae)

Summary The present study investigated the age at which insemination takes place in Polistes snelleni, a species in which mating begins while new reproductives are still emerging from the nest. Insemination of new reproductive females began as early as 5 days of age, and most females were inseminated by 10 days of age.     

Host nest preference and nest choice in the cuckoo paper wasppolistes sulcifer (Hymenoptera: Vespidae)

Polistes sulcifer is a cuckoo paper wasps, an obligate social parasite which must usurp a colony of another species in order to reproduce. Field data show thatP. sulcifer females usurp exclusively nests belonging to one species only (P. dominulus). Moreover, they are more frequently found on large and puparich nests. A series of laboratory trials, in which parasite females were offered a binary choice of nests with different characteristics, confirm both the species specificity betweenP. sulcifer andP. dominulus and the parasite's preference to usurp larger nests containing pupae. The data support the hypothesis thatP. sulcifer females choose between available nests. The biological meaning of these findings is discussed.     

Process of comb division of reused nests in the Australian paper waspRopalidia plebeiana (Hymenoptera,Vespidae)

Summary InRopalidia plebeiana, combs made in the previous year are often reused by foundresses in the following spring and structurally divided into subnests by them. Close observations of the comb dividing process revealed that: 1) combs that had multiple brood areas (areas where cells had eggs) were frequently divided into subnests, while those with single brood areas were never divided; 2) groups of foundresses each occupied a particular brood area even before comb division started; and 3) frequency with which a foundress practiced comb cutting was independent of her social status or oviposition frequency. These observations suggest that the initial grouping of foundresses that colonize an old nest leads to subsequent comb division, rather than the major egg layers cutting combs to safeguard their oviposition territories from their rivals.     

Nesting biology of tropical solitary and social sweat bees,Lasioglossum (Dialictus) figueresi Wcislo andL. (D.) aeneiventre (Friese) (Hymenoptera: Halictidae)

Summary The nesting biology of a mainly solitary bee,Lasioglossum (Dialictus) figueresi, is compared with that of a possible relative and mainly eusocial bee,L. (D.) aeneiventre. These bees nest in the ground in highly disturbed areas in the Meseta Central of Costa Rica. Information is provided on social organization, male production, diel and seasonal activity patterns, pollen utilization, natural enemies and nest architecture. L. (D.) figueresi nests within aggregations in vertical earthen banks, and 80–90 % of females are solitary during the nest-provisioning phase. Social nests contain two (or rarely three) females which may be either equal or unequal in reproductive status (i.e. mated with developed ovaries or not). Solitary nests and two-female nests do not experience different rates of parasitism. Mid-way through the dry season, females cease provisioning at a time when otherL. (Dialictus) remain active. Females typically remain within their nests, although they occasionally forage for nectar. This behavior is similar of that of spring gynes of temperate eusocial species. The egg-to-adult developmental rate ofL. (D.) figueresi is unusually slow for halictine bees, however, so that all the adult females die before their brood eclose in April and May, precluding overlap of generations. The eclosed offspring remain in open cells within their natal nests until mid-June, when both males and females emerge to mate. These newly mated females either establish new nests or re-use old ones. L. (D.) aeneiventre nests within aggregations in horizontal ground or in vertical banks. A foundress female digs a nest at the beginning of the dry season, although some re-activate old nests. Foundress nests develop into colonies with various kinds of social organization. In contrast toL. (D.) figueresi, L. (D.) aeneiventre is active nearly all year round, except during periods of heavy rain, and produces up to three broods per year.Sweat bees (Hymenoptera: Halictinae) are a socially heterogeneous group of mainly ground-nesting bees which are abundant world-wide. Intra-specific variation in social behavior is prevalent both within and among populations, presumably indicating social and environmental control of behavioral modifications (see e.g. Sakagami and Munakata, 1972; Eickwort, 1986; Packer, 1990; Yanega, 1988; reviewed in Michener, 1990). The initial stages of hymenopteran social evolution are represented by solitary individuals and those in undifferentiated societies, yet their biology is not well known, as is true for the numerous tropical halictine species or populations (see Michener, 1990).The subgenusDialictus ofLasioglossum is a primarily New World group of several hundred species (Moure and Kurd, 1987). These bees are monotonously similar in structure and appearance, yet diverse in social behavior. FemaleLasioglossum (Dialictus) figueresi are usually solitary, and structurally are very similar to their social relativeL. (D.) aeneiventre (Wcislo, 1990 a). The systematic placement of these species with respect to otherL. (Dialictus) is uncertain, but they have no obvious affinities to other recognized species groups (G. C. Eickwort, pers. comm.). Unusual morphological features, such as large size, yellowish wings and pubescence, and features of the genital organs, may indicate thatL. (D.) figueresi is the more derived of the pair, and may therefore be secondarily solitary, as is known for other sweat bees (Packer, 1991).