Sociobiology: Volume 40, Number 2, 2002

Feature Articles:

Alarm, Aggregation, and Defense by Reticulitermes flavipes in Response to a Naturally Occurring Isolate of Metarhizium anisopliae

By Timothy G. Myles

ABSTRACT

A virulent strain (pathotype) of the entomogenous fungus, Metarhizium anisopliae (Metschnikoff) Sokorin, causing green muscardine disease in insects, was isolated from the eastern subterranean termite, Reticulitermes flavipes Kollar. Studies carried out with this fungal strain on behavioral responses to conidia-dusted termites showed alarm, aggregation and defensive reactions by untreated termites. The alarm response consisted of rapid bursts of longitudinal oscillatory movement (LOM) by workers. The intensity of alarm peaked about 15 minutes after introduction of the conidia-dusted termites, at which time 50% of the termites in test groups were engaged in the behavior and 80% were aggregated near the treated individual. Alarm and aggregation significantly subsided after 24 minutes and gradually diminished, apparently due to habituation. Alarm and aggregation were then followed by grooming, biting, defecation, and burial of the infected termite. A significantly greater alarm response was observed to M. anisopliae dusted termites than to termites dusted with other fungal conidia or inorganic agents. These observations suggest that circumvention of behavioral defenses may be necessary in order to further develop effective microbial control of termites with M. anisopliae. Such defensive behavior may be circumvented in several ways, such as by masking the repellency of M. anisopliae, by overcoming the repellency with attractants, by reducing dosage levels below alarm thresholds, or by selection of strains that are less detectable. While the repellency of M. anisopliae appears to inhibit its pathogenicity in termite colonies, it may be exploitable in the development of termite repellent product additives and barriers.

KEY WORDS: Deuteromycotina, Hyphomycetes, Isoptera, Rhinotermitidae, biological control, Metarhizium anisopliae, behavior.

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Isolation of Metarhizium anisopliae (Deuteromycotina: Hyphomycetes) from Reticulitermes flavipes (Isoptera: Rhinotermitidae) with Convenient Methods for its Culture and Collection of Conidia

By Timothy G. Myles

ABSTRACT

A virulent strain (pathotype) of the entomogenous fungus causing green muscardine disease in insects, Metarhizium anisopliae, was isolated from the eastern subterranean termite, Reticulitermes flavipes, in Toronto, Ontario. The method of culturing the fungus involved the following steps: 1) dusting termites with conidia by swirling them in a glass petri plate for several minutes with conidia 2) allowing 2-4 days for the conidia dusted termites to die in a clean dry petri dish and for conidia to germinate and invade the termite body, 3) transferring the petri dish to a humidity chamber to promote growth of aerial hyphae, 4) transferring hyphae covered corpses to 2% potato dextrose agar or Sabouroud's dextrose agar with 0.05% ampicillin 5) followed by sequential daily transfer to new agar plates if necessary until all contaminant bacteria and fungi are removed. With spacing of corpses 1 cm apart the mycelium will grow over the whole plate producing a solid 0.5 mm spore mass within about 4 weeks. Conidia so grown are dark green rather than grey when grown on media alone. Conidia are harvested by gently loosening them with a sterile probe and then inverting the culture dish over a sterilized glass lid and applying an electric vibrator to the plate to dislodge them onto the lid. The pure conidia can then be weighed and applied to termites by swirling then in a dish with the termites. The dry conidia are adsorbed onto the epicuticle of the termites.

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Laboratory Studies on the Transmission of Metarhizium anisopliae in the Eastern Subterranean Termite, Reticulitermes flavipes (Isoptera: Rhinotermitidae), with a Method for Applying Appropriate Doses of Conidia to Trapped Termites for Release

By Timothy G. Myles

ABSTRACT

Five laboratory experiments were conducted on the transmission of green muscardine disease, Metarhizium anisopliae (Metschnikoff) Sokorin, in the eastern subterranean termite, Reticulitermes flavipes Kollar. In petri dish experiments supplied with one sporulated termite corpse, groups of 25, 50, and 100 termites were killed within three days. In petri dishes with nonnutrient agar as a tunneling substrate, groups of 100 termites were killed within 4 days when 10 conidia dusted termites were introduced. In experiments in which 100 termites were first allowed to excavate soil tunnels throughout large test tubes (2.5 x 25 cm), all termites died when 10 or 20 conidia-dusted termites were introduced, but some survived when only 1 or 5 conidia-dusted termites were introduced. A dosing method was used in which 100 termites were swirled in a glass dish for 2 minutes with 10 mg M. anisopliae conidia per 100 termites. This resulted in a uniform green coating of adsorbed conidia on the termites. Thus one termite equivalent dose (1TE) was defined as 0.1 mg conidia/termite. Conidia-dusted termites were then swirled for 2 minutes with groups of termites from 20 to 500 (with group size increasing in increents of 20). All termites dosed at these ratios died within 4 days. However those dosed at ratios in excess of 1:280 lived at least 2 days. In a final experiment, termites were dosed at rations of 1TE:100, 1TE:200, 1TE:300, 1TE:400, and 1TE:500 and then untreated termites were exposed to these at ratios from 1:100 to 10:100. 75-100% mortality occurred in all groups after 11 days at tansmission ratios of 10:100 to 5:100. At ratios of 1:100 to 4:100 a clear close to lethal time relationship was observed. These experiments demonstarte that live termites can act as carriers of M. anisopliae under laboratory conditions.

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Two New Tetramorium Species (Hymenoptera: Formicidae) from Vietnam with a Discussion of the mixtum, tonganum and scabrosum Groups

By Eric Roncin

ABSTRACT

Tetramorium securis sp. nov. and Tetramorium kieti sp. nov. are described from Vietnam. They both belong to the mixtum-group sensu Bolton (1977). Reconsideration of the characters that define this group led us to question its validity and to transfer its constituting species to the tonganum- and scabrosum-groups. The recently described species Tetramorium malabarensis Sheela & Naredran, 1998 and T. sentosus Sheela & Naredran, 1998, and the two new species described in this paper are here assigned to the scabrosum-group.

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Behavior of Atta sexdens rubropilosa (Hymenoptera: Formicidae) Workers During the Preparation of the Leaf Substrate for Symbiont Fungus Culture

By Ana Paula P. de Andrade, Luiz C. Forti, Aldenise A. Moreira, Maria Aparecida C. Boaretto, Vânia M. Ramos & Carlos Alberto O. de Matos

ABSTRACT

The behavioral repertory of Atta sexdens rubropilosa Forel (Hymenoptera: Formicidae) workers marked by size category was studied during the preparation of the leaf substrate in the laboratory. The workers were marked according to three physical castes, i.e., minima, generalist and forager. Seven types of behavioral acts were recorded for each caste, with the following frequencies: licking leaf fragments (64.6%), holding fragments on the surface of the fungus garden (16.4%), shredding the fragments (6.0%), chewing and crimping the edges of the fragments (9.0%), incorporating the fragments (2.7%), touching the surface of the fungus with their mandibles and other mouthparts after incorporation (0.3%), and depositing fecal fluid (0.1%). The minima workers were found to be more specialized in the activities related to the preparation of the leaf substrate, which represented 52% of the total number of tasks performed. The generalists performed 40.3% of these tasks, and the foragers 7.9%. Licking the substrate was the behavior most frequently recorded and performed for a longer period of time. In this way, the workers may feed and at the same time eliminate microorganisms that are harmful to the symbiont fungus. The smaller castes, minima and generalists, are those most responsible for the preparation of the leaf substrate and predominate within a colony. From a practical viewpoint, with the introduction of toxic bait containing insecticides, for example, these size categories will be those most intensely intoxicated, especially through the behavior of licking bait pellets. On the basis of the data obtained about these behaviors, we may raise the hypothesis that trophallaxis in not the major factor triggering contamination with an insecticide among the workers of a colony.

KEY WORDS: Atta sexdens rubropilosa, behavior, substrate preparation, leaf-cutting ants, castes.

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Morphometric Analysis of Soldiers of Microcerotermes strunckii (Isoptera: Termitidae, Termitinae)

By Juan Manuel Coronel & Eduardo Porcel

ABSTRACT

The intracolonial and intercolonial morphometric variations in the soldier caste of Microcerotermes strunckii (Sörensen) (Isoptera: Termitidae, Termitinae) were analyzed. Thirteen morphometric characters were measured on 116 soldiers obtained from four nests coming from two sites. The data were analyzed by means of univariate and multivariate statistical methods. The results indicated that the soldier caste has important intracolonial variations in the total body length and minimum width of the postmentum. The intercolonial variations were manifested among different sites and among the nests within each site. The obtained measurements for maximum width of head, length of left mandible, maximum width and median length of pronotum and length of the hind-tibia showed the highest values and a wider range than previously known.

KEY WORDS: termite, Microcerotermes strunckii, soldier caste, morphometric analysis.

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Size Dimorphism and Male Aggregation Behavior in the Sand Wasp, Steniolia nigripes (Sphecidae: Bembecinae)

By Jeffrey F. Thomas & Peter Nonacs

ABSTRACT

We observed aggregations of the sand wasp, Steniolia nigripes, in the Granite Mountains of Southern California. Males gathered in open areas between bushes in a sun-dancing behavior very close to the ground. They did not hold exclusive territories. Aggregations were highly visible, but occurred at low densities in the area. Males often chased each other and females, who would approach the aggregation, then leave with males following closely or attached to her. Females often burrowed around the edges of the aggregation. We captured and measured male and female head width, dry weight and thorax length. Males were significantly larger than females in all of these measurements. Intrasexual selection resulting from scramble competition for access to mates may drive this dimorphism. As these aggregations did not occur at obvious landmarks, it is possible that the aggregations themselves serve as a landmarks for females.

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Preference for Low-pH and Low-Nitrogen Foods in the Wood Roach, Cryptocercus punctulatus Scudder (Blattaria: Cryptocercidae)

By Deborah A. Waller

ABSTRACT

The wood roach Cryptocercus punctulatus Scudder lives in family groups in fallen logs and feeds on wood. I examined Cryptocercus nymphs' preferences for food pH and nitrogen content in laboratory choice tests with treated and control filter paper. The wood roaches ate significantly more filter paper treated with pH 2 solutions of hydrochloric acid, sulfuric acid and nitric acid than of control water-soaked paper. They ate similar amounts of treated and control paper when pH 3 solutions of sulfuric acid and nitric acid were tested, however. In nitrogen tests, Crytocercus nymphs ate similar amounts of treated and control paper in tests with 0.1% (w/v) solutions of urea and peptone, but they ate significantly more paper when it was treated with a 0.1% (w/v) solution of ammonium nitrate. The nymphs avoided paper treated with 1.0% (w/v) solutions of urea, peptone and ammonium nitrate and ate significantly more control paper. These results demonstrate a preference for low pH and low-nitrogen foods in Cryptocercus punctulatus.

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Chromosome Numbers in Spanish Formicidae (Hymenoptera)
IV. New data of Species from the Genera Camponotus, Formica, Lasius, Messor, and Monomorium

By Pedro Lorite, Jose A. Carrillo, Alberto Tinaut and Teresa Palomeque

ABSTRACT

In this paper we report new karyological data from seven species belonging to subfamilies Formicinae and Myrmicinae. Among them we include two that are considered as endemic Iberian species, Formica frontalis and Formica subrufa. Also the chromosome number of Formica gerardi is reported. In Lasius brunneus, a variation on chromosome number probably due to the presence of B-chromosomes was detected. For two other species (Camponotus cruentatus and Messor barbarus) we found different chromosome numbers from those previously published. Also we confirm the chromosome number reported for Monomorium subopacum.

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A Literature Review of the Biology and Ecology of Coptotermes formosanus (Isoptera: Rhinotermitidae) in China

By Changlu Wang, Janine E. Powell & Yuanzhi Liu

ABSTRACT

Coptotermes formosanus Shiraki is a serious pest to homes and structures in the south of China. It has been widely studied by Chinese researchers during the past 35 years. However, most studies are not known outside of China due to limited circulation and the language barrier. This paper summarizes the study on biology and ecology of C. formosanus in China. Included are infestations in China, colony dispersal flight, development of incipient colonies, mature colony age, colony size and life expectancy, production of supplementary reproductives, production of soldiers, nest structure, activity pattern, relationship between environment and C. formosanus distribution and activities, and nest development. Comparisons were made with studies conducted in the U.S. The production of supplementary reproductives is suggested for further investigation.

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The Occurrence and Foraging Behavior of the Army Ant Eciton vagans dubitatum in the Itirapina Area, São Paulo State, Brazil (Hymenoptera, Formicidae)

By Fernando José Zara, Carlos E.V. Toledo, Renato Matos Marques & Flávio Henrique Caetano

ABSTRACT

This paper discusses the occurrence of the army ant Eciton vagans dubitatum in a semi-deciduous forest, Itirapina area, São Paulo State, Brazil. Comparisons of bivouac and raiding pattern are done in relation to other subspecies of Eciton vagans.

KEY WORDS: army ant, Ecitoninae, Eciton vagans dubitatum.

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The Ant Assemblage Visiting Extrafloral Nectaries of Hibiscus pernambucensis (Malvaceae) in a Mangrove Forest in Southeast Brazil (Hymenoptera: Formicidae)

By Rodrigo Cogni & André V. L. Freitas

ABSTRACT

Ant species visiting extrafloral nectaries (EFNs) of Hibiscus pernambucensis were studied in a daily flooded mangrove forest in Picinguaba, Southeast Brazil. Nineteen ant species in five subfamilies were observed visiting the EFNs. The most common species (in order of abundance) were Camponotus sp.2, Brachymyrmex sp. and Pseudomyrmex gracilis during the warm season and Brachymyrmex sp., Camponotus crassus and Camponotus sp.2 during the cold season. A twenty-four hour census showed that ant activity significantly decreased at night, and was positively correlated with air temperature in both seasons. On almost half of the stems no ant was observed and the vast majority of visited stems had only one species present. Less than 1% of sampling sessions showed more than one ant species recorded simultaneously on the same stem. Living termite baits stuck to the plant were attacked by eight ant species. Although ants were more commonly found on new leaves, the percentage of termites attacked was not different between new and old leaves.

KEY WORDS: daily activity, foraging, Hibiscus pernambucensis, Malvaceae, mangrove, ant-plant interaction, plant defense

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Ant Diversity in Coastal Zones of Quintana Roo, Mexico, with Special Reference to Army ants

By S. Durou, A. Dejean, I. Olmsted & R.R. Snelling

ABSTRACT

This work was conducted along the Mexican Caribbean coastline on a strip of land with dunes and mangroves separated from upland communities by fossil lagoons. In Puerto Morelos, Quintana Roo, Mexico, we evaluated the ant diversity and the role of vegetation zonation in the distribution of ant species. We recorded a total of 96 species and 33 genera of ants from a 140 ha area. The Myrmicinae had the most species; Pheidole and Camponotus were the most common genera. The species composition was influenced by the ecological zones and the presence of aggressive ant species. The army ant Eciton burchelli was spatially constrained and bivouacs were recorded only in the mangrove zone, which contained the greatest ant diversity. In a completely flooded mangrove area of the Sian Ka'an Biosphere Reserve, we sampled only dry hollowed branches of the red mangrove and the pseudobulbs of an epiphytic orchid in order to determine the role the arboreal stratum plays on ant distribution. By focusing on this ant community, we show that Cephalotes spp. and Pseudomyrmex spp. dominated the dry hollowed branches, while the most frequent inhabitant of the Myrmecophila cristinae pseudobulbs was Dolichoderus bispinosus, an ant species that also nests in bromeliads.

KEY WORDS: ant diversity, coastal zone, Ecitoninae, mangrove, Mexico, plant distribution.

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Enzymatic Activity of Hypopharyngeal Gland Extracts From Workers of Apis mellifera (Hymenoptera, Apidae, Apinae)

By Rosiléia A. C. Costa & Carminda da Cruz-Landim

ABSTRACT

This research presents a comparative study of enzymatic activity of the hypopharyngeal gland extracts from workers of Apis mellifera in three physiologic stages: newly emerged, nurse and forager workers, with the objective of contributing to the comprehension of the gland function. In order to determinate the enzymes present in the extracts, the Api Zym kit (Bio Mérieux) was used to test the activity of 19 different enzymes. The enzymes found in larger amounts only in the hypo-pharyngeal glands from certain individuals were the following: in newly emerged workers, the N-acetyl-?-glucosaminidase that may be digesting the chitin of some food ingested by the bee; in forager workers, the acid phosphatase that is likely acting in authophagic processes, the a-glucosidase, in the processing of nectar into honey, and the ?-glucosidases, in the pollen digestion.

KEY WORDS: hypopharyngeal glands, workers, bees, honeybee, Apoidea, royal jelly, enzymes, glucosidase, acid phosphatase.

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A New, High Altitude Colombian Species of the Ant Genus Camponotus with Dimorphic Males and Females (Hymenoptera: Formicidae)

By William P. Mackay, Camilo López-Castro & Fernando Fernández

ABSTRACT

We describe a new, black carpenter ant (Camponotus polymorphicus) from the high altitude and páramo in the Andes Mountains of Colombia. This species is unusual in that it is extremely variable in size. We separate the workers into majors, intermediates and minors. The females and males are dimorphic in size. This species is unlikely to be confused with any other species in the Neotropics. It is much shiner than most other species, and is additionally black in color. It has abundant, erect, golden hairs on the cheeks, clypeus and malar area, but is without erect hairs along the sides of the head or on the scapes. It is one of the few tropical species found at high elevations, the only other relatively common tropical Camponotus at such elevations is C. nitens, which is much smaller and has a heart-shaped head.

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Polymorphism in a High Altitude Colombian Ant Species Camponotus polymorphicus (Homenoptera: Formicidae)

By Camilo López-Castro, Jaime Estévez-Varon, Carlos Sarmiento & Emilio Realpe

ABSTRACT

Polymorphism was determined in workers of Camponotus polymorphicus. Three morphological castes (minor, media, major) were detected through biometrical measurements. The media caste is not consolidated. The size of the head presents the greatest allometric variation.

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Field Experiments to Assess the Use of Repellent Substances by Wasmannia auropunctata (Formicidae: Myrmicinae) During Food Exploitation

By J. Le Breton, J. Chazeau & A. Dejean

ABSTRACT

The introduced tramp ant, Wasmannia auropunctata is a well known pest of agricultural areas and natural ecosystems in New Caledonia. This species is very successful in displacing native ants, but the proximal mechanisms of this success have not been fully investigated. We conducted field experiments to verify if W. auropunctata workers use repellent compounds on soybean oil baits. We compared the recruitment behavior of native ant species at treatment baits (which were exploited by W. auropunctata) and at control baits (non-exploited) after 30 and 60 minutes. The verification of the two categories of baits at the end of the two periods (30' and 60') revealed that the number of baits occupied and the number of native ant foragers present were not significantly different. These results imply that workers of W. auropunctata did not deposit repellent compounds on exploited food sources, thus indicating the predominance of "direct" interactions in the success of W. auropunctata to displace native ants populations.

KEY WORDS: interspecific competition, Wasmannia auropunctata, New Caledonia, unicoloniality

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Juvenile Hormone Promotes Changes in the Expression of Hypopharyngeal Gland Proteins of Worker Apis mellifera (Hymenoptera: Apidae)

By Luciana Fioretti Gracioli & Regina Lúcia Morelli Silva de Moraes

ABSTRACT

The present investigation compares the protein electrophoreses profiles of the hypopharyngeal glands of 12 and 25 day old Apis mellifera workers, some of which were experimentally treated with an analogue of juvenile hormone in the moment of the emergence while others were not treated. According to the evaluation of the presented variations by four main bands, it is concluded that the analogue juvenile hormone changes the glandular genetic expression pattern, promoting the disappearance of two from the four main bands in 25 day old workers. The effect of this hormone is discussed as an hypopharyngeal maturation inductor, in synergetic action with the bee age acting early in the glandular cycle.

KEY WORDS: electrophoresis, hypopharyngeal glands, juvenile hormone, Apis mellifera.

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Histological and Morphometric Comparisons of Worker and Queen Mandibular Glands of Melipona bicolor bicolor (Hymenoptera, Meliponini)

By Luciana Fioretti Gracioli & Regina Lúcia Morelli Silva de Moraes

ABSTRACT

In the present investigation we analyzed both histology and area of secretory cells from workers, virgin and physogastric queen mandibular glands of Melipona bicolor bicolor Lepeletier. The histological differences observed include the number of vacuoles present in the cell cytoplasm and the quantity and distribution of the secretion. The morphometry results demonstrated the occurrence of significative differences in the cell area values that were related to the secretory cell activity level, which is higher in the physogastric queens. Worker and queen glands have histological patterns quite similar, but the morphometric data indicated cast-specific differences, as well as differences between the queens, which were related to the posture activity.

KEY WORDS: Melipona bicolor, mandibular glands, morphometry, hematoxylin-eosin.

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Alterations Induced by Juvenile Hormone in Glandular Cells of the Apis mellifera Venom Gland
I - Application on the Larvae (Hymenoptera: Apidae)

By Nocelli, R.C.F., Roat, T.C. & Silva de Moraes, R.L.M.

ABSTRACT

Histological analyses were made in order to evaluate the effects of the topic application of a synthetic juvenile hormone (JH-III Sigma) on the development of the venom glands in workers of Apis mellifera. Three experimental groups were used: the first received 1 ul of a dilution of the juvenile hormone in hexane (2ug/ul); the second group received 1 ul of hexane; and the third group, the control, did not receive any kind of treatment. The application was made on larvae at the beginning of the fifth instar and the glands were collected at different developmental stages. The results showed that the application of the diluted hormone, as well as the hexane alone, accelerated gland development in relation to the control group at all developmental stages studied. These data suggest that the juvenile hormone acts on the development of the venom gland; nevertheless, this action could be amplified by the effect of the solvent used in the present work, as well as in other studies concerning this matter.

KEY WORDS: juvenile hormone, hexane, venom gland, Apis mellifera.

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Biometrics Studies of Caste Development in Nasutitermes coxipoensis (Isoptera; Termitidae)

By Maria Luisa Tunes Buschini & Ana Maria Costa Leonardo

ABSTRACT

A biometric study of caste development was carried out using Nasutitermes sp., by measuring the height, width, and length of the head, the length and width of the pronotum and mesonotum, and the length of the posterior tibia. These measurements were taken on 200 individuals, including larvae, nymphs, workers, pre-soldiers and soldiers. For instar separation, it was verified that the Principal Component Analysis (P.C.A.) was the most efficient methodology. Results of this analysis showed that Nasutitermes coxipoensis follows the general pattern of development presented by other Nasutitermes.

KEY WORDS: Insecta, Isoptera, Nasutitermes, caste, development.

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