Showing papers by "James H. Cane published in 1979"
Journal Article•
TL;DR: Nesting females of a neotropical sand wasp, Bembix multipicta, exhibit both preventive and active defensive behaviors in response to nest predation pressures, especially from ants.
Abstract: Nesting females of a neotropical sand wasp, Bembix multipicta, exhibit both preventive and active defensive behaviors in response to nest predation pressures, especially from ants. Three types of outer nest entrance closures which differ considerably in thickness and extents of compaction and concealment are em ployed?temporary, overnight, and final. The cost of a more secure closure is realized for the females during the longer periods of exposure to high surface temperatures, predators, and parasites if she opens the nest entrance when bearing prey. Active defensive behaviors directed mainly toward raiding Solenopsis ants are em ployed when preventive measures fail. The foraging time expenditures of females for tabanid flies around domestic horses is proportional to the relative prey density rather than to the horse's surface area. Vertical elongate dark ob jects, such as a horse's legs (rewarding) or wooden posts (non rewarding), proved to be powerful stimuli eliciting local search for prey. The nyssonine sand wasps are typified by their fossorial nesting aggre gations, and provisioning of nests with paralyzed or dead arthropod prey. They are perhaps best known for the ethological studies of the widely dis tributed subsocial genus Bembix (see Evans, 1957, 1966, and literature cited therein). The genus Bembix is characterized by progressive provisioning of the nest by the female, usually with dipteran prey. When nesting in or near areas frequented by livestock, these wasps may repeatedly take associated tabanid and muscoid flies, thereby earning the wasps the common name of "horse guards" (Bryant, 1870) or "insectos policia". In addition, these wasps have evolved an elaborate repertoire of nest concealment and closure behaviors which serve to reduce larval mortality inflicted by parasitic or predatory arthropods (Evans, 1966). 1 Contribution number 1697 from the Department of Entomology, The University of Kansas, Lawrence, Kansas 66045, U.S.A. 2 Department of Entomology, University of Kansas, Lawrence 66045. 3 Department of Biological Sciences, University of Southern California, University Park, Los Angeles, California 90007, U.S.A. Received for publication 22 November 1978. This content downloaded from 207.46.13.33 on Sat, 26 Nov 2016 04:07:09 UTC All use subject to http://about.jstor.org/terms 668 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY This study considers the adaptive implications for the foraging ethology and nest defense strategies of the neotropical wasp, Bembix multiple ta. Materials and Methods The nesting and foraging ethology of Bembix multipicta was studied for one week in mid-August 1978, during the rainy season, at the Sirena Ranger Station, Corcovado National Park, Osa Peninsula, Puntarenas Province, Costa Rica (8?29'N and 83?36'W, elevation 0 m). The study site was located at the end of a grass airstrip, approximately 300 meters south of the Pacific shoreline. Aggregations of Stictia heros and Bembecinus bolivari were also present. Uniquely paint-marked female individuals were observed at their nest sites from dawn to dusk for fifty man-hours. Three nests were subse quently excavated, sketched, and had their contents removed for later anal ysis. The foraging behavior of female wasps at pack horses was observed during the last two days of the study.
11 citations
Journal Article•
TL;DR: This study began as an investigation of the hind tibiotarsal articulations of bees, finding that although these spurs often arise from the corium itself, they sometimes arise from a common membrane that is isolated from the Corium, and even from altogether separate membranes or sockets.
Abstract: In sphecoid wasps and short-tongued bees as well as the Megachilidae the hind tibial spurs arise from the apical tibial corium, although in some taxa the bases of the spurs are partially isolated by sclerotic processes. In many of the An thophoridae and Apidae the bases of the spurs are partially or wholly isolated from the corium by processes or bridges, so that the spurs may arise from an isolated but common membrane or from separated membranous areas. The tibio-basitarsal artic ulation proper has been modified in orientation and morphology, and recessed prox imally into the tibia, in some of the higher bees. The functional, taxonomic, and phylogenetic implications of these characters are discussed. This study began as an investigation of the hind tibiotarsal articulations of bees. The tibiotarsal articulation is here interpreted as the entire region comprising the joint of the tibia and the basitarsus, composed of a transverse intersegmental membrane or corium, a tibial articulatory process or acetab ulum (Snodgrass, 1956) lying in the corium, a basitarsal articulatory process or condyle, and the exoskeletal rims and associated processes (Figs. 1 and 2). Pollen gathering and transport behavior and associated derived hind leg movements of female bees, especially in the family Apidae, initially seemed likely to have evolved in conjunction with morphologically recognizable modifications of the hind tibiotarsal articulation. Since such leg movements have been related to apoid phylogenies (Michener, Winston, and Jander, 1978), it would seem that morphological adaptations associated with the movements might contain phylogenetic and taxonomic information. Al though the structures of the condyles and acetabula proved to be only mod erately informative, striking differences in the articulations of the hind tibial spurs were observed. It appears not to have been previously noted that although these spurs often arise from the corium itself, they sometimes arise from a common membrane that is isolated from the corium, and even from altogether separate membranes or sockets. Materials and Methods The basitarsi of dried sphecids and apoids were broken away from the tibiae at their articulations. The revealed structures, both of the tibial apex and the tarsal base, were then measured and drawn using a dissecting mi Received for publication 17 April 1978. 1 Contribution number 1683 from the Department of Entomology, University of Kansas, Lawrence, Kansas 66045, U.S.A. This content downloaded from 207.46.13.81 on Sat, 17 Sep 2016 05:16:41 UTC All use subject to http://about.jstor.org/terms 124 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY Fig. 1. Apical view of the left tibia of Xylocopa virginica, female, with the basitarsus removed, showing the acetabulum (a), and both an exoskeletal bridge (b) and process (p) isolating or partially isolating the spurs from the corium (c). (Photo taken with a Philips 501 SEM. The scale line represents 0.25 mm.) croscope, employing a camera lucida and optical micrometer where appro priate. Resolution constraints limited this study to those bees and wasps gener ally over 4 mm in body length. The taxa represented are listed in Table 1, while Figures 1 and 2 illustrate the anatomy of the tibiotarsal structures. To allow meaningful comparisons of hind tibial structures for bees of varying sizes, the following ratios were used: spur length = inner spur length/outer spur length; spur diameter = least basal diameter of inner spur/same for outer spur; spur separation = least distance between spur bases/least width of the apical tibial cavity tangent to the apex of the articulatory process (=acetabulum); and spur remotion = distance from the apex of the ace tabulum to the middle of the shortest line between spur bases/least width of the apical tibial cavity tangent to the apex of the acetabulum. Note that the word acetabulum is for convenience used not only for the socket but for the entire articulatory process. Comparison of the means and variances of these size-adjusted measurements for arbitrarily selected groups of large and small species of bees yielded no significant correlations between overall bee size and any of these ratios. This content downloaded from 207.46.13.81 on Sat, 17 Sep 2016 05:16:41 UTC All use subject to http://about.jstor.org/terms VOLUME 52, NUMBER 1 125 Table 1. Basal isolation of inner and outer hind tibial spurs of female (F) and male (M) bees and wasps. Degrees of isolation of the spur bases from the corium by exoskeletal processes are assigned values as follows: 0 = no isolation apparent (Fig. 3), 1 = partial isolation (Fig. 5), 2 = considerable isolation (Fig. 11), 3 = primary bridge complete (Fig. 21), 4 = primary and secondary bridges (Fig. 19). Occasionally, a bridge (P) occurs that encircles only one spur base (Fig. 8). -Iand indicate greater or lesser isolation than is typical for categories 0 to 4. Sex Inner spur Outer spur Figure
6 citations