Journal of the Kansas Entomological Society 

About: Journal of the Kansas Entomological Society is an academic journal published by Kansas (Central States) Entomological Society. The journal publishes majorly in the area(s): Genus & Population. It has an ISSN identifier of 0022-8567. Over the lifetime, 2107 publications have been published receiving 23343 citations. The journal is also known as: Kansas Entomological Society. Journal.

Estimation of bee size using intertegular span (Apoidea)

Abstract: The dry weights of solitary female bees are accurately and readily estimated by a nonlinear, exponential regression equation using the shortest linear distance measured between a female bee's wing tegulae across her thoracic dorsum. The regression equation is y = 0.77(x)0405, where y is intertegular span and x is dry weight. Melittologists often have need of a reliable and direct means to estimate the "size" of a pinned museum specimen without reverting to the cumbersome task of taking dry weights. A size measure is necessary for standardizing comparisons made in studies of bee energetics, foraging ecology, allom etry, anatomy, chemical ecology, reproductive and sexual selection, and nesting biology. Weight, whether wet or dry, is complicated by variations in crop or scopal contents. For example, workers of Apis mellifera foraging at saguaro cacti carry, on average, nearly a fifth of their wet weight in corbicular nectar and pollen (Cooper et al., 1985; Schmidt and Buchmann, 1986). Glandular reservoir contents further complicate weight estimates. Females of the large bee Habropoda (=Emphoropsis) laboriosa will contain from nearly 0 to 6 mg of Dufour's gland lipid secretion (Cane and Carlson, 1984), dependent upon age, time of capture and recency of secretion. Head width has been successfully employed for body size estimation of live male Philanthus wasps (O'Neill, 1983). It is less suitable for comparing the genera of bees, owing to head allometry that may reflect mandibular/labial gland development or nesting biology (e.g., leaf-cutting megachilids have robust mandibular musculature). Body length too has allometric drawbacks, particularly for the more elongate and cylindrical bodies of stem-nesting taxa. An intuitively appealing estimate of bee size would be a measure of thoracic volume. The content of thoracic flight musculature should directly translate into the lift required for flight by a bee of a particular size. The tegulae covering a bee's wing bases provide suitable landmarks between which can be measured a chord distance, the intertegular span, which might satisfactorily estimate bee dry weight. A female of each of 20 species of bees was selected for measures for the regression analysis. None of these species are eusocial, but among them are parasitic taxa, groundand stem-nesting species, which range in size from nearly Drosophila-sized Dialictus to bumblebee-sized carpenter bees. The species measured are: Collet?s inaequalis, Hylaeus rugulosus (Colletidae); Andrena accepta, Calliopsis andreniformis, Per dita coreopsidis (Andrenidae); Protoxaea gloriosa (Oxaeidae); Augochlora pura, Dialictus versatus, Dufourea marginata, Nomia melanderi (Halictidae); Hesperapis carinata (Melitti dae); Anthidiellum notatum, Megachile texana (Megachilidae); Anthophora urbana, Centris atripes, Diadasia olivaceae, Exomalopsis solani, Melissodes agilis, Triepeolus verbesinae, and Xylocopa micans (Anthophoridae). These species together represent the six major (and one minor) non-eusocial bee families and 18 of the tribes. One intact and pinned female (with empty scopae) of each species was first measured using a Wild? dissecting stereomicroscope fitted with an ocular micrometer. The shortest distance between the bases of her tegulae was recorded to the nearest 105 m (Fig. 1, inset). Both tegulae were kept within the shallow focal plane to ensure their alignment. For preliminary comparisons, head widths were also taken, using the greatest perceived width of the head when viewed from the vertex. Bees were then slipped off of their pins (or in the case of smaller species, dry, unpinned specimens were used) and dried for 5 days at 45?C, until they ceased losing weight. They were weighed using a Sartorius model 1712MP8 balance to the nearest 10~5g. Additionally, the weights and intertegular spans of 12 females each of Xylocopa virginica and of Diadasia rinconis were measured as above to assess degrees of intraspecific variability in these measures for a relatively large and a medium-sized bee. They were not included in the regression calculations. The sample of female weights, head widths and intertegular spans of the 20 species were preliminarily submitted to a simple linear regression. Intertegular span linearly increased with bee dry weight (P < 0.01, R2 = 0.945), as did head width (P <0.0l,R2 = 0.904). While significant, these linear regressions yielded unsatisfactory fits for many of the data points when plotted for the smaller bees. This content downloaded from 207.46.13.158 on Wed, 16 Nov 2016 04:30:06 UTC All use subject to http://about.jstor.org/terms 146 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY

A Comparison of Pan Trap and Intensive Net Sampling Techniques for Documenting a Bee (Hymenoptera: Apiformes) Fauna

Abstract: Recent interest in pollinator sampling, often motivated by concerns about pollinator decline, has led to the increased use of standardized sampling protocols based on passive insect traps. Compared with netting insects at host plants, these protocols have the potential to limit some types of sampling bias, such as those associated with a researcher's observational and netting skills. The most commonly deployed recent protocol is the use of colored pan traps (bowls) filled with soapy water (Aguiar and Sharkov, 1997; Calbuig, 2001; Cane et al, 2000; Leong and Thorp, 1999; Toler et al, 2005). Insects approach the bowls, land on the water, and drown. The method is particularly good at catching numerous species of bees, but can also be effective for capturing various flower-visiting flies, skippers and a wide range of other insect taxa. As a bee sampling device, pan traps have several known biases: they catch bumble bees, honey bees and bees in the genus Colletes much less frequently than expected by their perceived abundance (e.g., Toler et al, 2005). Pan traps are especially good at catching halictid bees (Family Halictidae). Because of these biases, researchers sometimes use a modest amount of net collecting on flowers to accompany pan traps. Other potential biases remain to be studied, such as whether the effectiveness of pan traps is inversely related to flower abundance, a bias suspected by several researchers but not yet studied. Based on their pan-trapping study, Toler et al (2005) concluded that the predominant flower color in the plant community did not influence the relative attractiveness of particular pan trap colors, but they did not study the effect of floral abundance per se. Depending on a researcher's interest in deploying pan traps, these biases may or may not generate concern. Pan traps seem very well suited to testing for the presence of particular bee species in the community (Leong and Thorp, 1999), including many parasitic bee species that are seldom caught at flowers. They also provide a very valuable tool for augmenting other collecting methods, especially when there are few host plants to sample (e.g., early spring). Work by Cane et al. (2000) included a comparison of pan traps versus intensive netting to sample the very diverse and well known flower-visiting insect fauna of creosote bush. These workers concluded that pan trapping was of limited use in detecting the creosote bush fauna because of numerous species caught by netting but not by pan traps. Pan traps did catch many bee species not netted at creosote bush, however. Because netting in that study was restricted to creosote bush, there was no basis to compare the relative effectiveness of netting versus pan trapping for sampling a local bee fauna in the wider flower-rich community. In 2002 in northern Virginia, we carried out an intensive netting/observational survey of floral visitors within one hectare plots at Blandy Experimental Farm, an ecological experiment station of the University of Virginia. The sampled habitat was an open field and the sampling protocol comprised net sampling on the six most prominent plant species in the community from 8:00-16:00 hrs Eastern Daylight Time. Each plant species was surveyed for a total of 2.25 hrs, spread equally across the sampling period. Each of three researchers sampled all plant species in succession, one species at a time, three times across the sampling period (8:00-10:00, 11:00-13:00, 14:00-16:00). Survey periods lasted 15 mins per plant species per researcher, with researchers moving through the entire plot during that period. Bee species that could be recognized on the wing (e.g., Apis mellifera) were noted but not captured. To compare the effectiveness of pan trapping to such an intensive netting protocol at one of our sites, we placed a line of 30 pan traps (6 oz Solo bowls painted fluorescent blue, fluorescent yellow, or left white) in a diagonal line across the plot,

Sampling Bees (Hymenoptera: Apiformes) for Pollinator Community Studies: Pitfalls of Pan-trapping

Abstract: With the growing interest in pollinator conservation, a need has emerged for a simple, unbiased method to reliably sample local bee faunas One method, pan-trapping, has increased in popularity without critical evaluation of its efficacy and biases We compared traditional net collecting at flowers and pan trapping concurrently, sampling the local bee fauna of the dominant desert shrub, creosote bush (Larrea tridentata) growing at the Silver bell site of the International Biosphere Program (IBP) nw of Tucson Arizona Pan-traps on the ground yielded a faunal sample depauperate in many of the more common native bee species on creosote bush, particularly its floral specialists This pan-trap sample also corre sponded poorly with the previous four years' faunal samples at this site, with pairs of neigh boring net-sampled sites throughout the Southwest, and with all pairs of bee samples from Larrea across the Upper Sonoran desert The likely causes of this disparity and the utility of pan trapping for bees in faunal and community studies is discussed

Soils of ground-nesting bees (Hymenoptera: Apoidea): texture, moisture, cell depth and climate

Abstract: Nesting soils of 32 species of fossorial bees were sampled from diverse habitats across the continental United States. These soils classified texturally as sands or loams. Broadly diverse values for bee size, cell depth, soil moisture and texture, and average annual precipitation and temperature were represented in the sample, but each varied independently from the others, and was not predictable from a bee species' familial or tribal affiliation. Bee species secreting markedly different Dufour's gland lipids, which are used to waterproof the walls of their subterranean nest cells, could be found nesting under similar edaphic and climatic conditions. Most species of bees nest in the soil. Females excavate subterranean tunnels terminated by enlarged chambers or cells which they provision with pollen and nectar masses. Fossorial nesting is characteristic of the Andrenidae, Fideliidae, Halictidae, Melittidae, Oxaeidae and Stenotritidae. The majority of the Colletidae and Anthophoridae also nest underground. Nesting above-ground only predom inates among the Megachilidae, Apidae, Hylaeinae and Xylocopinae. Although bees are best known as adults that appear briefly each year, individuals of most species spend the greater part of their lives underground as immatures (Linsley, 1958; Malyshev, 1935; Michener, 1974; Roubik, 1989). Bees nest in diverse earthen habitats, ranging from weathered sandstone (Custer, 1928) and the mortar of prehistoric adobe walls (pers. obs.) to embankments of dense clay, deep alluvial silts, and sand dunes of deserts and beaches (Malyshev, 1935; Stephen et al., 1969; Roubik, 1989). Horizontal or vertical nesting sites are typically considered "well-drained" (Linsley, 1958), but species of neotropical Epicharis (Roubik and Michener, 1980), palearctic Dasypoda (J. Teng?, pers. comm.) and nearctic Nomia (P. Torchio, pers. comm.) are known to nest suc cessfully at sites that are periodically submerged. Many solitary bee species nest in dense aggregations, which suggests that females select sites with particular surface or edaphic attributes. The alkali bee, Nomia melanderi, for instance, may aggregate in the tens of thousands in soils charac terized by less than 8% clay and slow surface seepage (Stephen, 1960). Nesting females of this species respond to hot ambient temperatures by excavating nest burrows more deeply in the soil (W. P. Stephen, pers. comm.). In the blueberry barrens of Maine, Osgood (1972) found that species of Collet?s, Andrena and halictine bees nested more frequently in soils whose surface organic layers were thinner than neighboring locations. In contrast, a comparative study of Brazilian bank-nesting species (Michener et al., 1958) concluded that female philopatry was primarily responsible for the aggregation of nests, as neighboring, seemingly equiv alent sites in the same embankments remained unused. Few other comparative or quantitative studies have been made for the nesting soils of bees. Accepted for publication 4 March 1991. This content downloaded from 157.55.39.45 on Thu, 01 Sep 2016 05:08:35 UTC All use subject to http://about.jstor.org/terms VOLUME 64, NUMBER 4 407 My objectives here are to 1) survey the nesting soils of taxonomically diverse bee species across a broad range of soil moistures, textures, habitats, and biomes of North America, and 2) reveal any predictive correlations of these edaphic measures with bee size, climate, taxonomic affiliation or to each other. Materials and Methods Soil surrounding the shallowest provisioned cell of an active nest was collected into an airtight jar. The fresh 30-100 g sample was weighed, dried for 3-5 d in an oven at 30? to 40?C, and reweighed (?0.1 g). Soil moisture content was cal culated gravimetrically as: Weight loss/dry weight x 100 (Brady, 1984) Cell depth was measured vertically to the soil surface. The provisioning female bee was collected for identification. Her size was estimated by the shortest distance between her wing tegulae as measured using a dissecting stereomicroscope and ocular micrometer (Cane, 1987). Particle-size distribution of the dried soil was analyzed by standard sedimen tation techniques. Briefly, a sample was suspended in solution with the aid of a blender and a detergent dispersing agent. Specific gravity, measured using a hy drometer as the suspension settled, was used to calculate the proportion of silt and clay fractions, with sand as the remainder. In later analyses, particles >2 mm diam (gravel) were first removed by sieving. Textural classification of the soils follows the system of the U.S. Dep't. of Agriculture (Brady, 1984). Average annual temperature and precipitation were taken from the nearest reporting weather station (NOAA, 1983; Brown, 1982; Ting and Jennings, 1976) or more local sources (US Nat'l. Weather Service, Auburn, Ala.; Bodega Bay Marine Laboratories, Bodega Bay, Calif.; S'west. Research Station of the Amer. Museum Nat. Hist., Portal, Ariz.). Relationships among the variables were explored using several multivariate approaches available through NTSYS Ver. 1.50 (Rohlf, 1988). Following default standardization of the cases, a correlation matrix was calculated using all of the variables. The species were then clustered by UPGMA using the correlation val ues. These correlation values were also used to construct a matrix of cophenetic similarity values to assess the goodness of fit of the above clustering to the data. A second analysis, principal components, was performed with the standardized data for soil textures, moisture and nesting depth. Eigenvectors and eigenvalues were calculated from the correlation matrix. Data obtained for each bee species were then projected onto the first two or three eigenvectors and plotted against each other. In all, nests of 32 species of ground-nesting bees were analyzed, representing 22 genera and seven families of the North American fauna (Table 1). Results and Discussion Soil moistures for this sampling of bee species varied over a 15 x range, which reflected (at least in part) the 19 x range in annual rainfall. Soil textures ranged from sands to silt loams and clay loams. No bees were found nesting in clay or silt soils. All of the soils examined were at least %, and as much as 94% sand. The finer particle fractions, being silts and clays, were less abundant, ranging from absence to Vi of the soil dry weight (Table 1, Fig. 1). Bee species nesting in This content downloaded from 157.55.39.45 on Thu, 01 Sep 2016 05:08:35 UTC All use subject to http://about.jstor.org/terms Table 1. Species of ground-nesting bees sampled in this survey. "Size" is intertegular span in mm, annual precipitation and nest cell depth are in cm, and annual temperature is degrees C. The "Bee no." corresponds to those used in the figures. o 00 Family Subfamily/tribe Depth Moisture %clay %silt %sand %gravel Precip. Temp. Classification Macropodinae MEGACHILI DAE

Polygyny and the evolution of social behavior in wasps

Abstract: A survey of the group composition of primitively social (nest sharing, casteless) wasps reveals that virtually all are polygynous (have more than one egg-laying female per nest), and that life in groups of genetic relatives is common (except possibly in some species showing only occasional or short-term nest sharing). Furthermore, incipient and well developed worker castes are present in polygynous wasp societies. There fore polygynous family groups, rather than subsocial groups, matrifilial monogynous groups, or groups of non-relatives, have probably been a major setting for the evolution of a worker caste in wasps. General kin selection and mutualism hypotheses are more applicable as explanations for helping (worker) behavior in such groups than are the haplodiploidy or maternal control hypotheses. Long-term monogyny, which is required by the latter two hypotheses, probably more often followed rather than preceded the advent of sterile castes in the evolution of the social wasps. A "polyg ynous family hypothesis" is proposed as an alternative to the "subsocial" and "semisocial" hypotheses for the evolution of insect sociality.