Identifying drivers of dispersal limitation and genetic differentiation is a key goal in biogeography. We examine patterns of population connectivity and genetic diversity using restriction site-associated DNA sequencing (RADseq) in two bumble bee species, Bombus vosnesenskii and Bombus bifarius, across latitude and altitude in mountain ranges from California, Oregon and Washington, U.S.A. Bombus vosnesenskii, which occurs across a broader elevational range at most latitudes, exhibits little population structure while B. bifarius, which occupies a relatively narrow higher elevation niche across most latitudes, exhibits much stronger population differentiation, although gene flow in both species is best explained by isolation with environmental niche resistance. A relationship between elevational habitat breadth and genetic diversity is also apparent, with B. vosnesenskii exhibiting relatively consistent levels of genetic diversity across its range, while B. bifarius has reduced genetic diversity at low latitudes, where it is restricted to high-elevation habitat. The results of this study highlight the importance of the intersect between elevational range and habitat suitability in influencing population connectivity and suggest that future climate warming will have a fragmenting effect even on populations that are presently well connected, as they track their thermal niches upward in montane systems.

Global temperature changes have emphasized the need to understand how species adapt to thermal stress across their ranges. Genetic mechanisms may contribute to variation in thermal tolerance, providing evidence for how organisms adapt to local environments. We determine physiological thermal limits and characterize genome-wide transcriptional changes at these limits in bumble bees using laboratory-reared Bombus vosnesenskii workers. We analyze bees reared from latitudinal (35.7–45.7°N) and altitudinal (7–2154 m) extremes of the species’ range to correlate thermal tolerance and gene expression among populations from different climates. We find that critical thermal minima (CTMIN) exhibit strong associations with local minimums at the location of queen origin, while critical thermal maximum (CTMAX) was invariant among populations. Concordant patterns are apparent in gene expression data, with regional differentiation following cold exposure, and expression shifts invariant among populations under high temperatures. Furthermore, we identify several modules of co-expressed genes that tightly correlate with critical thermal limits and temperature at the region of origin. Our results reveal that local adaptation in thermal limits and gene expression may facilitate cold tolerance across a species range, whereas high temperature responses are likely constrained, both of which may have implications for climate change responses of bumble bees.

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The orchid bee genus Eufriesea Cockerell is documented for the first time from the southwestern United States, extending its apparent range north well beyond its previous tropical/subtropical boundaries. Eufriesea coerulescens (Lepeletier de Saint Fargeau 1841) is recorded from the Guadalupe Mountains of western Texas and southeastern New Mexico, USA. Whether E. coerulescens is resident in the USA, or merely a vagrant from Mexico, remains unclear. Distinctive morphological traits shared with the holotype are enumerated and illustrated. In addition, observations that question the current species concept and distribution of E. coerulescens are provided.

Psychologists, educators, and other professional persons have long been concerned with the problem of appraising the abilities of individuals who, because of language difficulties, are penalized on the usual psychometric devices. A wide variety of procedures have been devised for this handicapped group, including formboards, mazes, and other approaches that minimize the use of language. Recently, a new testing procedure has been introduced for use with such handicapped groups as the brain-injured, the non-reader, the retarded, and the withdrawn. This procedure, the Peabody Picture Vocabulary Test (PPVT) (I), provides alternate forms and norms for children within the age range of 2 years 6 months and 18 years 5 months. Testing time for the PPVT is between 10 to 15 minutes.A recent study by Kimbrellc2) indicates that the PPVT correlates significantly but low with WISC Full Scale and Verbal IQ's. Kimbrell's sample consisted of educable mental defectives.The purpose of the present investigation is to examine the relationship between these two tests of intelligence for a sample of children who are characterized as "emotionally disturbed." PROCEDUREThe sample consisted of 48 children referred to the Child-Family Guidance Center, Fort Smith, Ark., for emotional problems. Each child was tested with both the PPVT and the WISC during a single session, with the order of presentation varying, so that approximately half of the Ss received the PPVT first and half were administered the WISC first. Only Form A of the PPVT was utilized in this study.The children ranged in chronological age from 6 years 2 months to 14 years 8 months, mean CA 10.64 years. The WISC Full Scale IQ ranged from 63 to 135, mean IQ 95.33. RESULTSThe correlations of the PPVT IQ with Verbal, Performance. and Full Scale IQ's of t,he WISC are summarized fn Table 1. All &rrelations are significant beyond the .01 level of significance. As the test author suggests in the manual(', p. 12), the PPVT appears to be measuring verbal intelligence to a greater degree than it measures "mechanical" intelligence.Of special concern to clinicians who may intend to use the PPVT as a time-saving substitute for the WISC is the column of standard errors of estimate in Table 1. On the basis of the standard error, it can be expected that scores of the WISC will be within approximately eleven points of the predicted value two-thirds of the time. The clinician will need to decide for himself whether or not these probabilities are such that he would feel comfortable predicting WISC I Q on the basis of PPVT IQ. Child-Family Guidance Center, Fort Smith, Ark.For the present sample of emotionally disturbed children, a moderate correlation was obtained between PPVT IQ and WISC IQ. Although the magnitude of the r's can be interpreted as an indication of substantial relationship between the two tests, they fall within an intermediate range. The correlations are neither so low that the PPVT can be dismissed as a substitute for the WISC nor so high that the PPVT can be used as a replacement ...