John Hafernik - Academia.edu (original) (raw)

Papers by John Hafernik

The San Francisco Bay Area hosts a diverse insect fauna and a dense cluster of urban areas. The h... more The San Francisco Bay Area hosts a diverse insect fauna and a dense cluster of urban areas. The high diversity of insects in the Bay Area arises for three primary reasons: its location in the California biotic province, the diverse local environment and the entomologist-area effect. The juxtaposition of high insect diversity and an area intensively used by humans led to the first recorded extinction as well as the first efforts to conserve insects in the United States. Habitat loss due to urbanization, agriculture, and invasive species is largely responsible for local extinctions and reduction in abundance of the remaining species. Invasive species such as the Argentine ant and pathogens causing mortality of oaks and pines are poised to have substantial impacts on the insect fauna of the Bay Area in the near future. Understanding which taxa can or cannot persist in remnant habitat patches within an urban or agricultural matrix, and what management practices would encourage persisten...

The long-term goals of the recently started Biomedia project at SFSU are to provide multimedia in... more The long-term goals of the recently started Biomedia project at SFSU are to provide multimedia information systems and applications for the research and education needs of several projects in the SFSU Biology Department. These applications involve a considerable amount of images and image sequence data, in addition to traditional text, genomic, and experimental measurement data. Our systems will allow biology

Habitat degradation led to local extinction of the San Francisco forktail damselfly (Ischnura gem... more Habitat degradation led to local extinction of the San Francisco forktail damselfly (Ischnura gemina) in Glen Canyon Park, San Francisco, California. In this study, we reintroduced I. gemina into Glen Canyon after the damselfly’s habitat was restored. Upon release, we carried out a mark- release-recapture study to monitor the damselfly’s population dynamics. Our data were compared to two “baseline” studies on I. gemina, conducted in the park prior to the damselfly’s demise. Our recapture rates were significantly lower than the prior studies due to a large initial decline in marked individuals upon release. Despite a lower recapture rate, the reintroduction was initially successful since the damselflies reproduced throughout the summer and the following year. However, the population failed to persist during the second year when the habitat became degraded with excess vegetation. Future success is contingent on the continual management and upkeep of the habitat.

Annals of the Entomological Society of America, 1992

ABSTRACT In allopatry and in a hybrid zone, we analyzed the relationship between morphometric cha... more ABSTRACT In allopatry and in a hybrid zone, we analyzed the relationship between morphometric characters and the inferior abdominal appendage angle in two damselflies, Ischnura gemina (Kennedy) and Ischnura denticollis (Burmeister), to assess the taxonomic reliability and genetic basis of this genitalic trait. Changes in the morphometric-genitalic relationship in the hybrid zone strongly imply that introgression has occurred, although there is some evidence of hybrid unfitness and partial reproductive isolation. We conclude that the inferior appendage trait is not taxonomically reliable because it fails to convey the recombinant nature of individuals in the hybrid zone. A combination of field and lab data suggest that the genitalic angle trait is polygenic but controlled by only a few genes. We argue for retention of full species status for both I. gemina and I. denticollis, despite genetic exchange between the two.

Conservation Biology, 1992

this paper we address the following questions: What is the scope of the problem of conserving ins... more this paper we address the following questions: What is the scope of the problem of conserving insects in the Bay Area? What efforts have and are being made to assess the impact of urbanization on insects, to develop conservation plans for endangered insects, to restore or protect habitat, and to re-establish locally extirpated species? What then are the prospects for insect conservation in the Bay Area? The Bay Area is a nine county region of approximately 18,000 km that includes San Francisco Bay and surrounding lands (Figure 1). We define our region as the Bay Area standard metropolitan statistical area (SMSA) because information on human demography, economic conditions, and land use and land cover changes are reported for this area. We conceive of an 248 Figure 1. The Bay Area -- a nine-county region surrounding San Francisco Bay

Journal of Insect Conservation, 2014

Many species are altering their geographic range due to climate change creating new sympatric pop... more Many species are altering their geographic range due to climate change creating new sympatric populations of otherwise allopatric populations. We investigated whether climate change will affect the distribution and thus the pattern of hybridization between two pairs of closely related damselfly species [Ischnura damula and I. demorsa, and I. denticollis and I. gemina (this, an endangered species)]. Thus, we estimated the strength of pre and postmating reproductive barriers between both pairs of species, and we predicted future potential distribution under four different Global Circulation Models and a realistic emissions scenario of climate change by using maximum entropy modelling technique. Our results showed that reproductive isolation (RI) is complete in I. damula 9 I. demorsa individuals: F 1 (first generation) hybrids are produced but do not reach sexual maturation. However, RI in I. denticollis 9 I. gemina hybrids is high but incomplete and unidirectional: only I. gemina females produced F 1 hybrids which mate with males and females of I. denticollis and between them producing BC 1 (backcrosses) and F 2 (second generation) viable hybrids. Maximum entropy models revealed a northern and westward shift and a general reduction of the potential geographic ranges. Based on the pattern of hybridization, for I. damula and I. demorsa there is a current threat as well as a rapid displacement and/or extinction of I. gemina by I. denticollis. However, the current pattern of extinction may not continue due to the contraction in ranges of the four species. Keywords Climate change Á Range shifts Á Sympatric distributions Á MAXENT Á Hybridization and introgression Á Displacement and extinction Electronic supplementary material The online version of this article (

The American Naturalist, 1986

The Southwestern Naturalist, 1971

... CURCULIONIDAE)1 HORACE R. BURKE AND JOHN E. HAFERNIK2 ... The only information available on t... more ... CURCULIONIDAE)1 HORACE R. BURKE AND JOHN E. HAFERNIK2 ... The only information available on the host of Smicraulax arizonicus is from label data on specimens collected on "Phoradendron coryae on Quercus" in Cochise Co., Arizona by CW O'Brien. ...

PLoS ONE, 2012

Honey bee colonies are subject to numerous pathogens and parasites. Interaction among multiple pa... more Honey bee colonies are subject to numerous pathogens and parasites. Interaction among multiple pathogens and parasites is the proposed cause for Colony Collapse Disorder (CCD), a syndrome characterized by worker bees abandoning their hive. Here we provide the first documentation that the phorid fly Apocephalus borealis, previously known to parasitize bumble bees, also infects and eventually kills honey bees and may pose an emerging threat to North American apiculture. Parasitized honey bees show hive abandonment behavior, leaving their hives at night and dying shortly thereafter. On average, seven days later up to 13 phorid larvae emerge from each dead bee and pupate away from the bee. Using DNA barcoding, we confirmed that phorids that emerged from honey bees and bumble bees were the same species. Microarray analyses of honey bees from infected hives revealed that these bees are often infected with deformed wing virus and Nosema ceranae. Larvae and adult phorids also tested positive for these pathogens, implicating the fly as a potential vector or reservoir of these honey bee pathogens. Phorid parasitism may affect hive viability since 77% of sites sampled in the San Francisco Bay Area were infected by the fly and microarray analyses detected phorids in commercial hives in South Dakota and California's Central Valley. Understanding details of phorid infection may shed light on similar hive abandonment behaviors seen in CCD.

Oecologia, 1981

The population structure of the endemic San Francisco Bay Area damselfly, Ischnura gemina, is exa... more The population structure of the endemic San Francisco Bay Area damselfly, Ischnura gemina, is examined using mark-recapture methods. Average daily movements, sex ratios, population size, maturation times, survivorship, and dispersion patterns were recorded and calculated from two small (each less than one hectare) sites 150 m apart in Glen Canyon, San Francisco. Of 563 adults marked over 36 days, 412 (73%) were recaptured at least once. Average daily movements for males and females were less than 6 m, suggesting local movements. However, directional movements of 150 m were observed from one site to the other, indicating dispersal potential. One of the populations was a satellite composed entirely of emigrating individuals from the other site; no larvae or teneral adults were found at the satellite area. Males were more aggregated than females at both sites. Both sexes were highly clumped at one site, but were nearly randomly dispersed at the other site. Total population size for both sexes tended to be constant throughout the sampling period, at about 250. Adult population estimates showed more males were present than females, but larval counts at one site indicated only a slight excess of males. Average life span estimates ranged from 6.5 days (females) to 23.3 days (males). One male lived at least 36 days. Maturation time for males was about 5-7 days, 7-10 days for females. A long life span and long flight season (March to November) are probably adaptations to the foggy San Francisco climate. All populations of I. gemina located to date are small, possibly originating from founders from nearby demes, and may be subject to different selection pressures. The dispersal potential of L gemina may increase its chance of survival should small urban demes be threatened with destruction.

Annals of the Entomological Society of America, 1992

Conservation Biology, 1992

Journal of Insect Conservation, 2014

The American Naturalist, 1986

The Southwestern Naturalist, 1971

PLoS ONE, 2012

Oecologia, 1981