Jaret C. Daniels

Native wildflower plantings support wild bee abundance and diversity in agricultural landscapes across the United States.

Global trends in pollinator-dependent crops have raised awareness of the need to support managed and wild bee populations to ensure sustainable crop production. Provision of sufficient forage resources is a key element for promoting bee populations within human impacted landscapes, particularly those in agricultural lands where demand for pollination service is high and land use and management practices have reduced available flowering resources. Recent government incentives in North America and Europe support the planting of wildflowers to benefit pollinators; surprisingly, in North America there has been almost no rigorous testing of the performance of wildflower mixes, or their ability to support wild bee abundance and diversity. We tested different wildflower mixes in a spatially replicated, multiyear study in three regions of North America where production of pollinator-dependent crops is high: Florida, Michigan, and California. In each region, we quantified flowering among wildflower mixes composed of annual and perennial species, and with high and low relative diversity. We measured the abundance and species richness of wild bees, honey bees, and syrphid flies at each mix over two seasons. In each region, some but not all wildflower mixes provided significantly greater floral display area than unmanaged weedy control plots. Mixes also attracted greater abundance and richness of wild bees, although the identity of best mixes varied among regions. By partitioning floral display size from mix identity we show the importance of display size for attracting abundant and diverse wild bees. Season-long monitoring also revealed that designing mixes to provide continuous bloom throughout the growing season is critical to supporting the greatest pollinator species richness. Contrary to expectation, perennials bloomed in their first season, and complementarity in attraction of pollinators among annuals and perennials suggests that inclusion of functionally diverse species may provide the greatest benefit. Wildflower mixes may be particularly important for providing resources for some taxa, such as bumble bees, which are known to be in decline in several regions of North America. No mix consistently attained the full diversity that was planted. Further study is needed on how to achieve the desired floral display and diversity from seed mixes.

Ant Tending of Miami Blue Butterfly Larvae (Lepidoptera: Lycaenidae): Partner Diversity and Effects on Larval Performance

ABSTRACT The larvae of many lycaenid butterflies (Lepidoptera: Lycaenidae) are tended by ants that protect them from natural enemies in return for sugar-rich secretions that the larvae produce to attract and retain their ant guards. We investigated the relationship between larvae of the endangered Miami blue butterfly (Cyclargus thomasi bethunebakeri Comstock & Huntington) and potentially mutualistic ants. We observed 10 ant species interacting with Miami blue larvae in the field, and raised larvae successfully in captivity with 3 of these and 6 other ant species that are not known to tend larvae in the wild. In an experimental assessment of ant effects on larval performance, we found no differences in age at pupation, pupal mass, length of pupation, total time as an immature or ratio of time as a larva to time as a pupa among larvae raised with Camponotus floridanus Buckley, Linepithema humile Mayr, or in a no-ant control. Larvae raised with C. floridanus were significantly more likely to pupate in the ant harborage than larvae in the other treatments. We did not observe ants behaving antagonistically toward Miami blue larvae in field, laboratory, or experimental conditions; even ant species previously identified as potential predators tended larvae. Our results demonstrate that Miami blue larvae can elicit typical tending behaviors across diverse ant taxa and that ant tending does not substantially alter larval development, findings that may have implications for conservation and population restoration of the Miami blue butterfly. Translation provided by the authors.

Miami blue butterfly larvae (Lepidoptera: Lycaenidae) and ants (Hymenoptera: Formicidae): new information on the symbionts of an endangered taxon

Abstract Historical, anecdotal records of the state-endangered Miami blue butterfly, Cyclargus thomasi bethunebakeri (Comstock & Huntington) (Lepidoptera), have mentioned larval associations with the Florida carpenter ant, Camponotus sp. Recent population studies confirm that C. t. bethunebakeri larvae associate with Camponotus floridanus (Buckley) as well as another member of the genus, Camponotus planatus (Roger). Additionally, caterpillars have been observed tended by Crematogaster ashmeadi (Emery), Forelius pruinosus (Roger), and Tapinoma melanocephalum (Fab.). Field surveys of remaining Miami blue habitat and recent butterfly reintroduction sites reveal other potential ant associates, Paratrechina longicornis (Latreille) and Paratrechina bourbonica (Forel), and a host of possible predaceous ant species. The corresponding conservation implications are discussed. Detailed information is also presented about larval ant-associated organs and their mediation of this facultative symbiosis.

Cooperative conservation efforts to help recover an endangered south Florida butterfly

Abstract.  1 The Miami blue (Cyclargus thomasi bethunebakeri) (Lycaenidae) is a small, brightly coloured butterfly endemic to Florida. 2 It was once locally common across much of the south Florida mainland south through the Florida Keys to the Dry Tortugas. 3 Over the last few decades, ever‐expanding urbanisation and the associated loss of coastal habitat have lead to a significant reduction in the taxons overall geographical distribution and numerical abundance. 4 The butterfly is currently limited to two small extant populations in the Lower Florida Keys, making it one of the most imperilled insects in North American and warranting a state of Florida listing as endangered. 5 As part of a large‐scale, model cooperative recovery programme led by the Florida Fish and Wildlife Conservation Commission, the University of Florida, the National Park Service, and the Florida Department of Environmental Protection, efforts are underway to conserve the butterfly through captive propagation, organism re‐introduction to state and federal lands, and research on the biology, population ecology, genetic diversity, and non‐target impact of mosquito control adulticides.

Aerial Ultra-Low-Volume Application of Naled: Impact on Nontarget Imperiled Butterfly Larvae (Cyclargus thomasi bethunebakeri) and Efficacy Against Adult Mosquitoes (Aedes taeniorhynchus)

ABSTRACT We assessed the exposure and acute toxicity of naled, applied aerially as an ultra-low-volume spray for mosquito control, on late instar larvae of the Miami blue (Cyclargus thomasi bethunebakeri) (Comstock and Huntington 1943) (Lepidoptera: Lycaenidae), an imperiled South Florida butterfly. We concurrently evaluated the control efficacy against caged adult female salt-marsh mosquitoes (Aedes taeniorhynchus) (Wiedemann 1821) (Diptera: Culicidae). This 3-yr study was conducted in north Key Largo (Monroe County, FL) beginning in 2006. The field trials incorporated 15 sampling stations: nine in the target spray zone, three in the spray drift zone at varying distances from the target zone, and three in the control zone not subjected to naled spray drift. A total of six field spray trials were completed, three at an altitude of 30.5 m (100 feet), and three at 45.7 m (150 feet). For all trials, the ultra-low-volume application of Trumpet EC insecticide (78% naled) at a rate of 54.8 ml/ha (0.75 fl. oz/acre) was effective in killing caged adult mosquitoes in the target zone. Butterfly larvae survival was significantly reduced in the spray zone compared with drift and control zones. Analysis of insecticide residue data revealed that the mortality of the late instar butterfly larvae was a result of exposure to excess residues of naled. Additional research is needed to determine mitigation strategies that can limit exposure of sensitive butterflies to naled while maintaining mosquito control efficacy.

Size Effects on Mating and Egg Production in the Miami Blue Butterfly

Body size is often related to reproductive success in insects, but the direction and strength of this relationship differs greatly among systems. We studied the effects of adult size on probability of mating and egg production in the Miami blue butterfly. We found that likelihood of mating was invariant with respect to size. Larger females lived longer, and both size and lifespan positively influenced egg production. However, neither the number of copulations nor the size of male mates had any effect on female fecundity. We discuss these results in the context of butterfly mating systems, larval growth strategies and the possible effects of captive conditions on reproductive behavior.

Courtship Solicitation by Females of the Barred Sulphur Butterfly (Eurema daira) (Lepidoptera: Pieridae)

Virgin females of the subtropical pierid butterfly Eurema daira were observed to actively solicit male courtship. The resulting interactions involved both aggressive contact with male individuals and elaborate female posturing. Cage-based trials showed that there was a direct relationship between the frequency of courtship solicitation attempts and female age. Virgin females under 3 days old showed little or no interest in initiating courtship. By contrast, 23.2 percent of the virgin females over three days old actively solicited available males with peak solicitation behavior exhibited from five day old individuals.

Can butterflies evade fire? Pupa location and heat tolerance in fire prone habitats of Florida.

Butterflies such as the atala hairstreak, Eumaeus atala Poey, and the frosted elfin, Callophrys irus Godart, are restricted to frequently disturbed habitats where their larval host plants occur. Pupae of these butterflies are noted to reside at the base of host plants or in the leaf litter and soil, which may allow them to escape direct mortality by fire, a prominent disturbance in many areas they inhabit. The capacity of these species to cope with fire is a critical consideration for land management and conservation strategies in the locations where they are found. Survival of E. atala pupae in relation to temperature and duration of heat pulse was tested using controlled water bath experiments and a series of prescribed fire field experiments. Survival of E. atala pupae was correlated to peak temperature and heat exposure in both laboratory and field trials. In addition, E. atala survival following field trials was correlated to depth of burial; complete mortality was observed for pupae at the soil surface. Fifty percent of E. atala survived the heat generated by prescribed fire when experimentally placed at depths ≥ 1.75cm, suggesting that pupation of butterflies in the soil at depth can protect from fatal temperatures caused by fire. For a species such as E. atala that pupates above ground, a population reduction from a burn event is a significant loss, and so decreasing the impact of prescribed fire on populations is critical.

Development and characterization of polymorphic microsatellite loci in the endangered Miami blue butterfly (Cyclargus thomasi bethunebakeri).

The Miami blue butterfly (Cyclargus thomasi bethunebakeri) is a state‐endangered taxon in Florida and a candidate for federal listing. Here we report 12 polymorphic microsatellite loci appropriate for use in population and conservation studies. We genotyped 114 individuals sampled from a metapopulation in the lower Florida Keys over a 2‐year period (2005–2006). These results show 4–14 alleles per locus, and ranges of observed and expected heterozygosities are 0.02679–0.79630 and 0.06154–0.69565, respectively. Large deviations from Hardy‐Weinberg equilibrium (HWE) are observed across the whole sample set. When a single breeding population is analysed alone, seven of the loci are in HWE.

Predaceous Behavior by Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae: Heliothinae)

Helicoverpa zea (Boddie) (Noctuidae) is a well-documented pest of agricultural crops throughout most of North and South America (Wilcox et al. 1956; Hardwick 1965, 1996; Kimball 1965; Tietz 1972; Covell 1984; Heppner 2003; Capinera 2005; Wagner 2005). Hardwick (1965), in proposing the genus Helicoverpa as distinct from Heliothis Ochsenheimer, noted the polyphagous herbivory of H. zea (see also Kimball 1965; Tietz 1972; Covell 1984; Heppner 2003; Capinera 2005; Wagner 2005), but made no mention of predaceous behavior within the genus. Cannibalism was reported by Hardwick (1996) as common by young larvae of Heliothinae, particularly for individuals feeding in small flower heads. Capinera (2005) noted that aggressive killing and cannibalism occurs in late instar larvae of H. zea when occupying ears of corn. Hardwick (1996) documented a case of intergeneric predation in larval Heliothinae, where Euticropis nexilis Morrison (Noctuidae) was consumed by Schinia verna Hardwick (Noctuidae) when feeding within flower heads of Antennaria (Asteraceae) (see also Hardwick 1958, 1970). Huguenin (1914) documented a case of interfamilial predation where larvae of Heliothis dispaceus [sic] (Noctuidae) killed and consumed pupae of Pieris rapae (Linnaeus) (Pieridae) in captivity. The aforementioned represent the only previously documented carnivory by Heliothinae. Additional records of carnivorous behavior and the first known occurrence of interfamilial predation by larvae of Helicoverpa are reported herein. On 10 August 2006 an unidentified larva of Noctuidae, determined after eclosion as H. zea, was discovered feeding upon a final instar larva of Cyclargus thomasi bethunebakeri (Comstock and Huntington) (Lycaenidae) (generic nomenclature follows Nabokov 1945) reared within a captive laboratory culture located in J Insect Behav (2008) 21:143–146 DOI 10.1007/s10905-007-9113-0