Coping with drought: diapause plasticity in katydid eggs at high,mid-, and low elevations

1. Semi-arid rangeland productivity is limited by precipitation, and yet droughts are projected to increase in frequency and duration with unknown impacts on insect populations. As some katydids prolong diapause and remain in an egg bank as a blastoderm for multiple growing seasons, is it possible that drought could prolong diapause and promote outbreaks by synchronising embryonic development and hatching of Mormon crickets, Anabrus simplex, after moisture is restored? 2. In this study, a high-elevation Wyoming population (WY) was compared with a mid-elevation Idaho (ID) and a low-elevation Oregon population (OR). It was predicted that eggs from the drier ID and OR habitats would be more tolerant of desiccation. Developmental state and water loss of eggs were measured after drought treatments, and when moisture was restored. 3. The two drier treatments had significantly more WY eggs prolonging diapause until after drought ended compared with the two wetter treatments. Whether WY eggs developed in the second or subsequent warm periods was independent of drought treatments. Significantly fewer OR embryos developed in the driest treatment compared with the others, whereas almost all ID eggs developed irrespective of the drought treatment. 4. In conclusion, Mormon crickets can delay embryonic development to improve drought tolerance. Although drought did not synchronise development and hatching, diapause plasticity allowed insects to cope and await more favourable conditions. 5. Unexpectedly, eggs from WY (the highest, wettest site) were more tolerant, because postponing development resulted in less water loss than in developed embryos. OR egg loss was also reduced by prolonging diapause, relative to ID, which developed in even the driest conditions.     

Twelve novel microsatellite markers for the Great Plains toad,Bufo cognatus

Here I report on 12 microsatellite loci designed for populations of the Great Plains toad (Bufo cognatus) in the deserts of the southwestern USA. Diversity at these loci measured for 134 individuals from four breeding aggregations was relatively high with seven to 34 alleles per locus (mean = 17.8). Observed heterozygosities ranged from 0.444 to 0.949 and expected heterozygosities ranged from 0.597 to 0.951. These markers will be useful for studies of population genetic structure, parentage and relatedness in this explosively breeding amphibian.     

Characterization of expressed sequence tag‐derived microsatellites from the kuruma prawn,Marsupenaeus japonicus

The kuruma prawn, Marsupenaeus japonicus, is a commercially important benthic marine crustacean in East Asia. Understanding the species’ population structures will be very important for its proper stock assessment and management strategy. Herein, 13 polymorphic microsatellite loci originating from expressed sequence tag libraries of M. japonicus were isolated and characterized. Number of alleles per locus ranged from two to 15, observed and expected heterozygosities ranged from 0.250 to 0.906 and from 0.310 to 0.932, respectively. The adequate level of variability within the population renders these microsatellite loci ideal markers for population genetic analysis of M. japonicus.     

Microsatellites for the Neotropical ant,Camponotus leydigi (Hymenoptera: Formicidae)

Ants (Hymenoptera: Formicidae) are dominant social insects that play important ecological roles in terrestrial ecosystems. Camponotus leydigi (Forel) is widely distributed in the Neotropical region and is frequently found in the Brazilian cerrado savanna interacting with plants and other insects. Field observations indicate that C. leydigi has a polydomous nesting habit, but little is known about the genetic relationship among workers. In this study, we identify the first nine microsatellite loci for C. leydigi that will allow further investigation on its genetic diversity. We used a microsatellite-enriched library method. According to this method, repetitive sequences are captured with (CT)₈ and (GT)₈ biotin-linked probes, with subsequent recovery by streptavidin magnetic-coated beads. We observed that eight loci were polymorphic. The mean (± standard error) observed and expected heterozygosities were 0.55 ± 0.23 and 0.73 ± 0.28, respectively. The rarified allelic richness ranged from 1 to 5.32. The polymorphism contents were similar to diversity estimates found in markers previously developed for other Camponotus ants. These markers will be useful for future studies on population genetics and ecology of Camponotus ants in cerrado, including nesting ecology, colony structure, dispersal and conservation.     

Eleven microsatellite markers in Nasonia,Ashmead 1904 (Hymenoptera; Pteromalidae)

We designed primer sequences for 11 microsatellite markers in the jewel wasp Nasonia vitripennis. Most loci could be cross‐amplified in Nasonia longicornis and Nasonia giraulti, which make them amenable for linkage analysis in hybrid crosses. Eight loci were assigned to specific chromosomes. Additionally, 10 loci showed allelic variation in a Nasonia vitripennis field population. The observed number of alleles in this population ranged from two to seven, with observed heterozygosities from 0.0750 to 0.4750.     

Identification and characterization of EST-SSRs and cpSSRs in endangered <Emphasis Type="Italic">Cycas hainanensis</Emphasis>

We report on the identification and characterization of six EST-linked simple sequence repeats (EST-SSRs) and chloroplast SSRs (cpSSRs) in endangered Cycas hainanensis. The number of alleles ranged from two to eight for EST-SSRs, two to three for cpSSRs. Observed and expected heterozygosities ranged from 0.042 to 0.417 and 0.042 to 0.811 for EST-SSRs, respectively. Expected heterozygosities ranged from 0.156 to 0.457 for cpSSRs. All these markers gave successful cross-species amplification in C. fairylakea. These markers will allow analyses of the baseline genetic variability and population structure of C. hainanensis to provide strategies for effective conservation and management. The experiments were carried out in South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, P.R. China.     

Simulated aerial sprays for field cage evaluation of Beauveria bassiana and Metarhizium brunneum (Ascomycetes: Hypocreales) against Anabrus simplex (Orthoptera: Tettigoniidae) in Montana

Field efficacy of the entomopathogenic Ascomycetes Beauveria bassiana strain GHA and Metarhizium brunneum strain F52 was evaluated against nymphs of the Mormon cricket, Anabrus simplex. Fungi were applied with a new apparatus that allows simulated aerial sprays to 0.1-m² areas in the field. The Mormon crickets were then individually housed in cylindrical, metal hardware cloth cages on treated grass. Both fungi demonstrated only marginal success in reducing immature Mormon cricket survival in the field cages. After 28 days, the field mortality of insects, corrected for control deaths, was 28 and 45% for B. bassiana and M. brunneum, respectively. Field-exposed but laboratory-incubated insects, however, suffered 90–100% mortality within 12 days with initial deaths occurring on Day 6 (Beauveria) or Day 5 (Metarhizium), indicating a lethal rate was applied and acquired by the crickets in the field. Potential daily body temperatures were determined for the entire post-treatment observation period using special thermal surrogates. High ambient temperatures and/or thermoregulation by Mormon crickets, in excess of the upper thermal limits of both fungi, prevented higher mortality from being expressed in the field. Thermal surrogates were used to develop models for predicting onset of mortality from infections. The surrogate data indicated mortality should begin between 8 and 26 days after treatment with M. brunneum and 11 and 33 days after treatment with B. bassiana. The timing of mortality in field cages was consistent with the upper boundaries of the temporal models developed from the thermal surrogates, i.e., at or after 28 days after treatment.     

Characterization of microsatellite loci in the aphid species Metopeurum fuscoviride (Homoptera,Aphididae)

Small distance movements are of great importance for the dynamics of local populations of insects and can indirectly be assessed using molecular markers. We isolated six polymorphic microsatellite loci in the aphid species Metopeurum fuscoviride Stroyan, monophagous on the common Tansy (Tanacetum vulgare L.). Twenty‐five to 30 aphids from seven populations were analysed. Between three and 17 alleles were found per locus and expected heterozygosities ranged from 0.14 to 0.79. In total, 114 multilocus genotypes were found in 192 parthenogenetic aphids analysed, indicating that the resolution will be high enough to study differentiation on a small spatial scale.     

EST‐SSR markers from the Pacific oyster,Crassostrea gigas

Ten polymorphic microsatellite repeat markers were identified from Crassostrea gigas, expressed sequence tags (EST) deposited in public sequence database. Number of alleles per locus ranged from three to 18, expected and observed heterozygosities ranged from 0.071 to 0.738 and from 0.306 to 0.913, respectively. Marker transferability was tested on other two Crassostrea species and polymorphic products were detected at nine loci. EST‐derived simple sequence repeats provide robust, informative and potentially transferable polymorphic markers suitable for population genetic, parentage, and mapping studies of C. gigas.     

Experimental control of the Mormon cricket,Anabrus simplex,byNosema locustae [Microspora: Microsporida], a protozoan parasite of grasshoppers [Ort.: Acrididae]

Spores ofNosema locustae Canning were applied with aerial equipment for experimental control of the Mormon cricket,Anabrus simplex Haldeman. The application resulted in infections in crickets during the season of application and the season following application. Spores were observed in cricket feces which indicated probable vertical transmission between generations. Reduced densities of crickets during the second season suggested effective control byN. locustae.     

Development of EST‐SSRs in the Mediterranean blue mussel,Mytilus galloproviancialis

Eight polymorphic microsatellite repeat markers were identified from Mytilus galloproviancialis, expressed sequence tags (EST) deposited in public sequence database. Number of alleles per locus ranged from two to 10, and the observed and expected heterozygosities ranged from 0.029 to 0.872 and from 0.031 to 0.811, respectively. Three additional Mytiloida species assessed for cross‐species amplification revealed four loci could give positive amplifications. EST‐derived simple sequence repeats provide robust, informative and potentially transferable polymorphic markers suitable for population genetic, parentage, and mapping studies of M. galloproviancialis.     

Identification and characterization of microsatellite DNA markers developed in an endangered cyprinid of the Mekong River,the seven‐line barb (Probarbus jullieni Sauvage, 1880)

Microsatellite markers for an endangered cyprinid species of the Mekong River, the seven‐line barb (Probarbus jullieni Sauvage, 1880) were developed from the wild caught samples using (GT)₁₅ probe. The number of alleles per locus ranged from seven to 16. The expected heterozygosities ranged from 0.47 to 0.91. Also, these primers were successfully amplified in the two closely related species, P. labeamajor and P. labeaminor. These markers have proven to be very useful for the population genetic structure study in this species and other related cyprinids.     

Fourteen polymorphic microsatellite loci in the field gudgeon,Gnathopogon elongatus elongatus

We isolated and characterized 14 polymorphic microsatellite loci for the field gudgeon, Gnathopogon elongatus elongatus, a popular freshwater species in streams including agricultural canals in Japan. The number of observed alleles for each locus ranged from 9 to 24, and the values of observed and expected heterozygosities ranged from 0.750 to 1.000 and from 0.832 to 0.953, respectively. These microsatellite markers will be useful for studies of population genetic structure and genetic variability of the field gudgeon.     

Isolation and characterization of polymorphic microsatellite markers in Amorphophallus paeoniifolius (Dennst.) Nicolson,Araceae

Amorphophallus paeoniifolius is an herbaceous perennial tuber crop distributed widely in many Asian countries. We isolated 19 polymorphic loci from A. paeoniifolius using a dual‐suppression‐PCR technique. These loci provide microsatellite markers with high polymorphism ranging from three to 24 alleles per locus. The observed and expected heterozygosities ranged from 0.521 to 0.854 and from 0.766 to 0.930, respectively. This high allelic diversity indicates that our markers are suitable for a population study in A. paeoniifolius.     

Identification of 10 microsatellite loci in the earwig Labidura riparia (Dermaptera,Labiduridae)

Ten microsatellite loci were isolated from the earwig Labidura riparia (Pallas, 1773). The polymorphism of the loci was assessed in 24 individuals from one population. The number of alleles ranged from four to 11 alleles and observed and expected heterozygosities from 0.250 to 0.833 and from 0.551 to 0.861, respectively.     

Development and characterization of 24 microsatellite markers in Primula tosaensis,an endangered primrose,using MiSeq

Primula tosaensis (Primulaceae) is an endangered primrose endemic to Japan. In this study, 24 novel microsatellite markers were developed using Illumina MiSeq sequencing to facilitate conservation of this endangered species. The genetic diversity and polymorphisms of these novel markers were measured in 32 individuals from a wild P. tosaensis population. The number of alleles and expected heterozygosities ranged from 2 to 5 (mean = 2.8) and from 0.119 to 0.724 (mean = 0.395), respectively. All loci were in Hardy–Weinberg equilibrium. The markers developed in this study will provide a powerful and practical tool for investigating the population structure and genetic diversity of P. tosaensis.     

Development and characterization of 30 polymorphic microsatellite markers for the Atlantic surfclam, Spisula solidissima (Dillwyn, 1817)

Thirty polymorphic microsatellite markers were developed for the Atlantic surfclam, Spisula solidissima, from an enriched library and characterized in 24 clams from a wild population. The number of alleles ranged from 3 to 16 per locus. The expected and observed heterozygosities ranged from 0.1942 to 0.9238 and 0.0833 to 0.875 respectively. Six loci showed significant (P < 0.05 after Bonferroni correction) deviation from Hardy–Weinberg equilibrium, probably because of the presence of null alleles. Three primer pairs amplified duplicated loci with two involving tandem mini‐satellite repeats. Most of the microsatellite markers developed here should be useful for genetic studies in this species.     

Isolation, characterization and cross-species amplification of polymorphic microsatellite loci in Asclepias (Apocynaceae)

Ten polymorphic loci were isolated and characterized from the milkweed, Asclepias syriaca L., of North America. These loci successfully cross-amplified in A. exaltata L. Polymorphism ranged from two to 16 alleles per locus per species in 68 individuals of A. syriaca and 56 individuals of A. exaltata. Expected heterozygosities ranged from 0.017 to 0.851 and significant deviations from Hardy–Weinberg equilibrium were found for two and three loci in A. syriaca and A. exaltata, respectively. No linkage disequilibrium was detected. These markers should prove useful for assessing population genetic structure and interspecific gene flow in these and other species of Asclepias.     

Isolation and characterization of eight microsatellite loci in the mangrove mud‐nesting ant,Polyrhachis sokolova

We isolated and characterized eight anonymous microsatellite loci in the mangrove mud‐nesting ant, Polyrhachis sokolova. Three to 18 alleles were detected in 20 female workers collected from individual colonies at one location and observed heterozygosities ranged from 0.45 to 0.85. These microsatellite loci will be useful in studies on mating strategy, colony and population structure in P. sokolova.