Opportunistic foraging by the kangaroo rat Dipodomys deserti Stephens (Rodentia: Heteromyidae)

The kangaroo rat, Dipodomys deserti Stephens, was observed capturing and killing insects that were flying about an ultraviolet lamp. The white-lined sphinx moth, Hyles lineate (F.), and the carrot beetle, Bothynus gibbosus (DeGeer), were put into the cheek pouches and carried away from the collection area.     

Summer burrows of Ord's kangaroo rats ( Dipodomys ordii ) in western Nebraska: food content and structure

Extent of larder hoarding differs among species of kangaroo rats, and limited information is available for food stored in burrows by Ord’s kangaroo rat ( Dipodomys ordii )—the most widespread species of Dipodomys. I excavated 9 burrows recently used by adult D. ordii during summer in the Sandhill Region of Nebraska. I observed only small quantities of food stored in burrows. Eight of 9 burrows contained segments of sand dropseed ( Sporobolus cryptandrus ) in limited quantities. These segments consisted of upper leaves with fruits (containing seeds) housed in sheaths. My observations represent the first documentation of D. ordii storing food in burrows under natural conditions. Compared to the burrows of other species of kangaroo rat, burrows of D. ordii were simple in structure with 1 main tunnel and 1–3 entrances. In summer, Ord’s kangaroo rats commonly harvest seeds from plants in the Sandhill Region of Nebraska, but individuals apparently do not store large quantities of food in burrows, which suggests they store food in scatter hoards during this season.     

The banner-tailed kangaroo rat, Dipodomys spectabilis (Rodentia: Heteromyidae), in Utah

We report the discovery in Utah of Dipodomys spectabilis, a species previously unknown to occur in the state. We searched for D. spectabilis in extreme southeastern Utah, south of the San Juan River, and were successful in finding mounds and burrows characteristic of the species and in capturing one individual. This is the northernmost record for D. spectabilis and extends its known range ~84 km northwest of the nearest previously reported locality (Fruitland, San Juan County, New Mexico). A flea, Meringis rectus, collected from D. spectabilis, is also the first record of its species in Utah. Reportamos el descubrimiento en Utah de Dipodomys spectabilis, una especie cuya presencia en el estado no había sido observada previamente. Buscamos D. spectabilis en el extremo sureste de Utah, al sur del Río San Juan, y logramos encontrar montículos y túneles típicos de esta especie y capturar un espécimen. Este es el registro más al norte para D. spectabilis y se extiende su rango de distribución conocida a ~84 km al noroeste de la localidad más cercana previamente reportada (Fruitland, condado de San Juan, Nuevo Mexico). Es también el primer registro en Utah para Meringis rectus, una pulga recolectada en D. spectabilis.     

Occurrence of Ord's kangaroo rat ( Dipodomys ordii ) along its eastern distributional limit in Nebraska

Changes in land use continue to alter habitats throughout Nebraska, and few studies have examined how such changes affect distributional limits of mammals. The distribution of Ord’s kangaroo rat ( Dipodomys ordii ) was last examined in eastern Nebraska about 4 decades ago. We examined the current eastern distributional limits of D. ordii to see whether its range had expanded, contracted, or remained constant in the state since the 1960s. Based on our study, kangaroo rats have experienced little change in distribution during recent decades. Herein, we report on data for 8 counties without prior records and a marginal range extension, as well as comment on habitat, reproduction, and taxonomic status of kangaroo rats in eastern Nebraska. Los cambios en el uso del suelo siguen modificando los hábitats a lo largo del estado de Nebraska, y pocos estudios han examinado cómo estos cambios afectan los límites de distribución de los mamíferos. La última evaluación de la distribución de la rata canguro de Ord ( Dipodomys ordii ) en el este de Nebraska se llevó a cabo hace 4 décadas. Examinamos los límites orientales actuales de la distribución de D. ordii para ver si su área de distribución se ha expandido, contraído o permanecido igual en el estado desde los años 1960. Con base en nuestra investigación, es posible decir que la distribución de las ratas canguro ha cambiado poco en décadas recientes. Aquí reportamos datos para 8 condados para los cuales no existían registros anteriores e informamos sobre una pequeña expansión de su área de distribución. También comentamos sobre el hábitat, la reproducción y la situación taxonómica de las ratas canguro en el este de Nebraska.     

Growth of Dipodomys ordii (Rodentia: Heteromyidae)

Growth rates were determined for laboratory - reared Dipodomys ordii pallidus Durrant & Setzer. Instantaneous growth rates were used to express increase of body weight, total length, tail length, ear length and hind foot length as rates between times of measurements and the instantaneous percentage of maximum size. Data were analyzed for growth periods of 1 – 3, 4 – 15, 16 – 29 and 30 – 70 days. All five parameters provided significant correlations of growth with age during all growth periods. Even though all of the growth parameters correlate with age, these parameters cannot be reliably used to predict age.     

Figs (Ficus spp.) and fig-wasps (Chalcidoidea)

Summary

The host plant, trichobothria, male and female genitalia of Lestonia haustorifera China are discussed. The family Lestoniidae is closely related morphologically to the Plataspidae, more distantly related to the Scutelleridae, and unrelated to the Aphylidae.     

Caligids (Copepoda: Caligidae) found on the bream (Acanthopagrus spp.) of Australia

Eleven species of parasitic caligid copepods were recorded from approximately 1000 specimens of four congeneric species of Australian bream. New species were described and previously recorded species redescribed where necessary. Those caligids recovered in large numbers were liberal in choice of host species and displayed a wide geographical range within Australia.     

Fleas (Siphonaptera) in nests of boles ( Microtus spp.) in montane habitats of three regions of Utah

As a parallel study of a survey of fleas of trapped small mammals in montane southern Utah, we removed 77 adult fleas from 12 of 13 nests of voles ( Microtus longicaudus, M. montanus and M. richardsoni ) collected from montane meadows in the Abajo and La Sal Mountains, the Markagunt Plateau and Pine Valley Mountains, and the Uinta Mountains, May 1991-July 2002. Six species and subspecies of fleas parasitic on Microtus spp. were found, 1-3 species in each nest. Three specimens of the ubiquitous deer mouse ( Peromyscus spp.) flea Aetheca wagneri (Baker) were also found. We collected the following 7 taxa from the locations indicated: Catallagia decipiens Rothschild in 5 nests: Abajo and Pine Valley Mountains and Markagunt Plateau; Hystrichopsylla dippiei truncata Holland in 2 nests: La Sal and Uinta Mountains; H. occidentalis sylvaticus Campos & Stark in 5 nests: Pine Valley Mountains; Peromyscopsylla selenis (Rothschild) in 1 nest: Markagunt Plateau; A. wagneri in 2 nests: Abajo and Pine Valley Mountains; Megabothris abantis (Rothschild) in 5 nests: Abajo and Uinta Mountains and Markagunt Plateau; Malaraeus telchinus (Rothschild) in 2 nests: Abajo and Pine Valley Mountains. One preserved larva was identified as Hystrichopsylla prob. occidentalis sylvaticus , and 2 dead larvae, the only specimens found in nest 13, were identified as probably the same. Kane County is a new record for C. decipiens and P. selenis ; Kane and Summit Counties are new for M. abantis . Nest surveys can generally supplement rather than replace trapped-host surveys. Their main value is in population studies. They are also a source of larvae for morphology and taxonomy research.     

Population variation of web-invading spiders (Theridiidae: Argyrodes spp.) on host webs in Guam,Mariana Islands,Micronesia

Most Argyrodes spiders live in the webs of other spiders as kleptoparasites, stealing food from the host and scavenging small prey from the web. We observed three species of Argyrodes from the Micronesian island of Guam to learn (1) if Argyrodes species differ in their use of host-species webs, (2) whether some Argyrodes species occur more often in certain habitats, (3) whether population size of Argyrodes is a function of web size, and (4) how the presence of congeners affects population size on a web. Argyrodes lived most often in the large, long-lasting orb webs of Argiope appensa and Cyrtophora mollucensis, and, rarely, in the smaller, less durable orb webs of Neoscona spp. and Leucauge spp. Argyrodes argentatus and Argyrodes sp. A frequently co-occurred in Argiope webs, but A. argentatus was more common in beach strand and open disturbed habitats, while Argyrodes sp. A was more common in shaded native forest. The abundances of A. argentatus and Argyrodes sp. A in Argiope webs and the abundance of Argyrodes sp. B in Cyrtophora webs were positively correlated with the areas of the webs' prey-catching surfaces. The abundance of A. argentatus was inversely proportional to that of Argyrodes sp. A on Argiope webs and to that of Argyrodes sp. B on Cyrtophora webs, suggesting interspecific avoidance.     

Dominance relationships of the dark kangaroo mouse ( Microdipodops megacephalus ) and the little pocket mouse ( Perognathus longimembris ) in captivity

Interspecific interactions between the little pocket mouse ( Perognathus longimembris ) and the dark kangaroo mouse ( Microdipodops megacephalus ) were tested in the laboratory. P. longimembris was statistically dominant over M. megacephalus. The dominant - subordinate relationships shown by our laboratory results indicate that interspecific aggression may be one mechanism involved in keeping these sympatric species ecologically separated.       

Flowers,faeces and cadavers: natural feeding and laying habits of flesh flies in Thailand (Diptera: Sarcophagidae,Sarcophaga spp.)

Baiting and flower watching mainly in forest habitats throughout Thailand (1997–2002) yielded 46 species of Sarcophaga Meigen. About 50% of the species are new to Thailand and several new to science. All 67 species of Sarcophaga so far reported from Thailand are listed and their taxonomic status and nomenclature updated. Emphasis on rearing (523 broods) ensured species identification through the male progeny of the otherwise mostly unidentifiable females, and allowed several new correct male–female associations, besides offering new insights into the flies' breeding strategies. Three natural larviposition habits were observed in the wild: (1) on faeces of carnivorous and omnivorous, but not herbivorous, mammals (coprobiodotic), e.g. S. africa (Wiedemann), S. albiceps Meigen, S. misera Walker; (2) on cadaver (necrobiodotic), e.g. S. krathonmai Pape and Bänziger, S. nathani (Lopes), S. saprianovae Pape and Bänziger; and (3) on both of them (amphibiodotic), e.g. S. dux Thompson, S. ruficornis (Fabricius). However, larvae of copro- and necrobiodotic species experimentally transferred to cadaver and faeces, respectively, also developed to normal adults. The unexpected laying choosiness between excrement or carrion in the wild is discussed, together with the role played by laying habits in deceptive pollination systems and myiases.     

Occurrence, persistence, and expansion of saltcedar ( Tamarix spp.) populations in the Great Plains of Montana

Saltcedar ( Tamarix spp.), a shrub native to Eurasia, is associated with major alterations to wetland and riparian systems in the southwestern United States. Since the 1960s saltcedar has been naturalized in northern states of the U.S. where its growth potential and impacts are not well known. Here, we describe the occurrence, age, size, and relative cover of saltcedar populations in several river basins in central eastern Montana, USA, to identify potential patterns of spread across the region and changes in individual populations as they age. Stands were aged according to the oldest saltcedar individuals and were sampled for dominant plant cover and soil properties. Multiple introductions appear to have occurred in Montana, with the oldest stands occurring on the Bighorn River in southern Montana. Saltcedar absolute and relative cover and stand area increased significantly with stand age, while native tree and shrub relative cover remained low across all stand ages. These results suggest that saltcedar stands establish where woody natives are not abundant and that they persist and expand over time. Although soil salinity remained constant, soil pH decreased with saltcedar stand age, indicating a possible effect of organic matter inputs. An analysis of annual wood increment of saltcedar and sandbar willow (a native with analogous growth form) stems along a latitudinal gradient showed that stem growth of both species did not differ significantly among regions. Stem growth decreased inversely with elevation for both species while growth responses to elevation did not differ between species. Our results show an increase in number of populations and continued viability of these populations. Mechanisms of saltcedar increases in this region are yet to be determined. Anthropogenic influences, such as saltcedar plantings, watershed alterations (e.g., river flow control), and habitat disturbances (e.g., cattle grazing or habitat clearing) may facilitate its spread in similar climates of the Great Plains.     

Weevil (Coleoptera: Curculionoidea) seed-predators of Syzygium and Eugenia spp. (Myrtaceae), with description of the Alcidodes expansitarsis species group (Coleoptera: Curculionidae: Molytinae: Mecysolobini)

The weevils known to develop in Syzygium and Eugenia (Myrtaceae) fruit are reviewed. These weevils belong to the genera Curculio, Alcidodes, Acythopeus, Apotomorhinus (Curculionidae: Curculioninae, Molytinae and (the last two) Baridinae respectively) and Sitophilus (Dryophthoridae) in the Old World, and Atractomerus (Curculionidae: Anthonominae) in the Neotropics; two undescribed baridine species (one in Australia and the other in the USA) are also known to feed on the fruits, and the Omophorine Teleuropus (Curculionidae: Molytinae) has been found associated with them. Particular attention is paid to species of Alcidodes from aseasonal dipterocarp-dominated forests in South-East Asia. Two Bornean species (Alcidodes janetae sp. n. and A. eugeniophilus sp. n.) are the first of their genus to be reared from the fruit of Syzygium or Eugenia. These species, plus two other (A. expansitarsis sp. n. from Assam, Myanmar, Cambodia and Laos, and A. gymnasticus sp. n. from Malaysia) belong to a previously undescribed species group of Alcidodes; all four species are described and keyed.     

Individual and geographical variation in the stridulatory file of Omocestus viridulus (L.) (Orthoptera: Acrididae)

Summary

Samples of male specimens of Omocestus viridulus from 14 European countries were used to study the individual and geographical variation in the characters associated with the stridulatory file. Significant overall variation between the samples was demonstrated for the length of file, average density of pegs, length of hind femur and ratio of file length to hind femur length.

This variation was found to be significantly correlated with several environmental factors, particularly annual range of temperature and amount of precipitation. These factors were considered to be good indicators of continentality, specimens from more continental regions having longer hind femora and longer files with a lower density of pegs. File length was found to be inversely correlated with amount of precipitation even when considered as a proportion of the hind femur. Number of pegs was also found to be inversely correlated with precipitation. In showing that femur length and file length increase and density decreases with continentality, the results agree with those of my previous study (Pitkin, 1976), in which British samples were found to have shorter femora and shorter files with a greater density of pegs than German samples.

The present study, while establishing that the stridulatory file varies geographically, does not deny its usefulness as a taxonomic tool, particularly when it is used in combination with other characters. When stridulatory characters are used on their own, individual and geographical variability within the species must clearly be taken into account.     

Generalist hymenopteran parasitoids of the leaf-miner Chromatomyia fuscula (Zett.) (Dipt.: Agromyzidae)

In southeastern Norway, by the last week of June (1992), 48%of Chromatomyia fuscula emerged, based on the number of mines collected from Hordeum vulgare leaves. Among the parasitoids Diglyphus begini was the dominant species, but Cirrospilus vittatus and Neochrysocharis aratus also emerged in significant numbers. During June and July, N. aratus was the dominant species in the 1st and 2nd leaves, but D. begini was dominant in the 4th to 6th leaves. C. vittatus and Cyrtogaster vulgaris affected all larvae of the leaf-miner fly, living on various leaves. In central Norway, 48% of C. fuscula also emerged. C. vulgaris and D. begini were the dominant parasitoids and C. vittatus was also found. C. fuscula has no specialist parasitoids. Adults of the generalist parasitoids of the leafminers always search for different hosts. In investigation of the parasitoid complex of a lepidopteran leaf-miner, Phyllocnistis labyrinthella (living in Populus tremula leaves at the edge of the examined barley field), three shared parasitoids (C. vittatus, Pnigalio soemius and Pnigalio pectinicornis) were found. The complex network of host plant-phytophagous insect-insect parasitoid-facultative hyperparasitoid relationship is discussed.