Showing papers in "Journal of the Kansas Entomological Society in 2019"
TL;DR: The essential oils isolated from the different ecotypes of C. cyminum showed to be promising candidates for S. cretica management, and the decreasing haemocyte counts were found to be significant in the different Ecotypes of cumin essential oil.
Abstract: In this research, the effects of essential oils isolated from four ecotypes of cumin (Cuminum cyminum L.) Northern-Khorasan (NS), Fars (FS), Kerman (KK), and Kerman (KR) were evaluated on the 4th instar larvae of pink stem borer, Sesamia cretica Lederer. The essential oils were extracted from seeds and the chemical composition was assessed via Gas Chromatography-Mass Spectrometry (GC-MS). Cuminaldehyde (43.599-55.939%), γ-terpinene (13.134-21.750%), m-cymene (8.349-16.935%), s-pinene (6.320-14.130%), and α-phellandrene (2.137-4.742%) were the main components of the essential oils. Four types of blood cells: prohaemocytes, plasmatocyte, granulocyte, and oenocytoid were identified in the haemolymph of the 4th instar larvae of S. cretica. The decreasing haemocyte counts were found to be significant in the different ecotypes of C. cyminum essential oil. The utilized concentrations and specified times had significant effects on the reductions of the mentioned cell numbers. The fewest number of cells for all ecotypes was measured after 48 h. The highest decline in the total haemocyte count was related to the concentration of 8000 ppm in NS ecotype. The lowest LC50 value was observed in KR ecotype. Based on the results of the present study, the essential oils isolated from the different ecotypes of C. cyminum showed to be promising candidates for S. cretica management.
4 citations
TL;DR: This study investigates the expression of odorant-binding protein genes and chemosensory protein genes in different tissues of the adult and other developmental stages of Anomala corpulenta and finds the antenna had the highest expression levels for OBPs and CSPs of all tissues, except for OBP7 which was most highly expressed in the head without antenna.
Abstract: Anomala corpulenta is an insect pest that is widely distributed in China, and it can cause large economic losses in agriculture, horticulture, and forestry. It is difficult to control because most of the lifecycle is underground. Trapping adults would be an environmentally sustainable way to reduce damage caused by this insect. Odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) are considered to be important chemodetection proteins. In this study, we investigate the expression of odorant-binding protein genes and chemosensory protein genes in different tissues of the adult and other developmental stages. The antenna had the highest expression levels for OBPs and CSPs of all tissues, except for OBP7 which was most highly expressed in the head without antenna. Besides the antenna, the head without antenna had the next highest expression levels for all OBP and CSP genes. The expression of OBP2, OBP3, OBP14, and CSP in the adult was higher than in other stages, while, OBP7 was lower than in other stages. Before estimating the expression of OBPs and CSPs, seven candidate reference genes were tested for stability among the tissues of adult and other development stages. GAPDH was the best reference gene in different tissues of the adult, and RPL13a was the best reference gene in different development stages. Our results provide a foundation for further research on the molecular aspects of chemical communication of this insect.
3 citations
TL;DR: In 25 attacks observed over several years in the field in the Valle Central of Costa Rica, Polysphincta gutfreundi showed great flexibility, and few of the spider's defensive traits were effective against these wasps.
Abstract: Wasps of the Polysphincta clade are known to manipulate the behavior of their web-building spider hosts by injecting psychotropic chemicals, but the methods they use to hunt spiders are poorly documented. In 25 attacks observed over several years in the field in the Valle Central of Costa Rica, Polysphincta gutfreundi showed great flexibility. Wasps employed three basic hunting tactics to subdue the host spider Allocyclosa bifurca: strike the spider at its resting site at the hub of its orb web; land in the sticky spiral of the web, struggle, and then attack the spider when it approached; and wait immobile at the hub to await the return of a spider that had fled. The wasps moved and oriented agilely on their hosts' orbs. The only repeatedly effective spider defense was to drop immediately from the web and remain away for many minutes. Parasitism was strongly clumped spatially, suggesting that female wasps may learn where to hunt. Nearly all the details of P. gutfreundi attack behavior have also been observed in other species of the Polysphincta clade. They include the use of multiple attack strategies, surprise attacks from the air on spiders resting on their webs, attacks through the hub, agile movements on the spider's web, inducing the spider to approach by apparent imitation of prey, waiting for long periods in the web poised to strike, and inserting the ovipositor into the anterior end of the spider's cephalothorax. One unique detail of attack behavior in P. gutfreundi was to shuttle rapidly to the other side of the hub to reach the spider. Few of the spider's defensive traits were effective against these wasps. Species in the Polysphincta group are behaviorally flexible, but as a group these wasps utilize relatively uniform tactics to subdue their hosts.
3 citations
TL;DR: It was concluded that the loss in 1000-grain weight reached 10.9% and appropriate control measures should be taken against stem sawflies in high-infestation locations.
Abstract: The European wheat stem sawfly, Cephus pygmeus (Linnaeus, 1767) and the black grain stem sawfly, Trachelus tabidus (Fabricius, 1775) are important and common pests in wheat growing areas of Turkey. These sawfly species continue to be a threat to wheat production in the southeast Anatolia Region of the country. This study was conducted to determine larval infestation rates and yield losses caused by these sawfly species in common wheat cultivars grown in the southeast Anatolia Region. Durum and bread wheat fields were surveyed to record larval infestation and damage caused by these sawfly species in four provinces (Adiyaman, Diyarbakir, Mardin and Sanliurfa) of the region. A total 100 wheat fields were randomly selected and stem samples were taken from each field during the harvest period. Spike length, mean number of grains, grain weight and 1000-grain weight were recorded from 100 infested and healthy spikes and crop losses were calculated for 16 wheat cultivars.The surveyed provinces significantly differed in infestation rates, with the highest infestation level recorded for Diyarbakir province with a mean of 17.4% (range 2.1- 54.3%), while the minimum infestation was determined in Adiyaman province with a mean of 5.3% (range 1.4-17.3%). Durum and bread wheat cultivars had negligible effects on larval infestation. Spike length of infested wheat plants was reduced by 0.9-14.4% and the mean number of grains and grain weight were reduced by 0.5-19.7% and 7.2-28.5%, respectively. The loss in 1000-grain weight was 8.9% in bread wheat cultivars, while the loss was 7.9% in durum wheat cultivars. It was concluded that the loss in 1000-grain weight reached 10.9%. Therefore, appropriate control measures should be taken against stem sawflies in high-infestation locations.
3 citations
TL;DR: Resistance ratio data revealed that usage of pesticides has led to resistance in the psylla population of Rafsanjan and the Anar population was the most susceptible based on the LC50 ratios of insecticides.
Abstract: The common pistachio psylla, Agonoscena pistaciae Burckhardt and Lauterer is a key pest throughout all pistachio producing regions of Iran. Pest management depends primarily on the application of chemical insecticides. The lack of compatibility between natural enemies and pesticides is the main concern to ecologists in the integrated management of psylla. The susceptibility of the fifth instar nymphs of A. pistaciae from five populations of the Kerman province and third instar larvae of the lady beetle species, Oenopia conglobata L., were examined against three commonly used insecticides: acetamiprid, spirotetramat and hexaflumuron, using the spraying tower method. Probit regression analysis was conducted on mortality data at various insecticide concentrations using the POLO-PLUS program to estimate LC50 values. Resistance ratio data revealed that usage of pesticides has led to resistance in the psylla population of Rafsanjan. The results showed that the Rafsanjan psylla population (with LC50 values of 40.55, 43.65 and 95.10 mg a.i. L-1, for acetamiprid, spirotetramat and hexaflumuron, respectively) was the most resistant and the Anar population (with LC50 values of 11.92, 24.13 and 81.06 mg a.i. L-1 for acetamiprid, spirotetramat and hexaflumuron, respectively) was the most susceptible based on the LC50 ratios of insecticides. The LC50 values of acetamiprid, spirotetramat and hexaflumuron for the coccinellid predator O. conglobata in the Rafsanjan population were estimated to be 8.76, 5218.33 and 2268.81 mg a.i. L-1, respectively. The predator was more susceptible to acetamiprid and more tolerant to spirotetramat and hexaflumuron than the psylla A. pistaciae.
3 citations
TL;DR: The development of artificial diet can play an important role in sustaining the whole life cycle of A. coquebertii and allow the commercial production of this predator in the absence of its natural prey for biological control of D. keonigii as well as for research and development.
Abstract: Antilochus coquebertii Fabr is an important predator of the red cotton stainer (Dysdercus koenigii) in agricultural crops. The present study explores the development of A. coquebertii reared on three different artificial diets to enhance the efficiency of development and commercial production of this predator. Three artificial diets were prepared from the essential ingredients necessary for the insect's development and reproduction and tested under controlled conditions. The results showed that of all diet ingredients; both chicken liver and Nestle® bonyad provided a rich source of vitamin E, and efficiently supported the insect's fecundity and survival. The solid chicken liver (SCL) diet No. 3 showed good adult survival while adult longevity was enhanced with diet No. 2 containing chicken liver paste (CLP). Collectively, both diets, No. 2 (CLP) and No. 3 (SCL) were significantly effective in promoting the predator's development. The development of artificial diet can play an important role in sustaining the whole life cycle of A. coquebertii and allow the commercial production of this predator in the absence of its natural prey for biological control of D. keonigii as well as for research and development.
3 citations
2 citations
TL;DR: It is concluded that different food essences can enhance the capability of methyl eugenol to attract the fruit flies.
Abstract: This study was designed to use different food additives to improve the efficacy of the Male Annihilation Technique (MAT) against fruit flies. The experiment was carried out at the Jujube Section, Agriculture Research Institute, Tandojam, Pakistan, during the beginning of jujube season (January to April) 2017. Methyl eugenol was tested in the presence of different food essences i.e. lemon (T1), strawberry (T2), almond (T3) and orange (T4), whereas; methyl eugenol (T5) without any essence was used as control. The experiment was laid out in a randomized complete block design (RCBD) with four blocks. Two fruit fly species; Bacterocera zonata and B. dorsalis were identified from the captured individuals. Our data revealed that the mean number of B. zonata collected was 1914.88, while the mean number of B. dorsalis collected was 148.69. The most efficient trap was T1 (Methyl eugenol + lemon essence), whereas; the lowest number of captures was observed at control traps. Furthermore, the highest numbers of flies from both species were recorded during the month of April, while the lowest number of captures was observed in January. The highest number of B. zonata and B. dorsalis were 334.14±9.39 and 17.25±0.75, respectively. In terms of treatment, the highest number of B. dorsalis was recorded with the lemon flavor (46.68); whereas, the lowest was observed in the control (17.02). There was a positive association between temperature and wind velocity for both B. zonata and B. dorsalis, whereas there was negative association with humidity. On the basis of the above mentioned results it is concluded that different food essences can enhance the capability of methyl eugenol to attract the fruit flies.
2 citations
TL;DR: Results of the study suggest that while larvae move readily, they have minimal ability to avoid localized xeric soil micro-climatic conditions through movement, however, they will select less stressful moist soil environments.
Abstract: Laboratory experiments were conducted to determine larval movement of the spotted wing drosophila (Drosophila suzukii Matsumura). Movement of larvae outside of the wild blueberry fruit (Vaccinium angustifolium Aiton) can occur after exhausting fruit food resources pri- or to completion of development or just prior to pupation. We found that when provided a choice larvae select moist compared to dry environments both in plastic arenas providing only filter paper for shelter and in a soil filled petri dishes. Movement was usually limited to less than 7.5 cm in the soil from a release point. An exponential decay model suggests that only 0.1% of a larval population will move as far as 17.5 cm. Results of our study suggest that while larvae move readily, they have minimal ability to avoid localized xeric soil micro-climatic conditions through movement. However, they will select less stressful moist soil environments.
2 citations
TL;DR: Aluminum foil bags and vacuum-sealed plastic bags offered the best protection against T. castaneum adults when released on packaged wheat flour, and damage to the packaging materials along the edges or on the upper surfaces was observed in non-woven cloth bags and plastic compound bags.
Abstract: The influence of packaging materials on infestation by Tribolium castaneum (Herbst) in wheat flour was investigated under laboratory conditions at 27 ± 2and 75 ± 5% relative humidity. The tested packaging materials included vacuum-sealed plastic bags, aluminum foil bags, non-woven cloth bags, kraft paper bags, and plastic compound bags. When T. castaneum adults were released on packaged wheat flour, the degree of infestation varied depending on the packaging materials. The highest infestation was observed in refined wheat flour packaged with plastic compound bags (mean 46 ± 20 insects). For the flour packaged with non-woven cloth bag and kraft paper bags exposed to adults, insect infestation was nil or negligible (mean population < 3 ± 1 insects). For the flour packaged with aluminum foil bags and vacuum-sealed plastic bags exposed to adults, insect infestation was nil. Damage to the packaging materials along the edges or on the upper surfaces was observed in non-woven cloth bags and plastic compound bags. Aluminum foil bags and vacuum-sealed plastic bags offered the best protection against T. castaneum adults.
2 citations
TL;DR: Investigation of how urban bee-flower knowledge could be used to attract native bees to farms in Brentwood, Contra Costa Co. in Northern California yielded several findings, including that maintaining frequent professional contact with growers was considered crucial in conducting research over the long term.
Abstract: In 2009 the USDA-NRCS asked the Urban Bee Lab at the University of California, Berkeley if urban bee-flower knowledge could be used to attract native bees to farms in Brentwood, Contra Costa Co. in Northern California. The overarching question was, could native bees play a role in supplementing honey bees by providing pollination services for crop flowers? If so, how many native bee species were visiting farms and how frequently did they occur?Eight small farms (4-60 ha) were selected to investigate this question; four were control and four were treatment farms where bee habitat gardens were constructed. Habitat gardens were stocked with native and non-native ornamental plants known to attract native bees (and honey bees).Bees were monitored yearly in spring at each farm from 2010-2016 to evaluate species richness and abundance, which yielded several findings:I. Farms near urban areas and a creek were consistently more attractive to diverse and abundant bee speciesII. Inconsistent bee garden maintenance and major changes in farm operations in other farms resulted in consistently lower measurements of bee richness and abundanceIII. Over the seven-year monitoring period, 144 bee species were recorded among all farmsIV. Nearby urban areas had most of the same species as the agricultural areas, suggesting a relationship of bees moving between two areasV. A total of 23 diverse native bee species were recorded from apple, berry, and cherry flowers, and many of them in substantial numbers, indicating that native bees were providing pollination servicesFinally, maintaining frequent professional contact with growers was considered crucial in conducting research over the long term. These contacts were also critical in designing outreach packages to growers who expressed interest in applying our native bee findings to their farming operations.
TL;DR: The results provide an important clue to solve the following problem: How do ZnT and ZIP genes efficiently maintain zinc homeostasis in response to zinc changes at an individual level rather than a single cell?
Abstract: We conducted a series of experiments to determine how ZIP (Zip7, Zip10 and Zip13) and ZnT (ZnT1, ZnT2 and ZnT7) genes are regulated by over-supply and depletion of zinc in different body tissues. Each tissue showed a specific pattern rather than a unified pattern for zinc changes. The resulting data provide an important clue to solve the following problem: How do ZnT and ZIP genes efficiently maintain zinc homeostasis in response to zinc changes at an individual level rather than a single cell?
TL;DR: It is demonstrated that blue vane traps are an effective method of trapping bees and their results demonstrated that they are also effective in attracting some families of anthophilous Coleoptera and Diptera.
Abstract: The economic value of insect pollination to the world economy is tremendous, and pollination service is critical for our food supply and persistence of native plants. Little data are currently available on pollinator occurrence in the Southern High Plains (SHP) of Texas. Past studies on hybrid cottonseed production in the region documented high abundance of six species of Agapostemon and lower abundance of Diadasia spp., Melissodes spp., and Perdita spp. Historical records indicated the presence of Bombus fraternus and B. pensylvanicus which now have Endangered and Vulnerable IUCN status respectively. In 2013 and 2014, we used blue vane traps and targeted netting to collect insect pollinators and anthophiles on the three dominant land uses in the region; cropland, Conservation Reserve Program (CRP), and native grasslands. With capture methods combined, we collected 74,215 insect specimens; 63% of the specimens were Hymenoptera (289 taxa), 28.61% were Coleoptera (150 taxa), 4.48% were Diptera (115 taxa), 2.34% were Lepidoptera (60 taxa), and 1.61% were of other orders (15 taxa). Our capture included all previously documented bee genera, but we did not detect B. fraternus. Studies support that blue vane traps are an effective method of trapping bees and our results demonstrated that they are also effective in attracting some families of anthophilous Coleoptera and Diptera. However, we captured several species of Hymenoptera, Diptera, and Lepidoptera with aerial nets that we did not capture in blue vane traps. This study documents pollinator and anthophile species present in a highly altered landscape and is the most comprehensive list of pollinators and anthophiles in this region to date.
TL;DR: Two EOs, wintergreen and peppermint, demonstrated effective toxicity to L. reclusa and may have potential as alternatives to synthetic pesticides for this pest, warranting further investigation.
Abstract: There are several species of spiders in the midwestern United States that cohabit with humans, but probably the most concerning is the brown recluse spider, Loxosceles reclusa, (Araneae: Sicariidae) because of the potential for a venomous bite. Thus, managing the brown recluse spider is a continuous endeavor. Essential oils (EOs), i.e. specific plant extracts, have often been used to control or deter other arthropods and pests. In this study, several EOs were selected to test their effectiveness as alternatives to synthetic pesticides for L. reclusa control. Spiders were exposed to EOs by direct contact or as a fumigant (inhalation) treatment for 24 h, and mortality was recorded. Physical contact with the oils resulted in the greatest mortality, with wintergreen, peppermint and lavender to a lesser extent, showing potential for L. reclusa control. Mortality attributed to lemon, lemongrass or wild orange was too low to provide effective reduction of L. reclusa populations. Fumigants (inhalation) caused less mortality than contact treatments, never resulting in more than 20%. Two EOs, wintergreen and peppermint, demonstrated effective toxicity to L. reclusa and may have potential as alternatives to synthetic pesticides for this pest, warranting further investigation.
TL;DR: A huge, adult butterfly feeding aggregation of thousands of individuals in seven species, dominated by Asterocampa celtis (northern-race Hackberry Emperor), occurred in Douglas and Jefferson Counties, Kansas in June 2015, and provides new adult food records obtained from eight of the butterfly species in the aggregations.
Abstract: In June 2015, a huge, adult butterfly feeding aggregation of thousands of individuals in seven species, dominated by Asterocampa celtis (northern-race Hackberry Emperor), occurred in Douglas and Jefferson Counties, Kansas. This aggregation differed in species composition from smaller aggregations in the same observation area in 1970–1971. A rare A. celtis melanic form was in both the 1970 and 2015 aggregations. Vehicles killed thousands of butterflies in the 2015 aggregation. This study also summarizes data on local population sizes of A. celtis and Asterocampa clyton (Tawny Emperor) in the U.S. and provides new adult food records obtained from eight of the butterfly species in the aggregations.
TL;DR: It may be opined that the expression of HSP has a protective role in H. theivora during host switching when reared on in the primary host tea and its alternative host, Duranta.
Abstract: The tea mosquito bug (Helopeltis theivora) is a polyphagous pest, which is associated with a wide range of host plants, including dozens of families. Feeding on different plant species exposes the insects to diverse phytochemicals. The heat shock proteins (HSP) that are abundantly expressed in insects are important modulators of insect survival and expressed in response of various stress conditions such as abiotic stress and biotic stress. In this study, we compared the expression of HSPs in H. theivora when reared on in the primary host tea (Camellia sinensis) and its alternative host, Duranta (Duranta repens). While comparing the host-based variation, HSP70 was expressed more in Duranta than on tea-reared H. theivora, whereas there is no significant difference in HSP90 on both hosts. From the present investigation it may be opined that the expression of HSP has a protective role in H. theivora during host switching.
TL;DR: This paper reports on the death feigning behavior of B. metallicus and provides a review of the literature on this little studied group of beetles.
Abstract: Despite the tenebrionid genus Blapstinus being species rich with 91 described species in North America, individual beetles are not commonly observed. We collected Blapstinus metallicus (Fab.) in Maine wild blueberry fields in 2012 and in a Massachusetts wooded residential property in 2017. This species has the largest geographic range of all the Blapstinus species reported in North America. Our paper reports on the death feigning behavior of B. metallicus and provides a review of the literature on this little studied group of beetles.
TL;DR: Advection of two liquid termiticides was determined within two different building foundation aggregate fills, ODOT Base Type-A Gravel and Class A-#57 Crushed Rock, after over-the-surface applications, as residue amounts were similar for individual termiti-cides.
Abstract: Advection of two liquid termiticides was determined within two different building foundation aggregate fills, ODOT Base Type-A Gravel and Class A-#57 Crushed Rock, after over-the-surface applications. Residues within each aggregate were sampled as two composite soil cores taken in two 5.1-cm incremental partitions to a depth of 10.2-cm after 24 hours, and at 6 and 12 months post-application. Half the test plots were compacted and half remained not compacted. Advection was significantly influenced by aggregate type. Residues within compacted compared with not-compacted aggregates were similar for individual termiti-cides. Some termiticide dispersed completely through the aggregates to reach the soil beneath. Advection resulted in decreasing a.i. concentrations as depth increased within ODOT Base Type-A Gravel fill, with the greatest concentration located in the top 5.1-cm partition, likely due to the fine particle component, with almost no termiticide reaching underlying soil. In contrast, termiticides were more evenly distributed within Class A-#57 Crushed Rock fill, as residue amounts were similar throughout the 10.2-cm depth, with some reaching underlying soil.
TL;DR: Additional data on the monthly abundance of nests of the social paper wasps Polistes erythrocephalus Latreille at two localities on the Atlantic watershed region of Costa Rica over several years suggest a trend towards a greater abundance of active nests during wetter months in this region where there are more wetter weeks than dry months each year.
Abstract: *Department of Zoology, Milwaukee Public Museum Milwaukee, Wisconsin 53233 USA Corresponding author email: young@mpm.edu The primary purpose of this brief communique is to summarize additional data on the monthly abundance of nests (colonies) of the social paper wasps Polistes erythrocephalus Latreille at two localities on the Atlantic watershed region of Costa Rica over several years. These observations include both drier and wetter periods and build upon previous studies in this region (Young, 1979; 1986). This additional data suggests a trend towards a greater abundance of active nests during wetter months in this region where there are more wetter months than dry months each year. Some studies show that a pronounced dry season halts reproductive activity and colony growth in Polistes (Hunt et al., 1999). Caterpillars, the primary food source for brood, are more abundant in wetter months (Janzen, 1993). A previous study in Costa Rica reported on various aspects of highly variable multiyear nest activity in the widespread Neotropical social paper wasp, Polistes erythrocephalus Latreille (Young, 1986). That study did not disclose a definitive pattern of nest building over rainy and dry months. In the present paper, I report further multiyear observations of nest activity in P. erythrocephalus at two localities on the eastern slopes and lowlands of Costa Rica and tentative evidence of greater nest activity in rainy months. Based upon previous studies such as Young (1986), my hypothesis was that the abundance and sizes of P. erythrocephalus nests would be highly variable over several months and years with little or no evidence of seasonality. Seasonality in Neotropical social paper wasp colonies has been studied previously with varying results (Carithers, 1997; Hunt et al., 1999; O’Donnell and Joyce, 2001).
TL;DR: The fenitrothion resistant populations were highly resistant to propoxur indicating the possible involvement of their common target site (AChE 1) in the recorded resistance.
Abstract: Culex pipiens is considered the potential vector of West Nile virus outbreaks that have affected Tunisia. The objective of the present study was to evaluate the fenitrothion insecticide resistance status of Culex pipiens pipiens in three populations of insects from three Tunisian states. Standardized method bioassays were conducted to shed light on fenitrothion susceptibility status in field Culex pipiens pipiens populations.The cross-resistance between fenitrothion and propoxur, and the polymorphism of over-produced esterases and AChE 1 were also investigated. Resistances to fenitrothion were moderate and low in sample # 2 and 3 (12.9 and 7.2, respectively). The highest resistance ratio was observed in populations collected in Northern Tunisia (sample # 1) with a rate of 60.9 fold at the LC50 level. The use of a synergist suggested the non-involvement of CYP450, esterases and/or glutathione-S-transferase in resistance of Culex pipiens pipiens to the tested insecticide. However, the biochemical investigation of detoxification enzymes using starch electrophoresis showed the involvement of four esterases, including A2-B2, A4-B4 (and/or A5–B5), B12 and C1. The fenitrothion resistant populations were highly resistant to propoxur indicating the possible involvement of their common target site (AChE 1) in the recorded resistance. Our results are particularly interesting to update the information base for rational deployment of the existing tools for mosquito's control.
TL;DR: Spiders fed pyrethroid-killed crickets had significantly lower survival than did spiders utilizing crickets exposed to all other treatments and L. reclusa had significantly greater weight gain feeding as predators than as scavengers.
Abstract: Studies were conducted to determine if predation versus scavenging versus scavenging on insecticide-killed prey affected brown recluse spiders, Loxosceles reclusa. Indicators of possible effects were measured by weight change and survival. Live house crickets, Acheta domesticus, used as prey, were exposed to one of four treatments: live (untreated control), Spinosad or pyrethroid insecticide treated surface, or freeze-killed (scavenging control) and made available to spiders for twenty-four hours once/week for eight weeks. Spiders fed pyrethroid-killed crickets had significantly lower survival than did spiders utilizing crickets exposed to all other treatments. L. reclusa had significantly greater weight gain feeding as predators than as scavengers.
TL;DR: To assess ant biodiversity and activity levels in the northern Black Hills, ants were collected monthly from April through September 2016 at two sites (1250 m ponderosa pine – common juniper forest and 2060 m aspen-pine forest).
Abstract: The Black Hills are a mountain island surrounded by prairie on the eastern edge of the Rockies. The ant fauna of this area is known only from collections in the southern Black Hills and surrounding plains. To assess ant biodiversity and activity levels in the northern Black Hills, ants were collected monthly from April through September 2016 at two sites (1250 m ponderosa pine – common juniper forest and 2060 m aspen-pine forest). At each site, collections were made by opportunity collections and using 40 pitfall and 50 baited traps along perpendicular transect lines. We collected a total of 6180 ants. At the lower elevation, we identified nine genera consisting of 21 species in comparison to the higher elevation where we found only seven genera consisting of 13 species. Fourteen species and three genera were unique to the lower site while six species and one genus were unique to the higher site. Species accumulation graphs and richness estimates based on incidence data suggest more than 67% of the total number of species were collected at each of the sites. Diversity and evenness averages over the season are not significantly different between the two sites. Some of the species we collected are new records for South Dakota, with one well outside its known range.
TL;DR: Tunisian populations of Culex pipiens pipiens, an important vector of human diseases, have developed resistance to organophosphate insecticides and a positive correlation between both metabolic and target site resistance and the level of resistance is shown.
Abstract: Tunisian populations of Culex pipiens pipiens, an important vector of human diseases, have developed resistance to organophosphate insecticides. To understand the origin of this resistance, knowledge of the impact on agricultural pest and mosquito control activities and its significance for the resistance mechanisms will be required. Five populations of C. p. pipiens were collected at various sites with different agricultural pest and mosquito control activities throughout Tunisia and tested for fenitrothion resistance level. Results were compared to those obtained from a control population where no chemical activities have been carried out. Our results strongly suggest the presence of a correlation between agrochemical products and the recorded resistance despite a rather limited number of studied sites (five populations). On the other hand, organophosphates control activities let us suggest the existence of an important impact on fenitrothion resistance. However, it appears that the application of pyrethroids have little to no impact on fenitrothion (organophosphate) resistance. The recorded resistance of the control population should be due to anthropogenic factors; however, the combined effect of migration and gene flow on the evolution of insecticide resistance should also be taken into consideration. The recorded resistance was mediated by both enzymatic detoxification and target-site sensitivity. Our findings showed a positive correlation between both metabolic and target site resistance and the level of resistance. In conclusions, we can say that the use of pesticides and insecticides by both agricultural and public health departments in Tunisia should be more rationalized to reduce the development of resistance in C. p. pipiens populations.
TL;DR: Bt apparently did not have negative effects on insects that naturally parasitize larvae of P. quadristigmalis, and Bacillus thuringiensis-based products can have significant potential for the management of the pests in ornamentals and landscaped areas.
Abstract: Pest management in ornamentals and landscaped areas relies largely on synthetic pesticides, which usually are non-selective and may negatively impact human health, natural enemies and pollinators. It is important to develop integrated, biorational management plans for ornamentals. Palpita quadristigmalis Guenee (Lepidoptera: Crambidae) was observed in northeastern Mexico in 2017 causing severe defoliation and branch dieback of privet, Ligustrum sp. (extensively grown there as hedge and shade trees). We assessed the effect of Bacillus thuringiensis (Bt) (toxin crystals and spores) on privet leaves upon mortality and foliage consumption by P. quadristigmalis larvae, as well as the effect of Bt on larval parasite emergence. Larvae of three different instars (4th, 5th and 6th) were exposed to three concentrations of B. thuringiensis (DiPel®, Bayer) (1.0, 2.5 and 5.0 g/L) in the laboratory. Mortality increased while foliage consumed (as total area and percent) decreased in response to increasing Bt concentrations. At 48h, mortality values of 65.0-97.5% were observed across Bt-exposed larvae; also, there was a maximum of 2.5% foliar area consumed by all Bt-exposed larvae, compared to foliage consumed by unexposed larvae. Overall, 1.7 % of larvae used in these tests (Bt-exposed and control) were parasitized (Braconidae 25%, Ichneumonidae 12.5% and Tachinidae 62.5%). Bt apparently did not have negative effects on insects that naturally parasitize larvae of P. quadristigmalis. Bacillus thuringiensis-based products can have significant potential for the management of P. quadristigmalis larvae.