Registered users receive a variety of benefits including the ability to customize email alerts, create favorite journals list, and save searches.
Please note that a BioOne web account does not automatically grant access to full-text content. An institutional or society member subscription is required to view non-Open Access content.
Contact helpdesk@bioone.org with any questions.
Spalangia cameroni Perkins is used as a biological control agent of filth flies. These parasitoids are reared commercially, but little is known about the impact of colony age on host-seeking and life history parameters. Hostseeking in bedding from equine stalls (pine shavings and manure) was analyzed with two colonies, one established in 2000 and one in 2010 (144 and 24 generations in colony). These two colonies, and a colony established in 2012 colony (4 generations), were analyzed for differences in female longevity and fecundity. Wolbachia were analyzed in each colony to document sequence variants. All wasps collected to start parasitoid colonies were from the same dairy in Gilchrist County, FL, but collected on different dates. Parasitoids from the 2000 colony parasitized fewer hosts than ones from the 2010 colony when challenged in a complex environment. Life history parameters were different between individuals in the colonies. Differences in reproductive productivity between the colonies could not be correlated to the presence or sequence variant of Wolbachia. New Wolbachia wsp and ftsZ sequences were identified in these colonies. Multiple strains of Wolbachia were found in each colony, and their presence did not vary among colonies. The invariance in strain presence suggests that Wolbachia strains were not lost during colony maintenance, i.e., lost through selection or random genetic drift.
Exotic plants can alter habitat composition and reduce the diversity of pollinators by competing with native species for resources. In a forest fragment surrounded by coffee crops, Coffea arabica L. (Rubiaceae), in southeastern Brazil, the life history of the oil-collecting bee Tetrapedia diversipes Klug (Apidae) was studied. Besides providing data on the phenology, nesting biology, and natural enemies of this bee species, we aimed to investigate if the intense mass flowering of coffee trees would attract T. diversipes specimens rather than native plants in bloom. As T. diversipes females nest in preexisting cavities, we displayed in the study site two types of trapnests: bamboo canes and 5.8- by 0.6-cm black cardboard tubes. The trap-nests were inspected once a month from June 2011 to May 2013 and 494 nests were collected. Tetrapedia diversipes is a multivoltine species. Prepupal diapause occurred in nests collected at the end of the hot and wet season and during the cold and dry season. Nests were attacked by 14 species of natural enemies, and the most abundant species were the cuckoo bee Coelioxoides waltheriae Ducke (Apidae); the bee fly Anthrax oedipus F. (Bombyliidae); and the beetle Nemognatha cf. plaumanni Borchmann (Meloidae). Despite the mass flowering of coffee trees, pollen grains of C. arabica were not found in the pollen analysis. Our study reveals that even in the presence of an abundant source of floral resources of exotic origin, the studied population of T. diversipes preferred to use the native plant species to obtain the necessary resources for their survival.
Feeding behaviors of the redbanded stink bug, Piezodorus guildinii (Westwood), on vegetative (stem and leaflet) and reproductive (pod) tissues of soybean, Glycine max (L.), were recorded using an AC-DC electropenetrograph (EPG) apparatus. Eight different probing waveforms were characterized and defined: Pg1a, Pg1b, Pg1c, Pg1d, Pg2, Pg3a, Pg3b, and Pg4 grouped into three different families, P, I, and N. Histological studies of intact stylets within salivary sheaths observed during Pg1b, Pg1c, Pg2, and Pg3 waveforms were correlated with the specific penetration sites. Waveforms Pg1a, Pg1b, Pg1c, and Pg1d (pathway—family P) occurred at the start of probing activities and represent stylet penetration deep into plant tissue. Waveforms Pg2, Pg3a, and Pg3b (family I) represent the food ingestion phase. Pg2 waveform represents xylem sap ingestion primarily on leaves and stems. During Pg3a, stylets were moving, lacerating deeply into pod tissue and partially retracting; during Pg3b, stylets were motionless inside the pod tissue. Pg3b occurred interspersed with waveform Pg3a. Waveform Pg4 (family N) represented short interruptions that occurred within waveform Pg2. The study demonstrated that P. guildinii uses the cell rupture strategy to ingest from endosperm in soybean pod, and the same insect could switch to salivary sheath feeding to ingest from xylem in soybean leaves and stems. This unusual behavior explains symptoms of stink bug damage to soybean. The P. guildinii waveforms defined herein will allow future EPG studies to aid in development of soybean varieties that resist the feeding and damage caused by this and other stink bug pests.
Temperature greatly affects the developmental duration of insects at their different stages, and many mathematical models exist for describing their temperature-dependent developmental rates. It is important to choose a suitable model to predict outbreaks of pest insects under climate change. However, previous comparisons among these models were usually based on a single species. In the present study, we compared the six nonlinear models (the Briére-1, Briére-2, Lactin, Performance-2, beta, and Ratkowsky models) based on the goodness of fit and the trade-off between the model's goodness of fit and structural complexity, using 10 temperaturedependent developmental rate datasets on insects to make the conclusions general. We found that the square root model (i.e., the Ratkowsky model) fitted all datasets well, and the curve shape produced by this model also approximates the curve shape of thermodynamically based mathematical models. The square root model was originally derived to be applicable to the growth rates of bacteria, and until now it has been generally ignored in entomology. We were mainly concerned with the predicted results obtained by using this model on observations of temperature-dependent developmental rates. We found that the square root model described well the pooled developmental rates in the low-, mid-, and high-temperature ranges, and we believe that it merits wider use in entomology.
Coprophagous beetles (Coleoptera: Scarabaeidae) play an important ecological role in the management of grazing and cycling of nutrients within different ecosystems. Seasonal abundance, species richness, and alpha diversity of the dung beetles were investigated in Rawdhat Khorim Nature Preserve in the central Kingdom of Saudi Arabia (KSA). Adult beetles were trapped using UV light traps biweekly from November 2011 to October 2012 (for a total of 24 nocturnal trap samples). A total of 2,982 dung beetles were caught, representing 22 species in nine genera belonging to the subfamilies of Aphodiinae and Scarabaeinae. The total catch was dominated (58%) by Aphodius pruinosus Reitter and Aphodius wollastoni iranicus Balthasar, with the Aphodiinae constituting 94% of the total beetle richness. Most of the dung beetle species were dwellers (20 species). Aphodius luridus (F.) and Granulopsammodius plicatulus (Fairmaire) are new records for KSA. Abundance, richness, and alpha diversity of dung beetles peaked during spring. Alpha diversity increased with higher average air temperatures. Dung beetle abundance was positively correlated with the normalized difference vegetation index. Two clusters of species phenology were apparent, a summer-active group and those not active during the summer months. Our findings may enhance the understanding of dung beetle ecology in the rawdhat network within hyper-arid ecosystems of Arabian Peninsula and sustainable management of dung beetles for nutrient reincorporation through the consumption and storage of dung in the soil.
The trehalose analogue compound validamycin is a very strong competitive inhibitor of trehalase enzymatic activity in various insects, and it has been studied as a potential material for the development of new insecticides. The inhibitory effect of validamycin on trehalase activity in the red flour beetle, Tribolium castaneum Herbst, was investigated in the present study. We measured changes in glucose concentrations and assessed morphological abnormalities in the wings of T. castaneum after trehalase activity was inhibited by validamycin treatment. We found that the application of validamycin during the larval stage, via both feeding and injection methods, resulted in a significant decrease in trehalase activity during the larval, pupal, and adult stages. Injection of validamycin into pupae caused a reduction in trehalase enzyme activity and caused the glucose concentration to fall by 21% compared with the control. The dose-dependent lethal effect of validamycin treatment was recorded, with the highest mortality rate of ∼78%. This study is the first to demonstrate the dosedependent effect of validamycin on the wing morphology of T. castaneum adults, in that the injected insects exhibited wrinkled elytra and improperly folded hindwings. Reduction of elytral length and width was also recorded. The trehalase inhibitor validamycin is valuable for investigating the physiological function of trehalase in insects and may be useful as a pest control tool for T. castaneum.
Identification and quantitation of fatty acids (FAs) in nymphs, alates, workers, presoldiers, and soldiers of the Formosan subterranean termite, Coptotermes formosanus Shiraki, were determined by gas chromatography–mass spectrometry, showing quantitative and qualitative differences among groups. Total FAs content of nymphs and alate females was about 1.5-fold higher than alate males, about 2-fold higher than workers, 6-fold higher than presoldiers, and 12-fold higher than soldiers. Overall differences in total FAs content were due to oleic acid (C18:1), stearic acid (C18:0), linoleic acid (C18:2), and palmitic acid (C16:0). Soldiers contained two unique FAs among the castes—lignoceric (C24:0) and hexacosanoic acid (C26:0). Nymphs had the highest ratio between triacylglycerols and phospholipids probably for energy storage in alate development. Four branched FAs—13-methyl myristic, 14-methyl pentadecenoic, 15-methyl palmitic, and 14-methyl palmitic—and three oddnumbered FAs—pentadecanoic (C15:0), heptadecanoic (C17:0), and heptadecenoic (C17:1)—were found in nymphs, alates, workers, presoldiers, and soldiers. Interestingly, all FAs were distributed in different percentages both in triglycerides and phospholipids of the different developmental stages and castes, indicating a function both for energy storage and membrane components. Five different 2-hydroxy FAs—2-OH C16:0, 2-OH C18:0, 2-OH C20:0, 2-OH C22:0, and 2-OH C24:0—were identified, the latter only in soldiers. Total 2-hydroxy FAs content in soldiers was significantly higher than that in other groups (6.01–7.9-fold vs. presoldiers and 41.7–132.6-fold vs. nymphs, alates, and workers), and the quantity in presoldiers was significantly higher than in nymphs, alates, and workers, with no difference among nymphs, alates, and workers.
Concerns over the ecological impacts of insecticides have led researchers to look for environmentally friendly plant-derived pest control compounds such as plant growth regulators. Here we investigate whether the plant growth regulator abscisic acid (ABA) alters the life history traits and hemocytes of Galleria mellonella L. (Lepidoptera: Pyralidae) when injected into the hemocoel. The injection of ABA resulted in dose-dependent mortality of final-instar larvae, as well as an increase in the duration of the larval stage and adult emergence time, and decrease in pupation and adult emergence ratios. The mean adult longevity and fecundity of G. mellonella adults was lower at higher doses. Injection of different concentrations of ABA led to a remarkable decrease in the number of circulating hemocytes at all time intervals. Analyses of the differential hemocyte counts revealed that ABA altered the granulocyte and plasmatocyte ratio in a dose-dependent manner at different time intervals. The percentage of mitotic hemocytes also decreased at 10 and 50 mg/ml at 24 h post ABA injection. These findings demonstrate that ABA may interfere with development and the hemocytes of G. mellonella and could be a good candidate for pest control after detailed study of ingestion and contact effects in further studies.
The species of the tribe Brontini from Japan and Taiwan are revised. Two new species, Megahyliota cryptolucidussp. nov. and Macrohyliota sculptussp. nov. (misidentified with Mac. gracilicornis (Arrow)), are described. Also described are mature larvae of four species, Dendrophagus longicornis Reitter, Mac. sculptussp. nov., Meg. cryptolucidussp. nov., and Uleiota arboreus (Reitter), and pupae of three species, Mac. sculptussp. nov., Meg. cryptolucidussp. nov., and U. arboreus. These are the first larval descriptions for Macrohyliota and Megahyliota as well as the first pupal illustrations and detailed descriptions for the entire tribe Brontini. Macrohyliota gracilicornis and U. planatus (L.) should be excluded from the Japanese fauna. The diagnostic characters among brontine larvae and the character states of larval morphologies between Brontini and Telephanini are also discussed.
The pupa of Culicoides (Monoculicoides Khalaf) sonorensis Wirth and Jones is described for the first time in detail based on whole specimens and exuviae. A multitude of approaches were used in this description to offer one of the most in-depth comparative morphological studies of any ceratopogonid pupa. Illustrations were made using compound and dissecting light microscopy, and scanning electron microscopy. The pupal description for C. sonorensis was based on morphological comparisons with species of Culicoides Latreille including other members of the subgenus C. (Monoculicoides). This study highlights possible synapomorphies for the subgenus as well as the need for future pupal research.
Examination of minute pirate bugs, Orius spp. (Hemiptera: Heteroptera: Anthocoridae), from a broad geographic range in the western United States prompted a reappraisal of the taxonomic composition of the fauna native to the western United States and Canada. Current syntheses and catalogs list three species of Orius native to this region. In a previous study, we showed how geographic variation in external traits of one of these species, Orius diespeterHerring, 1966, had led to mistakes in identification of species within this complex. More extensive collecting efforts have now led to the discovery of specimens having traits not fully consistent with descriptions of any described species. We provisionally categorized these unresolved specimens into one of eight phenotypic groups based upon combinations of body size, visual appearance of genitalia, association with specific plant taxa, and geographic source. Genitalia from 382 specimens were then measured to determine whether phenotypic groupings were confirmed by statistical analysis of genitalic morphology. Principal components analysis showed that size and shape of the male's paramere differed among phenotypes. The paramere of unresolved specimens often diverged from the paramere of described species. Length of the female's copulatory tube differed between several of the unresolved phenotypes and described species. Analysis of DNA sequences showed that five of the eight phenotypes diverged genetically from other phenotypes and from described species. DNA sequence data did not separate two described species (Orius tristicolor (White, 1879) and Orius harpocratesHerring, 1966), suggesting that these two species are a single species. The combined morphological and genetic evidence indicates that the Orius fauna of the western United States is composed of a mix of two described species and possibly five undescribed cryptic species. We summarize the known distributions of described and cryptic undescribed species, and discuss the implications of our work for the biological control community.
This article is only available to subscribers. It is not available for individual sale.
Access to the requested content is limited to institutions that have
purchased or subscribe to this BioOne eBook Collection. You are receiving
this notice because your organization may not have this eBook access.*
*Shibboleth/Open Athens users-please
sign in
to access your institution's subscriptions.
Additional information about institution subscriptions can be foundhere