Plants damaged by insect herbivory often respond by inducing a suite of defenses that can negatively affect an insect's growth and fecundity. Ostrinia nubilalis (European corn borer, ECB) is one of the most devastating insect pests of maize, and in the current study, we examined the early biochemical changes that occur in maize stems in response to ECB herbivory and how these rapidly induced defenses influence the growth of ECB. We measured the quantities of known maize defense compounds, benzoxazinoids and the kauralexin class of diterpenoid phytoalexins. ECB herbivory resulted in decreased levels of the benzoxazinoid, 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one)-β-D-glucopyranose (DIMBOA-Glc), and a corresponding increase in 2-(2-hydroxy-4,7-dimethoxy-1,4-benzoxazin-3-one)-β-D-glucopyranose (HDMBOA-Glc). Total quantities of benzoxazinoids and kauralexins were increased as early as 24 h after the initiation of ECB feeding. The plant hormones, jasmonic acid (JA) and ethylene (ET), and the transcripts encoding their key biosynthetic enzymes also accumulated in response to ECB herbivory, consistent with a role in defense regulation. The combined pharmacological application of JA and the ET precursor, 1-aminocyclopropane-1-carboxylic acid to stem internode tissue likewise resulted in changes in benzoxazinoids similar to that observed with ECB damage. Despite the fact that maize actively mounts a defense response to ECB stem feeding, no differences in percent weight gain were observed between ECB larvae that fed upon non-wounded control tissues compared to tissues obtained from plants previously subjected to 24 h ECB stem herbivory. These rapid defense responses in maize stems do not appear to negatively impact ECB growth, thus suggesting that ECB have adapted to these induced biochemical changes.

Transcript levels of vitellogenins (Vgs) in the varroa mite, Varroa destructor (Anderson & Trueman), were variably induced by interactions between the developing honeybee, Apis mellifera L, as a food source and the capped honeybee cell environment. Transcripts for two Vgs of varroa mites were sequenced and putative Vg protein products characterized. Sequence analysis of VdVg1 and VdVg2 proteins showed that each had greater similarity with Vg1 and Vg2 proteins from ticks, respectively, than between themselves and were grouped separately by phylogenetic analyses. This suggests there was a duplication of the ancestral acarine Vg gene prior to the divergence of the mites and ticks. Low levels of transcript were detected in immature mites, males and phoretic females. Following cell invasion by phoretic females, VdVg1 and VdVg2 transcript levels were up-regulated after cell capping to a maximum at the time of partial cocoon formation by the honeybee. During oviposition the two transcripts were differentially expressed with higher levels of VdVg2 being observed. A bioassay based on assessing the transcript levels was established. Increases in VdVg1 and VdVg2 transcripts were induced experimentally in phoretic females when they were placed inside a cell containing an early metamorphosing last instar bee but not when exposed to the metamorphosing bee alone. The variable response of Vg expression to the food source as well as environmental cues within the capped cell demonstrates that perturbation of host-parasite interactions may provide avenues to disrupt the reproductive cycle of the varroa mites and prevent varroasis.

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Effective entomological surveillance planning stresses a careful consideration of methodology, trapping technologies, and analysis techniques. Herein, the basic principles and technological components of arthropod surveillance plans are described, as promoted in the symposium "Advancements in arthropod monitoring technology, techniques, and analysis" presented at the 58th annual meeting of the Entomological Society of America in San Diego, CA. Interdisciplinary examples of arthropod monitoring for urban, medical, and veterinary applications are reviewed. Arthropod surveillance consists of the three components: 1) sampling method, 2) trap technology, and 3) analysis technique. A sampling method consists of selecting the best device or collection technique for a specific location and sampling at the proper spatial distribution, optimal duration, and frequency to achieve the surveillance objective. Optimized sampling methods are discussed for several mosquito species (Diptera: Culicidae) and ticks (Acari: Ixodidae). The advantages and limitations of novel terrestrial and aerial insect traps, artificial pheromones and kairomones are presented for the capture of red flour beetle (Coleoptera: Tenebrionidae), small hive beetle (Coleoptera: Nitidulidae), bed bugs (Hemiptera: Cimicidae), and (Diptera: Ceratopogonidae) respectively. After sampling, extrapolating real world population numbers from trap capture data are possible with the appropriate analysis techniques. Examples of this extrapolation and action thresholds are given for termites (Isoptera: Rhinotermitidae) and red flour beetles.

We describe a system for the in situ collection of volatiles from bees enclosed on a standard Langstroth frame face. The system includes an observation frame consisting of a glass plate and an aluminum frame that encloses a single frame face. A push-pull airflow system and an in-line volatile collection filter allow for air exchange and headspace volatile capture. This system can provide insight into colony chemical communication. The emissions of four compounds (2-heptanone, methyl benzoate, decanal, and 3-carene) associated with adult bees or colony materials remained steady or increased slightly in repeated collections from frames with maturing larvae. The emissions of the larval food component octanoic acid reflected changes in food consumption patterns by differently aged larvae. The production of the primer pheromone E-β-ocimene was greatest in comb containing young larvae and recently capped brood, but was lower on comb with capping larvae.

Intraspecific attraction depends both on the cues provided by the attracting individual and the response of the attracted individual. These attracting cues are related not only to current conditions, but also are a reflection of individual and population life history. These relationships were examined by placing red flour beetle, Tribolium castaneum (Herbst.), adults in flasks at increasing densities and monitoring the changes in volatile chemical emission over time. Only certain chemicals were quantified: methyl benzoquinone, ethyl benzoquinone and 4,8-dimethyldecanal, all of which are known to impact the biology of T. castaneum. The flasks were used as sources for both quantification of the chemicals and for bioassays. Additional bioassays were conducted with synthetic 4,8-dimethyldecanal, a known aggregation pheromone component, to evaluate attraction with respect to population density. Tribolium castaneum density affected both the release of volatile chemicals and the responses of conspecifics to those chemicals. The results indicated that while there were important effects of beetle density on chemical emission and response, none of the chemicals evaluated emerged as promising synergists to the current aggregation pheromone 4,8-dimethyldecanal. The benzoquinones released in response to stress and density acted as anti-aggregation pheromones along with their accepted defensive function.

SummaryThis paper describes basic methods essential in elucidating chemically-mediated behavioural interactions among honey bees, and between honey bees and other arthropods. These range from bioassay methods used to demonstrate the role of specific behaviours, techniques and equipment used to collect and analyse semiochemicals (both volatiles and non-volatiles e.g. cuticular hydrocarbons) from individual honey bees, groups of bees or an entire colony in its native environments. This paper covers: collection and analysis of honey bee volatiles in the natural environment, collection and analysis of bee volatiles out of their natural environment and their antennal detection, collection and analysis of non-volatile cuticular hydrocarbons, bioassays with queen pheromone and finally a section focusing on in vitro bioassays as a tool for elucidation of mechanisms regulating pheromone gland activity. Métodos estándar para la investigación en la ecología química en Apis mellifera ResumenEste artículo describe los métodos esenciales básicos para dilucidar las interacciones de comportamiento mediadas por la química entre las abejas y entre éstas y otros artrópodos. Estos van desde los métodos de bioensayo usados para demostrar el rol de comportamientos específicos, hasta las técnicas y equipamientos usados para colectar y analizar semioquímicos (tanto volátiles como no volátiles, por ejemplo hidrocarburos cuticulares) en abejas al nivel individual, en grupos de abejas o en una colonia entera en su ambiente natural. Este artículo engloba: colección y análisis de los volátiles de la abeja de la miel en su ambiente natural, colección y análisis de los volátiles de la abeja fuera de su ambiente natural y con su detección por las antenas, colección y análisis de los hidrocarburos cuticulares no volátiles, bioensayos con la feromona real y finalmente una sección enfocada a los bioensayos in vitro como herramienta para dilucidar los mecanismos que regulan la actividad de la glándula que produce feromonas.

The complete genomic region and corresponding transcript of the most abundant protein in phoretic varroa mites, Varroa destructor (Anderson & Trueman), were sequenced and have homology with acarine hemelipoglycoproteins and the large lipid transfer protein (LLTP) super family. The genomic sequence of VdLLTP included 14 introns and the mature transcript coded for a predicted polypeptide of 1575 amino acid residues. VdLLTP shared a minimum of 25% sequence identity with acarine LLTPs. Phylogenetic assessment showed VdLLTP was most closely related to Metaseiulus occidentalis vitellogenin and LLTP proteins of ticks; however, no heme binding by VdLLTP was detected. Analysis of lipids associated with VdLLTP showed that it was a carrier for free and esterified C12 -C22 fatty acids from triglycerides, diacylglycerides and monoacylglycerides. Additionally, cholesterol and β-sitosterol were found as cholesterol esters linked to common fatty acids. Transcript levels of VdLLTP were 42 and 310 times higher in phoretic female mites when compared with males and quiescent deutonymphs, respectively. Coincident with initiation of the reproductive phase, VdLLTP transcript levels declined to a third of those in phoretic female mites. VdLLTP functions as an important lipid transporter and should provide a significant RNA interference target for assessing the control of varroa mites.