Visual stimulus brightness influences the efficiency of attractant-baited traps for catching Drosophila suzukii Matsumura (Diptera: Drosophilidae).

Drosophila suzukii (Matsumura) is an exotic pest of economic importance that affects several soft-skinned fruits in Mexico. Previously, we found that yellow or yellow-green rectangular cards inside a transparent trap baited with attractants improved D. suzukii capture. In this study, we evaluated the influence of rectangular cards with different yellow shades inside a transparent multi-hole trap baited with apple cider vinegar (ACV) on D. suzukii capture in the field. Second, we tested whether ACV-baited traps with cards of other geometric shapes affected D. suzukii catches compared to traps with rectangular cards. Third, we evaluated the effects of commercial lures combined with a more efficient visual stimulus from previous experiments on trapping D. suzukii flies. We found that ACV-baited traps plus a yellow-shaded rectangle card with 67% reflectance at a 549.74 nm dominant wavelength captured more flies than ACV-baited traps with yellow rectangle cards with a higher reflectance. Overall, ACV-baited traps with rectangles and squares caught more flies than did ACV-baited traps without visual stimuli. The traps baited with SuzukiiLURE-Max, ACV and Z-Kinol plus yellow rectangles caught 57, 70 and 101% more flies, respectively, than the traps baited with the lure but without a visual stimulus.

Coffee Berry Borer, Hypothenemus hampei (Ferrari) (Coleoptera: Curculionidae): Activity and Infestation in the High Mountain and Blue Mountain Regions of Jamaica.

Jamaica produces coffee marketed as Blue Mountain and high mountain (grown outside the Blue Mountains). Since the discovery of the coffee berry borer (CBB; Hypothenemus hampei) in Jamaica in 1978, chemical control has traditionally been the primary approach used to protect the crop from the pest. However, in the last 20 years, there has been an effort to shift towards more sustainable management strategies. The study was conducted to determine CBB activity (trap catch) and field infestation on coffee farms in the high mountains and Blue Mountains of Jamaica, over a crop cycle. A total of 27,929 and 12,921 CBBs were captured at high mountain and Blue Mountain farms, respectively. Peak CBB activity occurred in April in the high mountain region (365 CBBs/trap/month) and February in the Blue Mountain region (129 CBBs/trap/month). The highest levels of infestation were in November (33%) and October (34%) in the high mountain region and Blue Mountain region, respectively. There was no significant difference in the patterns of CBB activity and infestation between the study locations, and neither were related to the temperature or relative humidity. However, there was a significant relationship with rainfall. These data suggest that the population dynamics of the CBB may involve complex interactions among weather conditions, berry development, and agronomic practices.

Trapping of Retrachydes thoracicus thoracicus (Olivier) and Other Neotropical Cerambycid Beetles in Pheromone- and Kairomone-Baited Traps.

The subfamily Cerambycinae, one of the most diverse in longhorn beetles, is well known for its remarkable chemical parsimony in male-emitted pheromones. Conserved shared structural motifs have been reported in numerous species, sometimes working in combination with plant volatile kairomones. Among other compounds, the most ubiquitous male pheromone in cerambycine species is 3-hydroxyhexan-2-one. We conducted field trials using intercept traps baited with 3-hydroxyhexan-2-one and observed abundant captures of several Neotropical cerambycine species. These were Retrachydes thoracicus thoracicus (Olivier), Megacyllene acuta (Germar), Compsocerus violaceus (White), and Cotyclytus curvatus (Germar) in high numbers, as well as Chydarteres striatus striatus (Fabricius) and Odontocroton flavicauda (Bates) in smaller numbers. When ethanol was added to the traps, a remarkable increase in the attractiveness of 3-hydroxyhexan-2-one was observed for R. thoracicus thoracicus and M. acuta. Adding ethanol also resulted in the capture of Chrysoprasis aurigena (Germar). Finally, incidental catches in pheromone-baited traps of Trachelissa maculicollis (Audinet-Serville), Neoclytus pusillus (Laporte & Gory), Achryson unicolor (Bruch, 1908) and Achryson surinamum (Linnaeus), Megacyllene mellyi (Chevrolat) and Thelgetra adustus (Burmeister) were also observed. Pheromone chemistry has been reported for C. curvatus, M. acuta and N. pusillus, all three producing 3-hydroxyhexan-2-one, and for C. aurigena and A. surinamum, which produce other compounds. Our findings suggest that the captured species probably produce 3-hydroxyhexan-2-one for their pheromone communication system. Alternatively, they might be "eavesdropping" on the pheromones of other cerambycine species. The probable synergistic effect of ethanol is likely explained from its kairomonal role as a volatile cue for plant stress or ripeness.

Community of Bark and Ambrosia Beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae) Infesting Brazilian Peppertree Treated With Herbicide and the Volatile Tree Response.

Brazilian peppertree, Schinus terebinthifolia Raddi (Anacardiaceae), is one of the most invasive weeds of natural and agricultural areas of Florida, Hawaii, and Texas (USA). Herbicides are the main tool used to manage populations of this weed. Faunal inventories of the insects associated with invasive populations of the weed have mostly listed leaf-feeding phytophagous, pollinator, or predacious species. Among these, bark and ambrosia beetles were collected only once from S. terebinthifolia in the invaded range and there are no reports from the native range. A diverse assemblage of bark and ambrosia beetles, many well-known economic pests of ornamentals, was reared from S. terebinthifolia bolts collected at a restoration site in Florida that had been treated with herbicide (triclopyr ester). A similar collection of beetles was captured on ethanol-baited sticky traps. No beetles emerged from bolts of untreated trees, almost none emerged from those wounded with a machete (3.1% of total), whereas nearly all the beetles collected emerged from bolts that had been treated with herbicide (62.3%) or the combination wounded + herbicide (34.6%). Ethanol was detected from the herbicide and wound + herbicide-treated bolts suggesting this was the attractive kairomone. Abundant amounts of other volatiles were collected from all bolts, especially from the wounded treatment, but no association was detected between volatile emissions and beetle infestation. Further studies are needed to determine whether invasive populations of S. terebinthifolia treated with herbicides constitute reservoirs for pest bark and ambrosia beetles that may spill over onto neighboring ornamental hosts.

Grazer-Induced Chemical Defense in a Microcystin-Producing Microcystis aeruginosa (Cyanobacteria) Exposed to Daphnia gessneri Infochemicals.

Cyanobacteria are photosynthetic microorganisms that compose phytoplankton and therefore have a trophic relationship with zooplankton, which represent an important link for energy flux in aquatic food webs. Several species can form blooms and produce bioactive metabolites known as cyanotoxins. However, the ecological and adaptative role of these toxins are still under debate. Many studies have addressed the cyanotoxins' function in defense against herbivory when grazing pressure by zooplankton plays a role in phytoplankton top-down control. Thus, the present study evaluated the ecophysiological responses of the cyanobacterial strain Microcystis aeruginosa NPLJ-4 underlying the chemical induced defense against the cladoceran Daphnia gessneri. Exposure to predator infochemicals consisted of cultures established in ASM-1 medium prepared in a filtrate from a culture of adults of D. gessneri at an environmentally relevant density. Daphnia infochemicals promoted a significant increase in toxin production by M. aeruginosa. However, no differences in growth were observed, despite a significant increase in both maximum photosynthetic efficiency and electron transport rate in response to zooplankton. Additionally, there was no significant variation in the production of exopolysaccharides. Overall, although a grazer-induced defense response was demonstrated, there were no effects on M. aeruginosa fitness, which maintained its growth in the presence of Daphnia alarm cues.

α-Terpineol: An Aggregation Pheromone in Optatus palmaris (Coleoptera: Curculionidae) (Pascoe, 1889) Enhanced by Its Host-Plant Volatiles.

The Annonaceae fruits weevil (Optatus palmaris) causes high losses to the soursop production in Mexico. Damage occurs when larvae and adults feed on the fruits; however, there is limited research about control strategies against this pest. However, pheromones provide a high potential management scheme for this curculio. Thus, this research characterized the behavior and volatile production of O. palmaris in response to their feeding habits. Olfactometry assays established preference by weevils to volatiles produced by feeding males and soursop. The behavior observed suggests the presence of an aggregation pheromone and a kairomone. Subsequently, insect volatiles sampled by solid-phase microextraction and dynamic headspace detected a unique compound on feeding males increased especially when feeding. Feeding-starvation experiments showed an averaged fifteen-fold increase in the concentration of a monoterpenoid on males feeding on soursop, and a decrease of the release of this compound males stop feeding. GC-MS analysis of volatiles identified this compound as α-terpineol. Further olfactometry assays using α-terpineol and soursop, demonstrated that this combination is double attractive to Annonaceae weevils than only soursop volatiles. The results showed a complementation effect between α-terpineol and soursop volatiles. Thus, α-terpineol is the aggregation pheromone of O. palmaris, and its concentration is enhanced by host-plant volatiles.

Comparison of Different Trap Designs for Capture of Noctuid Moths (Lepidoptera: Noctuidae) With Pheromone and Floral Odor Attractants.

Six trap designs were assessed for capturing noctuid moths in field trials in the United Kingdom and Argentina. The traps were baited with either a sex pheromone for Autographa gamma in the UK trials and Helicoverpa gelotopoeon (Dyar) (Lepidoptera: Noctuidae) in Argentina, or a floral odor blend. In the UK trials the Universal Trap and a funnel sleeve trap were compared; in Argentina the funnel sleeve trap, a homemade bucket trap, and (L.) (Lepidoptera: Noctuidae) three sticky traps: LepTrap, wing trap, and delta trap were compared. Comparisons were made between the traps and attractants and captures of noctuid moths and nontarget insects. Traps baited with the floral attractant caught a lower number but a wider range of noctuid species including Helicoverpa, Spodoptera, Rachiplusia, Dargida, Mythimna, Chrysodeixis, Agrotis, and Autographa spp., and nontarget insects. In the UK trials, the funnel sleeve trap caught significantly more A. gamma than the Universal Trap. The addition of an insecticide to the Universal Trap marginally increased trap catches. In the Argentinian trials, the homemade bucket and the sleeve traps outperformed all sticky traps in most situations regardless of crop environment and attractant type. The homemade bucket and the funnel sleeve traps are also considerably cheaper than the other trap designs. Of the sticky traps the LepTrap caught more noctuids than the wing and delta traps. The results suggest that the bucket trap and the sleeve trap have a much greater maximum capacity and possibly a greater retention efficiency for noctuid moths compared to the sticky traps.

Anthonomus grandis aggregation pheromone induces cotton indirect defence and attracts the parasitic wasp Bracon vulgaris.

Insect-derived volatiles seem to provide reliable chemical cues that plants could employ to defend themselves. Here we investigated the effect of pheromone emission from a closely associated (Anthonomus grandis; boll weevil) and an unassociated (Tibraca limbativentris) herbivore on cotton volatile emission. Exposure to A. grandis aggregation pheromone induced cotton defence response by enhancing the emission of volatiles attractive to the natural enemy of A. grandis, the parasitic wasp Bracon vulgaris, but only when the pheromonal blend was complete (all four components). Individual components of A. grandis aggregation pheromone were not able to induce cotton plants to increase the release of volatiles. On the other hand, T. limbativentris sex pheromone did not induce any change in the cotton constitutive volatile profile. Our results support the hypothesis that plants are able to detect pheromones of tightly co-evolved herbivores. Moreover, A. grandis pheromone exposure induced similar volatile compounds to herbivore-induced cotton, such as linalool, (E)-ocimene, (E)-4,8-dimethylnona-1,3,7-triene (DMNT), and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT). We also showed that the larval ectoparasitoid B. vulgaris relies on boll weevil's aggregation pheromone and pheromone-induced plant volatiles as kairomones to locate suitable hosts.

Host-plant location by the Guatemalan potato moth Tecia solanivora is assisted by floral volatiles.

Insects locate their host plants using mainly visual and olfactory cues, generally of the exploited plant structure. However, when the resource is difficult to access, it could be beneficial to utilise indirect cues, which indicates the presence of reward (e.g., oviposition site or mate). In the present study, we investigated the host-plant location strategy of the monophagous Guatemalan potato moth Tecia solanivora (Lepidoptera: Gelechiidae). The larva of the moth feed exclusively on potato Solanum spp. (Solanaceae) tubers usually hidden below ground. Using electrophysiological and behavioural tests, we characterised the olfactory cues mediating the attraction of the moth towards their host plant. Odour blends were made to represent different potato structures: tubers, foliage, and flowers. Synthetic blends were created by combining potato-emitted compounds that were antennal active which showed positive dose-response. Attraction to these blends of compounds in relation to the mating status of males and females was tested in dual-choice Y-tube assays. Both males and females, virgin and mated, were attracted to a three-compound blend representing flower odour, while foliage and tuber blends attracted neither sexes. Oviposition bioassays indicated additionally that the floral blend enhances oviposition. We show that potato flower odour might indicate the presence of an oviposition site for the female and possibly an increased mating opportunity for both sexes. Our results provide one of the few examples of the use of floral odour as a reliable indicator of host and probably mating possibility for phytophagous insects exploiting a site spatially separated from the flower.

Lack of spatial segregation in the representation of pheromones and kairomones in the mouse medial amygdala.

The nervous system is organized to detect, internally represent and process sensory information to generate appropriate behaviors. Despite the crucial importance of odors that elicit instinctive behaviors, such as pheromones and kairomones, their neural representation remains little characterized in the mammalian brain. Here we used expression of the immediate early gene product c-Fos as a marker of neuronal activity to find that a wide range of pheromones and kairomones produces activation in the medial nucleus of the amygdala, a brain area anatomically connected with the olfactory sensory organs. We see that activity in this nucleus depends on vomeronasal organ input, and that distinct vomeronasal stimuli activate a dispersed ensemble of cells, without any apparent spatial segregation. This activity pattern does not reflect the chemical category of the stimuli, their valence or the induced behaviors. These findings will help build a complete understanding of how odor information is processed in the brain to generate instinctive behaviors.

Response of Diabrotica speciosa (Coleoptera: Chrysomelidae) to 1, 4-dimethoxybenzene and analogs in common bean crop

Several synthetic and commercial analogs of 1,4-dimethoxybenzene, a kairomone of Diabrotica speciosa, along with other compounds already shown to be attractive to other species of Diabrotica, were tested as attractant to D. speciosa. Yellow cup traps were lured with the compounds and installed in a common bean field. Assessments were conducted 24 h later. 1,4-dimethoxybenzene lured traps caught significantly more beetles than the control traps. Captures of traps lured with 1,4-dimethoxybenzene analogs did not differ from the control traps. Results showed that position and nature of the substituents on the aromatic ring played a crucial role in the activity of the natural compound. The aromatic ring was also very important to the activity of the kairomone.

Uma série de compostos, sintéticos e comerciais, análogos ao 1,4-dimetoxibenzeno, um cairomônio de Diabrotica speciosa, juntamente com outros compostos comerciais atrativos para outras espécies de Diabrotica, tiveram suas atividades testadas frente à D. speciosa. Armadilhas de copos amarelos contendo os compostos foram instaladas em plantação de feijão. As avaliações foram realizadas 24 horas depois. Armadilhas com 1,4-dimetoxibenzeno capturaram significativamente mais insetos do que armadilhas testemunha. Armadilhas com análogos do 1,4-dimetoxibenzeno não capturaram mais insetos que as armadilhas testemunha. Os resultados mostraram que a posição e a natureza dos substituintes, juntamente com a aromaticidade verificada na estrutura do composto natural, são cruciais para a atratividade.

Avaliação da armadilha HP iscada com diferentes taxas de liberação de octenol na captura de anofelinos (Diptera: Culicidae) em Brejo do Mutambal, Município de Varzelândia, Estado de Minas Gerais / Evaluation of the HP trap baited with different release rates of octenol for capturing anophelines (Diptera: Culicidae) in Brejo do Mutambal, municipality of Varzelândia, State of Minas Gerais

Para avaliar o papel do octenol na coleta de anofelinos foram utilizadas armadilhas HP iscadas com diferentes taxas de evaporação. Foram capturados 285 anofelinos e não houve diferença entre o número de anofelinos coletados com as armadilhas controle e as iscadas com octenol e nem entre as taxas de evaporação.

To evaluate the role of octenol in collecting anophelines, HP traps baited with different rates of evaporation. A total of 285 anophelines was captured and there was no significant difference in the numbers of anophelines captured between the control traps and the traps baited with octenol and no difference between the release rates.