Economic and Highly Effective Trap-Lure Combination to Monitor the Mexican Fruit Fly (Diptera: Tephritidae) at the Orchard Level

Simulation to investigate site-based monitoring of pest insect species for trade

Pest insect surveillance using lures is widely used to support market access requirements for traded articles that are hosts or carriers of quarantine pests. Modeling has been used extensively to guide the design of surveillance to support pest free area claims but is less commonly applied to provide confidence in pest freedom or low pest prevalence within sites registered for trade. Site-based surveillance typically needs to detect pests that are already present in the site or that may be entering the site from surrounding areas. We assessed the ability of site-based surveillance strategies to detect pests originating from within or outside the registered site using a probabilistic trapping network simulation model with random-walk insect movement and biologically realistic parameters. For a given release size, time-dependent detection probability was primarily determined by trap density and lure attractiveness, whereas mean step size (daily dispersal) had limited effect. Results were robust to site shape and size. For pests already within the site, detection was most sensitive using regularly spaced traps. Perimeter traps performed best for detecting pests moving into the site, although the importance of trap arrangement decreased with time from release, and random trap placement performed relatively well compared to regularly spaced traps. High detection probabilities were achievable within 7 days using realistic values for lure attractiveness and trap density. These findings, together with the modeling approach, can guide the development of internationally agreed principles for designing site-based surveillance of lure-attractant pests that is calibrated against the risk of non-detection.

Efficacy of lure mixtures in baited traps to attract different fruit fly species in guava and vegetable fields

Fruit flies (Diptera: Tephritidae) are major pests of fruits and vegetables worldwide. We measured the efficacy of attractive lure mixtures in baited traps on naturally-occurring fruit flies in commercial mosaic guava and vegetables fields in Pakistan. We tested three mixtures (methyl-eugenol [ME] and cue lure [CL]; GF-120 and methyl eugenol; and GF-120 and cue lure) in eleven ratios: 0:100, 10:90, 20:80, 30:70, 40:60, 50:50, 60:40, 70:30, 80:20, 90:10, and 100:0. We recorded three fruit fly species: Bactrocera zonata was the most abundant in baited traps, followed by Bactrocera dorsalis, while Zeugodacus cucurbitae was significantly less attracted to baited traps. We also found that the most attractive mixture and ratio varied among species: B. dorsalis was most attracted by 40CL:60ME, while B. zonata was most and equally attracted by 100ME, 10CL:90ME, 20CL:80ME, 30CL:70ME, and 40CL:60ME. Finally, Z. cucurbitae was most attracted by 10CL:90ME, which resulted in the highest total number of flies counted in 10CL:90ME-baited traps. Mixtures with GF-120 were less attractive to all three species. Our results suggest that lure mixtures in baited traps influence the attraction of fruit flies in a species-specific way. This needs to be considered in the integrated pest management of multiple species of fruit flies simultaneously. If Bactrocera species are most damaging and abundant, a 40CL:60ME mixture in baited traps will likely be most effective to reduce pest abundance and crop damage. However, if Z. cucurbitae is the main pest target causing most crop damage and yield loss, 10CL:90ME-baited traps will be a more effective in their monitoring and management.

Electrophysiological Responses of the Mediterranean Fruit Fly, Ceratitis capitata, to the Cera Trap® Lure: Exploring Released Antennally-Active Compounds

The Mediterranean fruit fly (medfly), Ceratitis capitata, is a worldwide pest of agriculture able to use olfactory cues to locate habitat, food sources, mates and oviposition sites. The sensitivity of medfly olfaction has been exploited to develop olfactory-based attractants that are currently important tools for detection, control and eradication of its populations. Among these is Cera Trap^® (BIOIBERICA, S.A.U.), a cost-effective bait. Here we used coupled gas chromatography/electroantennographic detection (GC-EAD) and GC/mass spectrometry (GC-MS) approaches to characterize the medfly antennally-active compounds released by this lure. We identified GC peaks corresponding to chemicals belonging to six different classes including heterocyclic aromatic compounds, aliphatic alcohols, aldehydes, esters, sesquiterpene hydrocarbons, and aromatic alcohols. We tested ten potential candidate volatiles belonging to these classes and predicted to be emitted by the lure and found that they were eliciting electroantennographic responses in medfly adults. These results will help in unravelling the physiological mechanisms of odor perception in both sexes, especially in relation to Cera Trap^® attractant activity, which in the field has been shown to be female-specific. These findings and their developments will ultimately expand the toolbox for medfly control in the field.

A First Glimpse of the Mexican Fruit Fly Anastrepha ludens (Diptera: Tephritidae) Antenna Morphology and Proteome in Response to a Proteinaceous Attractant

Anastrepha ludens is a key pest of mangoes and citrus from Texas to Costa Rica but the mechanisms of odorant perception in this species are poorly understood. Detection of volatiles in insects occurs mainly in the antenna, where molecules penetrate sensillum pores and link to soluble proteins in the hemolymph until reaching specific odor receptors that trigger signal transduction and lead to behavioral responses. Scrutinizing the molecular foundation of odorant perception in A. ludens is necessary to improve biorational management strategies against this pest. After exposing adults of three maturity stages to a proteinaceous attractant, we studied antennal morphology and comparative proteomic profiles using nano-LC-MS/MS with tandem mass tags combined with synchronous precursor selection (SPS)-MS3. Antennas from newly emerged flies exhibited dense agglomerations of olfactory sensory neurons. We discovered 4618 unique proteins in the antennas of A. ludens and identified some associated with odor signaling, including odorant-binding and calcium signaling related proteins, the odorant receptor co-receptor (Orco), and putative odorant-degrading enzymes. Antennas of sexually immature flies exhibited the most upregulation of odor perception proteins compared to mature flies exposed to the attractant. This is the first report where critical molecular players are linked to the odor perception mechanism of A. ludens.

Management of Euxesta spp. in Sweet Corn with McPhail Traps

Pests attacking the ear of sweet corn, such as Helicoverpa and Euxesta species, cause economic losses for the producer and the processing industry. Feeding on the style-stigmata preventing fertilization and on the developing grain and the association with pathogens are the main causes of product depreciation. The traditional control such as spraying with chemicals is not effective, even with several applications directed to the corn ear. Bacillus thuringiensis (Bt) corn also does not reach the fly. McPhail traps that have been used to monitor the pest can be a control strategy. This work evaluated the efficiency of food attractants placed inside McPhail traps to remove adult insects, in order to reduce ear damage. Twelve McPhail-type traps were installed in a randomized complete block design containing Bio Anastrepha® alone or combined with different doses of insecticide. Every 10 days, all the captured insects were counted and separated by species and sex. Only Euxesta eluta and Euxesta mazorca were found. The occurrence of insects was greater in the period between silk emergence and grain filling. The number of females was higher, probably due to the need to feed before oviposition. The number of E. mazorca females caught in the treatment containing only Bio Anastrepha® was higher compared with that of others. The mean ear damage was very low, and there was no interaction between the production parameters and the distance between the trap and the harvested plant. In short, the use of McPhail trap containing food attractants may be a viable alternative to control corn silk flies.

The Fruit Fly Lure CeraTrap: An Effective Tool for the Study of the Arboreal Ant Fauna (Hymenoptera: Formicidae)

Despite preliminary reports of ants trapped in food-baited fruit fly traps, little is known regarding the identity of the myrmecofauna that can be sampled using this technique. This study aimed to examine the inventory completeness, activity and species occurrence of canopy ant assemblages collected in baited traps used for monitoring fruit flies in different fruit orchards in central Veracruz, Mexico. The trap models used in the sampling were Multilure, McPhail glass, and 500 ml blue polyethylene bottles. Three commercial fruit fly food attractants (CeraTrap, Captor + Borax, and BioLure) and two grape juice products (Jumex grape juice and Tang) were used as baits for sampling. In total 3,626 ant workers belonging to 54 species, 19 genera, 10 tribes, and 5 subfamilies were collected. Among the five food attractants used in this study, CeraTrap recorded a markedly higher inventory completeness, ant activity and species occurrence per trap. This study reports for the first time the use of CeraTrap, as a promising and effective food attractant for collecting the foraging ants in the canopy of agroecosystems, which may be applicable to other habitats such as natural forests, mangroves, or agricultural settings such as coffee plantations.

Benzalkonium Chloride Provides Remarkable Stability to Liquid Protein Lures for Trapping Anastrepha obliqua (Diptera: Tephritidae)

Hydrolyzed protein lures are widely used to monitor fruit fly pests but are rapidly degraded by microbial activity and must be replaced frequently. To improve the stability of lures, the quaternary ammonium biocide, benzalkonium chloride (BC), was evaluated in mixtures with two hydrolyzed proteins commonly used to monitor Anastrepha spp. The mean number of Anastrepha obliqua adults captured during six consecutive weeks using Captor + borax with the addition of 240 mg BC/liter, not renewed during the test, was similar to Captor + borax that was replaced at weekly intervals and was more effective than Captor + borax without BC. Numbers of A. obliqua flies captured in 30% CeraTrap diluted in water containing 240 mg BC/liter were similar to those caught in traps baited with Captor + borax or 30% CeraTrap without BC in the first 9 d of evaluation but was significantly more effective than both lures after 56 d. After >2 mo of use, 30% CeraTrap containing 240 mg BC/liter remained as effective as newly prepared 30% CeraTrap. The addition of BC to lures reduced surface tension of liquid lures by ~40-50%. However, when BC was increased to 720 mg BC/liter, only a small additional reduction in surface tension was observed and higher concentrations of BC did not increase capture rates. These findings could contribute to reduced costs for trapping networks and the development of long-lasting formulations of liquid protein lures for bait stations and mass-trapping targeted at major tephritid pests.

Mass trapping is as effective as ground bait sprays for the control of Anastrepha (Diptera: Tephritidae) fruit flies in mango orchards

BACKGROUND

Anastrepha fruit flies are considered one of the main phytosanitary problems for the fresh fruit industry in the USA, Caribbean islands and Latin America. Since 1994, the Mexican government has implemented the National Fruit Fly Program using an area-wide integrated pest management approach. In this paper, we evaluate the effectiveness of mass trapping and compare it with ground GF-120 spraying against Anastrepha obliqua and Anastrepha ludens populations in mango cv. Ataulfo orchards.

RESULTS

Multilure® traps baited with Ceratrap® or Biolure® captured significantly more fruit flies than Captor 300 in field cage tests. Mass trapping and ground GF-120 spray significantly suppressed fruit fly populations compared with untreated plots. In Multilure traps placed in untreated plots, we captured significantly more fruit flies than in treated plots with mass trapping or GF-120 sprays. Plots treated with either mass trapping or GF-120 sprays reduced the percentage of infested fruit significantly compared with untreated plots. There was no difference between mass trapping and GF-120 ground bait spraying.

CONCLUSION

Our results demonstrate that mass trapping was as effective as GF-120 ground spraying for the control of fruit flies in mango cv. Ataulfo orchards. The suppression effect of mass trapping was similar to GF-120 ground bait spraying. © 2017 Society of Chemical Industry.

Development of a Low-Cost and Effective Trapping Device for Apple Maggot Fly (Diptera: Tephritidae) Monitoring and Control in Mexican Commercial Hawthorn Groves

Few efforts have been made in Mexico to monitor Rhagoletis pomonella (Walsh) (Diptera: Tephritidae) in commercial hawthorn (Crataegus spp.) crops. Therefore, the main objectives of this study were to evaluate infestation levels of R. pomonella in feral and commercial Mexican hawthorn and to assess the efficacy of different trap-lure combinations to monitor the pest. Wild hawthorn was more infested than commercially grown hawthorn at the sample site. No differences among four commercial baits (Biolure, ammonium carbonate, CeraTrap, and Captor + borax) were detected when used in combination with a yellow sticky gel (SG) adherent trap under field conditions. However, liquid lures elicited a slightly higher, although not statistically different, capture. Cage experiments in the laboratory revealed that flies tended to land more often on the upper and middle than lower-bottom part of polyethylene (PET) bottle traps with color circles. Among red, orange, green, and yellow circles attached to a bottle trap, only yellow circles improved fly captures compared with a colorless trap. A PET bottle trap with a red circle over a yellow background captured more flies than a similar trap with yellow circles. An SG adherent yellow panel trap baited with ammonium carbonate was superior to the improved PET bottle trap (red over a yellow background) baited with different liquid proteins, but a higher proportion of females and no differences in fly detection were measured in PET traps baited with protein lures. These trials open the door for future research into development of a conventional nonadherent trap to monitor or control R. pomonella.

Evaluation of Food Lures for Capture and Monitoring of Anastrepha fraterculus (Diptera: Tephritidae) on Temperate Fruit Trees

The Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) is the main pest of fruit trees grown in temperate climates in the southern region of Brazil. The objective of this work was to evaluate the efficiency of the major commercial food lures used in Brazil for trapping and monitoring of A. fraterculus in plum, pear, and feijoa orchards. The assessed lures were hydrolyzed proteins of animal origin (CeraTrap) and plant origin (BioAnastrepha), torula yeast + borax (Torula), and grape juice. Response variables included the rate of adult capture (flies per trap per day, FTD) and the percentage of females captured. We also evaluated the number of times the weekly capture rate exceeded the traditional threshold of 0.5 FTD for each lure. Traps baited with grape juice, currently used for monitoring A. fraterculus in Southern Brazil, captured fewer adults and a lower percentage of females compared with the other lures. CeraTrap trapped a greater number of A. fraterculus adults and, in some cases, a lower percentage of females compared with the other lures in pears. Traps baited with CeraTrap had greater capture rates (FTD), particularly during the stages of fruit maturation and harvest, and even in years with low population density of A. fraterculus, thus demonstrating greater sensitivity in the detection of this pest. These results show that, in order to detect and monitor the presence of A. fraterculus in plum, feijoa, and pear crops, protein-based lures are superior to grape juice, especially the animal protein CeraTrap.

Long-term attraction and toxic effects of tephritid insecticide-bait mixtures by applying Torricelli's barometer principle in a trapping device

BACKGROUND

The field activity of the mixtures of liquid baits and insecticides used in the control of tephritid pests is normally short, both when they are sprayed or when used in trapping or in attract-and-kill devices. A new lure-and-kill device based on Torricelli's barometer principle was tested as a long-lasting dispenser for two liquid hydrolysed protein baits mixed with insecticide, GF-120 and Captor 300 + malathion, against Anastrepha ludens (Loew) flies of laboratory origin. The dispensers were kept under field conditions for 42 days. Laboratory bioassays for insecticide properties and field cage studies for attraction capacity were carried out on a weekly basis after 22 and 42 days of weathering respectively.

RESULTS

Our results demonstrated that both mixtures of insecticides and phagostimulant baits killed up to 80% of the tested flies when they were 42 days old. The attraction capacity of both weathering-exposed mixtures was even higher than fresh insecticidal-bait mixtures after the same period.

CONCLUSION

The device is efficient when used with the liquid baits currently employed in the control of tephritid flies. It also offers a high potential for combining visual stimuli, such as shape and colour, and for improving trapping and bait station designs. Incorporating this new device in trapping and attract-and-kill methods could help to reduce the frequency of servicing of the traps and bait stations and lower their costs. © 2015 Society of Chemical Industry.

Comparison of Hydrolyzed Protein Baits and Various Grape Juice Products as Attractants for Anastrepha Fruit Flies (Diptera: Tephritidae)

Mexican fruit flies, Anastrepha ludens (Loew; Diptera: Tephritidae), have traditionally been trapped in citrus orchards in Mexico using protein hydrolysates as bait. Recently, CeraTrap(®), an enzymatic hydrolyzed protein, has emerged as an effective lure for monitoring A. ludens at the orchard level and is currently being used by growers in the region of Veracruz. Several studies have revealed that grape juice is highly attractive to A. ludens, and recent work supports its potential use for regulation purposes. In our study, the attraction of A. ludens to different grape products was evaluated in citrus orchards and in comparison to other Anastrepha species in an area composed of mango and chicozapote orchards. Attraction to grape lures was compared with CeraTrap and the standard protein Captor +borax trap. In general, CeraTrap was more attractive than different commercial grape products in several experiments. Only Jumex, a commercial grape juice, did not differ significantly from CeraTrap in the capture of A. ludens males and females in a citrus crop. However, several drawbacks were detected when using Jumex grape juice: 1) higher tendency to capture males, 2) less selectivity against non-targeted insects, 3) higher capture of beneficial lacewings, and iv) the need to re-bait weekly owing to lower stability. In the area containing mango and chicozapote, CeraTrap was more attractive than Captor + borax for Anastrepha obliqua and Anastrepha serpentina, followed by grape juice products, which were the least attractive for these fruit fly species.