Insecticidal Properties of Erythritol on Four Tropical Tephritid Fruit Flies, Zeugodacus cucurbitae, Ceratitis capitata, Bactrocera dorsalis, and B. latifrons (Diptera: Tephritidae)

Electroantennographic and Behavioral Responses of the Melon fly, Zeugodacus cucurbitae (Coquillett), to Volatile Compounds of Ridge Gourd, Luffa acutangular L

The melon fly, Zeugodacus cucurbitae (Coquillett), is a major invasive pest, widely distributed in the Asia-Pacific region and some parts of Africa. Melon fly attractants could improve the effectiveness of current pest management measures. Previous studies have shown that some host fruits are attractive to melon flies but few have investigated the chemical compounds responsible for their attraction. In this study, we aimed to identify the volatile compounds from Luffa acutangula L that attract Z. cucurbitae. In headspace trapping, chemical profiling identified 19 compounds from ridge gourds, with 1-pentadecene being the major component. EAG results revealed that seven compounds elicited antennal responses in Z. cucurbitae, and significant differences in antennal responses between male and female Z. cucurbitae adults were recorded to p-xylene, alpha-pinene, and 1-octadecene. Behavioral experiments demonstrated that the EAG-active compounds methyl isovalerate and methyl myristate had either attractive or repellent effects on Z. cucurbitae at different concentrations, and 1-octadecene attracted Z. cucurbitae. Our findings provide a theoretical basis producing repellents or attractants for effective Integrated Pest Management of Z. cucurbitae.

Re-evaluation of erythritol (E 968) as a food additive

This opinion addresses the re-evaluation of erythritol (E 968) as food additive and an application for its exemption from the laxative warning label requirement as established under Regulation (EU) No 1169/2011. Erythritol is a polyol obtained by fermentation with Moniliella pollinis BC or Moniliella megachiliensis KW3-6, followed by purifications and drying. Erythritol is readily and dose-dependently absorbed in humans and can be metabolised to erythronate to a small extent. Erythritol is then excreted unchanged in the urine. It does not raise concerns regarding genotoxicity. The dataset evaluated consisted of human interventional studies. The Panel considered that erythritol has the potential to cause diarrhoea in humans, which was considered adverse because its potential association with electrolyte and water imbalance. The lower bound of the range of no observed adverse effect levels (NOAELs) for diarrhoea of 0.5 g/kg body weight (bw) was identified as reference point. The Panel considered appropriate to set a numerical acceptable daily intake (ADI) at the level of the reference point. An ADI of 0.5 g/kg bw per day was considered by the Panel to be protective for the immediate laxative effect as well as potential chronic effects, secondary to diarrhoea. The highest mean and 95th percentile chronic exposure was in children (742 mg/kg bw per day) and adolescents (1532 mg/kg bw per day). Acute exposure was maximally 3531 mg/kg bw per meal for children at the 99th percentile. Overall, the Panel considered both dietary exposure assessments an overestimation. The Panel concluded that the exposure estimates for both acute and chronic dietary exposure to erythritol (E 968) were above the ADI, indicating that individuals with high intake may be at risk of experiencing adverse effects after single and repeated exposure. Concerning the new application, the Panel concluded that the available data do not support the proposal for exemption.

Erythritol sprays reduce Drosophila suzukii infestation without impacting honey bee visitation nor fruit quality

BACKGROUND

Spotted-wing drosophila, Drosophila suzukii, is an economic pest of small fruits and cherries. Insecticides primarily control this pest while alternative controls are in development. Laboratory studies show that erythritol is insecticidal to D. suzukii and other pests while approved for human consumption. Moreover, erythritol combined with sucrose or non-caloric sucralose can stimulate feeding and quicken mortality. Before growers can use erythritol, the impact on crop protection, non-target insects, and fruit quality need evaluation.

RESULTS

In three blueberry and cherry field cage trials, oviposition on fruit sprayed with erythritol:sucrose or erythritol:sucralose formulations was lowered by 59%-81% compared with unsprayed controls. Fly infestation (larval or adult counts from fruit) was 90% lower in a greenhouse blueberry trial, and 49% lower in an open field blueberry trial with 2 m erythritol : 0.5 m sucrose. Infestation was also 57% lower in an open field cherry trial with 1.5 m erythritol:0.5 m sucrose. Other field trials with very low pest pressure or frequent rains revealed no differences from controls. Field trials consistently revealed that honey bees did not preferentially visit plants sprayed with either erythritol formulation, although yellow jackets visited plants sprayed with erythritol:sucrose more frequently. Erythritol formulations consistently led to more leaf spotting, but there was no reduction in the quality of treated blueberries or cherries in terms of mold development, firmness, diameter, epidermal penetration force, and Brix° (total soluble solids) at harvest.

CONCLUSION

Eleven trials conducted over four years show that erythritol formulations can reduce D. suzukii pressure without attracting foraging honey bees nor negatively impacting fruit quality. © 2023 Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.