The photokinesis of oriental fruit flies, Bactrocera dorsalis, to LED lights of various wavelengths

Abstract

The oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae), is an invasive pest of orchards around the world, particularly in Asian countries such as China. Light traps offer a potential means for pest monitoring and management. This study aimed to evaluate the sensitivity of the fly to light and investigate the impact of monochromatic light in the sensitivity spectrum on B. dorsalis. Six light wavelengths in LEDs – green (522 nm), yellow (596 nm), blue (450 nm), red (633 nm), purple (440 nm), and white (compound light) – were adapted to test responses of 5‐, 10‐, and 20‐day‐old B. dorsalis adults kept in laboratory conditions. We also tested the effects of green and red lights on pupal development and adults’ life activities. The results indicated a phototaxis preference rank in B. dorsalis adults to monochromatic LEDs with, in decreasing order, green, yellow, purple, blue, and red. Moreover, positive phototaxis significantly increased with age. Male adults are more sensitive than female adults to test lights, mainly at the age of 10 and 20 days. Emergence rates of pupae exposed to 12 and 24 h green light daily were 42 and 67%, respectively, whereas controls held in red light emerged at 33 and 37%, respectively. Furthermore, body weight, female fecundity, and mortality of B. dorsalis in night‐time exposure of green light (from 21:00 to 09:00 hours; during daytime flies were illuminated by white LED light) were significantly higher than in red‐light test groups and dark controls. In conclusion, B. dorsalis displayed preference toward green light, and fly age and gender seemed to significantly impact the phototactic behavior. Green LED light exposure during nighttime remarkably improved the emergence rates of B. dorsalis, and it enhanced growth, development, and ovipositing peak period, but decreased adult lifespan. This research lays a foundation for the development of new trap models, e.g., with green sticky cards or green light, for monitoring and control of B. dorsalis in the field.

Comparison of Phototactic Behavior between Two Migratory Pests, Helicoverpa armigera and Spodoptera frugiperda

“…For the moth of Pelosia muscerda , rates of females and males tending to the light source were equal [ 20 , 47 ]. On the contrary, female moths of Loxostege sticticalis (Lepidoptera: Pyralidae) have displayed stronger phototactic responses than males [ 48 ]. Field experiments have shown that there are three sex ratios for the two moths, but in our study, no significant difference was found between the sexes.…”

Assessment of attractancy and safeness of (E)‐coniferyl alcohol for management of female adults of Oriental fruit fly, Bactrocera dorsalis (Hendel)

“…Nowadays, the monitoring and management of B. dorsalis largely relies on the lure-and-kill techniques of male flies using ME combined with toxicants. 2,5,6 However, in this strategy, only sexually mature males are affected, whereas females are much less lured.…”

“…The Oriental fruit fly, Bactrocera dorsalis (Hendel), is a serious polyphagous pest in horticulture 1–3 . Females of B. dorsalis oviposit eggs into ripening fruits, where the newly hatched larvae feed on the pulp until they migrate from fallen fruits on the ground to pupate in the soil 2,4–6 . Therefore, it is difficult to use pesticides to control fruit fly stages that are hidden in fruits and soil, thereby making insecticides unsuitable in this case 7 .…”

“…[1][2][3] Females of B. dorsalis oviposit eggs into ripening fruits, where the newly hatched larvae feed on the pulp until they migrate from fallen fruits on the ground to pupate in the soil. 2,[4][5][6] Therefore, it is difficult to use pesticides to control fruit fly stages that are hidden in fruits and soil, thereby making insecticides unsuitable in this case. 7 Moreover, resistance against synthetic pyrethroids, organophosphates, and abamectin insecticides is now prevalent among wild B. dorsalis populations.…”

The phototactic rhythm of pests for the Solar Insecticidal Lamp: A review

“…Unlike humans, the sensitive spectrum of pests is mainly concentrated in the 253 - 700 nm ( Pan et al., 2021 ). Thus, pests can perceive different light source wavelengths ( Liu et al., 2018 ). Currently, there are various studies on the phototropism of pests at different wavelengths.…”