Effects of monoterpenes on mortality, growth, fecundity, and ovarian development of Bactrocera zonata (Saunders) (Diptera: Tephritidae)

Abstract

The peach fruit fly (PFF), Bactrocera zonata, is a serious insect pest infesting fruits and vegetables. The insecticidal activity of three monoterpenes, namely, (R)-camphor, (R)-carvone, and (1R,2S,5R)-menthol, was evaluated on the second-instar larvae of B. zonata. In addition, the latent effects of monoterpenes on pupation, adult emergence, deformation, oviposition, adult longevity, and ovarian development were also examined. The three tested monoterpenes showed pronounced insecticidal activity against B. zonata larvae with (R)-carvone being the most potent toxicant. When the second-instar larvae of B. zonata were treated with monoterpenes at concentrations of 20, 50, and 70 mg/kg for 72 h, significant reduction in pupation and adult emergence was observed. The three monoterpenes caused complete suppression of adult emergence at 100 mg/kg. Moreover, monoterpenes induced complete inhibition of egg deposition at all tested concentrations. Some adult deformations were also noticed at 20, 50, and 70 mg/kg. However, (R)-carvone was more effective than (1R,2S,5R)-menthol and (R)-camphor on the examined biological parameters. On the other hand, histological examination of the ovaries of emerged females from larvae that fed on diet treated with (R)-carvone, (1R,2S,5R)-menthol, and (R)-camphor at 20 and 50 mg/L indicated that both concentrations caused retardation in the development of ovarioles. It is clear that all the egg chambers are empty; the germarium region is constricted at base due to the failure of oocyte formation. Many vacant spaces were present between ovarioles.

A review on dill essential oil and its chief compounds as natural biocide

“…Moreover, the egg deposition was completely inhibited at all concentrations of tested components. At 20 and 50 mg/L of carvone, menthol and camphor, the decrease in ovarian development was observed 122 …”

Toxics or Lures? Biological and Behavioral Effects of Plant Essential Oils on Tephritidae Fruit Flies

“…Several studies have addressed the toxic action of EOs to their main compounds, monoterpenoids, and phenylpropenes [ 45 , 134 , 141 , 148 ]. The fumigant toxic effect has been tested for several monoterpenoids, such as α-pinene, linalool, carvacrol, eugenol, p -cymene, cinnamaldehyde, anethole, terpineol, and cuminaldehyde [ 134 ].…”

“…Thymol is also able to bind to GABA receptors associated with chloride channels located on the membrane of postsynaptic neurons and disrupts the functioning of GABA synapses [ 152 ]. The monoterpene ( R )-carvone proved to be an efficient toxicant towards second-instar larvae of B. zonata , together with ( R )-camphor and (1 R ,2 S ,5 R )-menthol [ 148 ]. These compounds cause adult malformation and decrease female longevity, affecting the hormonal balance of the adult fruit flies.…”

“…These monoterpenes may act similarly to growth-regulating hormones, such as juvenile hormones [ 153 , 154 ]. In addition, ( R )-camphor, ( R )-carvone, and (1 R ,2 S ,5 R )-menthol show destructive effects on ovary and ovarioles of B. zonata females, where they can lead to complete inhibition of oviposition [ 148 ].…”

Terpenoids as Potential Geroprotectors

“…Immunomodulatory activity (increase in total leukocyte count) was detected in Balb/c mice after the consumption of limonene and perillic acid [ 46 ]. D-limonene has chemopreventive activity against mammary, skin, liver, lung, and forestomach cancer in rodents [ 47 ]. D-limonene and its derivatives have chemotherapeutic and chemoprophylactic efficacy in cancer in various preclinical model systems [ 48 ].…”