Black soldier fly (Hermetia illucens (Linnaeus, 1758)) larvae inhibit oviposition of house fly (Musca domestica Linnaeus, 1758) by releasing a semiochemical, although in some situations, inhibition is only partial. We hypothesized that there is a certain period in the life cycle of black soldier fly when it can cause antibiosis of the house fly. Choice and non-choice tests were used to separately examine the effectiveness of each developmental stage of black soldier fly (egg, larval (phase I, II, and III), prepupal and pupal stages) and crude extract of larvae on house fly oviposition. Tests using each developmental stage were compared with controls lacking black soldier fly. The effects of black soldier fly on the number of newly hatched house fly larvae were evaluated and there was a significant difference between the test and control in the number of eggs laid by house fly for all phases of the black soldier fly larval stage. Strong inhibition was found in some black soldier fly larval phases. Significant differences in the numbers of house fly eggs oviposited in food containers treated with crude extract were found when compared with a control, confirming that chemicals from black soldier fly larvae resulted in inhibition of oviposition of house fly. The results from experiment also indicated that chemicals from black soldier larvae influenced the number of house fly larvae newly hatched from eggs.
This research aimed to find indigenous plants and suitable solvents to extract substances with the capacity to suppress the immature stages of house fly populations in animal farms and urban areas. Seven native Thai plants were tested: Alstonia scholaris (L.) R.Br., Murraya paniculata (L.) Jack, Citrus aurantium L., Colocasia esculenta (L.) Schott, Limnophila aromatica (Lam.) Merr., Persicaria odorata (Lour.), and Manihot esculenta Crantz. Solvents with different polarities were used in series (hexane, ethyl acetate, acetone, ethanol, and water) to extract the active compounds from the plant tissues. The effects of extracts on immature stage were assessed separately in vitro using a completely randomized design with 5 replicates. The effects of each plant extract on the house fly stages varied depending on the solvent utilized. Extracts with high polarity solvents (ethanol and acetone) showed strong ovicidal activity but for larval and pupal stages, hexane, a low polarity solvent, demonstrated significant larvicidal and pupicidal activity. Acetone and ethanol solvents of P. odorata and L. aromatica caused notable mortality rate for the egg stage. Hexane extracts of M. paniculata and both hexane and ethyl acetate extracts of C. aurantium induced the highest percentage of larval mortality. Even if other plant extracts have less of an impact on the mortality of house fly eggs or larvae, they have an impact on the growth and development. The results showed that most plant extracts based on various solvents caused considerable mortality in house fly pupa. In this study, the hatching percentage of adult females was lower than the adult males after specific plant extracts were applied throughout the larval and pupal phases. High-efficiency plant extracts' LC50 and LC90 values for house fly immature stages were calculated. The acetone extract of P. odorata during the egg stage had LC50 and LC90 values of 7.816 and 31.117 mg/mL, respectively. At the larval stage, M. paniculata's hexane extract had concentrations of 4.865 and 22.284 mg/mL, while C. aurantium's ethly acetate extract had concentrations of 26.424 and 61.801 mg/mL. Significant active chemicals discovered by GC-MS analysis were included bioactive substances with insecticidal properties, including flavonoids, alkanes, coumarins, etc., were identified by GC-MS analysis.