To seek sufficient resources for growth, survival and reproduction, most insect species must tackle host selection problems. The development, survivorship and fecundity of the oriental fruit moth Grapholita molesta (Busck) on apricot Prunus armeniaca L., plum Prunus salicina L., nectarine Prunus persica var. nectarina L. Batsch, peach Prunus persica L., pear Pyrus sorotina Will. and apple Malus domestica Mill. were determined to test host suitability in the laboratory. Larval development rate was faster, and survival rate was higher on plum and nectarine compared with the other fruits. Adult longevity and the duration of oviposition were significantly longer on nectarine. Adult fecundity varied significantly among the tested host plants, with the highest fecundity being observed on apple (135.63 eggs/female), followed by pear (104.90 eggs/female). The intrinsic rate of increase (r m ) was greater on pear and apple (0.1574 and 0.1221 eggs per female per day, respectively). Different abilities to develop and reproduce on various host plants partly explain the seasonal host selection of G. molesta.
Plant colouration is known to be used by some nocturnal flower-visiting insects to foraging among colourful flowers in dim light. However, it remains unknown whether crepuscular species possibly reliably discriminate plant colouration (i.e. colour and/or brightness) for oviposition even driven by challenges of variably light conditions and similar leaf colouration. Here, we explored this question in the oriental fruit moth Grapholita molesta, a major pest of stone fruits worldwide, using coloured squares under changing illuminants (1000, 100, 1 and 0.01 mW/m 2 ). G. molesta female preferred to oviposit on green and orange over yellow, red, blue and purple with a lower discrimination at starlight (0.01 mW/m 2 ), whereas the preferential brighter white can be discriminated clearly from those achromatic grey and black at all tested light intensities. When both cues were presented in conflicting for oviposition, the moths were more attracted to brightness than colour cues irrespective of light intensity they are exposed to. Interestingly, there was a decrease in the reflectance between young and old leaves of P. persica at similar wavelengths between 500 and 550 nm, providing an apparent brightness. Ovipositing females preferred the brighter light green over the dark green. Our results indicate that as a more reliable cue, brightness of leaves rather than colour plays a more important role for mediating crepuscular moth G. molesta to lay eggs on young leaves in microhabitats in changing light environments. We discuss that the brightness oriented in oviposition task in complex orchards is relevant to leaf apparency.
The chive gnat, Bradysia odoriphaga , is a notorious pest of Allium species in China. Colour trapping is an established method for monitoring and control of Bradysia species. In order to clarify the effect of colour preference of B . odoriphaga for the perched substrate, multiple-choice tests were used to assess the response of the chive gnat to different colour hues and brightness levels under different intensities of white illumination and two spectrally different illuminations. Given the choice among four colours differing in hue under different intensities of white illumination and two spectrally different illuminations, chive gnat adults significant preferred the black substrate, a lesser preference to brown and green substrates, and the least preference to orange substrate irrespective of illumination. Given the choice among four levels of brightness under the same illumination conditions as those in the previous experiment (different intensities of white illumination and two spectrally different illuminations), chive gnats preferred black substrate over dark grey, light grey and white substrates. Meanwhile, both virgin and mated adults significantly preferred black over other colour hues and brightness. Based on our results, we conclude that the chive gnat adults significantly prefer black substrates irrespective of colour hues and brightness. This behaviour does not alter with ambient light condition changes. No difference observed between choices of female and male adults. Our results provide new insight for understanding the colour choice behaviour in chive gnat and pave a way to improve monitoring and control of chive gnats and management.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.