The larva of codling moth Cydia pomonella (Tortricidae, Lepidoptera) is known as the worm in the apple, mining the fruit for food. We here show that codling moth larvae are closely associated with yeasts of the genus Metschnikowia. Yeast is an essential part of the larval diet and further promotes larval survival by reducing the incidence of fungal infestations in the apple. Larval feeding, on the other hand, enables yeast proliferation on unripe fruit. Chemical, physiological and behavioral analyses demonstrate that codling moth senses and responds to yeast aroma. Female moths are attracted to fermenting yeast and lay more eggs on yeast-inoculated than on yeast-free apples. An olfactory response to yeast volatiles strongly suggests a contributing role of yeast in host finding, in addition to plant volatiles. Codling moth is a widely studied insect of worldwide economic importance, and it is noteworthy that its association with yeasts has gone unnoticed. Tripartite relationships between moths, plants, and microorganisms may, accordingly, be more widespread than previously thought. It, therefore, is important to study the impact of microorganisms on host plant ecology and their contribution to the signals that mediate host plant finding and recognition. A better comprehension of host volatile signatures also will facilitate further development of semiochemicals for sustainable insect control.
El artículo seleccionado no se encuentra disponible por ahora a texto completo por no haber sido facilitado todavía por el investigador a cargo del archivo del mismo.
We evaluated photosystem II (PSII) functionality in potato plants (Solanum tuberosum L.) before and after a 15 min feeding by the leaf miner Tuta absoluta using chlorophyll a fluorescence imaging analysis combined with reactive oxygen species (ROS) detection. Fifteen minutes after feeding, we observed at the feeding zone and at the whole leaf a decrease in the effective quantum yield of photosystem II (PSII) photochemistry (ΦPSII). While at the feeding zone the quantum yield of regulated non-photochemical energy loss in PSII (ΦNPQ) did not change, at the whole leaf level there was a significant increase. As a result, at the feeding zone a significant increase in the quantum yield of non-regulated energy loss in PSII (ΦNO) occurred, but there was no change at the whole leaf level compared to that before feeding, indicating no change in singlet oxygen (1O2) formation. The decreased ΦPSII after feeding was due to a decreased fraction of open reaction centers (qp), since the efficiency of open PSII reaction centers to utilize the light energy (Fv′/Fm′) did not differ before and after feeding. The decreased fraction of open reaction centers resulted in increased excess excitation energy (EXC) at the feeding zone and at the whole leaf level, while hydrogen peroxide (H2O2) production was detected only at the feeding zone. Although the whole leaf PSII efficiency decreased compared to that before feeding, the maximum efficiency of PSII photochemistry (Fv/Fm), and the efficiency of the water-splitting complex on the donor side of PSII (Fv/Fo), did not differ to that before feeding, thus they cannot be considered as sensitive parameters to monitor biotic stress effects. Chlorophyll fluorescence imaging analysis proved to be a good indicator to monitor even short-term impacts of insect herbivory on photosynthetic function, and among the studied parameters, the reduction status of the plastoquinone pool (qp) was the most sensitive and suitable indicator to probe photosynthetic function under biotic stress.
The common house mosquito, Culex pipiens (Diptera: Culicidae), which is considered the primary bridge vector of West Nile Virus (WNV) to humans, is a wide spread insect pest with medical importance and consists of two distinct bioforms, Cx. pipiens f. pipiens and Cx. pipiens f. molestus. Here, we consider the adult lifespan of male and female Cx. pipiens f. pipiens under controlled conditions at five constant temperature regimes (15, 20, 25, 27.5, and 30 °C). Our results show that adult longevity was affected by temperature, as it significantly decreased with increase in temperature. At the highest tested temperature, mean adult longevity did not exceed 12 days for both sexes and thus makes impossible the risk of WNV transmission. On the other hand at the lowest temperature, longevity was extremely high with some individuals surviving up to 129 and 132 days, males and females, respectively, and thus enable them to function as potential vectors of WNV for a prolonged period of time. As far as sex is concerned, adult females displayed a 1.2-1.4-fold longer longevity compared to the male ones. However, this difference was significant only at the lowest and highest tested temperature regime. This information is useful in determining the critical temperatures which may affect the distribution of Cx. pipiens and consequently the risk of WNV transmission. Moreover, the effect of environmental temperature should be considered when evaluating the abundance of these species.
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.