Competitive Ability and Fitness Differences between Two Introduced Populations of the Invasive Whitefly Bemisia tabaci Q in China

Abstract

BackgroundOur long-term field survey revealed that the Cardinium infection rate in Bemisia tabaci Q (also known as biotype Q) population was low in Shandong, China over the past few years. We hypothesize that (1) the Cardinium-infected (C +) B. tabaci Q population cannot efficiently compete with the Cardinium-uninfected (C −) B. tabaci Q population; (2) no reproductive isolation may have occurred between C + and C −; and (3) the C − population has higher fitness than the C + population.Methodology and ResultsTo reveal the differences in competitive ability and fitness between the two introduced populations (C + and C −), competition between C + and C − was examined over several generations. Subsequently, the reproductive isolation between C + and C − was studied by crossing C + with C − individuals, and the fitnesses of C + and C − populations were compared using a two-sex life table method. Our results demonstrate that the competitive ability of the C + whiteflies was weaker than that of C −. There is that no reproductive isolation occurred between the two populations and the C − population had higher fitness than the C + population.ConclusionThe competitive ability and fitness differences of two populations may explain why C − whitefly populations have been dominant during the past few years in Shandong, China. However, the potential role Cardinium plays in whitefly should be further explored.

Sex ratios in the haplodiploid herbivores, Aleyrodidae and Thysanoptera: A review and tools for study

“…However, the authors did not control for host genotype, which makes it difficult to distinguish how much of the difference seen is due to Cardinium relative to host differences coincidentally associated with Cardinium infection. Cardinium was not shown to manipulate reproduction or sex ratios in this study (Fang et al 2014).…”

“…tabaci MED whiteflies were infected with Cardinium in Shandong, China. After establishing infected and uninfected lines in the laboratory (all fixed for Portiera and Hamiltonella), Fang et al (2014) found that uninfected whiteflies greatly outnumber infected individuals after a few generations, and have higher growth rates, indicating that Cardinium may be detrimental to its host. However, the authors did not control for host genotype, which makes it difficult to distinguish how much of the difference seen is due to Cardinium relative to host differences coincidentally associated with Cardinium infection.…”

Development of Bemisia tabaci MEAM1 and MED on Tomato (Solanum lycopersicum) Alone and in a Mixed Population

“…We hypothesized that our test population of Eastern MED (Q2), collected from a residence in Palm Beach County, would demonstrate a competitive disadvantage on tomato in relation to MEAM1 as MED had in China. However, given that the pest status of MED populations can be influenced by endosymbiont fauna, host plant, and history of exposure to insecticides, it is difficult to predict how MED populations in Florida will behave based on information derived from countries where growing conditions are in many ways distinct from Florida (Fang et al 2014;Mouton et al 2014;Fujiwara et al 2015;Su et al 2016). In addition, we present the results of probit analysis for imidacloprid and thiamethoxam tolerance from 2 MED populations collected from hibiscus (Hibiscus rosa-sinensis L.; Malvaceae) in Palm Beach County, and 13 MEAM1 populations collected from commercial vegetable fields in south Florida between late 2016 and mid-2017.…”

Plant-mediated interspecific horizontal transmission of an intracellular symbiont in insects

“…The intracellular bacterium “ Ca. Cardinium hertigii” 1 (hereafter Cardinium ) is an intriguing arthropod symbiont capable of reproductive manipulation 2 3 4 5 or of determining effects ranging from stimulation of the host’s immune response 6 , to fecundity benefits 5 7 , or even to reduction of the host’s fitness 8 .…”