Inheritance of an extended diapause trait in theNorthern corn rootworm,Diabrotica barberi(Coleoptera:Chrysomelidae)

Abstract

Diapause is an adaptive trait that delays development or reproduction under unfavourable circumstances. The northern corn rootworm,Diabrotica barberi Smith & Lawrence, an important maize, Zea mays L., pest in the Diabroticite species complex, overwinters in diapause during the egg stage. Some NCR populations are adapted to crop rotation by expressing an extended diapause (ED) trait that delays embryonic development for 2 years. This ED trait has increased in frequency and geographic distribution since first reported in Illinois in 1932. Reciprocal single pair crosses among beetles from a laboratory colony with the ancestral 1-year diapause trait and field collected beetles with the 2-year ED trait indicated that ED females laid significantly more ED eggs than did females with the 1-year diapause trait regardless of male genotype. The ED trait was highly heritable [realized heritability (h 2 ) = 0.698 ± 0.314], with genetic dominance (D) of the trait strongly influenced by female genotype. Selection of the ED trait and maintenance of polymorphic diapause phenotypes within maize-soybean cropping systems is discussed in relation to response to a fluctuating environment and as a potentially advantageous life history adaptation. AbstractDiapause is an adaptive trait that delays development or reproduction under unfavourable circumstances. The northern corn rootworm, Diabrotica barberi Smith & Lawrence, an important maize, Zea mays L., pest in the Diabroticite species complex, overwinters in diapause during the egg stage. Some NCR populations are adapted to crop rotation by expressing an extended diapause (ED) trait that delays embryonic development for 2 years. This ED trait has increased in frequency and geographic distribution since first reported in Illinois in 1932. Reciprocal single pair crosses among beetles from a laboratory colony with the ancestral 1-year diapause trait and field collected beetles with the 2-year ED trait indicated that ED females laid significantly more ED eggs than did females with the 1-year diapause trait regardless of male genotype. The ED trait was highly heritable [realized heritability (h 2 ) = 0.698 ± 0.314], with genetic dominance (D) of the trait strongly influenced by female genotype. Selection of the ED trait and maintenance of polymorphic diapause phenotypes within maize-soybean cropping systems is discussed in relation to response to a fluctuating environment and as a potentially advantageous life history adaptation.

Inheritance of diapause regulation in the multicoloured Asian ladybird Harmonia axyridis (Coleoptera: Coccinellidae)

“…Earlier studies indicate that the male plays a more important role in the determination of diapause in its progeny, for example, in several species of Lepido ptera (Ikten et al, 2011;Chen et al, 2012;Xia et al, 2012;Huang et al, 2013;Fu et al, 2015;Xiao et al, 2015;Pruisscher et al, 2017). In some other insects in other orders, however, females have the same (Paolucci et al, 2016) or an even stronger (Kuang et al, 2011;Chen et al, 2014;French et al, 2014) infl uence than males on diapause in their progeny. In some cases, the relative importance of male and female parents depends on the parameter of diapause studied.…”

“…Similar to that recorded in this study, diapause is dominant in the linden bug, Pyrrhocoris apterus L. (Dolezel et al, 2005), Drosophila littoralis Meigen (Lumme et al, 1975) and two Tetranychus species (Ignatowicz & Helle, 1986;Takafuji & Goka, 1999). In contrast, in certain other insects and mites diapause is a recessive character (Sakakibara & Kawakami, 1992;Suwa & Gotoh, 2006;Han & Denlinger, 2009;Chen et al, 2012;French et al, 2014). In the face fl y, Musca autumnalis De Geer (Kim et al, 1995) and fl esh fl y Sarcophaga similis Meade (Goto, 2009) diapause is only partially dominant.…”

“…It is well established that photoperiodic, thermal, trophic and other diapauseregulating responses are well adapted to local climate and therefore may differ not only between species but also between geographically distant populations of the same species (Denlinger, 2002;Saunders et al, 2002;Saunders, 2010;Goto & Numata, 2014). This intra-specifi c variability has been thoroughly investigated in several model insects (Lumme et al, 1975;Henrich & Denlinger, 1983;Kim et al, 1995;McWatters & Saunders, 1997;Doležel et al, 2005;Williams et al, 2006;Goto, 2009;Han & Denlinger, 2009) and in some other, mostly economically important, Coleoptera (Sakakibara & Kawakami, 1992;Kuang et al, 2011;Chen et al, 2012Chen et al, , 2014French et al, 2014;Lehmann et al, 2016;Tanaka & Murata, 2016), Le-the photoperiodic response of invasive populations from Europe (Pardubice, 50.0°N) and the Caucasus (Sochi, 43.6°N) is weak (Reznik et al, 2015a).…”

Fitness trade‐offs in pest management and intercropping with colour: an evolutionary framework and potential application

“…; French et al. ). Due to the financial cost and difficulty of developing new pest control methods, continuously abandoning good strategies is surely not a sustainable practice.…”

Emerging issues in Integrated Pest Management Implementation and Adoption in the North Central USA

“…Rotation resistance subsequently spread to parts of surrounding states before stalling out in the mid 2000s ). The northern corn rootworm also evolved rotation resistance, but by a different mechanism: extended diapause, where eggs remain in diapause for two or more years (Krysan et al 1986;Levine et al 1992;French et al 2012). Although natural enemies of rootworms exist, there has been little success in enhancing population control in the USA (see Gray et al 2009).…”