Nutritional resources used by the invasive maize pest Diabrotica virgifera virgifera in its new South‐east‐European distribution range

Abstract

Food utilization by adults of the invasive maize ( Zea mays L.) (Poaceae) pest western corn rootworm (WCR; Diabrotica virgifera virgifera LeConte) (Coleoptera: Chrysomelidae) was investigated in the south-eastern part of its new European distribution range. At weekly intervals over a 10-week period, 10 beetles per field were collected from six fields that had a high abundance of flowering weeds and six fields with a low abundance of flowering weeds, with the aim of understanding adult feeding behaviour in Europe and comparing this behaviour with North American WCR. Gut content analysis was performed to determine the use of maize tissue and weed pollen with regard to maize phenology. Furthermore, all pollen found within the gut was quantified and identified to plant species level. The use of maize tissue by adult WCR changed over time according to maize phenology. Pollen originating from plants other than maize was used more frequently as the maize matured. Adults fed on pollen from 19 of 25 different plant species found in maize fields and showed a preference for the pollen of specific weeds. Pollen from weed species was found more often in beetles from fields with a high abundance of weeds compared to beetles from fields with a low abundance of weeds. Females consumed greater amounts of pollen than males, the latter feeding on a wider diversity of host plants. The pollen resources used by adult WCR in Hungary were more diverse compared to WCR in the USA, which may contribute to the invasion success of WCR in Europe.

Adaptation and Invasiveness of Western Corn Rootworm: Intensifying Research on a Worsening Pest

“…Western corn rootworms have been observed in southeastern Europe dispersing from maize fields to feed on other plants such as sunflower (Helianthus annuus), alfalfa (Medicago sativa), or flowering weeds present in field margins (79). Campbell & Meinke (11) reported that western corn rootworms moved frequently between the maize and prairie interface in east and central Nebraska study sites depending on the phenology of plants that served as food sources.…”

“…Economic losses on a global scale far exceed the $1 billion estimate since the western corn rootworm has continued to spread across Europe (40,44). Larvae of this univoltine chrysomelid feed on roots of maize and some other grass species (8, 9, 15, 91), and adults consume primarily leaf tissue, silks, tender kernels, and pollen (79). The insect overwinters as eggs which are laid in the soil of maize fields from late July through early September and from which larvae hatch the following spring.…”

Scientific Opinion on an application from Pioneer Hi‐Bred International and Dow AgroSciences LLC (EFSA‐GMO‐NL‐2005‐23) for placing on the market of genetically modified maize 59122 for food and feed uses, import, processing and cultivation under Regulation (EC) No 1829/2003

“…It was first detected near Belgrade (Serbia) in 1992, but has since spread across the continent (Hummel, 2003;Kiss et al, 2005a;Boriani et al, 2006;Ciosi et al, 2008;Gray et al, 2009;Meinke et al, 2009), resulting in well-established populations in approximately 19 European countries (EC, 2012). 5 It is expected that this invasive pest species will expand further in the EU (Hemerik et al, 2004;Moeser and Vidal, 2005;Ciosi et al, 2011;Aragón and Lobo, 2012).…”

Ethylene Contributes to maize insect resistance1-Mediated Maize Defense against the Phloem Sap-Sucking Corn Leaf Aphid

“…In addition, chrysomelid beetles (e.g. Diabrotica virgifera) feed from the maize silks, tender kernels, and pollen (Culy et al, 1992;Moeser and Vidal, 2005). Corn leaf aphids (CLA; Rhopalosiphum maidis), similar to other phloem sapfeeding aphids, use their slender stylets present in their piercing/sucking mouthparts to consume nutrients from the phloem sap that otherwise are used by the plants for their normal growth.…”