Habitat management in control of Astylus atromaculatus (Coleoptera: Melyridae) in maize under subsistence farming conditions in South Africa

Abstract

Studies were conducted in South Africa to assess the potential role of a habitat management strategy developed for the control of cereal stemborers in control of Astylus beetle. This strategy involves intercropping maize with a stemborer moth-repellent fodder plant (Desmodium) ('push'), with a stemborer moth-attractant host plant (Napier grass) ('pull'), planted as a perimeter/trap crop around the plot ('push-pull' system). Treatments were habitat managed plots, comprising of 'push-pull' and 'pull' plots, and maize monocrop plots (control). A combination of choice tests and field trials were employed to evaluate any impact of this system on Astylus beetle colonization of maize fields. Results showed Significant reductions in beetle populations in habitat managed plots (>60 %). Similarly, there was a significant reduction in beetle capture (>50%) in Desmodium-baited yellow water traps in two-choice tests, although the total number of beetles captured was generally low «50%). In addition, Desmodium caused a reduction of 11-15% in beetle captures in the multiple-choice tests. Habitat management thus shows potential for use in Astlyus beetle management in maize in the affected areas, largely through the barrier effects of Napier grass.

Pollen beetle (Astylus atromaculatus)-associated gastroenteric disease in cattle: report of 6 natural outbreaks

“…A. atromaculatus is a common pollen beetle in crops in South America, feeding mainly on maize, sunflower, and sorghum, among others. 4,7,12,21 The areas in which these outbreaks occurred are well known for their intensive agricultural activity. During the summer of 2023, severe drought was recorded in these areas (http://www.inia.uy/Publicaciones/Documentos%20compartidos/Informe%20agroclimatico%20INIA-GRAS%20Enero%20de%202023.pdf, Spanish; https://www.smn.gob.ar/sites/default/files/informe_sequia.pdf, Spanish) with consequent low crop production and flowering rate.…”

“…This beetle is commonly named the spotted maize beetle, astilo moteado, or 7 de oro. 4,12,21 Flowers of the crops are necessary for the survival of A. atromaculatus . Adult stages are 7–9 mm long and are identified by yellow wing coverts (elytra) with symmetrical black spots, and black thorax, legs, and antennae.…”

Determining the efficacy of push-pull for management of Eldana saccharina (Walker (Lepidoptera: Pyralidae) in sugarcane through on-farm field trials in KwaZulu-Natal.

“…Push-pull technology is a habitat management strategy that seeks to manipulate the distribution of insect pest populations within an agroecosystem (Conlong and Rutherford 2009). The push-pull programme in South African sugarcane is based on research that was conducted in East Africa for the control of cereal stemborers, such as Chilo partellus Swinhoe (Lepidoptera: Crambidae) and Busseola fusca Fuller (Lepidoptera: Noctuidae) (Khan et al 1997a;Midega et al 2005). This method of push-pull uses plants that both repel and attract targeted pests in a manner that decreases crop infestations (Kasl 2004; Barker et al 2006).…”