INFLUENCE OF CULTURAL PRACTICES ON DAMAGE CAUSED BY INOPUS RUBRICEPS (MACQUART) (DIPTERA: STRATIOMYIDAE) TO SUGARCANE

Abstract

A survey of damage caused by Inopus rubriceps to sugarcane was carried out in the Millaquin-Qunaba mill area near Bundaberg. Damage was less frequent in first and second ratoon crops than in older ratoons. An effect of sugarcane varieties was evident, but damage levels were the same for the 3 main varieties in the district. No damage was recorded in fields treated with suSCon Blue (controlled-release chlorpyrifos granules) against canegrubs (Coleoptera: Scarabaeidae). Damage was more frequent in cane fields that had been replanted immediately after ploughout of the previous crop than in those that had an interval without cane. This interval could be a bare fallow or a rotation with a vegetable crop. Other factors including rotary hoeing, past use of dieldrin, and use of chlorpyrifos EC at planting were not shown to affect the frequency of damage. IntroductionThe sugarcane soldier fly Inopus rubriceps (Macquart) is a pest of sugarcane in central and southern Queensland (Hitchcock 1970) and in northern New South Wales (Osborn and Halbert 1972). Cane is grown by planting pieces of stalk (setts) to produce the first harvestable crop. Subsequent crops are produced by regrowth (ratooning) of the stubble after each harvest. After several ratoon crops the old stubble is ploughed out and the field planted again with fresh setts. The soil-dwelling larvae of the sugarcane soldier fly feed on the cane roots causing poor growth and ratoon failures. Germination of the cane setts can be inhibited in severe infestations. Affected fields are frequently ploughed out prematurely.

A larva de Chiromyza vittata Wiedemann (Diptera: Stratiomyidae)

“…I. rubriceps, endêmica da Austrália, foi introduzida nos Estados Unidos da América (Kessel 1948, McFadden 1967, Robertson 1985. Suas larvas são reconhecidas como praga efetiva de cultivos de cana-de-açúcar, e têm sido intensamente estudadas naqueles países (Robertson 1986, Samson et al 1991, Samson & Harris 1995, chamando a atenção o trabalho de Samson & McLennan (1992), onde foi testado o desenvolvimento das larvas de Inopus rubriceps em 13 espécies de diferentes famílias de plantas (Gramineae, Cruciferae, Curcubitaceae, Leguminosae e Solanaceae). Segundo os autores, as larvas obtiveram rápido crescimento não só na canade-açúcar, mais também em sorgo, "legumes" e tomate, demostrando grande adaptação alimentar das larvas em hospedeiros alternativos.…”