The most critical issues we face in managing cereal aphids currently is the lack of local knowledge about the likely impact of infestations on yield and quality (the damage thresholds). (http://thebeatsheet-ipmnews.blogspot.com/2008/09/cereal-aphids-in-wheat-and-barley.html).
In recent days we have received a number of reports of slater activity in winter cereal crops in southern Queensland and northern NSW. Slaters are not generally regarded as a pest of broad acre agriculture and tend to feed on decaying vegetation and dead animal matter. Overall they perform an important recycling role in the environment however on rare occasions… Read more »
Over the past couple of weeks there have been numerous reports of armyworm in both barley and wheat. The appearance of armyworm in wheat raises a number of questions: 1) Do they behave the same way in wheat as in barley in relation to the type of damage they cause 2) what is their damage potential and is there an… Read more »
Grubs in winter cereals are not unusual at this time of year, and already there have been reports of high numbers (up to 20/m2) in Central Queensland wheat (Figure 1). More grubs can be expected in southern districts as the season warms up. The two most likely larvae (grubs) found in winter cereals are the corn earworm, Helicoverpa armigera, and… Read more »
Cereal aphid numbers have increased rapidly over the past 3 weeks as the temperatures have increased. Whilst low numbers of aphids have been present in many crops (wheat and barley) for some time, it was not until a couple of weeks ago that numbers reached levels of concern to agronomists and growers. Until the last few seasons, cereal aphids have… Read more »
Both Helicoverpa armigera and armyworm larvae are occurring together in wheat and barley. It is important to be able to separate the helicoverpa larvae from the armyworm larvae in order to determine whether the numbers are above or below threshold, and, if needed, to make the most appropriate decision about control options. Armyworm larvae have three white stripes on… Read more »
Corn earworm, Helicoverpa armigera, are frequently found in winter cereals but usually numbers are too low to warrant control. Occasionally, however, corn earworm numbers may be sufficient to cause economic damage. The high value of today’s grain is further reason to carefully check for grub infestations. It is not unusual to find both corn earworm and armyworm in cereal crops…. Read more »
With the current high value of barley, growers should closely monitor armyworm infestations as crops approach maturity. Armyworms are important pests in southern Queensland where they attack winter cereals, particularly barley and oats, in September and October. Larvae appear in plague proportions in some years, and are patchy in others. Head cutting by large larvae can lead to serious losses… Read more »
Making decisions about control of Cereal Aphids This post is an update on cereal aphid management following a number of enquiries from growers and agronomists over the last week or so. Which species in crops? There are two species of aphid you are most likely to encounter in winter cereals (oats, wheat and barley). They are the oat aphid (Rhopalosiphum… Read more »
Aphid control decisions tend to be more problematic in moisture stressed winter cereal crops, since in a well supplied crop the level of moisture extracted from the crop by aphids is of little concern. However, in dry times every drop seems precious. Had we not received the recent rain over the last few days throughout southern Queensland and northern NSW… Read more »
