Be on the alert for fall armyworms this fall. Increased-than-normal populations of this lawn-eating insect have been reported from many areas in Texas this previous summer season and we’ve got began to see them in San Antonio and Austin areas.
Whereas fall armyworms are nothing new, based on Wizzie Brown, Extension Program Specialist for IPM in Austin, these worms began showing in dwelling lawns in late July to early August. Often, infestations happen in late summer season or early fall, however the climate can play a giant half. The quantity of rain we’ve got had this yr helped with egg survival and it will possibly additionally delay predators from feeding on the eggs.
Fall armyworm (FAW) is the caterpillar stage of a colorless grey moth, identified scientifically as Spodoptera frugiperda. It feeds totally on grasses, although it has been reported feeding on dozens of non-grass crops and weeds. It earns the identify “armyworm” from its behavior, throughout occasions of main outbreaks, of marching, army-like, throughout fields, roads, and yards, consuming all the pieces in its path.
The armyworm caterpillar is recognized by three skinny white or yellow stripes on the defend behind the top (pronotum), an inverted white Y on the face between the eyes, and by 4 darkish hair-bearing bumps (tubercles) on the highest of the eighth belly section. It takes three to 4 weeks of feeding to succeed in its full size of about 1.25 inches (34 mm). For a video that may assist you to acknowledge this worm take a look at this episode of Yard Bug Hunt.
The grownup FAW moth has a wingspan of about 1.5 in. The hind wings are white; the entrance wings are darkish grey, mottled with lighter and darker splotches. On male moths every forewing has a noticeable whitish spot close to the acute tip.
Injury and Management
Injury typically seems to happen in a single day, although armyworms want not less than three to 4 weeks to finish their six larval phases (instars). The final week or two of the larval stage is when a lot of the feeding, and injury, happens.
Fall armyworms feed on commonest garden grasses like bermudagrass and St. Augustinegrass. However as a result of armyworms feed on the leaves, and never on the essential roots and stolons, a bit irrigation or a rain ought to restore lawns to their unique situation inside per week or two.
If that is unacceptable to your buyer or faculty district, FAW is comparatively simple to manage with any pyrethroid insecticide. Natural buyer lawns may be handled with merchandise containing spinosad, a naturally occurring microbial toxin. Remember to keep away from treating areas with flowering weeds or clovers which may appeal to bees, or else mow the garden (and flowerheads) previous to treating. It will assist defend pollinators which may in any other case be drawn to freshly sprayed lawns.
Fall armyworm grownup are sturdy fliers, travelling a whole bunch of miles from overwintering websites in south Florida, south Texas, and Mexico every spring. In a wierd, obvious case of migration suicide, offspring of those northern migrants can not survive freezing winter climate. And in contrast to monarch butterflies which return to Mexico every winter, FAWs by no means return south. Due to this fact, they and all their offspring perish within the chilly climate. The evolutionary benefit of this uncommon conduct, if any, is just not properly understood.
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Unsure what you’ve in relation to odd wanting “worms” in your yard, take a look at this publish on the College IPM web site “What worm are you?”