Insect Management
Rice Insect Management
Long-Horned (Antennae) Grasshoppers
Family Tettigoniidae (katydids) In AR rice field: Conocephalus
fasciatus (DeGeer) and Orchelimum vulgare Harris Occasional Pests
Description
Adults of Conocephalus usually are about 1 inch in length and adults of
Orchelimum are 1 to 2 inches in length. The body is green with brown wing
covers. The antennae are longer than the body.
Distribution
Southern Canada and east of the Rocky Mountains to Northern Mexico.
Life Cycle
Adults and nymphs are most often found among grasses near margins of streams,
lakes, ditches, and in rice fields. It is not known if species taken in rice use
the plants or soil on levees for oviposition sites. Several generations are
possible.
Damage and Symptoms
Nymphs more than adults feed on young leaves. This is not believed to cause
economic damage. Adults and nymphs will feed on anthers of rice flowers and have
been found with 'starchy materials', presumably from rice kernels, in the
digestive system. Feeding on anthers and kernels is not believed to cause
economic damage.
Scouting
Long-horned grasshoppers can be sampled with a standard sweep net. The
efficiency of a sweep net on long-horned grasshoppers is not well known because
adults and nymphs drop or move deeper into the foliage when approached. No
treatment thresholds are available.
Commentary on Long-Horned Grasshoppers (LHG)
The food of LHG before it is digested is stored in a portion of the digestive
system called the crop. The contents of crops were examined in a season long
study. Rice leaf tissue was found at low levels throughout the season, but was
found in nymphs more often than in adults. Prior to flowering (anthesis) of
rice, LHG had remains of arthropods in the crop. Rice water weevils were a
favorite meal of the LHG. Once rice began flowering the frequency of pollen
replaced arthropods as a favorite meal.
Does feeding on anthers (pollen containing structures) cause a yield loss in
rice? Rice is self-pollinating, that is, the anthers rupture just before or
immediately after the hulls open to expose the stigma for pollination. LHG could
cause sterile florets, but probably not enough for economic losses. Starchy
material was found in LHG very late in the season. Feeding on kernels appear
limited and not enough to cause economic losses.
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