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We can only hope recent cold reduced overwintering pests DR. M.O. “MO” WAY
TEXAS Rice Research Entomologist moway@aesrg.tamu.edu Southeast Texas experienced a severe cold snap lasting almost a week beginning about Valentine’s Day. The temperatures (both high and low) were well below freezing for several days. Some Texans were still without power and water the week of Feb. 22. I don’t know how the weather affected our Texas rice farmers, but possibly storage facilities, stored rice and farm equipment may have been damaged. One benefit for stored rice is very cold outside air may have been circulated in storage bins to minimize stored insect pests. Some of our rice farmers also raise crawfish and cattle, which may have been affected. Southeast Texas has not experienced weather this severe in over 100 years. Since I am an entomologist, I will make some conjectures concerning the severe weather effects on rice arthropod pests. As you know, I am an applied entomologist — not an evolutionary biologist — so please don’t take my comments as gospel. This lengthy cold snap may have adversely affected overwintering populations of certain insects that could impact population densities this coming season. The rice water weevil and rice
stink bug are native to the southeastern United States. The weevil overwinters as an adult in perennial clump grasses like Paspalum spp., while the stink bug overwinters as an adult in duff on the ground or even under pine bark. I know the weevil can enter a state of diapause, which can be triggered by day length and temperature. Diapause can cause physiological changes in the insect to allow it to survive adverse conditions. Some diapausing insects increase the concentration of glycerol in their blood, which acts like an anti-freeze. I’m not sure if the rice stink bug enters diapause in preparation for the winter. In any event, native insects in Southeast Texas have evolved over eons to adapt to our climate. Thus, I would think these insects may be less affected by the recent cold snap than invasive pests, like the rice planthopper, which hails from the tropics (Central and South America). Maybe this cold snap wiped out any surviving planthoppers in Texas — we can only hope! The same may be said for the channeled apple snail, which is native to Brazil. Some of you Texas rice farmers also grow soybeans. As you know, the redbanded stink bug has become the major pest of Texas soybeans, and this stink bug originated in South America. Another invasive pest is the sugarcane aphid, which has become a big problem on sorghum in the South; however, this aphid is thought to originate in the African Tropics. Another Texas rice pest is the Mexican rice borer, which overwinters as a late instar larvae or pupa in rice stubble and weedy grasses. Maybe overwintering populations this year will be reduced, since this stem borer originated in Mexico as its name implies. Only time will tell.
MO WAY
The view from Jeanie and Mo Way’s back porch in Fannett, Texas, Feb. 16, when the temperature was 16 degrees Fahrenheit. Their corgi, Sophie, enjoyed the cold.
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MARCH 2021
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