Entomologists at New Mexico State University are warning growers of the possibility of finding new invasive insect pests in New Mexico affecting numerous crops including alfalfa hay, sorghum and a number of vegetables and fruits.
“It’s a continual struggle,” said Jane Pierce, NMSU Extension entomologist. “We try to intercept them before they get into the U.S., then before they get into New Mexico, but insects are often very good at migrating into new areas. We try to eradicate them when there are isolated pockets but some insects will get established in New Mexico and we need to learn how to minimize damage.”
Carol Sutherland, NMSU Extension entomologist and New Mexico Department of Agriculture state entomologist, said new pests can reduce yields as well as diminish product quality, affecting financial stability and potentially jobs.
“Marketing problems can be compounded by the negative responses of other states or countries to the arrival and establishment of a new invasive pest,” Sutherland said. “While diversification of crops can cushion some of the impacts of a new invasive pest, it may make crops affected by this pest less attractive or useful for crop rotation.”
Pierce explained that alfalfa hay has an impact of $300 million in annual revenue, making it New Mexico’s number one crop. Alfalfa growers are sometimes surprised, though, to find unexplained damage from the white fringed beetle.
The larvae of this beetle, which causes the damage, cannot be treated, but adult populations can be reduced by treating them with an insecticide.
“Growers don’t always recognize the damage because it looks like damage from diseases,” Pierce explained. “You need to look for thinning spots, then dig up plants and check the roots to see if there are any holes.”
Spotted winged drosophila flies are causing significant damage to cane berries in some parts of the New Mexico. Specialists in Colorado consider this tiny red-eyed fly a “game changer” for the fruit industry in that state. New Mexico’s grape and wine industries should be on the lookout for this fruit destroyer, as well as a very large leafhopper – the glassy-winged sharpshooter – a potential vector of Pierce’s disease that can kill grape vines.
The Bagrada bug, another insect that has caused problems in New Mexico before, was first detected in southern New Mexico in 2010. The next year populations were present in Luna, Socorro and Valencia counties, followed by Santa Fe in 2012.
This bug is attracted to cruciferous vegetables, canola, potatoes, corn, sorghum, cotton and some legumes. In New Mexico, the Bagrada bug prefers Chinese greens, arugula and mustards as well as various weeds, including London rocket, wild mustards and pepperweed.
This bug is known to leave scorched leaves and blind terminals. They hide at the base of the plant and on soil cracks or crevices. It is best to check the plants during mid-morning when temperatures are higher and the insects are more active.
The list of invasive pests almost on New Mexico’s doorstep continues to grow. Tree-killing emerald ash borers were confirmed in Colorado, Arkansas and Louisiana in 2013, 2014 and 2015, respectively. Japanese beetles are established in parts of Colorado and the eastern parts of Oklahoma and Kansas, where significant amounts of nursery stock are sourced for New Mexico’s nursery industry.
Exotic fruit flies from Mexico, Central America or elsewhere pose a particular threat since their larvae can be difficult to detect in large amounts of imported fresh produce entering the U.S.; these invasive pests represent a threat not to just fruit growers (apple, cherry, peach) but also to the chile industry since chile pods are botanically fruits.
Pierce said the Southwest region of the United States also needs to be on the lookout for the brown marmorated stink bug, which is now common in much of the eastern U.S. It has previously been found in Texas and once in New Mexico.
“Sooner or later it will get into New Mexico, so we can try to control it by detecting it shortly after it arrives, and this way, we may be able to eradicate that local population before it gets established.”
New Mexico sorghum growers should anticipate the arrival of a particularly destructive pest called the sugar cane aphid. This aphid expanded its diet from eating sugarcane to sorghum, and over the last year moved from south Texas to the Panhandle.
“Last year it was spotted northwest of Lubbock, Texas. It is not far away, and it could be in New Mexico this season,” Pierce said.
Crops are not the only economic issue. European honey bees have been plagued by invasive pests including honeybee tracheal mites, varroa mites and pathogens they transmit, and most recently, small hive beetles.
Pierce urges growers to talk to their county agents and take any insects or damaged plants to them to be examined if they see unusual problems.
“With such an extensive list of invasive insects and problems they present, every New Mexican should be aware of our agricultural vulnerability,” Sutherland added. “While high quality photographs can help document some pest problems or their consequences, the best evidence of a potential pest problem is a good sample of the pests themselves. Contact your county Extension agent for instructions on how to take such a sample and submit it for identification.”