Jhalendra Rijal1 CommentMarch 22, 2017Insects

Seasonal Insect Pest Monitoring Updates in Almonds

This year has been a challenging year to conduct any winter cultural practices due to constant rainstorms and flood situations. By now, however, mummy nut removal from the trees and ground should have been completed. Orchard sanitation is a very effective cultural method to control navel orangeworm (NOW) in nut crops. Almond mummies not only harbor overwintering larvae (Fig. 1), but also serve as the resource for egg laying (Fig. 2) by NOW females in the spring, during which new nuts are not yet vulnerable to NOW infestation. For insect monitoring in almonds, we already passed the trap placement timing (February 15) for Oriental fruit moth (remember the biofix of OFM was February 16 last year). Put navel orangeworm egg traps out by March 15 (South San Joaquin Valley) or by April 1 (North San Joaquin and Sacramento Valleys). Use black egg traps filled with the almond meal + 10% crude almond oil. Hang the traps at head height on the north side of the Nonpareil tree, at least 5 trees in from the edge. Put one trap per 10 acres with at least 4 traps per orchard. Remember to change the bait frequently as wet and lumpy bait is not effective in attracting females for egg laying. The biofix of NOW egg laying was April 18 last year. Follow the link for the details. Pheromone traps and lures are available to monitor male NOW activity. Although the relationship between egg and pheromone traps has not been fully understood, pheromone trap capture data still helps in making NOW control decision. In the orchard with NOW mating disruption, use of the pheromone trap is strongly recommended to assess whether the mating disruption is working. Negligible to no moth capture is expected if the mating disruption is working properly. For San Jose scale,

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David Doll1 CommentMay 2, 2010Insects

Managing Orchard Ants – time to scout for activity!

Pavement and Fire ants can cause significant damage to the almond crop. Feeding throughout the year on seeds of grasses and broadleaves, ants are only problematic once the almonds are shaken to the ground. Ants can completely hollow out the nut, leaving only the pellicle behind. Damage increases the longer the almonds are on the ground. Within the San Joaquin Valley, the southern fire ant has a wider distribution and usually causes more damage than the pavement ant. Pavement ants are found in the northern San Joaquin Valley and into the Sacramento Valley. Within Merced County, we have both the Southern Fire Ant and the Pavement Ant. Recently, Merced County has had infestations of the Red Imported Fire Ant (RIFA), a third problematic ant for almond growers, requiring quarantine actions to control this invasive pest. Please see Guide to Identifying Orchard Ants to help identify ants. Ants tend to be problematic on drip or sprinkler irrigated orchards. Within flood irrigated blocks, ants are limited to tree berms. Moist, cool temperatures increase above ground activity of ants; hot temperatures drive the ants deeper into the colony. Varieties with a tight shell seal are more resistant to ant damage, or with shell splits less than 0.03 inches wide. Shell seal can vary greatly year to year depending on crop load, nut size, and horticultural practices. The orchard should be surveyed for ant colonies 2-3 days after an irrigation in the months of April – May in order to determine if a treatment is needed. Once the temperatures increase, problematic ant surface activity decreases, giving an inaccurate count of the population. In scouting for ants to determine if treatment is necessary, choose five survey areas per orchard, each about 1000 sq. ft., including the soil area from mid-alley to mid-alley beneath trees. Count the number

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