David Doll2 CommentsApril 5, 2018Insects

Put Leaffooted Bug Monitoring on Your To-Do List

Written By Kris Tollerup, UC IPM Advisor for the San Joaquin Valley Unlike many of the moth pests, we do not have an effective lure that acts to attract leaffooted bug (LFB) to a monitoring trap of some sort.  An LFB lure could be used in almond beginning at mid-March for detecting the pest when they first begin moving into the crop.  Unfortunately, development of a lure remains elusive; researchers out of the University of California, Riverside have worked on the issue for several years now.  They have recently identified compounds used by LFB for sexual and aggregation communication, but synthesis of the compounds has proven quite difficult. This means that good-old visual scouting provides the only viable option.  About this time (mid-March – early April) leaffooted bug begin moving into almond from their overwintering sites.  A caveat to this is that the recent cool weather may have slow their movement and caused some individuals to re-aggregate.  For instance, during early March, we observed signs that LFB had begun to disperse from overwintering sites; however, stopped short and reformed aggregations on nearby citrus trees.  This likely occurred due to cool, wet weather. With warmer weather certainly coming soon, begin monitoring in locations that historically have sustained damage and notably locations near pomegranate and riparian areas.  The bug typically prefers the sunny side of the tree and will rest on nuts on the outside area of the canopy.  Take about 15 seconds to visually inspect about 100 nuts per tree; monitoring 15 to 20 trees in a 5 to 10-acre area. Moreover, the University of California, Pest Management Guidelines recommends monitoring by examining nuts on the ground and in the tree for gummosis.  Keep in mind that gummosis from LFB or other stink bug feed appears clear while gummosis from other

Read More
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,

Read More
Kris Tollerup5 CommentsFebruary 5, 2017Insects

Where are Leaffooted Bug Overwintering?

Written by Kris Tollerup, University of California Cooperative Extension Area-wide IPM Advisor, Kearney Agricultural Research and Extension Center, Parlier, CA For a few seasons now, I have been interested in understanding more and ultimately finding better monitoring tools for Leaffooted bug, Leptoglossus spp.  Most growers and PCAs have a  good working knowledge of this bug and likely have attended one or more of my talks covering the subject.  We know that leaffooted bug overwinters in aggregations consisting of just a few to several hundred individuals.  The aggregations tend to occur on citrus, palm frowns, Cyprus trees, pomegranate, walnut (Fig. 1), olive, and on/in non-plant substrates like pump houses, farm equipment, and wood piles.  The list is extensive.  The reason why aggregations can occur on such a diversity of substrates is that they are not necessary interested in feeding but more so in seeking a protected area to survive winter.  An  interesting behavior that I have made is that aggregations typically occur where the group can best collect heat from the sun during peak solar radiation periods.  In spring or as early as late winter, individuals begin leaving aggregations.  I, as well as other researchers, found that dispersion is closely associated with temperature and not necessarily dependent on other environmental factors such as day length.  I observed some moderately large aggregations on pomegranate in Tulare Co. and after warm mid-February temperatures of about 80 F, nearly all the LFB dispersed.  To particularly where, at that early time in the season, we did not determine.  The site had neighboring plantings of citrus and olive, which we surveyed but did not observe LFB in those crops.  Typically at mid-March, LFB starts moving into almond and history shows that they can cause substantial economic damage.  Because of work conducted by a host of researchers

Read More
David Doll0 commentsApril 17, 2015Horticulture, Insects

Early Nut Split – Nut Drop or Bug Damage?

A few samples and farm calls have yielded nuts that are splitting pre-maturely. These nuts tend to be yellow in color and are often found dropping from the tree during high winds. Sometimes, the nuts have gum along the suture, or gum “specks” on the outside of the hull. These nuts could either be a “June Drop” as the tree is balancing the crop load or it could be kernel death caused by leaf-footed plant bug. The nuts dropped  could be the last dropping period within almonds. These nuts, when cut open, would be brown at the base of the nut, indicating the death of the connective tissue. Gum may exude from the suture of the hull. More importantly, there would be no noticeable holes through the hull or in the shell, although some degradation of the shell cells may occur. In contrast, Leaf-footed plant bug would have a pin hole through the hull. This hole would often extend through the shell and into the kernel, causing a darkened spot at the point of entry and a shriveling of the kernel. Gum may appear on the exterior of the hull where the bug entered its mouth parts, but does not always occur. Although gumming is usually immediate (if it occurs), nut yellowing and subsequent drop — based on research — occurs 14-23 days after the point of feeding/damage, variety dependent. Gumming is not as frequent on younger nuts. Knowing the cause of drop can provide information relevant to treatment decisions. If the drop is due to leaf footed plant bug, a treatment may be warranted. It is important, however, to determine if the bugs are still within the orchards. Since the nut drop is visible several weeks post feeding, the bugs may have moved out of the orchard and the

Read More
David Doll4 CommentsMarch 20, 2015Insects

Leaffooted Bug Advisory for Almonds

Written by Kris Tollerup and David Haviland University of California Cooperative Extension and UC Statewide IPM Program Pest control advisors need to be on the lookout for leaffooted bug. All indications are that 2015 has the potential to be a significant year for leaffooted bug damage to almonds.  This prediction is based on observations of very high populations of LFB during the fall of 2014 and a high overwintering survival rate due to mild winter weather.  During the past few days (~March 15th) multiple reports from across Kern County have been sent to UC Cooperative Extension offices that PCAs are starting to see movement into crops.  Although no known reports of leaffooted bugs have occurred in the mid and more northern growing areas, it would be prudent to begin monitoring now. Monitor for LFB at least once a week from mid-March through May, and then every one to two weeks through June.  The most effective monitoring method is to do a visual survey for the presence of bugs.  This can be done by using a long pole to knock branches in the upper tree canopy, causing the bugs to fly such that they can be seen or heard. Visual inspections should be coupled with inspections of the fruit by looking for gummosis on the almond hull.  However, by the time gummosis is seen, damage has already occurred.  Gummosis can also occur due to physiological damage.  Therefore, if the method is used, cross-section the area with gummosis to determine the presences of a pin-sized discolored wound caused by the penetration of the insect’s mouthparts.  Also inspect fruit on the ground for the presence of gummosis and a stinging wound to determine if LFB is the culprit.  Be sure not to confuse gummosis caused by LFB (clear to light amber color) with

Read More
David Doll0 commentsJune 3, 2011Insects

Diagnosing Leaffooted Plant Bug Damage – Video

Still working out a few glitches with taking and editing videos, but here is the latest edition focusing on the identification of damage caused by Leaf Footed Plant Bug. More information regarding control can be found at the UC IPM website. Also note that a new chemistry, Clothiandin (trade name Belay, Valent) has been registered and has been reported by a few independent consultants to do a good job in knocking down adult populations. Being a second generation neonicotinoid, it has been reported to reduce disruption of some beneficials within the orchard systems in comparison to pyrethroid insecticides. Enjoy!

Read More