This year, National Pollinator Week is June 22 to June 28, celebrating the value that pollinators such as bees, birds, butterflies, bats, and beetles provide to the ecosystem.

Pollinators, and natural enemies, can be harmed by pesticides when people are trying to control pests in their gardens and landscapes. Pollinators can be killed or harmed if they are sprayed or exposed directly to a pesticide, and when they encounter pesticide residues in the environment. You can protect pollinators in your garden and landscapes by doing the following:

• Use pesticides sparingly. Many pests can be managed using an integrated approach without the need to apply pesticides.
• Read labels carefully. Proper application of pesticides can reduce pesticide exposure to pollinators and natural enemies.
• Choose selective and nonpersistent pesticides. Avoid broad-spectrum, persistent insecticides such as carbamates, organophosphates, and pyrethroids.
• Select less toxic insecticides when possible. Look for soaps, insecticidal oils, microbial insecticides and botanical insecticides to manage pest outbreaks.

For more information, see this page on protecting natural enemies and pollinators and find recommended practices to protect bees from pesticides.

 

 

[From the Spring issue of the UC IPM Green Bulletin]

Argentine ants can be a damaging ant pest species in both agricultural and urban environments in California. Outdoors, they disrupt biological control by tending honeydew-producing pests and protecting them from natural enemies. Argentine ants are also common invaders of urban residential settings, making them the nuisance ant species most often treated by pest management professionals (PMPs).

Contact insecticide sprays are frequently used control options for Argentine ants due to practical advantages, such as easy application and relatively quick suppression of ant pest populations.In urban settings, sprays containing phenylpyrazole (i.e., fipronil) and various pyrethroids (e.g. deltamethrin, permethrin) are often used by PMPs to control these pests. When applied to hardscapes, these pesticides can run off into storm drains, and some of these insecticides are detected in urban waterways. For more details about pesticide runoff, see the June 2010 and July 2010 issues of the Green Bulletin.

Application restrictions

In an effort to reduce pesticide runoff, in 2012 the California Department of Pesticide Regulation (DPR) issued restrictions for pyrethroid use on hardscapes by licensed professionals. In addition, the U.S. Environmental Protection Agency approved new label amendments in April 2017 for fipronil products that will significantly change the way PMPs can apply fipronil in outdoor settings for Argentine ant control. While it is not yet known how these new changes will reduce off-site pesticide contamination, it is a good time to start investigating effective alternatives for ant control.

Improving baiting

Baiting with sugar-based liquid baits has been shown to be an effective control method for Argentine ants but requires bait stations to store and dispense the bait. Bait stations can be expensive and labor-intensive to maintain. To overcome these challenges, a group of researchers at UC Riverside—Drs. Jia-Wei Tay, Mark Hoddle, Ashok Mulchandani, and Dong-Hwan Choe—developed a natural hydrogel matrix to deliver liquid ant baits (Figure 1). The use of hydrogels may allow practitioners to apply liquid bait directly to the surface of the ground where ants forage without the need for a bait station.

What is hydrogel and how does it work?

Beads of alginate hydrogel, derived from seaweed, were mass-produced using a modified shower head nozzle (view the 11-minute video at youtu.be/NVMql2xClBk or the 36-second video below). The hydrogel beads were conditioned for 24 hours in a liquid bait (25% sucrose solution with a small amount of the insecticide thiamethoxam). This amount of thiamethoxam is significantly less than the percentage found in current commercial ant bait products. The highly absorbent hydrogel acts as a controlled-release formulation that keeps the liquid bait available and palatable for an extended period. The team determined the hydrogel's properties such as water uptake and water loss characteristics, pesticide intake, and the acceptance by foraging Argentine ants. In small-scale laboratory tests, the hydrogel bait provided excellent control against all stages (e.g., workers, brood, and queens) of the Argentine ant colony within 14 days.

Field results and future uses

To determine the efficacy of the alginate hydrogel bait in urban areas, it was field-tested around residential homes in the summer of 2016 (Figure 2). Argentine ant activity levels were estimated by consumption of a sucrose solution put out in monitoring vials over a 24-hour period. Based on the monitoring data, hydrogel bait containing 0.0001% of thiamethoxam provided a 79% reduction in ant activity eight weeks after treatment.

In 2017, the team coordinated field trials to evaluate the effectiveness of alginate hydrogel baits in controlling Argentine ant populations in commercial citrus groves. While this bait delivery system is currently only experimental, the research team hopes to find a pesticide manufacturer interested in commercializing this patent-pending technology to provide a highly-efficient, low-impact outdoor baiting option for Argentine ants and other sugar-seeking pest ant species.

This Earth Day, Sunday April 22, help natural enemies by growing insectary plants. Natural enemies, also called beneficials or biological control agents, include lady beetles (ladybugs), lacewings, spiders, parasitic wasps, and even some mites! These natural enemies feed on pests in the garden and landscape and may reduce the need for insecticides. Protect natural enemies by avoiding the use of pesticides that kill them and keeping ants out of pest-infested plants.

Insectary plants provide nectar, pollen, and shelter throughout the year for natural enemies. In order to provide a year-round source of food for them, choose plant species and cultivars that flower at different times and are well-adapted to your area. Here are a few that you may already be growing in your garden or landscape:

• Sweet alyssum
• Western redbud
• Flannel bush
• Toyon
• Milkweed
• California poppy

Visit UC IPM's Insectary Plants web page to learn more about the benefits of planting insectaries around the garden and to see a longer list of insectary plant species.

[From the Summer issue of the UC IPM Retail Nursery & Garden Center News]

Don't let the bed bugs bite? That's easier said than done, it seems. Bed bugs (Figure 1) continue to be important household pests globally, driving a growing sector of the pest control industry. Professionals have access to effective insecticides and specialized techniques, such as heat treatments, to control bed bug infestations. These services, however, can be expensive: a recent survey revealed the average cost of professional insecticide treatments and heat treatments to be $425 and $1,400, respectively, (see complete survey results.) Many people faced with infestations cannot afford these treatments.

You could be looking for do-it-yourself (DIY) ways to manage bed bugs, and see that many stores may carry dozens of products claiming to provide cheap and easy bed bug control. Research has shown, however, that bed bugs are very difficult to eradicate, even for knowledgeable professionals equipped with advanced pest control methods. So how can you be successful?

Know Your Rights as a Tenant

Owners and managers of rental properties are required to maintain housing that is safe and habitable. If you are a tenant in a rental housing situation, you should report infestations to the landlord or property manager. In cases where landlords refuse to help, there are regional tenants' rights groups that can help find justice for suffering tenants.

Identify the Problem

Bed bugs cannot be confirmed by dermal symptoms (“bites,” wheals, or rashes). The bugs themselves or their signs; such as cast skins, fecal spots, or eggs (Figure 2); must be recovered to positively identify the problem and move forward with pest management. For help identifying a bed bug infestation go to the UC IPM Pest Notes: Bed Bugs.

You can confirm a bed bug infestation by using bed bug monitors. Many models exist, though the most effective may be “interceptors,” pitfall traps that can be placed under the legs of beds and other furniture items (Figure 3). For more on bed bug monitors, read the ‘Pests in the Urban Landscape' blog article entitled “Bed Bug Monitors.”

Promote Nonchemical Tactics

Many times, small bed bug populations can be significantly reduced or even eradicated without using insecticides. Household washers and dryers used at the hot setting will kill all bed bug life stages within bedding, clothing, and other household items. Dissolving laundry bags will enable you to easily transport and wash infested items without spreading bugs around. Clutter management is crucial when battling bed bugs, since bugs can hide and breed within household clutter such as stacks of paper and piles of clothes. Purchase storage and organizational products to help manage clutter.

Mattress encasements (Figures 4a. and 4b.), fine-mesh cloth covers for mattresses and box springs, help to prevent bed bug establishment by eliminating cracks and crevices and can also be used to trap bed bugs within; they will eventually die of starvation. Vacuums are very effective at removing exposed bed bugs; ensure a HEPA filter is in place to minimize airborne allergens.

Consider Insecticides Carefully!

Insecticides can be dangerous when used incorrectly. Every year, people are injured while trying to control bed bugs. Total-release foggers, or “bug bombs,” are especially dangerous since they may contain flammable propellants. In addition, most retail insecticides simply don't work for bed bugs. Most liquid or aerosol products are “contact insecticides” that only kill bugs that come into contact with the spray or wet residue. Bed bugs only come out of hiding for minutes at a time while seeking their hosts and feeding, so you are unlikely to have opportunities to directly spray them.

Desiccants such as silica gel and diatomaceous earth may work better for a DIY approach; these powders absorb the waxy cuticles of bed bugs, causing them to die of water loss. Desiccants should be applied to cracks, crevices, and void spaces where bed bugs live and breed. They should never be applied liberally in the open where they can be breathed in; this may cause respiratory irritation.

Finally, your local store may carry products that claim to repel bed bugs, but almost none of them have been proven to work by research-based science.

Hopefully this information will help you control bed bugs if you decide to do it yourself. Please note, however, that professional services are almost always required to eradicate large infestations.