Beneficial Insects Work Hard in Summer Gardens

Beneficial Insects Work Hard in Summer Gardens

I know this is going to come as a shock to some readers, but not all bugs are bad.  In fact, while there are over 1 million species of insects worldwide, less than 1% are problem pests!  This problem 1%, composed of common garden pests, including aphids, stinkbugs, nuisance caterpillars, and scales, get all the attention and for good reason; they can be extremely destructive to home and commercial crops.  However, the good guys, beneficial predatory insects, are out there too, providing valuable pest control day and night and should be considered in part of a quality garden pest management strategy.

Beneficials come in many shapes and sizes.  Some are commonly known predators, such as spiders, Lady Beetles and Praying Mantids, while others are lesser known pest nemeses, like Paper Wasps, Pirate Bugs, and Lacewings.  Regardless, gardeners should do their homework and be able to identify beneficials when they see them and allow them to do their jobs. The presence, or not, of a handful of Lady Beetles or Lacewings on the attack can be the difference between needing to treat with insecticides for an aphid outbreak or just letting nature take its course.  Studies have shown that just one individual Lady Beetle in the larval stage can consume as many as 500 aphids; adult Lady Beetles are even hungrier aphid eaters!  Paper Wasps, you know the ones who make the large “papery” nests around eaves of house and other structures, play an important beneficial role, frequently preying on caterpillars.  If their nests aren’t near highly trafficked areas around your home and you don’t have family members allergic to wasp stings, your garden will thank you for leaving a few paper wasp colonies as caterpillar insurance!

Lacewing eggs on a Jade plant in close proximity to the author’s vegetable garden.

In many instances, beneficial insects can keep pest insect infestations at bay, allowing gardeners to spot treat outbreaks when they get out of hand or even prevent the problem from needing chemical intervention altogether. 

As helpful as they are, beneficial insects in the garden won’t totally negate the need for chemical treatment entirely.  From time to time, garden pest populations outpace the beneficials’ abilities to kill them and intervention from humans is needed.  In these times, it is advisable to use a couple of best practices to limit exposure to beneficial insects.  First, try to use selective insecticides that only target specific pests and are nontoxic to other bugs, like the product Bt for caterpillar pests (sold under many brands like Dipel, Garden Safe Bt Worm and Caterpillar Killer, Thuricide, etc).  However, if a nonselective, general insecticide, like the Pyrethroids (many common homeowner insecticide brands) and carbamates (Sevin and others), is needed, timing these broad spectrum sprays for early in the morning and late in the evening when many beneficials are not very active can help reduce friendly fire casualties.  Care should also be taken to only spot treat infested plants and not the entire garden, this helps reduce beneficial exposure to these broadly toxic pesticides.

Every gardener should have a plan for pest control and beneficials can play an important role in this overall strategy.  Gardeners can help ensure that nature pulls its weight in controlling problem pests by taking a little time to scout for beneficial insect populations, keeping a close eye on developing pest outbreaks, using selective insecticides when you can, and only spraying broad spectrum products as spot treatments when necessary and timing those applications for very early or late in the day.  If you have a question about whether or not a garden insect is a good guy or a pest or want more information on garden pest control strategies, contact your local UF/IFAS County Extension Office!  Happy Gardening!

The following resources were used in the development of this article:

https://gardeningsolutions.ifas.ufl.edu/care/florida-friendly-landscapes/beneficial-insects.html

https://sfyl.ifas.ufl.edu/sarasota/gardening-and-landscaping/horticulture-commercial/integrated-pest-management/beneficial-insects/

http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/other/beneficial-insects.aspx

Spiny Spiders

Spiny Spiders

The year’s mild winter and frequent rain showers have created lush lawns and gardens with an abundance of insects. As a result, we are seeing many predator arthropods taking advantage of the available feast.  One of the morning interesting creatures in the garden is the spiny orb weaver spider (Gasteracantha cancriformis) that has an interesting body shape.

Spiny orb weavers are common spiders in landscapes that might not be noticed since they are much smaller than the Yellow garden spider (Argiope aurantia) and the Golden silk spider (Nephila clavipes). Once viewed, the spiny orb weaver will catch your attention because it’s abdomen has six ‘spines’ or points that extend out.  Spiders also have a mix of yellow, white, red, or black marking on the abdomen.

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Spiny orb weaver in the center of the web waiting for a meal. Photo by Beth Bolles

 

Although spiders are small, the webs which are common amongst shrubs, trees, and edges of woods become quite substantial in the fall. There may be up to 30 spirals that extend out with the spider situated in the center.  You may unexpectedly encounter a web when walking through the garden or mowing around trees and shrubs.  There is no worry if a spider accidently gets on you as bites are not common and not considered serious.

Spider working on her web. Photo by Beth Bolles

Spider working on her web. Photo by Beth Bolles

Some may refer to the spiny orb weaver as a crab spider based on its shape, but it is a web building where the true crab spiders are active hunters often found resting on flowers in order to ambush a meal.

Enjoy our fall weather and look out for this beneficial spider in your landscape.

Green Lynx Spider

Green Lynx Spider

Take a walk through the garden or woods this fall and you are sure to pass by a Green lynx spider. Unless you are very observant though, you will probably not realize that this common spider is perched upon flowers and low shrubs, ready to catch an insect meal.

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An adult spider blends in well with plants. Photo by Beth Bolles, Escambia County Extension

Even though Green lynx spiders are very large, they are often well camouflaged in plant material. Spiders are bright green with a lighter color on the abdomen including some small red markings. The legs have distinctive black spines.

This spider does not spin a web but actively hunts insects using a dragline as it quickly moves or jumps over plants. It is an opportunistic feeder catching many types of insects that are visiting flowers. It has been noted as an important predator of some crop damaging insects.

Females will normally lay one egg sac in the fall and guard it from predators. It is constructed in the upper portions of branches and has webbing connecting it to nearby plant leaves. This webbing becomes a protective area for the emerged spiderlings until they are able to take care of themselves.

Lynx spiders pose no harm to people and should be considered one of many beneficial arthropods that we see in Florida.

 

Young spiderlings on a blackberry guarded by the adult. Photo by Beth Bolles, Escambia Extension