Page Intro: Hippodamia convergens, or Ladybugs, Convergent Ladybird Beetles, ladybeetles, etc. are cost-effective aphid predators who may eat other soft-bodied pests. On this page you will find a description, life-cycle info, benefits, drawbacks, scouting info, advisories, usages, and other good stuff such as ordering.
Description
Ladybugs, as they called by the masses, are voracious predators. These orange/red, black-spotted beetles are recognized the world over. They’re the subject of a few songs, folklore tales, nursery rhymes and more. Nowadays, they’re also an icon symbolic of biocontrol and Integrated Pest Management (IPM). And the latter for good reason because, despite some of their unfavorable characteristics (see Drawbacks), they are effective predators — or can be if used correctly. Ladybug beetles definitely prefer to dine on aphids.
They are considered an aphid predator. However, as most beetles are, H. convergens are very opportunistic and will eat pests other than aphids: mites, insect eggs, etc. I do not recommend using these beetles for other pests, though. I believe control of other pests cannot be obtained by typical ladybug releases. Coincidental cross-predation should be regarded as a bonus of the application and nothing more. I am aware of claims of ladybugs being an end-all, be-all, cure-all predator, but it is regarded, at least by myself, with skepticism, at best. With aphids, though, the ladybugs have proven themselves more than worthy. I have personally had phenomenal results with their use. H. convergens are shipped as adults which have been field collection from their mass aggregation sites in the foothills of California’s Sierra-Nevada mountains. Ladybugs are usually shipped to consumers directly from a collector/contractor out west. Various quantities of the beetles are sacked in cotton/muslin sacks filled with excelsior/aspen strips to accommodate the predators during storage and travel. [Intro]
Life-style
The large 8 mm. adult female beetles lay orange, football-shaped eggs usually on the upper-sides of the leaves of infested plants — up to 50 of them per day! The eggs hatch into black, alligator-like larvae with orange markings. These, too, are fierce predators, consuming 400 or so aphids. The life-span of these predators is roughly 28 days in their immature stages, then around 11 months as adults. The conditions for optimum performance will be between 66-88°F with a relative humidity of 40% or greater. But these are optimum conditions and not necessarily a prerequisite of successful implementation. Please note, however, significantly cooler or warmer temperatures and humidity fluctuations may hamper reproduction and development a certain degree. [Intro]
Benefits
Ladybugs can be very cost-effective. And at the recommended rates, they can be a very loud bang for the buck! Another benefit is the IPM symbolism of ladybugs. They provide an excellent educational conduit between the grower and his or her customers. Most people will readily accept plants which are being treated with ladybugs. This can be an IPM medium upon which your customers’ knowledge and acceptance of the Green Methods can flourish. Most biocontrol recommendations address the need for repeated releases. This is especially true with H. convergens. This requirement can be easily satisfied with H. convergens without spending a great deal on the freight necessary to comply with the recommendations for these beetles. Why? They are refrigerator storable (see Advisories). You can therefore buy in bulk and, if you do, you’ll save on product and freight. [Intro]
Drawbacks
First and foremost: they’re flighty. If not released properly, ladybugs can disperse completely within 24 hours. Even when they are released properly, 90-95% will bolt anyway; it is expected, it is in their nature. We know of this phenomenon, and our release rates take this into consideration. It is the 5-10% which stick around that do the job for us (see Advisories for other info). Another drawback, or more aptly labeled, an inconvenience, is the unavailability of these beetles around mid-May. Moreover, their springtime storage life, which is usually 2-3 months, is greatly reduced. This period marks the end of a ladybug generation. [Intro]
Scouting
Decimated pests, clean new growth, adult and larval presence, and egg-clusters are indicators the scout should look for. The scout may find damage such as that shown in the photograph above. (However, after just a short time of using ladybugs, new growth will take off; the plant will start growing again. It, as was several other plants, was badly infested. Ladybugs were released as per our instructions, and in two weeks, the plants were clean and new growth was plentiful. Ladybugs saved the day!) [Intro]
Advisories
The refrigerator storage ability of H. convergens is more than just a convenience and cost-saver, it helps increase the effectiveness of these beetles. To do it properly try the following:
Beetle Storage Facts
- Hold beetles between 35-45°F, better if cooler.
- Store beetles in an older, not-so-frost-free fridge if possible.
- Remove the beetles from the fridge once a month, mist the bags with water, allow to dry and return them to storage.
- Hold beetles for no longer than 2-3 months.
- Beetles purchased before May can be stored until mid-May to June first only; purchased after June first, the beetles can be stored full term. Many months under certain conditions.
Aside from watering the site before releasing and doing so in the evening, there are other things you can do to ensure the maximum number of beetles stick around. Flowering, pollen producing plants are a big plus (commercial seed blends with an appropriate variety of plants useful to ladybugs are available). Pollen isn’t the only thing these beetles will eat. They will also consume aphid honeydew. A product such as a commercial honeydew substitute may help retain beetles. [Intro]
Usages
Where can’t they be used would a more appropriate question. I’ve seen the successful implementation of these species in just about every conceivable situation. [Intro]
Rates, Instructions, and Purchase
Need more information? Check out our release rates or our short-term storage, handling, and release instructions. You may also purchase H. convergens. [Intro]
