|
||
|
||
Interior Landscapes – Scale and Mealybugs
Scale Controls
Armored scale parasite: Aphytis melinus
This tiny yellow wasp lays its eggs under the covering of mid-sized scales. Larvae develop over 2-3 weeks, pupate, and emerge as adults by cutting a hole in the outer covering of the scale.
Target pests: Oleander, California Red, Yellow, & Dictyospermum scales
Scale Predator: Lindorus lophanthae or Rhyzobius lophanthae
Singular lady beetle or ‘scale destroyer’.
A small beetle with a black wing covers and burnt-orange head, thorax and abdomen. Adult females lay hundreds of eggs under scales that hatch as alligator-shaped larvae that feed on scale eggs and crawlers for about two weeks before pupating. Adults feed on all stages of scales and are quite voracious.
Target pests: California Red, Purple, and other armored and soft scales
Optimal environment: 75-80° F (OK down to 40°F)
Mealybug Controls
Predator: Cryptolaemus montrouzieri
(‘Crypts’ for short, also, the ‘mealybug destroyer’)
These tropical lady beetles exert rapid control over high populations of citrus mealybugs. They do not do well when the mealybug population is sparse. Both adult and larval crypts actively prey on mealybugs. Adult crypts are about 1/6 inch long, and black with orange heads and “tails”. Crypt larvae are covered with white waxy filaments, which makes them look similar to mealybugs. Adults lay 200-700 eggs during their 27-70 day lifespan. Development from egg to adult is nearly twice as fast at 80°F as it is at 70°F. Crypts are inactive at temperatures below 60°F, slow at 70° but stop searching when the temperature is above 90°F.
Optimal Environment: 75-80°F, 60% RH
Application Rate: 2-5 per infested plant or 2-5 per 10 square feet. 20-100 per tree.
Predator: Lacewing larvae These voracious young of the familiar lacewing insect are known as “aphid lionsâ€, but they also feed on mealybugs, scales, spider mites, and other pests. Lacewings are shipped as eggs or larvae. After hatching, the larvae remain active for 10-14 days. Mature larvae pupate and later emerge as adults, which typically disperse before laying eggs for future generations of larvae.
Optimal Environment: 60-80°F
Application Rate:
| Lacewing eggs on card, 30 strips/card |
5,000 eggs |
0.5 strip per pot (1-6 sq ft) biweekly |
| Lacewing eggs, loose |
1,000 | Minimum order, 2000, 20+ eggs per square foot, biweekly |
| Lacewing larvae, bottle or frame |
1,000 larvae |
10 per square foot of infested area, biweekly |
IPM Laboratories, Inc. warrants that the biological controls you receive will be alive and healthy when received and will contain the correct number of the species you ordered. However, as with any pest control measure, success cannot be guaranteed. IPM Laboratories, Inc. makes no guarantee, express or implied, as to the effectiveness of these products.
All images are copyrighted to IPM Laboratories, Inc. and may not be copied or reproduced without permission.
Interior Landscapes – Scale and Mealybugs
Description
Scale identity has a large impact on biological control success. Scales are sucking insects about 1/16 to 1/4 inch in diameter. They are covered with a tan or brown scale that protects the soft underparts, and may look like plant bumps. Scales suck plant juices and are classified as soft or armored. Both have hard shells, but the shell may be removed from armored scales by lifting with a sharp knife. Only soft scales and mealybugs secrete a sweet, sticky honeydew which may drop onto lower leaves or floors and support the growth of a black, powdery fungus called sooty mold.. Soft scales usually have one generation per year; armored scales, several. The females are the immobile lumps. Under the scales, each may hatch up to 1000 eggs at a time. When eggs hatch, the first larval stage is mobile and known as crawlers.
Know your mealybugs!! Mealybugs are small, sucking insects with a white, waxy covering that gives them a woolly appearance. One species, the citrus mealybug, Planococcus citri, is oval and pink, with short filaments of wax radiating from the body. Citrus mealybug eggs are laid in cottony appearing groups. The other common mealybug species, the longtailed mealybug, (Pseudococcus longispinus) has long ‘tail’ filaments which may stick up like little spikes from each cottony mass of long-tailed mealybugs. Longtailed mealybugs lay live young, not eggs.
Identifying
There are many species of scale. IPM Labs offers a scale identification service.
Crop Management
Avoid over-fertilizing with nitrogen, and control ants that may protect aphids from predators.
Early Detection
Control mealybugs and scales first by limiting new introductions on new plants brought into the interiorscape. Inspect new plants carefully and control the pests before installation. Monitoring every other week for scales and mealybugs will give you a better probability of early detection and more effective biological control. Examine leaves, stems and leaf axils and plan for action on first detection.
Physical or Chemical Controls
Reduce scale and mealybug populations directly by pruning infested plant parts and carefully removing them so that pests do not accidentally transfer onto clean areas of the plant.
Syringing ”knocking mealybugs off plants with a water spray” is a time-honored method of mealybug control.
Insecticidal soaps, horticultural oils (when not phytotoxic), and insect growth regulators can be effective. Avoid using most residual insecticides for a period of three months prior to planned use of biological controls.
All images are copyrighted to IPM Laboratories, Inc. and may not be copied or reproduced without permission.
Fungus Gnats and Shore Flies in Bedding Plants
Predatory Mite for Control of Fungus Gnats and Shoreflies: Hypoaspis miles
Fungus Gnats: Apply one liter of Hypoaspis miles per 1000 square feet at the beginning of the crop. This predatory mite is a scavenger that will survive in the absence of fungus gnats, but consume the larvae as they appear. It also eats western flower thrips. It is not good for knocking down a fungus gnat outbreak.
Shoreflies: Hypoaspis can exert control on shoreflies similar to that with fungus gnats provided that there is no standing water. Shorefly larvae can survive under standing water, whereas Hypoaspis can not.
ScanMask™ for Control of Fungus Gnats
A single application of ScanMask™ beneficial nematodes is sufficient for preventing fungus gnat outbreaks or in the beginning phase of an outbreak. The nematodes do not attack shoreflies. They kill only fungus gnat larvae. Adult fungus gnats will linger for several weeks after treatment as they gradually age and die off. The application should be repeated once if the first treatment was not effective. The best strategy to detect effectiveness is to count fungus gnat larvae in potato slices (see below). Larval numbers should decline rapidly over the week after treatment. Adult numbers will decline over a period of three weeks and are easily monitored on yellow sticky cards.
Acknowledgements: Information in this program is based on writings of and personal communications with Albert Pye, Mary Harris, Richard Lindquist, John Sanderson, James Matteoni, Don Elliot, Gerard Ferrentino, Bastian Drees,and Margery Daugherty. IPM Laboratories, Inc. gratefully acknowledges their work in IPM and biological control.IPM Laboratories, Inc. warrants that the biological controls you receive will be alive and healthy when received and will contain the correct number of the species you ordered. However, as with any pest control measure, success cannot be guaranteed.
IPM Laboratories, Inc. warrants that the biological controls you receive will be alive and healthy when received and will contain the correct number of the species you ordered. However, as with any pest control measure, success cannot be guaranteed. IPM Laboratories, Inc. makes no guarantee, express or implied, as to the effectiveness of these products.
All images are copyrighted to IPM Laboratories, Inc. and may not be copied or reproduced without permission.
Crop Management
Minimize moisture under the benches to reduce breeding of fungus gnats there. Ample moisture favors development of fungus gnat larvae. However, existing larvae may attack plant roots if pots are under watered. Depending on level of fungus gnats, apply either a pesticide or biocontrol under benches to minimize fungus gnat numbers prior to starting crop. High numbers of fungus gnat larvae can cause serious damage to plant roots. Shore fly larvae feed only on algae and can breed in standing water. It is important to be able to distinguish between the two insects for control purposes.
Identifying
 Fungus gnat adults are delicate black insects usually less than 1/8 inch long, with long legs and antennae. Their wings are clear, and have a distinctive Y-shaped vein that distinguishes them from shoreflies (both are about the size of fruit flies). Fungus gnat larvae are slender with clear bodies and a black head capsule. |
 Shore fly adults are more stout and usually larger than fungus gnat adults. They have short legs and antennae, and dark wings with clear spots on each wing. Larvae are yellowish-brown, maggot-shaped, and do not have a distinct head capsule. Larvae of both shore flies and fungus gnats are found in the surface of the growing medium. |
Monitoring
Yellow Sticky Cards: Count fungus gnat and shorefly adults weekly on yellow sticky cards. Place some horizontally a little above soil level; others, vertically at the plant canopy level. Examine sticky cards weekly and renew them every 1-4 weeks. Your time is an important factor in choosing the number of cards that will be monitored. A few cards counted per week is infinitely better than none at all. However, fungus gnat and shorefly populations vary considerably from place to place in the greenhouse, so place them thoughtfully.
Potato Slice Inspections: You can monitor the relative number of fungus gnat larvae in the soil by placing a disk of raw potato on the soil surface.
After 7 days, turn the disk over and count the number of fungus gnat larvae. Mary Harris used this technique to study fungus gnats and their control at the University of Georgia. You can assess whether a control measure has killed fungus gnats by comparing larval numbers before and after treatment. Make disks of thesame diameter by punching them out of potato slices with a cork borer or sharpened piece of pipe. Place 10 disks per 1000 square feet of growing area.
IPM Laboratories, Inc. warrants that the biological controls you receive will be alive and healthy when received and will contain the correct number of the species you ordered. However, as with any pest control measure, success cannot be guaranteed. IPM Laboratories, Inc. makes no guarantee, express or implied, as to the effectiveness of these products.
All images are copyrighted to IPM Laboratories, Inc. and may not be copied or reproduced without permission.
For green peach and melon aphids. Aphidius colemani is a small parasitic wasp that lays its eggs in aphids. The eggs hatch inside and the larvae spin cocoons which swell the aphid’s body. The adult wasp then exits the aphid body, leaving behind a hard brown shell called an aphid mummy. Larval development takes 2 weeks at 21° C. (70° F.). These wasps do not diapause, and in fact are most effective from September -March because their own parasites are not present. Used with Aphidoletes in greenhouse peppers in Canada.
Optimal Environment: 50-76°F. Tolerates cool temp., low light.
Tiny parasitic wasps that are unique in their ability to control potato aphids and greenhouse potato aphids.
This delicate midge produces orange larvae that feed on aphids. Females lay 100-200 tiny orange eggs near aphid colonies. Each larva kills from 4-65 aphids. The short days of winter can cause diapause (dormancy) – prevent by supplemental lighting (one 60 watt bulb per 30 feet, or 100 watt bulb per 65 feet).
Optimal Environment: 73-77°F, OK to 60°F; 80-90% RH.
Lacewings are general predators: aphids are the main prey, but they also feed on mealybugs, scales, spider mites, thrips, and small caterpillars. The adult is 1/2-3/4 in. long, green or light brown, and has large clear wings with lacy markings. The larvae are voracious predators known as aphid lions, and look like small, mottled alligators. A single aphid lion will consume 200-300 aphids. Lacewing eggs are light green and elevated on tall slender stalks, but lacewings almost never reproduce in the greenhouse.
Optimal Environment: 60-80°F.
Ladybeetles are general predators that prefer aphids, but will also feed on scales, thrips, and small caterpillars. They are expecially attracted by aphids. Adult females lay clusters of orange, bullet shaped eggs on the underside of leaves, but only near heavy aphid infestations. Adults can consume 5000 aphids each during their lifetime. One pint contains approximately 9,000 ladybeetles
Optimal Environment: 61-82°F, OK to 55°F.
Barley with bird cherry oat aphids (aphids that attack cereals but do not attack broad leaved plants. Aphid banker plants are used to support a healthy beneficial population. Grow your own investment in beneficials and protect plants season-long.
Optimal temperature: 70 to 75 F.
Can I still spray if I need to?
Yes. If pest populations reach threshold levels, you can choose pesticides that will not harm beneficials. Or you can move the banker plants out of the greenhouse until the pesticide has dissipated.
When should I order?
4 to 6 weeks before you expect aphids. Beneficials reproduce at a much slower rate than their prey. Help them get well established before pests arrive.
Protocol
Results
Season Long Average Key Indicators
Guardian Plants Pull Pests and Host Their Natural Enemies
Spider mites have 4 pairs of legs, thus they are arachnids, not insects. They are susceptible to miticides more than insecticides. The most common species in interior environments is the two spotted spider mite, Tetranychus urticae. With a hand lens, two lateral spots on the body and red eye spots may be seen. Mites puncture cells and suck up cell contents, causing spotting or stippling of leaves. They are found first on the undersides of leaves, sometimes with silken webbing.