Re. fig tree pests - infested tree pictures - Ask Extension
Attached are the pictures of the infested nearby tree.
Knowledgebase
Re. fig tree pests - infested tree pictures #475101
Asked August 01, 2018, 3:53 PM EDT
Attached are the pictures of the infested nearby tree.
County Outside United States
Expert Response
Wow---now I see what you mean. I'll bet you can magnify the closeup that you took---the closest one to the tree and the problem---middle picture above.
I see little lumps on the thin twigs, leaf petioles and on the upper surface of that large leaf on the lower left. They appear to be 'wax scales' (common name for the appearance, not their composition). Scientifically, they belong to the insect order Hemiptera, Family Coccidae (soft scales), Genus is either Ceroplastes or something close since you're in Jordan and I'm familiar with the pests in the U.S. I'll attach some pictures for comparison---see Ceroplastes.
Yes, these are insects, although scales only have insect features just after they hatch. You probably are seeing adults and nearly mature nymphs.
Let's start with a general summary of the life cycle for wax scales and other coccids.
Eggs have been laid by the female under her scale covering. (You might find
some eggs under the largest scales by prying off the adult with a small knife.
Eggs may resemble 'dust' particles, maybe as large as a bit of corn meal. if the
area under the scale is empty, the eggs have hatched and nymphs have
departed. The female has been dead for a while.)
Hatchling nymph. These would be barely visible to the naked eye. They should be
oval, with 6 legs, perhaps some antennae, a pair of tiny, probably red eyes and possibly some body segments visible only with good magnification.
Settled nymphs. These will be smaller and probably less wrinkled than mature adults. They are immobile and have progressively lost their eyes, legs,
antennae and visible body segments as they transform into adult scales.
Adult male wax scales. I'm not sure I've ever seen one---some scales lack flying
males---but some scales do have flying males. These would likely be ultra-
small and not easily noticed. Obviously, they would mate with the mature
females that remain immobile as they feed on host plant sap.
Adult female wax scales. Use a magnifying glass to see these creatures. They
resemble a drop of hot wax that hit the plant, quickly cooling. The female has
already lost all of the body parts that might make her readily identifiable as an
insect. As she matures, she produces a 'scale' covering that physically
protects her.She's feeding on plant sap as she mates and matures her eggs.
After she lays her eggs under her 'wax scale' she dies. Her scale covers her
developing offspring, at least until they hatch as 'crawlers' and leave the shelter
of her dead, scale-like body.
How do these insects damage their host plant? By feeding on its sap with needle-like, hollow mouthparts (all nymphs and adult females) and by injecting their saliva into the host as they feed.
All nymphs and the adults have piercing-sucking mouthparts; they are like hollow needles that the insect jabs into its host plant. Once the mouthparts are inserted, the insect remains there for the rest of its life. The saliva aids the insect in keeping the flow going and probably by pre-digesting some of the carbohydrates the insect is about to imbibe.
The plant reacts by getting curled, drying leaves that will likely fall off the plant early, dead spots on foliage, die-back on twigs followed by die-back on larger branches. See that the crawlers moved onto leaf petioles and developing fruit where they might mature into adults. The lumpy bodies of scale insects disfigure the fig tree, obviously, but that's not the real problem.
The fig tree is under severe stress---being sucked to death by these pests. Secondly, fruit from this tree may not be palatable because scales are now feeding on them. Frequently, the fruit area around scale insects is dry, woody or discolored or worse--definitely not appealing, tasty or of the usual consistency of a ripe fig.
The next question: can the tree be saved? Maybe or maybe not. Battling the scale could take some time, effort and possibly hard decisions. There's no magical insecticide that will kill all of the pests in one treatment and reverse months or possibly years of damage by the scales. I assume you or your neighbor will have access to some of the products I'll mention.
1)Your photos show a bushy, dense canopy. Thinning it, probably after the growing season is over, could improve air circulation in the canopy as well as expose foliage, twigs and pests to brighter light and higher temperatures---not favoring the scales.
2)Scale insects are easy prey for various beneficial insects including lacewings, various predatory bugs and a variety of tiny to small parasitoid wasps. They may help more when the canopy is more open. However, they alone may not be able to save the tree.
3)Water the tree more often or with larger amounts of water. It's struggling.
4)Are ants running up and down the trunk? They are feeding on scale waste products called 'honeydew.' They may even be protecting the scales since the scales are the source of this sugary, sticky ant food. Control the ants the best you can. Prune branches that touch walls. Cut down plants or weeds that touch the fig's trunk. In the US we have products like Tanglefoot, Stick-em and others. These can be applied to the fig's trunk in a 4-6 inch band; start closer to the ground. If the ants persist in climbing the tree, try another band a little higher up.
5)Most scales are susceptible to insecticidal sprays when the crawlers are present; otherwise, the scales developed by the immobile stages protect these insects like raincoats.
I assume it's summer in Jordan? Hatching probably occurred earlier in spring. The easy way to find hatchling scale insects (crawlers) would be to find a white dishpan or something similar. Hold the pan directly under a branch with one hand and whack the branch with a small stick or garden tool with the other hand. See what's fallen into the pan. Shortly, tiny insects start moving and crawling around. See what they might resemble in the photo attached (the one labeled Coccus).
Some products to consider for foliar treatments now could include: insecticidal soap, neem/neem oils, horticultural oils (petroleum derivatives), and canola oils. Hopefully, all of these products will have labels that you need to read to make correct applications. Some considerations here: water well before any application, a lot of oils recommend NOT making treatments if the temperatures are above 90F (30C) and relative humidity is above 90%. Do not apply if you expect rain within 24 hours of application. These products are fairly mild to people and pets but read the labels for precautions to take anyway. The 'idea' behind most is to smother the pests. Their residue can be harmful to beneficial insects---like the scale predators and parasitoids you want, so don't overdo spraying. You're trying to restore a balance between pest and beneficials.
As an aside....this infested tree is 'contagious' to other fig trees and garden shrubs and trees. Additional plants might need the same treatments as above. The tiny crawlers can blow in the breezes to other plants where they can start new infestations.
I hope this information is helpful. Good luck with this project.
I see little lumps on the thin twigs, leaf petioles and on the upper surface of that large leaf on the lower left. They appear to be 'wax scales' (common name for the appearance, not their composition). Scientifically, they belong to the insect order Hemiptera, Family Coccidae (soft scales), Genus is either Ceroplastes or something close since you're in Jordan and I'm familiar with the pests in the U.S. I'll attach some pictures for comparison---see Ceroplastes.
Yes, these are insects, although scales only have insect features just after they hatch. You probably are seeing adults and nearly mature nymphs.
Let's start with a general summary of the life cycle for wax scales and other coccids.
Eggs have been laid by the female under her scale covering. (You might find
some eggs under the largest scales by prying off the adult with a small knife.
Eggs may resemble 'dust' particles, maybe as large as a bit of corn meal. if the
area under the scale is empty, the eggs have hatched and nymphs have
departed. The female has been dead for a while.)
Hatchling nymph. These would be barely visible to the naked eye. They should be
oval, with 6 legs, perhaps some antennae, a pair of tiny, probably red eyes and possibly some body segments visible only with good magnification.
Settled nymphs. These will be smaller and probably less wrinkled than mature adults. They are immobile and have progressively lost their eyes, legs,
antennae and visible body segments as they transform into adult scales.
Adult male wax scales. I'm not sure I've ever seen one---some scales lack flying
males---but some scales do have flying males. These would likely be ultra-
small and not easily noticed. Obviously, they would mate with the mature
females that remain immobile as they feed on host plant sap.
Adult female wax scales. Use a magnifying glass to see these creatures. They
resemble a drop of hot wax that hit the plant, quickly cooling. The female has
already lost all of the body parts that might make her readily identifiable as an
insect. As she matures, she produces a 'scale' covering that physically
protects her.She's feeding on plant sap as she mates and matures her eggs.
After she lays her eggs under her 'wax scale' she dies. Her scale covers her
developing offspring, at least until they hatch as 'crawlers' and leave the shelter
of her dead, scale-like body.
How do these insects damage their host plant? By feeding on its sap with needle-like, hollow mouthparts (all nymphs and adult females) and by injecting their saliva into the host as they feed.
All nymphs and the adults have piercing-sucking mouthparts; they are like hollow needles that the insect jabs into its host plant. Once the mouthparts are inserted, the insect remains there for the rest of its life. The saliva aids the insect in keeping the flow going and probably by pre-digesting some of the carbohydrates the insect is about to imbibe.
The plant reacts by getting curled, drying leaves that will likely fall off the plant early, dead spots on foliage, die-back on twigs followed by die-back on larger branches. See that the crawlers moved onto leaf petioles and developing fruit where they might mature into adults. The lumpy bodies of scale insects disfigure the fig tree, obviously, but that's not the real problem.
The fig tree is under severe stress---being sucked to death by these pests. Secondly, fruit from this tree may not be palatable because scales are now feeding on them. Frequently, the fruit area around scale insects is dry, woody or discolored or worse--definitely not appealing, tasty or of the usual consistency of a ripe fig.
The next question: can the tree be saved? Maybe or maybe not. Battling the scale could take some time, effort and possibly hard decisions. There's no magical insecticide that will kill all of the pests in one treatment and reverse months or possibly years of damage by the scales. I assume you or your neighbor will have access to some of the products I'll mention.
1)Your photos show a bushy, dense canopy. Thinning it, probably after the growing season is over, could improve air circulation in the canopy as well as expose foliage, twigs and pests to brighter light and higher temperatures---not favoring the scales.
2)Scale insects are easy prey for various beneficial insects including lacewings, various predatory bugs and a variety of tiny to small parasitoid wasps. They may help more when the canopy is more open. However, they alone may not be able to save the tree.
3)Water the tree more often or with larger amounts of water. It's struggling.
4)Are ants running up and down the trunk? They are feeding on scale waste products called 'honeydew.' They may even be protecting the scales since the scales are the source of this sugary, sticky ant food. Control the ants the best you can. Prune branches that touch walls. Cut down plants or weeds that touch the fig's trunk. In the US we have products like Tanglefoot, Stick-em and others. These can be applied to the fig's trunk in a 4-6 inch band; start closer to the ground. If the ants persist in climbing the tree, try another band a little higher up.
5)Most scales are susceptible to insecticidal sprays when the crawlers are present; otherwise, the scales developed by the immobile stages protect these insects like raincoats.
I assume it's summer in Jordan? Hatching probably occurred earlier in spring. The easy way to find hatchling scale insects (crawlers) would be to find a white dishpan or something similar. Hold the pan directly under a branch with one hand and whack the branch with a small stick or garden tool with the other hand. See what's fallen into the pan. Shortly, tiny insects start moving and crawling around. See what they might resemble in the photo attached (the one labeled Coccus).
Some products to consider for foliar treatments now could include: insecticidal soap, neem/neem oils, horticultural oils (petroleum derivatives), and canola oils. Hopefully, all of these products will have labels that you need to read to make correct applications. Some considerations here: water well before any application, a lot of oils recommend NOT making treatments if the temperatures are above 90F (30C) and relative humidity is above 90%. Do not apply if you expect rain within 24 hours of application. These products are fairly mild to people and pets but read the labels for precautions to take anyway. The 'idea' behind most is to smother the pests. Their residue can be harmful to beneficial insects---like the scale predators and parasitoids you want, so don't overdo spraying. You're trying to restore a balance between pest and beneficials.
As an aside....this infested tree is 'contagious' to other fig trees and garden shrubs and trees. Additional plants might need the same treatments as above. The tiny crawlers can blow in the breezes to other plants where they can start new infestations.
I hope this information is helpful. Good luck with this project.
