| | A number of insects that are considered nuisance or “minor” pests in certain situations or may become problematic of some crops
Crops Affected:
Wasps / Yellowjackets / Hornets (Vespula spp., Dolichovespula spp., Vespa spp.); – strawberries, raspberries & other fruit crops
Life Cycle:
- Not pests but are scavengers
- Queens build a nest in a range of sheltered areas, such as buildings, woodpiles, underground or unprotected areas like trees and shrubs
- Populations increase over the summer, peaking in fall
- Workers scavenge for insects or rotting fruit
- Mating occurs in the fall and fertilized queens overwinter
Symptoms:
- Don’t damage crops, but feed on damaged or over-ripe fruit
- May be present during harvest
Monitoring:
- Nests may be difficult to locate
- Large numbers of visible wasps may indicate the presence of a nest
- Warm, dry springs can produce larger wasp problems in August than cool, wet springs
Management:
- Regular sanitation can help keep populations lower; this would include prompt harvesting of all ripe berries and clean picking practices
- It has been suggested that the presence of another nest will deter settlement of an area, therefore false nests may be effective deterrents
- Careful destruction or removal of existing nests
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Wasp Adult | |
Photos by Robert Spencer | |
Hawthorn Lace bug (Corythucha cydoniae) – Saskatoon berry and other plants in the Rose family (apples, hawthorn, pear, cotoneaster, etc.); other species may affect Saskatoon, chokecherry, etc.
Life Cycle:
- Overwinter as adults (Two generations per season)
- Black eggs are laid in clusters on the underside of leaves in early spring
- Nymphs emerge and feed on the underside of the leaves after about 3 weeks
- 5 instars; 1st generation of adults emerge in midsummer, 2nd in fall
- Feed by piercing leaves and sucking out plant juices
Symptoms:
- Stippled or mottled leaves with many lace bugs present
- Feed in large numbers
- leaves may be stained with their excrement
- Adults are small bugs which appear to be covered in lace
- Nymphs are dark brown to black and covered in varying amounts of spines
Monitoring:
- Not required, but can be detected while scouting for other insect pests
Management:
- Not typically required, as do not typically cause economic damage
- May be controlled during chemical applications for other registered pests
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Hawthorn lace bug nymph | Hawthorn lace bug adults | |
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Severe leaf stippling and discolouration | Lace bug injury on Saskatoon berry – yellowing / stippling | Evidence of lace bugs on leaf undersides – nymphs, adults, frass and stippling of leaves |
Photos by Robert Spencer |
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