Lecture 19 Flashcards
what type of insect leaves visible damage?
insects with chewing mouthparts
what is the damage caused by chewing insects?
defoliate leaves, feed on roots, bore through stems, etc.
what are 2 exs of insects with chewing mouthparts?
Flea beetles, Colorado potato beetles
what insects puncture plant & suck fluids?
sucking & piercing insects
what are the signs of sucking & piercing insects damaging plants? (4)
puckering of leaves
thin sections of leaf
leaf rolling
galls
what are exs of sucking & piercing insects?
aphids, scale, thrips, leaf hoppers
how long are flea beetles?
1/16 - 1/4 inch long
what colour are flea beetles?
black to brown or striped
what plants do flea beetles favour?
crucifers
such as radish, broccoli, cabbage and turnip
when do flea beetles do most of their damage?
in the spring
plants will tolerate ____% of defoliation done by flea beetles
30-40%
where do adult flea beetles overwinter?
leaf litter
garden debris
shelter places
why is it important to understand the lifecycle of insects?
determine management strategy
flea beetles have ______ gen/year
1
what is the biggest prob with flea beetles?
seedlings are growing in may-june when the insects are feeding
summarize the flea beetle lifecycle
feed may - June
overwinter as adults
emergence of adults in fall
how do you reduce overwintering of flea beetles near your garden?
remove garden debris, litter & weeds
what are the measures to be taken to control flea beetles? (8)
remove garden debris, litter & weeds
grow early season trap crops (ex: radishes) to deter from others plants
use floating row covers during seedling est
delay planting
use yellow or white sticky traps
Use transplants instead of direct seeding (larger means less vulnerable)
Catnip, and garlic or hot pepper sprays repel the beetles
insecticides
when using trap plants, what should be done with them once the risk of damage to other plants has passed?
harvest or destroy
when should floating row covers be removed?
once plants have 4-5 leaves
cabbage worms
4 diff lepidopteran spp feed on crucifers such as cabbage, broccoli, kale, etc.
what is the most common cabbage worm?
cabbage butterfly
is the cabbage butterfly domestic or foreign?
foreign
the cabbage butterfly hatch from _____ in the spring
chrysalis
what colour & shape are the cabbage butterfly eggs?
yellow
oval
where do cabbage butterflies lay their eggs?
undersurface of leaves
Larvae feed on crucifers until they make ________-
chrysalis
what are 3 cabbage worms?
cabbage butterfly
cabbage looper
diamondback moth
how do you control cabbage worms?
floating row covers
inspect & remove underside of leaves for eggs & larvae
apply Bacillus thuringiensis (Bt) insecticide
cover heads with nylon stocking until harvest
when should floating row covers be used to control cabbage worm growth?
spring and early summer
how do floating row covers control the growth of cabbage worms ?
protect plants from egg-laying adults
is the Bacillus thuringiensis (Bt) insecticide considered organic?
yes
root maggots
maggots of diff flies
what do root maggots commonly infest?
radishes, turnips, onions, cabbage, broccoli or cauliflower
where do root maggots lay their eggs?
in soil at base of plants
what do root maggots feed on?
root
what pest causes a loss in quality & quantity?
root maggots
what is a plant variety that is resistant to root maggots?
red cabbage varieties
what are some ways to control root maggots? (5)
choose resistant varieties
floating row covers early in the season
delay seeding
rotate susceptible crops from previously infested areas
apply insecticide granule in row at time of planting or use liquid drench after seedling emergence
when can you remove floating row covers from your plants that being protected from root maggots?
once plants have 4-5 leaves
how do floating row covers prevent infestation of root maggots?
prevent egg-laying near plants
what life stages of the Colorado potato beetle feed on crops?
larval & adults
what does the Colorado potato beetle feed on?
vegetation of potato, tomato, peppers and other Solonaceae plants
what characteristic of the Colorado potato beetle enables it to completely defoliate plants?
prolific reproduction
Adults overwinter in soil & emerge in late _______ or _______
may or june
how does the Colorado potato beetle reach its host once it is finished overwinter?
walks or flies
how do you control the Colorado potato beetle? (4)
Rotate areas of susceptible spp if possible
crush eggs or hand-pick larvae & adults from plants
row covers
Bt based insecticides
when is crushing eggs or hand-picking larvae & adults from plants practical when controlling Colorado potato beetles?
small scale
what protective measure needs to be taken when crushing eggs or hand-picking larvae & adults from plants when controlling Colorado potato beetles?
wear gloves or wash hands thoroughly afterwards
chemical in beetle can irritate eyes and skin
