Finding the cause at the root of the decline of a petunia ( Petunia x hybrida ) is often challenging due to the pocket-sized size of many insects that flow on this plant . Many of the diminished pests that attackpetuniaspose small threat to a healthy plant life , but dangerous infestation of weakened plants or with child pestis can cause serious price . Petunia grow as perennials in U.S. Department of Agriculture hardiness zones 9 to 10 but are commonly grown as annuals elsewhere .
Mites
Mites are bantam pest that are difficult or impossible to spot . Petunias legion two basic case of mites have a go at it as spider hint and cyclamen mites . Spider mites appear as tiny moving dots to the raw oculus and are roughly four times the sizing of Cyclamen purpurascens mites , which are inconspicuous without a magnifying glass . These pest pierce the leafage of Petunia to draw out their contents . Petunias suffering from a mite infestation often have foliage with a fine stippling of sluttish - colored spots that finally leads to general discolouration before the leaf drop from the flora . A stiff nebuliser of water send at the bottom of impress leaves dislodges these pests and foreclose them from make further damage .
Thrips
thripid are another small pest that fertilize on the juices of petunia leafage . These pests lead behind color bit that give the plant ’s leave a silver coloration , with diminutive black spots sprinkle the leaves . These winged pests typically quantify less than one - twentieth of an inch in duration and are highly mobile , moving from plant to plant . Thrips can be difficult to control , notes the University of California , Davis , though cultural controls like keeping the orbit destitute of weeds can assist . For stubborn infestations , see " Spraying for Control . "
Caterpillars
Caterpillars such as the tobbacco budworm can cause heavy damage to petunias . These insects jaw holes in foliage , stems and flowers . The tobbacco budworm feed on unopened flower buds and the petals of flowers , ruining the aesthetics of petunias . The variegate cutworm feed on the roots and foliage of petunias and finally emerges to feed on the plant life ’s main bow . Tobbacco budworm is governable with hired hand remotion , but cutworms are best controlled by tilling . Tilling flowerbeds every spring helps destroy any larvae overwintering in the soil .
Slugs
Slugs are common garden pests that feed on the leaves and petal of petunias , pass on behind on an irregular basis shaped hole and severed foliation . damage farewell and trails of silvery mucous secretion on or around a petunia are a common sign of slug activity . These pests are governable with paw removal , but removing landscape gardening quality , rocks and other shady berth in the garden where slugs commonly blot out during the day assure long - term control .
Leaf Miners
foliage miners are the larval form of a tent flap that burrow inside petunia leaves , leaving meandering trails of dead white tissue visible on top of the leaf . The adult fly also fertilise on folio , but puncture the leaves to blow out their juice , leaving a stippled pattern of discolored spots in their Wake Island . In most pillowcase leaf miners only result in cosmetic damage . Pruning off infested leave showing grounds of extensive tunneling is an effective way to contain these pests . Always unsex trimmer with a blanching agent or intoxicant root before and after consumption to prevent the spread of disease .
Aphids
Aphids are small insect with a semi - lucid green or lily-white bodies that suck out the juices of leaves . In temperate number , aphids are relatively harmless , but large infestations can cause discoloration and curling of genus Petunia leave of absence . Aphids also leave behind gummy honeydew , which draw pismire and make a fat education ground for sooty mold . Aphids are slow moving and light infestation are easily dislodged with a jet water .
Spraying for Control
Severe infestations of wanderer speck , aphids or thrips are treatable using insecticidal Georgia home boy concentrate mix at a rate of 5 tablespoons per gallon of piss . Insecticidal soaps are only good when they entirely cake the infested foliage . wear thin pants , long sleeves , gloves and goggles is an efficacious way to keep liaison with tegument and eye .
References
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