There are more than 350,000 distinguish coinage of beetle in the orderColeoptera . These insects constitute one - half of all the known animals on the planet . That ’s a raft of beetles ! There are also predatory beetles that consume other dirt ball as part of their dieting . But the beetle species that have become most infamous in the garden are herbivore , exhaust plant leaf , roots or woody tissue paper as a food source . While species that crunch on works roots as larvae ( include ashen grubs , iris woodborer , wireworm and the like ) are certainly problematic , those species that feed on foliage are more frequently encountered in the vegetable patch .
The beetle family is host to an tremendous range of life cycles and feeding habit . Some mallet species are decomposers , feeding on animal and plant wastes , while others feed on fungus , pollen or nectar . All members of the mallet order have two pairs of wings . The outer wing constitute a duad of treated wing case that make a shell - similar breed over the membranous wing used for flight . All beetle specie go through consummate metabolism , passing through life history first as an egg , then a larva , a pupa and in the end an adult . Here ’s the lowdown on some of the most common pest garden beetles and what you may do to keep their universe in hindrance .
1. Colorado Potato Beetles (Leptinotarsa decemlineata)
Adult Colorado potato beetles are 1/3 in long with heavy , rounded wing covers that are black - and - tan striped . The fat , reddish - pinkish larvae are 1/2 in long , have rows of black dots on their sides and a small smutty caput . Colorado Irish potato beetles are very common across the U.S. , except in the Pacific Northwest and the Deep South . They feed on all members of the tomato family , though Irish potato are by far their favorite .
Adult Colorado potato beetle overwinter in the soil , emerging in spring to feed and breed , make up to three generations each year . Both adult and larval Colorado potato mallet skeletonize the leaf of host plant very quickly . To make out them , covernewly planted seed potatoeswith floating row cover version and pull up stakes it in station until the spud are quick for harvest — pollination does n’t postulate to pass for potatoes to be produced . Handpicking both adult and larvae is also very effectual . Because Colorado white potato beetles have develop underground to many synthetical pesticide , use biologic pesticides based onBacillus thuringiensisvar . San Diego or var . tenebrionis ( normally called Bt — just be indisputable to select the right variety ) . Other effective biopesticides include those based on spinosad .
2. Mexican Bean Beetles (Epilachna varivestis)
Adult Mexican bean beetles look a lot likeladybugson steroids , though the absence seizure of white marking between the head and torso easy distinguish them from their well-disposed cousins . Their wing covers are copper - colour with 16 black spots . Mexican bean plant overhang larvae measure about 1/3 inch long , are light chicken and are covered in bristly spines . They ’re find in almost every nation east of the Rocky Mountains .
Mexican bean beetles pass the winter as adults nestled under garden debris . Eggs are repose in late spring on the underside of leaves of horde plant , admit nearly every species of noodle , with each female person place hundred of testis . The spikey larva and adults give on leaf back , leaving only the folio veins intact . They ’ll also feed on the beans themselves . Damage is most severe in July and August .
To prevent an onslaught of these beetles , choose early bonce varieties that mature before the pestis becomes debatable . Handpick grownup and squelch larvae — their spines are very soft . Cover susceptible works with floating row masking at once after embed , but slay the covers when the plants begin to blossom to reserve pollenation . Mexican edible bean beetles fall target to legion species of beneficial insects , including parasitic wasps , plagiarizer germ , assassin bugs , ladybugs and many others . Plant a lot of prime in the veggie patch up to provide nectar for these predators . Effective product control let in Bt var . San Diego or volt-ampere tenebrionsis , and anything with the alive ingredients of spinosad , neem and citrus oil — all three can be good .
3. Cucumber Beetles (striped:Acalymma vittata; spotted:Diabrotica undecimpunctata howardi)
Both common specie of cucumber beetle , strip down and spotted , measure about 1/4 column inch long . The adult striped mallet are smart yellow and suffer three broad , black stripes running the length of their wing covers . Spotted mallet are greenish - yellow with 11 ( Eastern metal money ) or 12 ( Western metal money ) black spots on the wing concealment . Both species overwinter as adults in underweight areas . mallet emerge in spring to couple and position eggs in the land or on plants . Larvae burrow into the land and provender on roots for several week .
Adults masticate ragged holes in plant leaves and can consume entire efflorescence of best-loved plants , including all members of the Cucurbitaceae fellowship . freshly implant seedlings can be consumed promptly . Most importantly , cucumber mallet can transmit deadly bacterial wilt andcucumber mosaic virus , so control the beetles is central to preventing the spread of these pathogens . You should only plant varieties with a known electric resistance to these pathogens .
To see to it cuke beetles , trap adults on yellow sticky cards position just above plant tip . To draw in more beetles , attach cotton nut soak in allspice , clove or true laurel oil to the cards . These crude oil contain eugenol , a pheromone that attract distaff cucumber beetles . For added protection , delay planting Cucumis sativus by a few weeks to help break the beetle ’s feeding cycle and prevent major damage from the initial other leap eating period .
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A metal money of beneficial roundworm ( Heterorhabditis bacteriophora ) is particularly effective at attack the filth - bound larva and killing them before they reach maturity . These nematode worm can be shuffle with water supply and spray throughout the planting area any fourth dimension during the develop time of year , as long as the soil temperature is above 65 arcdegree F. Spinosad - based production are also good against adults .
4. Japanese Beetles (Popillia japonica)
enter to North America from Asia in the early nineties , Japanese beetleshave become a ill-famed pestis . grownup are metal light-green with copper - colored wing covers . They evaluate about 1/2 inch in duration and are half as wide . Their ground - dwelling house larvae are C - shaped , grayish - white chow with light-colored - brown head . The larvae grow up to 1 in long and spend the wintertime several in beneath the ground .
As adults , Japanese beetles consume more than 300 dissimilar ornamental , beginning in midsummer . They release collection pheromones as they feed , leave in large numbers of grownup come together to “ feed and breed ” on the same host plant . As larvae , Japanese mallet grub assault the root of turf sess and many ornamental . When serious infestation are present—10 or more grubs per square foot of soil — the sward might flake off back in a rug - like style . chuck damage is most evident in leap and fall when the grubs are actively feeding in the upper bed of filth .
Hand - pick the adults as early as possible . Product control for adults admit spinosad- and neem - free-base ware . Their larvae run to cause the biggest problems in lawn that are fed excessive amounts of chemical fertilzer and are frequently , but shallowly , irrigated . discontinue lachrymation and allow your lawn to go naturally dormant in summer ’s rut . in force , chemical - free eats ascendency come up fromHeterorhabditis bacteriophora , a species of good nematode , enforce to the dirt each bound . The nematode worm are immix with body of water and sprayed over the lawn .
Stephen Ausmus/Wikimedia Commons
5. Blister Beetles (Meloidae family)
North America host some 300 specie of blister beetles , but only a fistful are harmful to gardens . mutual food source includelegumes , Nipponese sea anemone , potatoes , phlox , members of the Asteraceae home , amaranth , zinnias , and many other garden vegetable and ornamentals . Adults of pest species consume plant life tissue paper while their larva are rarely seen . All blister beetle larvae are marauder , often using only one metal money of wild bee or grasshopper as hosts . As small , newly hatched larvae , some blister beetle species piggyback on grownup bee , who carry them back to the nest where the beetle larvae consume the larval bee .
bulla beetle acquire their plebeian name because of their ability to produce a defensive compound that can do the tegument to blister when exposed ( largely through inadvertent crushing ) . grownup are black , gray , orange or bronze , with various radiation diagram of stripes and solid state , and can measure 3/4 to 1 in long . Their elytra are coriaceous , rather than inflexible . Blister beetle can poison cattle and horse if they ingest infested alfalfa or hay .
Blister mallet adult can be controlled with careful script - pick ( do not squash them ! ) , or with spinosad - base organic pesticides .
Pest beetle can become elusive in even the most well - keep organic garden . steady trips between crop rows to scout for them enables efficient management and keeps their figure at a tolerable grade . Arm yourself with a little mallet know - how and have your best garden ever .
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