Greenhouse ornamentals-Mealybug


Citrus mealybug (Planoccoccus citri)
Longtailed mealybug (Pseudococcus longispinus)

Pest description and crop damage Like other soft-bodied, piercing mouthpart insects, mealybugs suck plant juices , cause tissue distortion, and plant decline, and secrete honeydew copiously. Keys are commercially available to distinguish species of mealybugs, scales, and whiteflies. Citrus mealybug, Planoccoccus citri, is a common pest in such situations. The longtailed mealybug, Pseudococcus longispinus is another familiar species in protected systems distinguished by two long waxy filaments forming a 'tail.'

Biology and life history Adult mealybugs lay their eggs generally in an ovisac or egg sack often near a stem juncture or under thick stipules. The ovisac is made out of a white, waxy secretion and may be filled with several hundred eggs. Once the eggs hatch, the tiny nymphs move around the plant where they feed. Adult female mealybugs resemble the nymphs, though larger, but the males look like small white-colored flies and are uncommonly seen.

Scouting and thresholds Scout for the white egg sacs near stem nodes and branch connections. Some species of mealybugs spend time as a root infesting aphid, so new plant acquisitions should be inspected for infestations above and below the plant surface.

Management-biological control

Natural enemies include:

  • lady beetle, Cryptolaemus montrouszieri, "mealybug destroyer"
  • predatory wasp, Leptomastix (for citrus mealybugs), Pseydaphycus angelicus (for longtailed mealybug),

Management-chemical control

Mealybug and scale pests are best controlled at the "crawler" stage: the immature, active stage when the insects are most sensitive to insecticides.

  • acephate (Precise, Orthene TR) at 0.024 lb ai/1,000 sq ft broadcast (0.6 oz). REI 24 hr.
  • acetamiprid (Tristar 30SG) at 0.5 lb ai/100 gal (2.7 oz). REI 12 hr.
  • azadiractin (Azahar, Azatin XL)-Some formulations are OMRI-listed for organic use.
  • Beauvaria bassiana (Botanigard, Mycotrol, Naturalis L)-Some formulations are OMRI-listed for organic use.
  • bifenthrin (Talstar) at 0.168 to 0.335 lb ai/1,000 sq ft. REI 12 hr. Restricted use pesticide.
  • buprofesin (Talus 70DF) at 0.75 lb ai/a. REI 12 hr. Works on immature stage.
  • chlorpyrifos (Quali-Pro Chlorpyrifos) at 0.5 lb ai/100 gal. REI 24 hr. Restricted use pesticide.
  • clarified hydrophobic extract of neem oil (Triact 70)
  • clothianidin (Arena 0.25G) at 0.45 to 0.63 oz ai /100 gal. REI 12 hr. Soil treatment refer label.
  • cyclaniliprole/flonicamid (Pradia) at 10 to 17.5 fl oz/100 gal.
  • cyfluthrin (Decathlon) at 1.9 oz/100 gal. REI 12 hr.
  • cyfluthrin/imidacloprid (Discus N/G) at 0.063 lb ai/100 gal foliar; 0.009 to 0.014 lb ai/1,000 ft soil. REI 12 hr.
  • dinotefuran (Safari 20SG) at 0.1 to 0.2 lb ai/1,000 ft sq; 0.05 to 0.1 lb ai/100 gal. REI 12 hr.
  • fenpropathrin (Tame 2.4EC) at 0.3 lb ai/a (16 fl oz). REI 24 hr.
  • fenproxymate (Akari 5SC) at 0.079 lb ai/100 gal. REI 12 hr.
  • flonicamid (Aria) at 0.067 to 0.134 lb ai/100 gal. REI 12 hr.
  • flupyradifurone (Altus) at 10.5 to 14 fl oz/a. REI 4 hr.
  • garlic oil/powder (Allityn)-Some formulations are OMRI-listed for organic use.
  • imidacloprid (Marathon II) at 0.027 oz ai /100 gal foliar. REI 12 hr. Drench and irrigation permitted.
  • Isaria fumosoroseus (PFR 97) at 0.175 to 3.5 lb ai/100 gal foliar. REI 4 hr.
  • kaolin (Surround)-Some formulations are OMRI-listed for organic use.
  • lambda-cyhalothrin (Scimitar GC) at 0.013 to 0.043 lb ai/100 gal. REI 24 hr.
  • mineral oil/petroleum distillate (Biocover LS)-Some formulations are OMRI-listed for organic use.
  • naled (Dibrom 8) as vapor treatment
  • potassium laurate (several labels)-Some formulations are OMRI-listed for organic use.
  • pyrethrins/canola oil (E.B. Stone, Earth-tone, Worryfree)
  • pyrethrins/piperonyl butoxide
  • pyrifluquinazon (Rycar) at 0.09 lb ai/100 gallonsgal. REI 12 hr. Limit 2 treatments per crop.
  • pyriproximate (Distance) at 0.054 to 0.081 lb ai/100 gal (8 to 12 fl oz) foliar. REI 12 hr. Works on immature stages.
  • s-kinoprene (Enstar AQ) at 0.012 to 0.024 lb ai/10,000 sq ft. REI 4 hr.
  • soybean oil (Golden Pest Spray)-Some formulations are OMRI-listed for organic use.
  • spirotetramat (Kontos) at 0.027 to 0.053 lb ai /100 gal. REI 24 hr. Systemic activity.
  • tau-fluvalinate (Mavrik Aquaflow) at 0.063 to 0.156 lb ai/100 gal. REI 12 hr.
  • thiamethoxam (Flagship 25WG) as fogger. REI 12 or 24 hr.
  • thyme oil/phenethyl propionate (EcoVia WD) at 1 to 4 oz product per 1,000 sq ft. FIFRA Section 25b exempt product.
  • tolfenpyrad (Hachi-Hachi) at 14 to 32 fl oz/100 gal. REI 12 hr.