California Red Louse

The California Red Louse is a species of hemipteran insect of the family Diaspididae. It is one of the main pests affecting citrus in Spain and other countries of the world, being especially serious where the fruit is marketed for fresh consumption and in areas with a relatively dry climate.

The follicle (shield) of the female is circular (about 2 mm in diameter) reddish brown, with a central exuvia of darker color. Males are smaller (1 mm in length) with an oval-shaped, off-center scutum. In the adult stage, males are winged and yellowish in color.

Why does red louse COME OUT on our plants?

Its life cycle is closely linked to health and temperature, so that its peak or phase of greatest damage is usually in summer when trees can suffer water stress.

How does the red louse AFFECT our plants?

The damage of this pest is caused by the presence of adult females. The form they obtain is reddish waxy shields on branches, leaves and fruits.

In branches and leaves, the red louse can cause a weakening of the plant. The main economic damage occurs when fruit is destroyed by the presence of shields. Although these do not alter the organoleptic qualities of the fruit.

Light is very important in the red louse, which manifests a positive phototropism (tendency to go towards the light), making its density much lower at the base and inside the tree.

How to ELIMINATE lice naturally?

PREDATORS OF THE RED LOUSE

• Rhyzobius lophantae has an oval shape. Head and pronotum reddish brown. Black elytra with greenish or coppery sheen. reddish brown in color. Underside reddish brown, legs, antennae and mouthparts of the same color. Score not very apparent. Double hairs: short, bushy, decumbent whitish hairs interspersed with a few erect, long, blackish hairs.

• Chilocorus bipustulatus is a coleopteran belonging to the family Cooccinelidae, predator of diacids such as Aonidiella aurantii and Aspidiotus nerii, although when this food source is scarce, it can also prey on aphids such as Cinara maritimae, Cinara pinea or Eulachnus rileyi . It is a predator of all its stages, although the relevance it may have in its biological control is unknown for the time being.

PARASITOIDS OF THE RED LOUSE.

• Aphytis Melinus and Chrysomphali introduce an egg under the mealybug’s shield, depositing it on the victim’s body after having paralyzed it. In addition, a large proportion of the diaspidids die directly when the parasite pierces them with its ovipositor to feed on the fluids that arise from the wound caused by the parasite. This predation action (feeding bites) is very important in the field for the control of dipterans.

• In Encarsia perniciosi the female deposits the egg inside the body of the diapsid. It does not paralyze the host when parasitizing (koinobiont). It is solitary, only one parasitoid develops per host. Adults are uniparental, where the offspring is almost entirely female, without the need for male fertilization. Unlike parasitoids of the genus Aphytis and Compariella bifasciata, it prefers to parasitize those found on branches and leaves.

• Comperiella bifasciata is a solitary endoparasitoid of which several races have been described. The female tends to parasitize the scutes of the California red louse that are located on leaves and fruits. They can lay eggs from the first day they emerge. Unlike Aphytis, it does not feed on the fluids of diapaids.