Scab,Braconids,Damsel bugs,Encarsia

Scab
Symptoms
Attacked leaves have dark-brown to black circular and somewhat angular lesions. As the lesions enlarge, they become white to gray with narrow and dark margins. Attacked stems have grayish and irregular blotches. Infected fruit's skin has blemishes. The early infection appears as grayish-brown lesions with irregular margins. As the disease develops, it causes cracked and corky appearance. Even if the disease is only found on the skin, the numerous spots lessen the appeal of the consumers.

Prevention and control
Hot water treatment (refer to p. 17, Anthracnose,
prevention and control)
Stem-end rot
Symptoms
The infected fruit has initially violet lesion at the stem-end, turning light-brown, and finally becoming black.  The inner tissues of the fruit become soft and watery.
Prevention and control
Hot water treatment (refer to p. 17, Anthracnose, prevention and control)



Natural enemies
Braconids 
Hosts
Ants, aphids, armyworms, beetle's larvae, bollworms, cabbageworms, caterpillars, codling  moths, corn borers, cutworms, imported tent caterpillars, leafhoppers, leafminers, maggots, midges, plant bugs, scales, tomato hornworms, weevils, and many more.

Description
Eggs and larvae of Bracons are found inside the hosts' bodies.

 The larvae are tiny, cream-colored grubs that
feed in or on other insects. Larvae molt five times and undergo 5 instars.

Pupae of some species live and pupate within the host until they mature; others pupate in silken cocoons on the outside of the body of the host, while others spin silken cocoons away from the host.

Adult wasps are tiny, about 2.5 mm in size, slender black or brown with threadlike waists. Female wasps lay eggs into the eggs of hosts' pests  but prefer caterpillars' bodies.

In cases where aphids are the host pests, aphids are not killed instantly. Aphids continue to feed on plants tissues until the Braconid larvae inside their bodies completely consume them. The fully-grown Braconid larvae cement the dead aphids to the leaf surface making aphids' shells black and mummified. About a week later, the adult Bracon wasps cut round holes in the mummies and emerge. The empty mummies remain on the leaf. The presence of mummies in a colony of aphids is a sign
that Bracons are present.

 Conservation
Adult Bracons feed on nectar, honeydew, or pollen before laying eggs. Dill, parsley, yarrow, zinnia, clover,  lfalfa, parsley, cosmos, sunflower, and marigold are flowering crops that attract the native braconid  opulations and provide good habitats for them.

Damsel bugs
Hosts
Aphids, armyworms, asparagus beetle, Colorado potato beetle eggs and nymphs, corn earworm, corn borer, imported cabbageworm, leafhoppers, mites, moth eggs, sawfly larvae, and tarnished plant bug nymphs. Although they can survive for about two weeks without food, they will eat each other if no other prey is available.

Description
Eggs are deposited in soft plant tissues where they are so difficult to find.

Nymphs resemble adults and  develop through 5 nymphal stages in about 50 days.

Adults are tiny, about 2-4 mm long, with slender bodies and are yellowish or gray or reddish-brown in color. They have piercing-sucking mouthparts, a 4- segmented beak, elongated heads, and 4 long segmented antennae. They are fast runners with long slender back legs and enlarged forelegs for grasping prey. They are commonly found in most agricultural crops, especially  legumes, throughout the year. Adults begin laying eggs soon after emergence.

Conservation
They prefer to live in soybeans, grassy fields, and alfalfa. You can collect damsel bugs in alfalfa fields and release them around your garden.

Encarsia
Hosts
Various whitefly species
Description
Eggs are found inside the body of the host larva.

The larvae develop within the whitefly larvae passing through four larval stages. The host pupa turns black when Encarsia pupates inside the whitefly. Adult wasps emerge from the parasitized pupae by chewing a hole in the top of the scale. Adults are very tiny wasps, about 1 mm in size. These parasitic wasps can look actively and effectively for whiteflies. They can cover distances of 10-30 m looking for hosts. Adult females attack young whitefly larvae by stinging and laying eggs inside them. An adult female wasp can lay 60-100
eggs. The life cycle is completed within 2-4 weeks depending on the climatic conditions. Adults can live
for 30 days but are active for about 10 days. Adult wasps feed on honeydew and the body fluids of whitefly larvae. They also feed directly on the scales. However, honeydew restricts their movements so that it is   difficult for them to have a wider feeding coverage. With the exception of the adult, all stages of Encarsia occur inside the whitefly host.

Conservation
Conserving natural enemies is probably the most important practice farmers could do. Practicing
multiple cropping (including flowering crops) provides pollen, honeydew, and nectar for adult
wasps. The practice can increase the diversity of habitats that provide shelter and other food sources
to the natural enemies. Some Encarsia species are native to crop production environments. When introduced, they
have the tendency to adapt to the local environments. Weekly field monitoring or a visual inspection of
plants is important to notice the presence of pests and beneficial insects in order to consider when to
make pest management decisions.


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