Melon thrips

Thrips palmi

Thrips palmi is of the genus Thrips in the order of Thysanoptera and commonly known as melon thrips. It is a prominent vector for plant viruses. Melon thrips is able to damage various ornamental plants and vegetables. They specifically target plants from the Curcurbitaceae and Solanaceae families such as cucumber, eggplant, tomato, and pepper. Adults and nymphs feed by sucking the cellular contents of leaves, stems, flowers, and fruit surfaces. This type of feeding leaves silver scars and leaf chlorosis. Plants who are victim to this pest can become deformed and killed in the case of heavy infestations. Melon thrips are thought to have originated in Southeast Asia and currently has been observed throughout Asia, the Pacific, Florida, the Caribbean, South America, Africa and Australia.

Onion thrips

Thrips tabaci

Thrips tabaci is a species of very small insect in the genus Thrips in the order Thysanoptera commonly known as onion thrips, potato thrips, tobacco thrips, or cotton seedling thrips. It is an agricultural pest that damages onion crops and other plants. This pest also transmits plant viruses. In some populations almost all onion thrips are female, and males are very rare. Adult onion thrips are about 1 to 1.3 mm ( 0.04 to 0.05 in) long. The body is yellow, brown, or a blend of the two. The antennae have seven segments and the wing are well developed. The females have an ovipositor at the tip of the abdomen. Onion thrips are believed to have originated in the Mediterranean region and now occupy every continent besides Antarctica. It infests a wide range of host plants including onions, leeks, and garlic. They also feed on brassicaceous plants such as cabbage, cauliflower, and broccoli. The list goes on, including asparagus, beets, melons, squash, marrow, cucumbers, strawberries, potatoes, tobacco, cotton, and ornamental plants.Onion thrips were the first identified vector for tomato leaf spot wilt virus in 1927. There are now a few identified populations of onion thrips that are incapable of transmitting tomato spot wilt virus, possibly due to genetic spread in the global population. The female inserts her saw-shaped ovipositor into plant tissues and deposits her eggs under the epidermis. The eggs start out white, become orange, and hatch in four to five days. The larvae are white or slightly yellow and suck the sap from plant tissues. These larvae go through two nine day stages followed by a pre-pupal and non-feeding pupal stages which last four to seven days total. The adult survives for two or three weeks during which the females lay around eighty eggs. Most eggs are not fertilized and are produced by parthenogenesis. The ratio of males to females in populations vary across different areas. A study published in 1990 suggests a correlation between longitude and male population numbers. The study found the highest male counts happened in the western hemisphere. Onion thrips is the dangerous pest to onion crops in the tropics. Thrips scrape and punctuer the plant surface with their mouthparts and generally feast on young plants. They then add digestive juices and suck out the fluid that leaks from the puncture wounds. As the plant part grows, so do the damaged regions which leave silvery streaks. When more thrips are present, a larger area of the plant is damaged, which may reduce the foliage area available for photosynthesis. When plants are severely damaged, the leaves my wither and the entire plant may become silver, the crop then ripens prematurely and produces a smaller yield than a healthy mature plant. Onion thrips is a vector of certain plant viruses including iris yellow spot tospovirus, strawberry necrotic shock virus, tobacco leaf blight virus and tomato spot wilt virus. It also is a vector of Alternaria porri, which causes the fungal disease known as purple spot.

Housefly

Musca domestica

Musca domestica, known by the common name housefly, is a species of brachyceran dipterous (flies) in the family Muscidae. It is one of the most common insects and a regular presence in most climates on Earth. The fly can land on food, contaminating it with bacteria, being responsible for the spread of numerous diseases.
Adult specimens of M. domestica can measure around 5-8 mm in length. It has a gray color on the thorax, with four longitudinal lines on the back. The lower part of the abdomen is yellowish. The body is covered with relatively long hair. The compound eyes are reddish in color. Females are slightly larger than males and have wider eye spacing. They feature two functional wings, with the other pair converted into gimbals that stabilize flight.
Each female can lay about 8,000 white eggs, about 1.2 mm long. 24 hours after oviposition, the larvae hatch, which feed on nutrient-rich organic remains. They are pale in color and 3 to 9 mm long, fusiform, with a terminal mouth and no legs. When food is sufficient, they turn into pupae about 8 mm long and color ranging from red to brown. Upon completing the metamorphosis, the adult breaks one of the ends of the pupa with a circular cut, emerges and flies in search of congeners to mate and complete its life cycle. Adults can live a fortnight in the wild, and can reach longer life spans in the laboratory. The complete life cycle of a fly in the wild ranges from 25 to 30 days.

Leafhopper

Dalbulus maidis

Dalbulus maidis, popularly known as corn leafhopper, is a straw-white insect, which may appear slightly greyish, about 0.5 cm in size, which feeds on the sap of the corn plant and lays eggs under the epidermis of the leaf, preferably on the leaf midrib of the seedling cartridge. Infection with mollicutes occurs in maize seedlings at early stages of development. These pathogenic microorganisms proliferate in the phloem tissues and the plant only shows stunting symptoms in the production phase. This insect-vector of mollicutes survives only on maize and usually migrates from fields with adult plants to fields with newly emerged seedlings. Mollicutes systemically invade and multiply in the phloem tissues of the maize plant and are transmitted from diseased plants to healthy plants by the leafhopper.

Source: Embrapa Portal

White fly

Bemisia tabaci

Bemisia tabaci is one of the 34 species of the genus Bemisia, known in Brazil as the white fly or bean white fly. It is a polyphagous insect that is currently found in dozens of countries around the world and on five continents. Attacks several crops, such as pumpkin, zucchini, cotton, eggplant, broccoli, chayote, cabbage, cauliflower, peas, beans, flowers, tobacco, eggplant, papaya, cassava, watermelon, melon, cucumber, pepper, bell pepper, okra, cabbage, soybean, tomato and grape. Their eggs are 0.2mm long and pear-shaped. When they hatch, the larvae have whitish-yellow scales and measure 0.3 to 0.6 mm in length. The pupae are oval in shape and are flat, irregular and measure 0.7 mm in length. Adult individuals are 1mm long, females being slightly larger than males. The insects have a body and two pairs of wings covered by powdery and waxy secretion, white or yellowish in color. The insect Bemisia tabaci has great reproduction capacity, rapidly increasing the population in the affected area. In the most serious cases, it ends up colonizing the plants and remaining on the underside of the leaves. The most affected crops are tomatoes, beans, cotton, melons, watermelons, pumpkins, vegetables, fruit trees and ornamental plants. It transmits several viruses causing a variety of symptoms. When infected, the plants show only or joint yellowing of the veins, the leaves can also turn yellow, wrinkled and curled. There are cases of thickening of the veins of the leaves and also their rooting, digging of the leaves, twisting of the stem. Plants can suffer from dwarfism.